command-line-options.html revision 82a2ff27ee83c3408dce06c0f129386bd13eb17f
1<!DOCTYPE html> 2<html lang="en"> 3<head> 4 <meta charset="utf-8"> 5 <meta http-equiv="X-UA-Compatible" content="IE=edge"> 6 <meta name="viewport" content="width=device-width, initial-scale=1"> 7 <title>ImageMagick: Command-line Options</title> 8 <meta http-equiv="content-language" content="en-US"> 9 <meta http-equiv="content-type" content="text/html; charset=utf-8"> 10 <meta http-equiv="reply-to" content="magick-users@imagemagick.org"> 11 <meta name="application-name" content="ImageMagick"> 12 <meta name="description" content="ImageMagick® is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, JPEG-2000, GIF, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves."> 13 <meta name="application-url" content="http://www.imagemagick.org"> 14 <meta name="generator" content="PHP"> 15 <meta name="keywords" content="command-line, options, ImageMagick, PerlMagick, image processing, image, photo, software, Magick++, OpenMP, convert"> 16 <meta name="rating" content="GENERAL"> 17 <meta name="robots" content="INDEX, FOLLOW"> 18 <meta name="generator" content="ImageMagick Studio LLC"> 19 <meta name="author" content="ImageMagick Studio LLC"> 20 <meta name="revisit-after" content="2 DAYS"> 21 <meta name="resource-type" content="document"> 22 <meta name="copyright" content="Copyright (c) 1999-2015 ImageMagick Studio LLC"> 23 <meta name="distribution" content="Global"> 24 <meta name="magick-serial" content="P131-S030410-R485315270133-P82224-A6668-G1245-1"> 25 <link rel="icon" href="/images/wand.png"> 26 <link rel="shortcut icon" href="/images/wand.ico" type="images/x-icon"> 27 <link rel="stylesheet" href="css/bootstrap.min.css"> 28 <link rel="stylesheet" href="css/magick.css"> 29</head> 30 31<body> 32<div class="main"> 33<div class="magick-masthead"> 34 <div class="container"> 35 <script type="text/javascript"> 36 <!-- 37 google_ad_client = "pub-3129977114552745"; 38 google_ad_slot = "5439289906"; 39 google_ad_width = 728; 40 google_ad_height = 90; 41 //--> 42 </script> 43 <center><script type="text/javascript" src="http://localhost/pagead/show_ads.js"> 44 </script></center> 45 <nav class="magick-nav"> 46 <a class="magick-nav-item " href="/index.html">Home</a> 47 <a class="magick-nav-item " href="binary-releases.html">Downloads</a> 48 <a class="magick-nav-item " href="command-line-tools.html">Tools</a> 49 <a class="magick-nav-item active" href="command-line-options.html">Options</a> 50 <a class="magick-nav-item " href="api.html">Development</a> 51 <a class="magick-nav-item" href="http://www.imagemagick.org/discourse-server/">Community</a> 52 <a class="magick-nav-item pull-right " href="http://www.imagemagick.org/script/search.php">Search</a> 53 </nav> 54 </div> 55</div> 56<div class="container"> 57<div class="magick-header"> 58<p class="text-center"><a href="command-line-options.html#adaptive-blur">‑adaptive‑blur</a> • <a href="command-line-options.html#adaptive-resize">‑adaptive‑resize</a> • <a href="command-line-options.html#adaptive-sharpen">‑adaptive‑sharpen</a> • <a href="command-line-options.html#adjoin">‑adjoin</a> • <a href="command-line-options.html#affine">‑affine</a> • <a href="command-line-options.html#alpha">‑alpha</a> • <a href="command-line-options.html#annotate">‑annotate</a> • <a href="command-line-options.html#antialias">‑antialias</a> • <a href="command-line-options.html#append">‑append</a> • <a href="command-line-options.html#attenuate">‑attenuate</a> • <a href="command-line-options.html#authenticate">‑authenticate</a> • <a href="command-line-options.html#auto-gamma">‑auto‑gamma</a> • <a href="command-line-options.html#auto-level">‑auto‑level</a> • <a href="command-line-options.html#auto-orient">‑auto‑orient</a> • <a href="command-line-options.html#backdrop">‑backdrop</a> • <a href="command-line-options.html#background">‑background</a> • <a href="command-line-options.html#bench">‑bench</a> • <a href="command-line-options.html#bias">‑bias</a> • <a href="command-line-options.html#black-point-compensation">‑black‑point‑compensation</a> • <a href="command-line-options.html#black-threshold">‑black‑threshold</a> • <a href="command-line-options.html#blend">‑blend</a> • <a href="command-line-options.html#blue-primary">‑blue‑primary</a> • <a href="command-line-options.html#blue-shift">‑blue‑shift</a> • <a href="command-line-options.html#blur">‑blur</a> • <a href="command-line-options.html#border">‑border</a> • <a href="command-line-options.html#bordercolor">‑bordercolor</a> • <a href="command-line-options.html#borderwidth">‑borderwidth</a> • <a href="command-line-options.html#brightness-contrast">‑brightness‑contrast</a> • <a href="command-line-options.html#cache">‑cache</a> • <a href="command-line-options.html#canny">‑canny</a> • <a href="command-line-options.html#caption">‑caption</a> • <a href="command-line-options.html#cdl">‑cdl</a> • <a href="command-line-options.html#channel">‑channel</a> • <a href="command-line-options.html#charcoal">‑charcoal</a> • <a href="command-line-options.html#chop">‑chop</a> • <a href="command-line-options.html#clamp">‑clamp</a> • <a href="command-line-options.html#clip">‑clip</a> • <a href="command-line-options.html#clip-mask">‑clip‑mask</a> • <a href="command-line-options.html#clip-path">‑clip‑path</a> • <a href="command-line-options.html#clone">‑clone</a> • <a href="command-line-options.html#clut">‑clut</a> • <a href="command-line-options.html#coalesce">‑coalesce</a> • <a href="command-line-options.html#colorize">‑colorize</a> • <a href="command-line-options.html#colormap">‑colormap</a> • <a href="command-line-options.html#color-matrix">‑color‑matrix</a> • <a href="command-line-options.html#colors">‑colors</a> • <a href="command-line-options.html#colorspace">‑colorspace</a> • <a href="command-line-options.html#combine">‑combine</a> • <a href="command-line-options.html#comment">‑comment</a> • <a href="command-line-options.html#compare">‑compare</a> • <a href="command-line-options.html#complex">‑complex</a> • <a href="command-line-options.html#compose">‑compose</a> • <a href="command-line-options.html#composite">‑composite</a> • <a href="command-line-options.html#compress">‑compress</a> • <a href="command-line-options.html#connected-components">‑connected‑components</a> • <a href="command-line-options.html#contrast">‑contrast</a> • <a href="command-line-options.html#contrast-stretch">‑contrast‑stretch</a> • <a href="command-line-options.html#convolve">‑convolve</a> • <a href="command-line-options.html#crop">‑crop</a> • <a href="command-line-options.html#cycle">‑cycle</a> • <a href="command-line-options.html#debug">‑debug</a> • <a href="command-line-options.html#decipher">‑decipher</a> • <a href="command-line-options.html#deconstruct">‑deconstruct</a> • <a href="command-line-options.html#define">‑define</a> • <a href="command-line-options.html#delay">‑delay</a> • <a href="command-line-options.html#delete">‑delete</a> • <a href="command-line-options.html#density">‑density</a> • <a href="command-line-options.html#depth">‑depth</a> • <a href="command-line-options.html#descend">‑descend</a> • <a href="command-line-options.html#deskew">‑deskew</a> • <a href="command-line-options.html#despeckle">‑despeckle</a> • <a href="command-line-options.html#direction">‑direction</a> • <a href="command-line-options.html#displace">‑displace</a> • <a href="command-line-options.html#display">‑display</a> • <a href="command-line-options.html#dispose">‑dispose</a> • <a href="command-line-options.html#dissimilarity-threshold">‑dissimilarity‑threshold</a> • <a href="command-line-options.html#dissolve">‑dissolve</a> • <a href="command-line-options.html#distort">‑distort</a> • <a href="command-line-options.html#distribute-cache">‑distribute‑cache</a> • <a href="command-line-options.html#dither">‑dither</a> • <a href="command-line-options.html#draw">‑draw</a> • <a href="command-line-options.html#duplicate">‑duplicate</a> • <a href="command-line-options.html#edge">‑edge</a> • <a href="command-line-options.html#emboss">‑emboss</a> • <a href="command-line-options.html#encipher">‑encipher</a> • <a href="command-line-options.html#encoding">‑encoding</a> • <a href="command-line-options.html#endian">‑endian</a> • <a href="command-line-options.html#enhance">‑enhance</a> • <a href="command-line-options.html#equalize">‑equalize</a> • <a href="command-line-options.html#evaluate">‑evaluate</a> • <a href="command-line-options.html#evaluate-sequence">‑evaluate‑sequence</a> • <a href="command-line-options.html#extent">‑extent</a> • <a href="command-line-options.html#extract">‑extract</a> • <a href="command-line-options.html#family">‑family</a> • <a href="command-line-options.html#features">‑features</a> • <a href="command-line-options.html#fft">‑fft</a> • <a href="command-line-options.html#fill">‑fill</a> • <a href="command-line-options.html#filter">‑filter</a> • <a href="command-line-options.html#flatten">‑flatten</a> • <a href="command-line-options.html#flip">‑flip</a> • <a href="command-line-options.html#floodfill">‑floodfill</a> • <a href="command-line-options.html#flop">‑flop</a> • <a href="command-line-options.html#font">‑font</a> • <a href="command-line-options.html#foreground">‑foreground</a> • <a href="command-line-options.html#format">‑format</a> • <a href="command-line-options.html#format_identify_">‑format[identify]</a> • <a href="command-line-options.html#frame">‑frame</a> • <a href="command-line-options.html#frame_import_">‑frame[import]</a> • <a href="command-line-options.html#function">‑function</a> • <a href="command-line-options.html#fuzz">‑fuzz</a> • <a href="command-line-options.html#fx">‑fx</a> • <a href="command-line-options.html#gamma">‑gamma</a> • <a href="command-line-options.html#gaussian-blur">‑gaussian‑blur</a> • <a href="command-line-options.html#geometry">‑geometry</a> • <a href="command-line-options.html#gravity">‑gravity</a> • <a href="command-line-options.html#grayscale">‑grayscale</a> • <a href="command-line-options.html#green-primary">‑green‑primary</a> • <a href="command-line-options.html#hald-clut">‑hald‑clut</a> • <a href="command-line-options.html#help">‑help</a> • <a href="command-line-options.html#highlight-color">‑highlight‑color</a> • <a href="command-line-options.html#hough-lines">‑hough‑lines</a> • <a href="command-line-options.html#iconGeometry">‑iconGeometry</a> • <a href="command-line-options.html#iconic">‑iconic</a> • <a href="command-line-options.html#identify">‑identify</a> • <a href="command-line-options.html#ift">‑ift</a> • <a href="command-line-options.html#immutable">‑immutable</a> • <a href="command-line-options.html#implode">‑implode</a> • <a href="command-line-options.html#insert">‑insert</a> • <a href="command-line-options.html#intensity">‑intensity</a> • <a href="command-line-options.html#intent">‑intent</a> • <a href="command-line-options.html#interlace">‑interlace</a> • <a href="command-line-options.html#interpolate">‑interpolate</a> • <a href="command-line-options.html#interline-spacing">‑interline‑spacing</a> • <a href="command-line-options.html#interword-spacing">‑interword‑spacing</a> • <a href="command-line-options.html#kerning">‑kerning</a> • <a href="command-line-options.html#kuwahara">‑kuwahara</a> • <a href="command-line-options.html#label">‑label</a> • <a href="command-line-options.html#lat">‑lat</a> • <a href="command-line-options.html#layers">‑layers</a> • <a href="command-line-options.html#level">‑level</a> • <a href="command-line-options.html#level-colors">‑level‑colors</a> • <a href="command-line-options.html#limit">‑limit</a> • <a href="command-line-options.html#linear-stretch">‑linear‑stretch</a> • <a href="command-line-options.html#linewidth">‑linewidth</a> • <a href="command-line-options.html#liquid-rescale">‑liquid‑rescale</a> • <a href="command-line-options.html#list">‑list</a> • <a href="command-line-options.html#log">‑log</a> • <a href="command-line-options.html#loop">‑loop</a> • <a href="command-line-options.html#lowlight-color">‑lowlight‑color</a> • <a href="command-line-options.html#magnify">‑magnify</a> • <a href="command-line-options.html#map">‑map</a> • <a href="command-line-options.html#map_stream_">‑map[stream]</a> • <a href="command-line-options.html#mask">‑mask</a> • <a href="command-line-options.html#mattecolor">‑mattecolor</a> • <a href="command-line-options.html#median">‑median</a> • <a href="command-line-options.html#mean-shift">‑mean‑shift</a> • <a href="command-line-options.html#metric">‑metric</a> • <a href="command-line-options.html#mode">‑mode</a> • <a href="command-line-options.html#modulate">‑modulate</a> • <a href="command-line-options.html#moments">‑moments</a> • <a href="command-line-options.html#monitor">‑monitor</a> • <a href="command-line-options.html#monochrome">‑monochrome</a> • <a href="command-line-options.html#morph">‑morph</a> • <a href="command-line-options.html#morphology">‑morphology</a> • <a href="command-line-options.html#mosaic">‑mosaic</a> • <a href="command-line-options.html#motion-blur">‑motion‑blur</a> • <a href="command-line-options.html#name">‑name</a> • <a href="command-line-options.html#negate">‑negate</a> • <a href="command-line-options.html#noise">‑noise</a> • <a href="command-line-options.html#normalize">‑normalize</a> • <a href="command-line-options.html#opaque">‑opaque</a> • <a href="command-line-options.html#ordered-dither">‑ordered‑dither</a> • <a href="command-line-options.html#orient">‑orient</a> • <a href="command-line-options.html#page">‑page</a> • <a href="command-line-options.html#paint">‑paint</a> • <a href="command-line-options.html#path">‑path</a> • <a href="command-line-options.html#pause_animate_">‑pause[animate]</a> • <a href="command-line-options.html#pause_import_">‑pause[import]</a> • <a href="command-line-options.html#perceptible">‑perceptible</a> • <a href="command-line-options.html#ping">‑ping</a> • <a href="command-line-options.html#pointsize">‑pointsize</a> • <a href="command-line-options.html#polaroid">‑polaroid</a> • <a href="command-line-options.html#poly">‑poly</a> • <a href="command-line-options.html#posterize">‑posterize</a> • <a href="command-line-options.html#precision">‑precision</a> • <a href="command-line-options.html#preview">‑preview</a> • <a href="command-line-options.html#print">‑print</a> • <a href="command-line-options.html#process">‑process</a> • <a href="command-line-options.html#profile">‑profile</a> • <a href="command-line-options.html#quality">‑quality</a> • <a href="command-line-options.html#quantize">‑quantize</a> • <a href="command-line-options.html#quiet">‑quiet</a> • <a href="command-line-options.html#radial-blur">‑radial‑blur</a> • <a href="command-line-options.html#raise">‑raise</a> • <a href="command-line-options.html#random-threshold">‑random‑threshold</a> • <a href="command-line-options.html#red-primary">‑red‑primary</a> • <a href="command-line-options.html#regard-warnings">‑regard‑warnings</a> • <a href="command-line-options.html#region">‑region</a> • <a href="command-line-options.html#remap">‑remap</a> • <a href="command-line-options.html#remote">‑remote</a> • <a href="command-line-options.html#render">‑render</a> • <a href="command-line-options.html#repage">‑repage</a> • <a href="command-line-options.html#resample">‑resample</a> • <a href="command-line-options.html#resize">‑resize</a> • <a href="command-line-options.html#respect-parentheses">‑respect‑parentheses</a> • <a href="command-line-options.html#reverse">‑reverse</a> • <a href="command-line-options.html#roll">‑roll</a> • <a href="command-line-options.html#rotate">‑rotate</a> • <a href="command-line-options.html#sample">‑sample</a> • <a href="command-line-options.html#sampling-factor">‑sampling‑factor</a> • <a href="command-line-options.html#scale">‑scale</a> • <a href="command-line-options.html#scene">‑scene</a> • <a href="command-line-options.html#screen">‑screen</a> • <a href="command-line-options.html#seed">‑seed</a> • <a href="command-line-options.html#segment">‑segment</a> • <a href="command-line-options.html#selective-blur">‑selective‑blur</a> • <a href="command-line-options.html#separate">‑separate</a> • <a href="command-line-options.html#sepia-tone">‑sepia‑tone</a> • <a href="command-line-options.html#set">‑set</a> • <a href="command-line-options.html#shade">‑shade</a> • <a href="command-line-options.html#shadow">‑shadow</a> • <a href="command-line-options.html#shared-memory">‑shared‑memory</a> • <a href="command-line-options.html#sharpen">‑sharpen</a> • <a href="command-line-options.html#shave">‑shave</a> • <a href="command-line-options.html#shear">‑shear</a> • <a href="command-line-options.html#sigmoidal-contrast">‑sigmoidal‑contrast</a> • <a href="command-line-options.html#silent">‑silent</a> • <a href="command-line-options.html#similarity-threshold">‑similarity‑threshold</a> • <a href="command-line-options.html#size">‑size</a> • <a href="command-line-options.html#sketch">‑sketch</a> • <a href="command-line-options.html#smush">‑smush</a> • <a href="command-line-options.html#snaps">‑snaps</a> • <a href="command-line-options.html#solarize">‑solarize</a> • <a href="command-line-options.html#sparse-color">‑sparse‑color</a> • <a href="command-line-options.html#splice">‑splice</a> • <a href="command-line-options.html#spread">‑spread</a> • <a href="command-line-options.html#statistic">‑statistic</a> • <a href="command-line-options.html#stegano">‑stegano</a> • <a href="command-line-options.html#stereo">‑stereo</a> • <a href="command-line-options.html#stretch">‑stretch</a> • <a href="command-line-options.html#strip">‑strip</a> • <a href="command-line-options.html#stroke">‑stroke</a> • <a href="command-line-options.html#strokewidth">‑strokewidth</a> • <a href="command-line-options.html#style">‑style</a> • <a href="command-line-options.html#subimage-search">‑subimage‑search</a> • <a href="command-line-options.html#swap">‑swap</a> • <a href="command-line-options.html#swirl">‑swirl</a> • <a href="command-line-options.html#synchronize">‑synchronize</a> • <a href="command-line-options.html#taint">‑taint</a> • <a href="command-line-options.html#text-font">‑text‑font</a> • <a href="command-line-options.html#texture">‑texture</a> • <a href="command-line-options.html#threshold">‑threshold</a> • <a href="command-line-options.html#thumbnail">‑thumbnail</a> • <a href="command-line-options.html#tile">‑tile</a> • <a href="command-line-options.html#tile-offset">‑tile‑offset</a> • <a href="command-line-options.html#tint">‑tint</a> • <a href="command-line-options.html#title">‑title</a> • <a href="command-line-options.html#transform">‑transform</a> • <a href="command-line-options.html#transparent">‑transparent</a> • <a href="command-line-options.html#transparent-color">‑transparent‑color</a> • <a href="command-line-options.html#transpose">‑transpose</a> • <a href="command-line-options.html#transverse">‑transverse</a> • <a href="command-line-options.html#treedepth">‑treedepth</a> • <a href="command-line-options.html#trim">‑trim</a> • <a href="command-line-options.html#type">‑type</a> • <a href="command-line-options.html#undercolor">‑undercolor</a> • <a href="command-line-options.html#unique-colors">‑unique‑colors</a> • <a href="command-line-options.html#units">‑units</a> • <a href="command-line-options.html#unsharp">‑unsharp</a> • <a href="command-line-options.html#update">‑update</a> • <a href="command-line-options.html#verbose">‑verbose</a> • <a href="command-line-options.html#version">‑version</a> • <a href="command-line-options.html#view">‑view</a> • <a href="command-line-options.html#vignette">‑vignette</a> • <a href="command-line-options.html#virtual-pixel">‑virtual‑pixel</a> • <a href="command-line-options.html#visual">‑visual</a> • <a href="command-line-options.html#watermark">‑watermark</a> • <a href="command-line-options.html#wave">‑wave</a> • <a href="command-line-options.html#weight">‑weight</a> • <a href="command-line-options.html#white-point">‑white‑point</a> • <a href="command-line-options.html#white-threshold">‑white‑threshold</a> • <a href="command-line-options.html#window">‑window</a> • <a href="command-line-options.html#window-group">‑window‑group</a> • <a href="command-line-options.html#write">‑write</a> </p> 59 60<p class="lead magick-description">Below is list of command-line options recognized by the ImageMagick <a href="command-line-tools.html">command-line tools</a>. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it. Unless otherwise noted, each option is recognized by the commands: <a href="convert.html">convert</a> and <a href="mogrify.html">mogrify</a>.</p> 61 62<div style="margin: auto;"> 63 <h3 class="magick-header"><a id="adaptive-blur"></a>-adaptive-blur <var>radius</var>[x<var>sigma</var>]</h3> 64</div> 65 66<p class="magick-description">Adaptively blur pixels, with decreasing effect near edges.</p> 67 68<p>A Gaussian operator of the given radius and standard deviation (<var>sigma</var>) is used. If <var>sigma</var> is not given it 69defaults to 1.</p> 70 71<div style="margin: auto;"> 72 <h3 class="magick-header"><a id="adaptive-resize"></a>-adaptive-resize <var>geometry</var></h3> 73</div> 74 75<p class="magick-description">Resize the image using data-dependent triangulation.</p> 76 77<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <a href="command-line-options.html#adaptive-resize">-adaptive-resize</a> 78option defaults to data-dependent triangulation. Use the <a href="command-line-options.html#filter">-filter</a> to choose a different resampling algorithm. 79Offsets, if present in the geometry string, are ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p> 80 81<div style="margin: auto;"> 82 <h3 class="magick-header"><a id="adaptive-sharpen"></a>-adaptive-sharpen <var>radius</var>[x<var>sigma</var>]</h3> 83</div> 84 85<p class="magick-description">Adaptively sharpen pixels, with increasing effect near edges.</p> 86 87<p>A Gaussian operator of the given radius and standard deviation 88(<var>sigma</var>) is used. If <var>sigma</var> is not given it 89defaults to 1.</p> 90 91<div style="margin: auto;"> 92 <h3 class="magick-header"><a id="adjoin"></a>-adjoin</h3> 93</div> 94 95<p class="magick-description">Join images into a single multi-image file.</p> 96 97<p>This option is enabled by default. An attempt is made to save all images of 98an image sequence into the given output file. However, some formats, such as 99JPEG and PNG, do not support more than one image per file, and in that case 100ImageMagick is forced to write each image as a separate file. As such, if 101more than one image needs to be written, the filename given is modified by 102adding a <a href="command-line-options.html#scene">-scene</a> number before the suffix, in order to 103make distinct names for each image. </p> 104 105<p>Use <a href="command-line-options.html#adjoin">+adjoin</a> to force each image to be written to 106separate files, whether or not the file format allows multiple images per file 107(for example, GIF, MIFF, and TIFF). </p> 108 109<p>Including a C-style integer format string in the output filename will 110automagically enable <a href="command-line-options.html#adjoin">+adjoin</a> and are used to specify 111where the <a href="command-line-options.html#scene">-scene</a> number is placed in the filenames. These 112strings, such as '<code>%d</code>' or '<code>%03d</code>', are familiar to those 113who have used the standard <code>printf()</code>' C-library function. As an 114example, the command</p> 115 116<pre> 117convert logo: rose: -morph 15 my%02dmorph.jpg 118</pre> 119 120<p>will create a sequence of 17 images (the two given plus 15 more created by 121<a href="command-line-options.html#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg, 122my02morph.jpg, ..., my16morph.jpg. </p> 123 124<p>In summary, ImageMagick tries to write all images to one file, but will 125save to multiple files, if any of the following conditions exist...</p> 126<ol> 127<li>the output image's file format does not allow multi-image files,</li> 128<li>the <a href="command-line-options.html#adjoin">+adjoin</a> option is given, or</li> 129<li>a printf() integer format string (eg: "%d") is present in the output 130 filename.</li> 131</ol> 132 133 134<div style="margin: auto;"> 135 <h3 class="magick-header"><a id="affine"></a>-affine 136 <var>s<sub>x</sub></var>,<var>r<sub>x</sub></var>,<var>r<sub>y</sub></var>,<var>s<sub>y</sub></var>[,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>]</h3> 137</div> 138 139<p class="magick-description">Set the drawing transformation matrix for combined rotating and scaling.</p> 140 141<p>This option sets a transformation matrix, for use by subsequent <a href="command-line-options.html#draw">-draw</a> or <a href="command-line-options.html#transform">-transform</a> options. </p> 142 143<p>The matrix entries are entered as comma-separated numeric values either in 144quotes or without spaces. </p> 145 146<p>Internally, the transformation matrix has 3x3 elements, but three of them 147are omitted from the input because they are constant. The new (transformed) 148coordinates (<var>x'</var>, <var>y'</var>) of a pixel at 149position (<var>x</var>, <var>y</var>) in the original 150image are calculated using the following matrix equation.</p> 151 152<div class="eqn"> 153<img alt="affine transformation" src="/images/affine.png"> 154</div> 155 156<p> The size of the resulting image is that of the smallest rectangle that 157contains the transformed source image. The parameters 158<var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> 159subsequently shift the image pixels so that those that are moved out of the 160image area are cut off.</p> 161 162<p>The transformation matrix complies with the left-handed pixel coordinate 163system: positive <var>x</var> and <var>y</var> directions 164are rightward and downward, resp.; positive rotation is clockwise.</p> 165 166<p> If the translation coefficients <var>t<sub>x</sub></var> and 167<var>t<sub>y</sub></var> are omitted they default to 0,0. Therefore, 168four parameters suffice for rotation and scaling without translation.</p> 169 170<p>Scaling by the factors <var>s<sub>x</sub></var> and 171<var>s<sub>y</sub></var> in the <var>x</var> and <var>y</var> directions, 172respectively, is accomplished with the following.</p> 173 174<p>See <a href="command-line-options.html#transform">-transform</a>, and the <a href="command-line-options.html#distort">-distort</a> method '<code>Affineprojection</code> for more 175information </p> 176 177 178<pre> 179-affine <var>s<sub>x</sub></var>,0,0,<var>s<sub>y</sub></var> 180</pre> 181 182<p>Translation by a displacement (<var>t<sub>x</sub></var>, <var>t<sub>y</sub></var>) is accomplished like so:</p> 183 184<pre> 185-affine 1,0,0,1,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var> 186</pre> 187 188<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle 189<var>a</var> by letting <var>c</var> = cos(<var>a</var>), <var>s</var> 190= sin(<var>a</var>), and using the following.</p> 191 192<pre> 193-affine <var>c</var>,<var>s</var>,-<var>s</var>,<var>c</var> 194</pre> 195 196<p>The cumulative effect of a sequence of <a href="command-line-options.html#affine">-affine</a> 197transformations can be accomplished by instead by a single <a href="command-line-options.html#affine">-affine</a> operation using the matrix equal to the product of the matrices 198of the individual transformations.</p> 199 200<p>An attempt is made to detect near-singular transformation matrices. If the 201matrix determinant has a sufficiently small absolute value it is rejected.</p> 202 203<div style="margin: auto;"> 204 <h3 class="magick-header"><a id="alpha"></a>-alpha <var>type</var></h3> 205</div> 206 207<p class="magick-description">Gives control of the alpha/matte channel of an image.</p> 208 209<p>Used to set a flag on an image indicating whether or not to use existing alpha 210channel data, to create an alpha channel, or to perform other operations on the alpha channel. Choose the argument <var>type</var> from the list below.</p> 211 212 213<div class="table-responsive"> 214<table class="table table-condensed table-striped"> 215 <tbody> 216 <tr> 217 <th>Type</th> 218 <th>Description</th> 219 </tr> 220 221 <tr> 222 <td><code>Activate</code> or <code>On</code></td> 223 <td> 224 Enable the image's transparency channel. Note normally <code>Set</code> 225 should be used instead of this, unless you specifically need to 226 preserve existing (but specifically turned <code>Off</code>) transparency 227 channel. </td></tr> 228 229 <tr> 230 <td><code>Associate</code></td> 231 <td> 232 associate the alpha channel with the image.</td></tr> 233 234 <tr> 235 <td><code>Deactivate</code> or <code>Off</code></td> 236 <td> 237 Disables the image's transparency channel. Does not delete or change the 238 existing data, just turns off the use of that data.</td></tr> 239 240 <tr> 241 <td><code>Disassociate</code></td> 242 <td> 243 disassociate the alpha channel from the image.</td></tr> 244 245 <tr> 246 <td><code>Set</code></td> 247 <td> 248 Activates the alpha/matte channel. If it was previously turned off 249 then it also resets the channel to opaque. If the image already had 250 the alpha channel turned on, it will have no effect.</td></tr> 251 252 <tr> 253 <td><code>Opaque</code></td> 254 <td> 255 Enables the alpha/matte channel and forces it to be fully opaque. 256 </td></tr> 257 258 <tr> 259 <td><code>Transparent</code></td> 260 <td> 261 Activates the alpha/matte channel and forces it to be fully 262 transparent. This effectively creates a fully transparent image the 263 same size as the original and with all its original RGB data still 264 intact, but fully transparent. </td></tr> 265 266 <tr> 267 <td><code>Extract</code></td> 268 <td> 269 Copies the alpha channel values into all the color channels and turns 270 '<code>Off</code>' the the image's transparency, so as to generate 271 a gray-scale mask of the image's shape. The alpha channel data is left 272 intact just deactivated. This is the inverse of '<code>Copy</code>'. 273 </td></tr> 274 275 <tr> 276 <td><code>Copy</code></td> 277 <td> 278 Turns '<code>On</code>' the alpha/matte channel, then copies the 279 gray-scale intensity of the image, into the alpha channel, converting 280 a gray-scale mask into a transparent shaped mask ready to be colored 281 appropriately. The color channels are not modified. </td></tr> 282 283 <tr> 284 <td><code>Shape</code></td> 285 <td> 286 As per '<code>Copy</code>' but also colors the resulting shape mask with 287 the current background color. That is the RGB color channels is 288 replaced, with appropriate alpha shape. 289 </td></tr> 290 291 <tr> 292 <td><code>Remove</code></td> 293 <td> 294 Composite the image over the background color. 295 </td></tr> 296 297 <tr> 298 <td><code>Background</code></td> 299 <td> 300 Set any fully-transparent pixel to the background color, while leaving 301 it fully-transparent. This can make some image file formats, such as 302 PNG, smaller as the RGB values of transparent pixels are more uniform, 303 and thus can compress better. 304 </td></tr> 305 </tbody> 306</table> 307</div> 308 309<p>Note that while the obsolete <code>+matte</code> operation was the 310same as "<code><a href="command-line-options.html#alpha">-alpha</a> Off</code>", the <code> 311>-matte</code> operation was the same as "<code><a href="command-line-options.html#alpha">-alpha</a> 312Set</code>" and not "<code><a href="command-line-options.html#alpha">-alpha</a> On</code>". </p> 313 314 315<div style="margin: auto;"> 316 <h3 class="magick-header"><a id="annotate"></a> 317 -annotate <var>degrees</var> <var>text</var><br> 318 -annotate <var>Xdegrees</var>x<var>Ydegrees</var> <var>text</var><br> -annotate <var>Xdegrees</var>x<var>Ydegrees</var> {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var><br> -annotate {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var></h3> 319</div> 320 321<p class="magick-description">Annotate an image with text</p> 322 323<p>This is a convenience for annotating an image with text. For more precise 324control over text annotations, use <a href="command-line-options.html#draw">-draw</a>.</p> 325 326 327<p>The values <var>Xdegrees</var> and <var>Ydegrees</var> 328control the shears applied to the text, while <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are offsets that give the location of the text relative any <a href="command-line-options.html#gravity">-gravity</a> setting and defaults to the upper left corner of the image.</p> 329 330<p>Using <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var> 331or <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>x<var>degrees</var> produces an unsheared rotation of the text. The 332direction of the rotation is positive, which means a clockwise rotation if <var>degrees</var> is positive. (This conforms to the usual mathematical 333convention once it is realized that the positive <var>y</var>–direction is 334conventionally considered to be <var>downward</var> for images.)</p> 335 336<p>The new (transformed) coordinates (<var>x'</var>, <var>y'</var>) of a pixel at position (<var>x</var>, <var>y</var>) in the image are calculated using the following matrix 337equation.</p> <div class="eqn"><img alt="annotate transformation" src="/images/annotate.png"></div> 338 339<p>If <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are omitted, they default to 0. This makes the 340bottom-left of the text becomes the upper-left corner of the image, which is 341probably undesirable. Adding a <a href="command-line-options.html#gravity">-gravity</a> option in this 342case leads to nice results.</p> 343 344<p>Text is any UTF-8 encoded character sequence. If <var>text</var> 345is of the form '@mytext.txt', the text is read from the file 346<code>mytext.txt</code>. Text in a file is taken literally; no embedded 347formatting characters are recognized.</p> 348 349<div style="margin: auto;"> 350 <h3 class="magick-header"><a id="antialias"></a>-antialias</h3> 351</div> 352 353<p class="magick-description">Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines.</p> 354 355<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when 356drawn. Use <a href="command-line-options.html#antialias">+antialias</a> to disable the addition of 357antialiasing edge pixels. This will then reduce the number of colors added to 358an image to just the colors being directly drawn. That is, no mixed colors 359are added when drawing such objects. </p> 360 361<div style="margin: auto;"> 362 <h3 class="magick-header"><a id="append"></a>-append</h3> 363</div> 364 365<p class="magick-description">Join current images vertically or horizontally.</p> 366 367<p>This option creates a single longer image, by joining all the current 368images in sequence top-to-bottom. Use <a href="command-line-options.html#append">+append</a> to 369stack images left-to-right. </p> 370 371<p>If they are not of the same width, narrower images are padded with the 372current <a href="command-line-options.html#background">-background</a> color setting, and their 373position relative to each other can be controlled by the current <a href="command-line-options.html#gravity">-gravity</a> setting. </p> 374 375 376<div style="margin: auto;"> 377 <h3 class="magick-header"><a id="attenuate"></a>-attenuate <var>value</var></h3> 378</div> 379 380<p class="magick-description">Lessen (or intensify) when adding noise to an image.</p> 381 382<p>If unset the value is equivalent to 1.0, or a maximum noise addition</p> 383 384<div style="margin: auto;"> 385 <h3 class="magick-header"><a id="authenticate"></a>-authenticate <var>password</var></h3> 386</div> 387 388<p class="magick-description">Decrypt a PDF with a password.</p> 389 390<p>Use this option to supply a <var>password</var> for decrypting 391a PDF that has been encrypted using Microsoft Crypto API (MSC API). The 392encrypting using the MSC API is not supported.</p> 393 394<p>For a different encryption method, see <a href="command-line-options.html#encipher">-encipher</a> 395and <a href="command-line-options.html#decipher">-decipher</a>. </p> 396 397 398<div style="margin: auto;"> 399 <h3 class="magick-header"><a id="auto-gamma"></a>-auto-gamma</h3> 400</div> 401 402<p class="magick-description">Automagically adjust gamma level of image.</p> 403 404<p>This calculates the mean values of an image, then applies a calculated <a href="command-line-options.html#gamma">-gamma</a> adjustment so that is the mean color exists in the 405image it will get a have a value of 50%. </p> 406 407<p>This means that any solid 'gray' image becomes 50% gray. </p> 408 409<p>This works well for real-life images with little or no extreme dark and 410light areas, but tend to fail for images with large amounts of bright sky or 411dark shadows. It also does not work well for diagrams or cartoon like images. 412</p> 413 414<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the 415'<var>sync</var>' flag for channel synchronization), to determine which color 416values is used and modified. As the default <a href="command-line-options.html#channel">-channel</a> setting is '<var>RGB,sync</var>', channels are modified 417together by the same gamma value, preserving colors. </p> 418 419 420 421<div style="margin: auto;"> 422 <h3 class="magick-header"><a id="auto-level"></a>-auto-level</h3> 423</div> 424 425<p class="magick-description">Automagically adjust color levels of image.</p> 426 427<p>This is a 'perfect' image normalization operator. It finds the exact 428minimum and maximum color values in the image and then applies a <a href="command-line-options.html#level">-level</a> operator to stretch the values to the full range of 429values. </p> 430 431<p>The operator is not typically used for real-life images, image scans, or 432JPEG format images, as a single 'out-rider' pixel can set a bad min/max values 433for the <a href="command-line-options.html#level">-level</a> operation. On the other hand it is the 434right operator to use for color stretching gradient images being used to 435generate Color lookup tables, distortion maps, or other 'mathematically' 436defined images. </p> 437 438<p>The operator is very similar to the <a href="command-line-options.html#normalize">-normalize</a>, <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>, and <a href="command-line-options.html#linear-stretch">-linear-stretch</a> operators, but without 'histogram binning' or 'clipping' 439problems that these operators may have. That is <a href="command-line-options.html#auto-level">-auto-level</a> is the perfect or ideal version these operators. </p> 440 441<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the 442special '<var>sync</var>' flag for channel synchronization), to determine 443which color values are used and modified. As the default <a href="command-line-options.html#channel">+channel</a> setting is '<var>RGB,sync</var>', the 444'<var>sync</var>' ensures that the color channels will are modified 445together by the same gamma value, preserving colors, and ignoring 446transparency. </p> 447 448 449<div style="margin: auto;"> 450 <h3 class="magick-header"><a id="auto-orient"></a>-auto-orient</h3> 451</div> 452 453<p class="magick-description">adjusts an image so that its orientation is suitable for viewing (i.e. top-left orientation).</p> 454 455<p>This operator reads and resets the EXIF image profile setting 'Orientation' 456and then performs the appropriate 90 degree rotation on the image to orient 457the image, for correct viewing. </p> 458 459<p>This EXIF profile setting is usually set using a gravity sensor in digital 460camera, however photos taken directly downward or upward may not have an 461appropriate value. Also images that have been orientation 'corrected' without 462reseting this setting, may be 'corrected' again resulting in a incorrect 463result. If the EXIF profile was previously stripped, the <a href="command-line-options.html#auto-orient">-auto-orient</a> operator will do nothing. </p> 464 465 466<div style="margin: auto;"> 467 <h3 class="magick-header"><a id="average"></a>-average</h3> 468</div> 469 470<p class="magick-description">Average a set of images.</p> 471 472<p>An error results if the images are not identically sized.</p> 473 474 475<div style="margin: auto;"> 476 <h3 class="magick-header"><a id="backdrop"></a>-backdrop</h3> 477</div> 478 479<p class="magick-description">Display the image centered on a backdrop.</p> 480 481<p>This backdrop covers the entire workstation screen and is useful for hiding 482other X window activity while viewing the image. The color of the backdrop is 483specified as the background color. The color is specified using the format 484described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 485 486<div style="margin: auto;"> 487 <h3 class="magick-header"><a id="background"></a>-background <var>color</var></h3> 488</div> 489 490<p class="magick-description">Set the background color.</p> 491 492<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option. The default background color (if none is 493specified or found in the image) is white.</p> 494 495<div style="margin: auto;"> 496 <h3 class="magick-header"><a id="bench"></a>-bench <var>iterations</var></h3> 497</div> 498 499<p class="magick-description">Measure performance.</p> 500 501<p>Repeat the entire command for the given number of <var>iterations</var> and report the user-time and elapsed time. For instance, 502consider the following command and its output. Modify the benchmark with the 503-duration to run the benchmark for a fixed number of seconds and -concurrent 504to run the benchmark in parallel (requires the OpenMP feature).</p> 505 506<pre> 507convert logo: -resize 1000% -bench 5 logo.png 508Performance[4]: 5i 0.875657ips 6.880u 0:05.710 509</pre> 510 511<p>In this example, 5 iterations were completed at 0.875657 iterations per 512second, using 4 threads and 6.88 seconds of the user's allotted time, for 513a total elapsed time of 5.71 seconds.</p> 514 515<div style="margin: auto;"> 516 <h3 class="magick-header"><a id="bias"></a>-bias <var>value</var>{<var>%</var>}</h3> 517</div> 518 519<p class="magick-description">Add bias when convolving an image.</p> 520 521<p>This option shifts the output of <a href="command-line-options.html#convolve">‑convolve</a> so that 522positive and negative results are relative to the specified bias value. </p> 523 524<p>This is important for non-HDRI compilations of ImageMagick when dealing 525with convolutions that contain negative as well as positive values. This is 526especially the case with convolutions involving high pass filters or edge 527detection. Without an output bias, the negative values are clipped at 528zero.</p> 529 530<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 531negative results without clipping to the color value range 532(0..QuantumRange).</p> 533 534<p>See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High Dynamic-Range Images</a>. For more 535about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this 536<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 537entry. </p> 538 539<div style="margin: auto;"> 540 <h3 class="magick-header"><a id="black-point-compensation"></a>-black-point-compensation</h3> 541</div> 542 543<p class="magick-description">Use black point compensation.</p> 544 545<div style="margin: auto;"> 546 <h3 class="magick-header"><a id="black-threshold"></a>-black-threshold <var>value</var>{<var>%</var>}</h3> 547</div> 548 549<p class="magick-description">Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</p> 550 551<p> The threshold value can be given as a percentage or as an absolute integer 552value within [0, <var>QuantumRange</var>] corresponding to the 553desired <a href="command-line-options.html#channel">‑channel</a> value. See <a href="command-line-options.html#threshold">‑threshold</a>for more details on thresholds and resulting values. </p> 554 555 556<div style="margin: auto;"> 557 <h3 class="magick-header"><a id="blend"></a>-blend <var>geometry</var></h3> 558</div> 559 560<p class="magick-description">blend an image into another by the given absolute value or percent.</p> 561 562<p>Blend will average the images together ('plus') according to the 563percentages given and each pixels transparency. If only a single percentage 564value is given it sets the weight of the composite or 'source' image, while 565the background image is weighted by the exact opposite amount. That is a 566<code>-blend 30%</code> merges 30% of the 'source' image with 70% of the 567'destination' image. Thus it is equivalent to <code>-blend 30x70%</code>.</p> 568 569 570<div style="margin: auto;"> 571 <h3 class="magick-header"><a id="blue-primary"></a>-blue-primary <var>x</var>,<var>y</var></h3> 572</div> 573 574<p class="magick-description">Set the blue chromaticity primary point.</p> 575 576<div style="margin: auto;"> 577 <h3 class="magick-header"><a id="blue-shift"></a>-blue-shift <var>factor</var></h3> 578</div> 579 580<p class="magick-description">simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</p> 581 582<div style="margin: auto;"> 583 584<div style="margin: auto;"> 585 <h3 class="magick-header"><a id="blur"></a>-blur <var>radius</var><br>-blur <var>radius</var>x<var>sigma</var></h3> 586</div> 587 588<p class="magick-description">Reduce image noise and reduce detail levels.</p> 589 590<p>Convolve the image with a Gaussian or normal distribution using the given 591<var>Sigma</var> value. The formula is:</p> 592 593<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"> 594</div> 595 596<p>The <var>Sigma</var> value is the important argument, and 597determines the actual amount of blurring that will take place. </p> 598 599<p>The <var>Radius</var> is only used to determine the size of the 600array which will hold the calculated Gaussian distribution. It should be an 601integer. If not given, or set to zero, IM will calculate the largest possible 602radius that will provide meaningful results for the Gaussian distribution. 603</p> 604 605<p>The larger the <var>Radius</var> the slower the 606operation is. However too small a <var>Radius</var>, and sever 607aliasing effects may result. As a guideline, <var>Radius</var> 608should be at least twice the <var>Sigma</var> value, though three 609times will produce a more accurate result. </p> 610 611<p>This option differs from <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a> simply 612by taking advantage of the separability properties of the distribution. Here 613we apply a single-dimensional Gaussian matrix in the horizontal direction, 614then repeat the process in the vertical direction.</p> 615 616<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how 617pixels which are outside the image proper are blurred into the final result. 618</p> 619 620 621<div style="margin: auto;"> 622 <h3 class="magick-header">-blur <var>Width</var>[x<var>Height</var>[+<var>Angle</var>]]</h3> 623</div> 624 625<p class="magick-description">Variably blur an image according to the overlay mapping.</p> 626 627<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted 628Average (EWA) of the source image, scaled according to the grayscale 629mapping. </p> 630 631<p>The ellipse is weighted with sigma set to the given <var>Width</var> and <var>Height</var>. The <var>Height</var> 632defaults to the <var>Width</var> for a normal circular Gaussian 633weighting. The <var>Angle</var> will rotate the ellipse from 634horizontal clock-wise. </p> 635 636<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how 637pixels which are outside the image proper are blurred into the final result. 638</p> 639 640 641<div style="margin: auto;"> 642 <h3 class="magick-header"><a id="border"></a>-border <var>geometry</var></h3> 643</div> 644 645<p class="magick-description">Surround the image with a border of color. </p> 646 647<p>Set the width and height using the <var>size</var> portion of the 648<var>geometry</var> argument. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets are 649ignored. </p> 650 651<p>As of IM 6.7.8-8, the <var>geometry</var> arguments behave as follows:</p> 652 653<table id="borderTable"> 654 <col width="20%"> <col width="80%"> 655 <thead> 656 <tr> 657 <th style="text-align:center"><var>size</var></th> 658 <th>General description</th> 659 </tr> 660 </thead> 661 <tbody> 662 <tr> 663 <td><var>value</var></td> 664 <td>value is added to both left/right and top/bottom</td> 665 </tr> 666 <tr> 667 <td><var>value-x</var>x</td> 668 <td>value-x is added only to left/right and top/bottom are unchanged</td> 669 </tr> 670 <tr> 671 <td>x<var>value-y</var></td> 672 <td>value-y is added only to top/bottom and left/right are unchanged</td> 673 </tr> 674 <tr> 675 <td><var>value-x</var>x<var>value-y</var></td> 676 <td>value-x is added to left/right and value-y added to top/bottom</td> 677 </tr> 678 <tr> 679 <td><var>value-x</var>x<code>0</code></td> 680 <td>value-x is added only to left/right and top/bottom are unchanged</td> 681 </tr> 682 <tr> 683 <td><code>0</code>x<var>value-y</var></td> 684 <td>value-y is added only to top/bottom and left/right are unchanged</td> 685 </tr> 686 <tr> 687 <td> </td> 688 <td> </td> 689 </tr> 690 <tr> 691 <td><var>value</var>%</td> 692 <td>value % of width is added to left/right and value % of height is added to top/bottom</td> 693 </tr> 694 <tr> 695 <td><var>value-x</var>x%</td> 696 <td>value-x % of width is added to left/right and to top/bottom</td> 697 </tr> 698 <tr> 699 <td>x<var>value-y</var>%</td> 700 <td>value-y % of height is added to top/bottom and to left/right</td> 701 </tr> 702 <tr> 703 <td><var>value-x</var>%x<var>value-y</var>%</td> 704 <td>value-x % of width is added to left/right and value-y % of height is added to top/bottom</td> 705 </tr> 706 <tr> 707 <td><var>value-x</var>%x<code>0</code>%</td> 708 <td>value-x % of width is added to left/right and top/bottom are unchanged</td> 709 </tr> 710 <tr> 711 <td><code>0</code>%x<var>value-y</var>%</td> 712 <td>value-y % of height is added to top/bottom and left/right are unchanged</td> 713 </tr> 714 </tbody> 715 </table> 716 717 718<p>Set the border color by preceding with the <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p> 719 720<p>The <a href="command-line-options.html#border">-border</a> operation is affected by the current <a href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default 721'<code>Over</code>' composition method. It generates an image of the appropriate 722size colors by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> before 723overlaying the original image in the center of this net image. This means that 724with the default compose method of '<code>Over</code>' any transparent parts may 725be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p> 726<p>See also the <a href="command-line-options.html#frame">-frame</a> option, which has more 727functionality.</p> 728 729<div style="margin: auto;"> 730 <h3 class="magick-header"><a id="bordercolor"></a>-bordercolor <var>color</var></h3> 731</div> 732 733<p class="magick-description">Set the border color.</p> 734 735<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 736 737<p>The default border color is <code>#DFDFDF</code>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p> 738 739<div style="margin: auto;"> 740 <h3 class="magick-header"><a id="borderwidth"></a>-borderwidth <var>geometry</var> </h3> 741</div> 742 743<p class="magick-description">Set the border width.</p> 744 745<div style="margin: auto;"> 746 <h3 class="magick-header"><a id="brightness-contrast"></a>-brightness-contrast <var>brightness</var><br>-brightness-contrast <var>brightness</var>{x<var>contrast</var>}{<var>%</var>}}</h3> 747</div> 748 749<p class="magick-description">Adjust the brightness and/or contrast of the image.</p> 750 751<p>Brightness and Contrast values apply changes to the input image. They are 752not absolute settings. A brightness or contrast value of zero means no change. 753The range of values is -100 to +100 on each. Positive values increase the 754brightness or contrast and negative values decrease the brightness or contrast. 755To control only contrast, set the brightness=0. To control only brightness, 756set contrast=0 or just leave it off.</p> 757 758<p>You may also use <a href="command-line-options.html#fill">-channel</a> to control which channels to 759apply the brightness and/or contrast change. The default is to apply the same 760transformation to all channels.</p> 761 762<p>Brightness and Contrast arguments are converted to offset and slope of a 763linear transform and applied 764using <a href="command-line-options.html#fill">-function polynomial "slope,offset"</a>.</p> 765 766<p>The slope varies from 0 at contrast=-100 to almost vertical at 767contrast=+100. For brightness=0 and contrast=-100, the result are totally 768midgray. For brightness=0 and contrast=+100, the result will approach but 769not quite reach a threshold at midgray; that is the linear transformation 770is a very steep vertical line at mid gray.</p> 771 772<p>Negative slopes, i.e. negating the image, are not possible with this 773function. All achievable slopes are zero or positive.</p> 774 775<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5 776at brightness=+100. Thus, when contrast=0 and brightness=100, the result is 777totally white. Similarly, when contrast=0 and brightness=-100, the result is 778totally black.</p> 779 780<p>As the range of values for the arguments are -100 to +100, adding the '%' 781symbol is no different than leaving it off.</p> 782 783<div style="margin: auto;"> 784 <h3 class="magick-header"><a id="cache"></a>-cache <var>threshold</var></h3> 785</div> 786 787<p class="magick-description">(This option has been replaced by the <a href="command-line-options.html#limit">-limit</a> option).</p> 788 789<div style="margin: auto;"> 790 <h3 class="magick-header"><a id="canny"></a>-canny <var>radius</var><br>-canny <var>radius</var>x<var>sigma</var>{<var>+lower-percent</var>}{<var>+upper-percent</var>}</h3> 791</div> 792 793<p class="magick-description">Canny edge detector uses a multi-stage algorithm to detect a wide range of edges in the image.</p> 794 795<p>The thresholds range from 0 to 100% (e.g. -canny 0x1+10%+30%) with {<var>+lower-percent</var>} < {<var>+upper-percent</var>}. If {<var>+upper-percent</var>} is increased but {<var>+lower-percent</var>} remains the same, lesser edge components will be detected, but their lengths will be the same. If {<var>+lower-percent</var>} is increased but {<var>+upper-percent</var>} is the same, the same number of edge components will be detected but their lengths will be shorter. The default thresholds are shown. The <var>radius</var>x<var>sigma</var> controls a gaussian blur applied to the input image to reduce noise and smooth the edges.</p> 796 797<div style="margin: auto;"> 798 <h3 class="magick-header"><a id="caption"></a>-caption <var>string</var></h3> 799</div> 800 801<p class="magick-description">Assign a caption to an image.</p> 802 803<p>This option sets the caption meta-data of an image read in after this 804option has been given. To modify a caption of images already in memory use 805"<code><a href="command-line-options.html#set">-set</a> caption</code>". </p> 806 807<p>The caption can contain special format characters listed in the <a href="escape.html">Format and 808Print Image Properties</a>. These attributes are expanded when the caption 809is finally assigned to the individual images. </p> 810 811<p>If the first character of <var>string</var> is <var>@</var>, the image caption is read from a file titled by the 812remaining characters in the string. Comments read in from a file are literal; 813no embedded formatting characters are recognized.</p> 814 815<p>Caption meta-data is not visible on the image itself. To do that use the 816<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options 817instead.</p> 818 819<p>For example,</p> 820 821<pre> 822-caption "%m:%f %wx%h" bird.miff 823</pre> 824 825<p>produces an image caption of <code>MIFF:bird.miff 512x480</code> (assuming 826that the image <code>bird.miff</code> has a width of 512 and a height of 827480.</p> 828 829 830<div style="margin: auto;"> 831 <h3 class="magick-header"><a id="cdl"></a>-cdl <var>filename</var></h3> 832</div> 833 834<p class="magick-description">color correct with a color decision list.</p> 835 836<p>Here is an example color correction collection:</p> 837 838<pre> 839<?xml version="1.0" encoding="UTF-8"?> 840<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 841 <ColorCorrection id="cc06668"> 842 <SOPNode> 843 <Slope> 0.9 1.2 0.5 </Slope> 844 <Offset> 0.4 -0.5 0.6 </Offset> 845 <Power> 1.0 0.8 1.5 </Power> 846 </SOPNode> 847 <SATNode> 848 <Saturation> 0.85 </Saturation> 849 </SATNode> 850 </ColorCorrection> 851</ColorCorrectionCollection> 852</pre> 853 854<div style="margin: auto;"> 855 <h3 class="magick-header"><a id="channel"></a>-channel <var>type</var></h3> 856</div> 857 858<p class="magick-description">Specify those image color channels to which subsequent operators are limited.</p> 859 860<p>Choose from: <code>Red</code>, <code>Green</code>, <code>Blue</code>, 861<code>Alpha</code>, <code>Gray</code>, <code>Cyan</code>, <code>Magenta</code>, 862<code>Yellow</code>, <code>Black</code>, <code>Opacity</code>, 863<code>Index</code>, <code>RGB</code>, <code>RGBA</code>, <code>CMYK</code>, or 864<code>CMYKA</code>.</p> 865 866<p>The channels above can also be specified as a comma-separated list or can be 867abbreviated as a concatenation of the letters '<code>R</code>', '<code>G</code>', 868'<code>B</code>', '<code>A</code>', '<code>O</code>', '<code>C</code>', 869'<code>M</code>', '<code>Y</code>', '<code>K</code>'. 870 871For example, to only select the <code>Red</code> and <code>Blue</code> channels 872you can either use </p> 873<pre> 874-channel Red,Blue 875</pre> 876<p>or you can use the short hand form</p> 877<pre> 878-channel RB 879</pre> 880 881<p>All the channels that are present in an image can be specified using the 882special channel type <code>All</code>. Not all operators are 'channel capable', 883but generally any operators that are generally 'grey-scale' image operators, 884will understand this setting. See individual operator documentation. </p> 885 886<br> 887 888<p>On top of the normal channel selection an extra flag can be specified, 889'<code>Sync</code>'. This is turned on by default and if set means that 890operators that understand this flag should perform: cross-channel 891synchronization of the channels. If not specified, then most grey-scale 892operators will apply their image processing operations to each individual 893channel (as specified by the rest of the <a href="command-line-options.html#channel">-channel</a> 894setting) completely independently from each other. </p> 895 896<p>For example for operators such as <a href="command-line-options.html#auto-level">-auto-level</a> and 897<a href="command-line-options.html#auto-gamma">-auto-gamma</a> the color channels are modified 898together in exactly the same way so that colors will remain in-sync. Without 899it being set, then each channel is modified separately and 900independently, which may produce color distortion. </p> 901 902<p>The <a href="command-line-options.html#morphology">-morphology</a> '<code>Convolve</code>' method 903and the <a href="command-line-options.html#compose">-compose</a> mathematical methods, also understands 904the '<code>Sync</code>' flag to modify the behaviour of pixel colors according 905to the alpha channel (if present). That is to say it will modify the image 906processing with the understanding that fully-transparent colors should not 907contribute to the final result. </p> 908 909<p>Basically, by default, operators work with color channels in synchronous, and 910treats transparency as special, unless the <a href="command-line-options.html#channel">-channel</a> 911setting is modified so as to remove the effect of the '<code>Sync</code>' flag. 912How each operator does this depends on that operators current implementation. 913Not all operators understands this flag at this time, but that is changing. 914</p> 915 916<p>To print a complete list of channel types, use <a href="command-line-options.html#list">-list 917channel</a>.</p> 918 919<br> 920 921<p>By default, ImageMagick sets <a href="command-line-options.html#channel">-channel</a> to the value 922'<code>RGBK,sync</code>', which specifies that operators act on all color 923channels except the transparency channel, and that all the color channels are 924to be modified in exactly the same way, with an understanding of transparency 925(depending on the operation being applied). The 'plus' form <a href="command-line-options.html#channel">+channel</a> will reset the value back to this default. </p> 926 927<p>Options that are affected by the <a href="command-line-options.html#channel">-channel</a> setting 928include the following. 929 930<a href="command-line-options.html#auto-gamma">-auto-gamma</a>, 931<a href="command-line-options.html#auto-level">-auto-level</a>, 932<a href="command-line-options.html#black-threshold">-black-threshold</a>, 933<a href="command-line-options.html#blur">-blur</a>, 934<a href="command-line-options.html#clamp">-clamp</a>, 935<a href="command-line-options.html#clut">-clut</a>, 936<a href="command-line-options.html#combine">-combine</a>, 937<a href="command-line-options.html#composite">-composite</a> (Mathematical compose methods only), 938<a href="command-line-options.html#convolve">-convolve</a>, 939<a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>, 940<a href="command-line-options.html#evaluate">-evaluate</a>, 941<a href="command-line-options.html#function">-function</a>, 942<a href="command-line-options.html#fx">-fx</a>, 943<a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>, 944<a href="command-line-options.html#hald-clut">-hald-clut</a>, 945<a href="command-line-options.html#motion-blur">-motion-blur</a>, 946<a href="command-line-options.html#morphology">-morphology</a>, 947<a href="command-line-options.html#negate">-negate</a>, 948<a href="command-line-options.html#normalize">-normalize</a>, 949<a href="command-line-options.html#ordered-dither">-ordered-dither</a>, 950<a href="command-line-options.html#radial-blur">-radial-blur</a>, 951<a href="command-line-options.html#random-threshold">-random-threshold</a>, 952<a href="command-line-options.html#separate">-separate</a>, 953<a href="command-line-options.html#threshold">-threshold</a>, and 954<a href="command-line-options.html#white-threshold">-white-threshold</a>. 955</p> 956 957<p>Warning, some operators behave differently when the <a href="command-line-options.html#channel">+channel</a> default setting is in effect, verses ANY user defined <a href="command-line-options.html#channel">-channel</a> setting (including the equivalent of the 958default). These operators have yet to be made to understand the newer 'Sync' 959flag. </p> 960 961<p>For example <a href="command-line-options.html#threshold">-threshold</a> will by default gray-scale 962the image before thresholding, if no <a href="command-line-options.html#channel">-channel</a> setting 963has been defined. This is not 'Sync flag controlled, yet. </p> 964 965<p>Also some operators such as <a href="command-line-options.html#blur">-blur</a>, <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>, will modify their handling of the 966color channels if the '<code>alpha</code>' channel is also enabled by <a href="command-line-options.html#channel">-channel</a>. Generally this done to ensure that 967fully-transparent colors are treated as being fully-transparent, and thus any 968underlying 'hidden' color has no effect on the final results. Typically 969resulting in 'halo' effects. The newer <a href="command-line-options.html#morphology">-morphology</a> 970convolution equivalents however does have a understanding of the 'Sync' flag 971and will thus handle transparency correctly by default. </p> 972 973<p>As a alpha channel is optional within images, some operators will read the 974color channels of an image as a greyscale alpha mask, when the image has no 975alpha channel present, and the <a href="command-line-options.html#channel">-channel</a> setting tells 976the operator to apply the operation using alpha channels. The <a href="command-line-options.html#clut">-clut</a> operator is a good example of this. </p> 977 978 979 980<div style="margin: auto;"> 981 <h3 class="magick-header"><a id="charcoal"></a>-charcoal <var>factor</var></h3> 982</div> 983 984<p class="magick-description">Simulate a charcoal drawing.</p> 985 986<div style="margin: auto;"> 987 <h3 class="magick-header"><a id="chop"></a>-chop <var>geometry</var></h3> 988</div> 989 990<p class="magick-description">Remove pixels from the interior of an image.</p> 991 992<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>width</var> 993and <var>height</var> given in the of the <var>size</var> 994portion of the <var>geometry</var> argument give the number of 995columns and rows to remove. The <var>offset</var> portion of 996the <var>geometry</var> argument is influenced by 997a <a href="command-line-options.html#gravity">-gravity</a> setting, if present.</p> 998 999<p>The <a href="command-line-options.html#chop">-chop</a> option removes entire rows and columns, 1000and moves the remaining corner blocks leftward and upward to close the gaps.</p> 1001 1002<p>While it can remove internal rows and columns of pixels, it is more 1003typically used with as <a href="command-line-options.html#gravity">-gravity</a> setting and zero 1004offsets so as to remove a single edge from an image. Compare this to <a href="command-line-options.html#shave">-shave</a> which removes equal numbers of pixels from oppisite 1005sides of the image. </p> 1006 1007<p>Using <a href="command-line-options.html#chop">-chop</a> effectively undoes the results of a <a href="command-line-options.html#splice">-splice</a> that was given the same <var>geometry</var> and <a href="command-line-options.html#gravity">-gravity</a> settings. </p> 1008 1009<div style="margin: auto;"> 1010 <h3 class="magick-header"><a id="clamp"></a>-clamp</h3> 1011</div> 1012 1013<p class="magick-description">set each pixel whose value is below zero to zero and any the pixel whose value is above the quantum range to the quantum range (e.g. 65535) otherwise the pixel value remains unchanged.</p> 1014 1015<div style="margin: auto;"> 1016 <h3 class="magick-header"><a id="clip"></a>-clip</h3> 1017</div> 1018 1019<p class="magick-description">Apply the clipping path if one is present.</p> 1020 1021<p>If a clipping path is present, it is applied to subsequent operations.</p> 1022 1023<p>For example, in the command</p> 1024 1025<pre> 1026convert cockatoo.tif -clip -negate negated.tif 1027</pre> 1028 1029<p>only the pixels within the clipping path are negated.</p> 1030 1031<p>The <a href="command-line-options.html#clip">-clip</a> feature requires SVG support. If the SVG 1032delegate library is not present, the option is ignored.</p> 1033 1034<p>Use <a href="command-line-options.html#clip">+clip</a> to disable clipping for subsequent operations.</p> 1035 1036<div style="margin: auto;"> 1037 <h3 class="magick-header"><a id="clip-mask"></a>-clip-mask</h3> 1038</div> 1039 1040<p class="magick-description">Clip the image as defined by this mask.</p> 1041 1042<p>Use the alpha channel of the current image as a mask. Any areas that is 1043white is not modified by any of the 'image processing operators' that follow, 1044until the mask is removed. Pixels in the black areas of the clip mask are 1045modified per the requirements of the operator. </p> 1046 1047<p>In some ways this is similar to (though not the same) as defining 1048a rectangular <a href="command-line-options.html#region">-region</a>, or using the negative of the 1049mask (third) image in a three image <a href="command-line-options.html#composite">-composite</a>, 1050operation. </p> 1051 1052<p>Use <a href="command-line-options.html#clip-mask">+clip-mask</a> to disable clipping for subsequent operations.</p> 1053 1054<div style="margin: auto;"> 1055 <h3 class="magick-header"><a id="clip-path"></a>-clip-path <var>id</var></h3> 1056</div> 1057 1058<p class="magick-description">Clip along a named path from the 8BIM profile.</p> 1059 1060<p>This is identical to <a href="command-line-options.html#clip">-clip</a> except choose a specific clip path in the event the image has more than one path available. </p> 1061 1062<p>Use <a href="command-line-options.html#clip-path">+clip-path</a> to disable clipping for subsequent operations.</p> 1063 1064<div style="margin: auto;"> 1065 <h3 class="magick-header"><a id="clone"></a>-clone <var>index(s)</var></h3> 1066</div> 1067 1068<p class="magick-description">make a clone of an image (or images).</p> 1069 1070<p>Inside parenthesis (where the operator is normally used) it will make a 1071clone of the images from the last 'pushed' image sequence, and adds them to 1072the end of the current image sequence. Outside parenthesis 1073(not recommended) it clones the images from the current image sequence. </p> 1074 1075<p>Specify the image by its index in the sequence. The first image is index 10760. Negative indexes are relative to the end of the sequence; for 1077example, <code>−1</code> 1078represents the last image of the sequence. Specify a range of images with a 1079dash (e.g. <code>0−4</code>). Separate multiple indexes with commas but no 1080spaces (e.g. <code>0,2,5</code>). A value of '<code>0−−1</code> will 1081effectively clone all the images. </p> 1082 1083<p>The <a href="command-line-options.html#clone">+clone</a> will simply make a copy of the last image 1084in the image sequence, and is thus equivalent to using a argument of 1085'<code>−1</code>'. </p> 1086 1087<div style="margin: auto;"> 1088 <h3 class="magick-header"><a id="clut"></a>-clut</h3> 1089</div> 1090 1091<p class="magick-description">Replace the channel values in the first image using each corresponding channel in the second image as a <b>c</b>olor <b>l</b>ook<b>u</b>p <b>t</b>able.</p> 1092 1093<p>The second (LUT) image is ordinarily a gradient image containing the 1094histogram mapping of how each channel should be modified. Typically it is a 1095either a single row or column image of replacement color values. If larger 1096than a single row or column, values are taken from a diagonal line from 1097top-left to bottom-right corners.</p> 1098 1099<p>The lookup is further controlled by the <a href="command-line-options.html#interpolate">-interpolate</a> setting, which is especially handy for an 1100LUT which is not the full length needed by the ImageMagick installed Quality 1101(Q) level. Good settings for this are the '<code>bilinear</code>' and 1102'<code>bicubic</code>' interpolation settings, which give smooth color 1103gradients, and the '<code>integer</code>' setting for a direct, unsmoothed 1104lookup of color values. </p> 1105 1106<p>This operator is especially suited to replacing a grayscale image with a 1107specific color gradient from the CLUT image. </p> 1108 1109<p>Only the channel values defined by the <a href="command-line-options.html#channel">-channel</a> 1110setting will have their values replaced. In particular, since the default <a href="command-line-options.html#channel">-channel</a> setting is <code>RGB</code>, this means that 1111transparency (alpha/matte channel) is not affected, unless the <a href="command-line-options.html#channel">-channel</a> setting is modified. When the alpha channel is 1112set, it is treated by the <a href="command-line-options.html#clut">-clut</a> operator in the same way 1113as the other channels, implying that alpha/matte values are replaced using the 1114alpha/matte values of the original image. </p> 1115 1116<p>If either the image being modified, or the lookup image, contains no 1117transparency (i.e. <a href="command-line-options.html#alpha">-alpha</a> is turned 'off') but the <a href="command-line-options.html#channel">-channel</a> setting includes alpha replacement, then it is 1118assumed that image represents a gray-scale gradient which is used for the 1119replacement alpha values. That is you can use a gray-scale CLUT image to 1120adjust a existing images alpha channel, or you can color a gray-scale image 1121using colors form CLUT containing the desired colors, including transparency. 1122</p> 1123 1124<p>See also <a href="command-line-options.html#hald-clut">-hald-clut</a> which replaces colors 1125according to the lookup of the full color RGB value from a 2D representation 1126of a 3D color cube. </p> 1127 1128 1129<div style="margin: auto;"> 1130 <h3 class="magick-header"><a id="coalesce"></a>-coalesce</h3> 1131</div> 1132 1133<p class="magick-description">Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</p> 1134 1135<p>Overlay each image in an image sequence according to 1136its <a href="command-line-options.html#dispose">-dispose</a> meta-data, to reproduce the look of 1137an animation at each point in the animation sequence. All images should be 1138the same size, and are assigned appropriate GIF disposal settings for the 1139animation to continue working as expected as a GIF animation. Such frames 1140are more easily viewed and processed than the highly optimized GIF overlay 1141images. </p> 1142 1143<p>The animation can be re-optimized after processing using 1144the <a href="command-line-options.html#layers">-layers</a> method '<code>optimize</code>', although 1145there is no guarantee that the restored GIF animation optimization is 1146better than the original. </p> 1147 1148 1149<div style="margin: auto;"> 1150 <h3 class="magick-header"><a id="colorize"></a>-colorize <var>value</var></h3> 1151</div> 1152 1153<p class="magick-description">Colorize the image by an amount specified by <var>value</var> using the color specified by the most recent <a href="command-line-options.html#fill">-fill</a> setting.</p> 1154 1155<p>Specify the amount of colorization as a percentage. Separate colorization 1156values can be applied to the red, green, and blue channels of the image with 1157a comma-delimited list of colorization 1158values (e.g., <code>-colorize 0,0,50</code>).</p> 1159 1160<div style="margin: auto;"> 1161 <h3 class="magick-header"><a id="colormap"></a>-colormap <var>type</var></h3> 1162</div> 1163 1164<p class="magick-description">Define the colormap type.</p> 1165 1166<p>The <var>type</var> can be <code>shared</code> or <code>private</code>.</p> 1167 1168<p>This option only applies when the default X server visual 1169is <code>PseudoColor</code> or <code>GrayScale</code>. Refer 1170to <a href="command-line-options.html#visual">-visual</a> for more details. By default, 1171a shared colormap is allocated. The image shares colors with 1172other X clients. Some image colors could be approximated, 1173therefore your image may look very different than intended. 1174If <code>private</code> is chosen, the image colors appear exactly 1175as they are defined. However, other clients may go <var>technicolor</var> 1176when the image colormap is installed.</p> 1177 1178<div style="margin: auto;"> 1179 <h3 class="magick-header"><a id="colors"></a>-colors <var>value</var></h3> 1180</div> 1181 1182<p class="magick-description">Set the preferred number of colors in the image.</p> 1183 1184<p>The actual number of colors in the image may be less than your request, 1185but never more. Note that this a color reduction option. Images with fewer 1186unique colors than specified by <var>value</var> will have any 1187duplicate or unused colors removed. The ordering of an existing color 1188palette may be altered. When converting an image from color to grayscale, 1189it is more efficient to convert the image to the gray colorspace before 1190reducing the number of colors. Refer to 1191the <a href="quantize.html"> 1192color reduction algorithm</a> for more details.</p> 1193 1194<div style="margin: auto;"> 1195 <h3 class="magick-header"><a id="color-matrix"></a>-color-matrix <var>matrix</var></h3> 1196</div> 1197 1198<p class="magick-description">apply color correction to the image.</p> 1199 1200<p>This option permits saturation changes, hue rotation, luminance to alpha, 1201and various other effects. Although variable-sized transformation matrices 1202can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 1203for CMYKA (or RGBA with offsets). The matrix is similar to those used by 1204Adobe Flash except offsets are in column 6 rather than 5 (in support of 1205CMYKA images) and offsets are normalized (divide Flash offset by 255).</p> 1206 1207<p>As an example, to add contrast to an image with offsets, try this command:</p> 1208 1209<pre> 1210convert kittens.jpg -color-matrix \ 1211 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \ 1212 0.0 1.5 0.0 0.0, 0.0, -0.157 \ 1213 0.0 0.0 1.5 0.0, 0.0, -0.157 \ 1214 0.0 0.0 0.0 1.0, 0.0, 0.0 \ 1215 0.0 0.0 0.0 0.0, 1.0, 0.0 \ 1216 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png 1217</pre> 1218<div style="margin: auto;"> 1219 <h3 class="magick-header"><a id="colorspace"></a>-colorspace <var>value</var></h3> 1220</div> 1221 1222<p class="magick-description">Set the image colorspace.</p> 1223 1224<p>Choices are:</p> 1225 1226<pre> 1227CMY CMYK Gray HCL 1228HCLp HSB HSI HSL 1229HSV HWB Lab LCHab 1230LCHuv LMS Log Luv 1231OHTA Rec601YCbCr Rec709YCbCr RGB 1232scRGB sRGB Transparent xyY 1233XYZ YCbCr YCC YDbDr 1234YIQ YPbPr YUV 1235</pre> 1236 1237<p>To print a complete list of colorspaces, use <a href="command-line-options.html#list">-list colorspace</a>.</p> 1238 1239<p>For a more accurate color conversion to or from the linear RGB, CMYK, or grayscale colorspaces, use the <a href="command-line-options.html#profile">-profile</a> option. Note, ImageMagick assumes the sRGB colorspace if the image format does not indicate otherwise. For colorspace conversion, the gamma function is first removed to produce linear RGB.</p> 1240 1241<table class="table table-condensed table-striped"> 1242 <caption>Conversion of RGB to Other Color Spaces</caption> 1243 <tr><th valign="middle">CMY</th></tr> 1244 <tr><td valign="middle">C=<var>QuantumRange</var>−R</td></tr> 1245 <tr><td valign="middle">M=<var>QuantumRange</var>−G</td></tr> 1246 <tr><td valign="middle">Y=<var>QuantumRange</var>−B</td></tr> 1247 <tr><th valign="middle">CMYK — starts with CMY from above</th></tr> 1248 <tr><td valign="middle">K=min(C,Y,M)</td></tr> 1249 <tr><td valign="middle">C=<var>QuantumRange</var>*(C−K)/(<var>QuantumRange</var>−K)</td></tr> 1250 <tr><td valign="middle">M=<var>QuantumRange</var>*(M−K)/(<var>QuantumRange</var>−K)</td></tr> 1251 <tr><td valign="middle">Y=<var>QuantumRange</var>*(Y−K)/(<var>QuantumRange</var>−K)</td></tr> 1252 1253 <tr><th valign="middle">Gray</th></tr> 1254 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr> 1255 1256 <tr><th valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr> 1257 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1258 <tr><td valign="middle">S=distance from axis outward</td></tr> 1259 <tr><td valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <var>intensity-like</var></td></tr> 1260 1261 <tr><th valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr> 1262 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1263 <tr><td valign="middle">S=distance from axis outward</td></tr> 1264 <tr><td valign="middle">L=distance along axis from bottom upward; L=0.5*max(R,G,B) + 0.5*min(R,G,B); <var>intensity-like</var></td></tr> 1265 1266 <tr><th valign="middle">HWB — Hue, Whiteness, Blackness</th></tr> 1267 <tr><td valign="middle">Hue (complicated equation)</td></tr> 1268 <tr><td valign="middle">Whiteness (complicated equation)</td></tr> 1269 <tr><td valign="middle">Blackness (complicated equation)</td></tr> 1270 1271 <tr><th valign="middle">LAB</th></tr> 1272 <tr><td valign="middle">L (complicated equation relating X,Y,Z)</td></tr> 1273 <tr><td valign="middle">A (complicated equation relating X,Y,Z)</td></tr> 1274 <tr><td valign="middle">B (complicated equation relating X,Y,Z)</td></tr> 1275 1276 <tr><th valign="middle">LOG</th></tr> 1277 <tr><td valign="middle">I1 (complicated equation involving logarithm of R)</td></tr> 1278 <tr><td valign="middle">I2 (complicated equation involving logarithm of G)</td></tr> 1279 <tr><td valign="middle">I3 (complicated equation involving logarithm of B)</td></tr> 1280 1281 <tr><th valign="middle">OHTA — approximates principal components transformation</th></tr> 1282 <tr><td valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <var>intensity-like</var></td></tr> 1283 <tr><td valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1284 <tr><td valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1285 1286 <tr><th valign="middle">Rec601Luma</th></tr> 1287 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr> 1288 1289 <tr><th valign="middle">Rec601YCbCr</th></tr> 1290 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr> 1291 <tr><td valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1292 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1293 1294 <tr><th valign="middle">Rec709Luma</th></tr> 1295 <tr><td valign="middle">Gray=0.212656*R+0.715158*G+0.072186*B</td></tr> 1296 1297 <tr><th valign="middle">Rec709YCbCr</th></tr> 1298 <tr><td valign="middle">Y=0.212656*R+0.715158*G+0.072186*B; <var>intensity-like</var></td></tr> 1299 <tr><td valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)+(<var>QuantumRange</var>+1)/2</td></tr> 1300 <tr><td valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)+(<var>QuantumRange</var>+1)/2</td></tr> 1301 1302 <tr><th valign="middle">sRGB</th></tr> 1303 <tr><td valign="middle">if R ≤ .0.0031308 then Rs=R/12.92 else Rs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr> 1304 <tr><td valign="middle">if G ≤ .0.0031308 then Gs=B/12.92 else Gs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr> 1305 <tr><td valign="middle">if B ≤ .0.0031308 then Bs=B/12.92 else Bs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr> 1306 1307 <tr><th valign="middle">XYZ</th></tr> 1308 <tr><td valign="middle">X=0.4124564*R+0.3575761*G+0.1804375*B</td></tr> 1309 <tr><td valign="middle">Y=0.2126729*R+0.7151522*G+0.0721750*B</td></tr> 1310 <tr><td valign="middle">Z=0.0193339*R+0.1191920*G+0.9503041*B</td></tr> 1311 1312 <tr><th valign="middle">YCC</th></tr> 1313 <tr><td valign="middle">Y=(0.298839*R+0.586811*G+0.114350*B) (with complicated scaling); <var>intensity-like</var></td></tr> 1314 <tr><td valign="middle">C1=(−0.298839*R−0.586811*G+0.88600*B) (with complicated scaling)</td></tr> 1315 <tr><td valign="middle">C2=(0.70100*R−0.586811*G−0.114350*B) (with complicated scaling)</td></tr> 1316 1317 <tr><th valign="middle">YCbCr</th></tr> 1318 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr> 1319 <tr><td valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1320 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1321 1322 <tr><th valign="middle">YIQ</th></tr> 1323 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr> 1324 <tr><td valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1325 <tr><td valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1326 1327 <tr><th valign="middle">YPbPr</th></tr> 1328 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr> 1329 <tr><td valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1330 <tr><td valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1331 1332 <tr><th valign="middle">YUV</th></tr> 1333 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr> 1334 <tr><td valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1335 <tr><td valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<var>QuantumRange</var>+1)/2</td></tr> 1336</table> 1337 1338<p>Note the scRGB colorspace requires HDRI support otherwise it behaves just like linear RGB.</p> 1339 1340<div style="margin: auto;"> 1341 <h3 class="magick-header"><a id="combine"></a>-combine</h3> 1342</div> 1343 1344<p class="magick-description">Combine one or more images into a single image.</p> 1345 1346<p>The channels (previously set by <a href="command-line-options.html#channel">-channel</a>) of the 1347combined image are taken from the grayscale values of each image in the 1348sequence, in order. For the default -channel setting of <code>RGB</code>, this 1349means the first image is assigned to the <code>Red</code> channel, the second 1350to the <code>Green</code> channel, the third to the <code>Blue</code>.</p> 1351 1352<p>This option can be thought of as the inverse to <a href="command-line-options.html#separate">-separate</a>, so long as the channel settings are the same. 1353Thus, in the following example, the final image should be a copy of the 1354original. </p> 1355 1356<pre> 1357convert original.png -channel RGB -separate sepimage.png 1358convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \ 1359 -combine imagecopy.png 1360</pre> 1361 1362<div style="margin: auto;"> 1363 <h3 class="magick-header"><a id="comment"></a>-comment <var>string</var></h3> 1364</div> 1365 1366<p class="magick-description">Embed a comment in an image.</p> 1367 1368<p>This option sets the comment meta-data of an image read in after this 1369option has been given. To modify a comment of images already in memory use 1370"<code><a href="command-line-options.html#set">-set</a> comment</code>". </p> 1371 1372<p>The comment can contain special format characters listed in the <a href="escape.html">Format and 1373Print Image Properties</a>. These attributes are expanded when the comment 1374is finally assigned to the individual images. </p> 1375 1376<p>If the first character of <var>string</var> is <var>@</var>, the image comment is read from a file titled by the 1377remaining characters in the string. Comments read in from a file are literal; 1378no embedded formatting characters are recognized.</p> 1379 1380<p>Comment meta-data are not visible on the image itself. To do that use the 1381<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options 1382instead.</p> 1383 1384<p>For example,</p> 1385 1386<pre> 1387-comment "%m:%f %wx%h" bird.miff 1388</pre> 1389 1390<p>produces an image comment of <code>MIFF:bird.miff 512x480</code> (assuming 1391that the image <code>bird.miff</code> has a width of 512 and a height of 1392480.</p> 1393 1394<div style="margin: auto;"> 1395 <h3 class="magick-header"><a id="compare"></a>-compare</h3> 1396</div> 1397 1398<p class="magick-description">mathematically and visually annotate the difference between an image and its reconstruction</p> 1399 1400<p>This is a convert version of "<code>compare</code>" for two same sized images. The syntax is as follows, but other metrics are allowed.</p> 1401 1402<pre> 1403convert image.png reference.png -metric RMSE -compare \ <br> difference.png 1404</pre> 1405 1406<p>To get the metric value use the string format "%[distortion]".</p> 1407 1408<pre> 1409convert image.png reference.png -metric RMSE -compare -format \ 1410 "%[distortion]" info: 1411</pre> 1412 1413<div style="margin: auto;"> 1414 <h3 class="magick-header"><a id="complex"></a>-complex <var>operator</var></h3> 1415</div> 1416 1417<p class="magick-description">perform complex mathematics on an image sequence</p> 1418 1419Choose from these operators: 1420 1421<pre> 1422add 1423conjugate 1424divide 1425magnuitude-phase 1426multiply 1427real-imaginary 1428subtract 1429</pre> 1430 1431<p>Optionally specify the <code>divide</code> operator SNR with <code><a href="command-line-options.html#define">-define</a> complex:snr=float</code>.</p> 1432 1433<div style="margin: auto;"> 1434 <h3 class="magick-header"><a id="compose"></a>-compose <var>operator</var></h3> 1435</div> 1436 1437<p class="magick-description">Set the type of image composition.</p> 1438 1439<p>See <a href="compose.html">Alpha Compositing</a> for 1440a detailed discussion of alpha compositing.</p> 1441 1442<p>This setting effects image processing operators that merge two (or more) 1443images together in some way. This includes the operators, 1444<a href="command-line-options.html#composite">-compare</a>, 1445<a href="command-line-options.html#composite">-composite</a>, 1446<a href="command-line-options.html#layers">-layers</a> composite, 1447<a href="command-line-options.html#flatten">-flatten</a>, 1448<a href="command-line-options.html#mosaic">-mosaic</a>, 1449<a href="command-line-options.html#layers">-layers</a> merge, 1450<a href="command-line-options.html#border">-border</a>, 1451<a href="command-line-options.html#frame">-frame</a>, 1452and <a href="command-line-options.html#extent">-extent</a>. </p> 1453 1454<p>It is also one of the primary options for the "<code>composite</code>" 1455command. </p> 1456 1457 1458<div style="margin: auto;"> 1459 <h3 class="magick-header"><a id="composite"></a>-composite</h3> 1460</div> 1461 1462<p class="magick-description">Perform alpha composition on two images and an optional mask</p> 1463 1464<p>Take the first image 'destination' and overlay the second 'source' image 1465according to the current <a href="command-line-options.html#compose">-compose</a> setting. The location 1466of the 'source' or 'overlay' image is controlled according to <a href="command-line-options.html#geometry">-geometry</a>, and <a href="command-line-options.html#geometry">-geometry</a> 1467settings. </p> 1468 1469<p>If a third image is given this is treated as a gray-scale blending 'mask' image 1470relative to the first 'destination' image. This mask is blended with the 1471source image. However for the '<code>displace</code>' compose method, the 1472mask is used to provide a separate Y-displacement image instead. </p> 1473 1474<p>If a <a href="command-line-options.html#compose">-compose</a> method requires extra numerical 1475arguments or flags these can be provided by setting the <a href="command-line-options.html#set">-set</a> '<code>option:compose:args</code>' 1476appropriately for the compose method. </p> 1477 1478<p>Some <a href="command-line-options.html#compose">-compose</a> methods can modify the 'destination' 1479image outside the overlay area. You can disable this by setting the special <a href="command-line-options.html#set">-set</a> '<code>option:compose:outside-overlay</code>' 1480to '<code>false</code>'. </p> 1481 1482<p>The SVG compositing specification requires that color and opacity values range between zero and QuantumRange inclusive. You can permit values outside this range with this option: <a href="command-line-options.html#set">-set</a> '<code>option:compose:clamp=false</code></p> 1483 1484 1485<div style="margin: auto;"> 1486 <h3 class="magick-header"><a id="compress"></a>-compress <var>type</var></h3> 1487</div> 1488 1489<p class="magick-description">Use pixel compression specified by <var>type</var> when writing the image.</p> 1490 1491<p>Choices are: <code>None</code>, <code>BZip</code>, <code>Fax</code>, <code>Group4</code>, <code>JPEG</code>, <code>JPEG2000</code>, <code>Lossless</code>, <code>LZW</code>, <code>RLE</code> or <code>Zip</code>.</p> 1492 1493<p>To print a complete list of compression types, use <a href="command-line-options.html#list">-list 1494compress</a>.</p> 1495 1496<p>Specify <a href="command-line-options.html#compress">+compress</a> to store the binary image in an 1497uncompressed format. The default is the compression type of the specified 1498image file.</p> 1499 1500<p>If <code>LZW</code> compression is specified but LZW compression has not been 1501enabled, the image data is written in an uncompressed LZW format that can be 1502read by LZW decoders. This may result in larger-than-expected GIF files.</p> 1503 1504<p><code>Lossless</code> refers to lossless JPEG, which is only available if the 1505JPEG library has been patched to support it. Use of lossless JPEG is generally 1506not recommended.</p> 1507 1508<p> 1509When writing an ICO file, you may request that the images be encoded in 1510PNG format, by specifying <code>Zip</code> compression.</p> 1511 1512<p> 1513When writing a JNG file, specify <code>Zip</code> compression to request that 1514the alpha channel be encoded in PNG "IDAT" format, or <code>JPEG</code> 1515to request that it be encoded in JPG "JDAA" format.</p> 1516 1517<p>Use the <a href="command-line-options.html#quality">-quality</a> option to set the compression level 1518to be used by JPEG, PNG, MIFF, and MPEG encoders. 1519Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to set the 1520sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling 1521the chroma channels.</p> 1522 1523<div style="margin: auto;"> 1524 <h3 class="magick-header"><a id="connected-components"></a>-connected-components <var>connectivity</var></h3> 1525</div> 1526 1527<p class="magick-description">connected-components uniquely labeled, choose from 4 or 8 way connectivity.</p> 1528 1529<p>Use <code><a href="command-line-options.html#define">-define</a> connected-components:verbose=true</code> to output statistics associated with each unique label.</p> 1530 1531<div style="margin: auto;"> 1532 <h3 class="magick-header"><a id="contrast"></a>-contrast</h3> 1533</div> 1534 1535<p class="magick-description">Enhance or reduce the image contrast.</p> 1536 1537<p>This option enhances the intensity differences between the lighter and 1538darker elements of the image. Use <a href="command-line-options.html#contrast">-contrast</a> to enhance 1539the image or <a href="command-line-options.html#contrast">+contrast</a> to reduce the image 1540contrast.</p> 1541 1542<p>For a more pronounced effect you can repeat the option:</p> 1543 1544<pre> 1545convert rose: -contrast -contrast rose_c2.png 1546</pre> 1547 1548<div style="margin: auto;"> 1549 <h3 class="magick-header"><a id="contrast-stretch"></a>-contrast-stretch <var>black-point</var><br>-contrast-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}}</h3> 1550</div> 1551 1552<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p> 1553 1554<p>While performing the stretch, black-out at most <var>black-point</var> pixels and white-out at most <var>white-point</var> pixels. Or, if percent is used, black-out at most 1555<var>black-point %</var> pixels and white-out at most <var>white-point %</var> pixels.</p> 1556 1557<p>Prior to ImageMagick 6.4.7-0, <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> will black-out at most <var>black-point</var> pixels and white-out at most <var>total pixels 1558minus white-point</var> pixels. Or, if percent is used, black-out at most <var>black-point %</var> pixels and white-out at most <var>100% minus white-point %</var> pixels.</p> 1559 1560<p>Note that <code>-contrast-stretch 0</code> will modify the image such that 1561the image's min and max values are stretched to 0 and <var>QuantumRange</var>, respectively, without any loss of data due to burn-out or 1562clipping at either end. This is not the same as <a href="command-line-options.html#normalize">-normalize</a>, which is equivalent to <code>-contrast-stretch 0.15x0.05%</code> (or 1563prior to ImageMagick 6.4.7-0, <code>-contrast-stretch 2%x99%</code>).</p> 1564 1565<p>Internally operator works by creating a histogram bin, and then uses that 1566bin to modify the image. As such some colors may be merged together when they 1567originally fell into the same 'bin'. </p> 1568 1569<p>All the channels are normalized in concert by the came amount so as to 1570preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a> 1571setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a> 1572setting will normalize the RGB channels independently.</p> 1573 1574<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect' 1575normalization of mathematical images. </p> 1576 1577<p>This operator is under review for re-development. </p> 1578 1579 1580<div style="margin: auto;"> 1581 <h3 class="magick-header"><a id="convolve"></a>-convolve <var>kernel</var></h3> 1582</div> 1583 1584<p class="magick-description">Convolve an image with a user-supplied convolution kernel.</p> 1585 1586<p>The <var>kernel</var> is a matrix specified as 1587a comma-separated list of integers (with no spaces), ordered left-to right, 1588starting with the top row. Presently, only odd-dimensioned kernels are 1589supported, and therefore the number of entries in the specified <var>kernel</var> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25, 15907<sup>2</sup>=49, etc. </p> 1591 1592<p>Note that the <a href="command-line-options.html#convolve">‑convolve</a> operator supports the <a href="command-line-options.html#bias">‑bias</a> setting. This option shifts the convolution so that 1593positive and negative results are relative to a user-specified bias value. 1594This is important for non-HDRI compilations of ImageMagick when dealing with 1595convolutions that contain negative as well as positive values. This is 1596especially the case with convolutions involving high pass filters or edge 1597detection. Without an output bias, the negative values is clipped at zero. 1598</p> 1599 1600<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 1601negative results without clipping to the color value range (0..QuantumRange). 1602See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High 1603Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this 1604<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 1605entry. </p> 1606 1607 1608<div style="margin: auto;"> 1609 <h3 class="magick-header"><a id="crop"></a>-crop <var>geometry</var>{<var>@</var>}{<var>!</var>}</h3> 1610</div> 1611 1612<p class="magick-description">Cut out one or more rectangular regions of the image.</p> 1613 1614<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 1615 1616<p>The <var>width</var> and <var>height</var> of the <var>geometry</var> argument give the size of the image that remains 1617after cropping, and <var>x</var> and <var>y</var> in the 1618<var>offset</var> (if present) gives the location of the top left 1619corner of the cropped image with respect to the original image. To specify the 1620amount to be removed, use <a href="command-line-options.html#shave">-shave</a> instead.</p> 1621 1622<p>If the <var>x</var> and <var>y</var> offsets are 1623present, a single image is generated, consisting of the pixels from the 1624cropping region. The offsets specify the location of the upper left corner of 1625the cropping region measured downward and rightward with respect to the upper 1626left corner of the image. If the <a href="command-line-options.html#gravity">-gravity</a> option is 1627present with <code>NorthEast</code>, <code>East</code>, or <code>SouthEast</code> 1628gravity, it gives the distance leftward from the right edge of the image to 1629the right edge of the cropping region. Similarly, if the <a href="command-line-options.html#gravity">-gravity</a> option is present with <code>SouthWest</code>, 1630<code>South</code>, or <code>SouthEast</code> gravity, the distance is measured 1631upward between the bottom edges.</p> 1632 1633<p>If the <var>x</var> and <var>y</var> offsets are 1634omitted, a set of tiles of the specified geometry, covering the entire input 1635image, is generated. The rightmost tiles and the bottom tiles are smaller if 1636the specified geometry extends beyond the dimensions of the input image.</p> 1637 1638<p>You can add the <var>@</var> to the geometry argument to equally divide the image into the number of tiles generated.</p> 1639 1640<p>By adding a exclamation character flag to the geometry argument, the 1641cropped images virtual canvas page size and offset is set as if the 1642geometry argument was a viewport or window. This means the canvas page size 1643is set to exactly the same size you specified, the image offset set 1644relative top left corner of the region cropped. </p> 1645 1646<p>If the cropped image 'missed' the actual image on its virtual canvas, a 1647special single pixel transparent 'missed' image is returned, and a 'crop 1648missed' warning given. </p> 1649 1650<p>It might be necessary to <a href="command-line-options.html#repage">+repage</a> the image prior to 1651cropping the image to ensure the crop coordinate frame is relocated to the 1652upper-left corner of the visible image. 1653 1654Similarly you may want to use <a href="command-line-options.html#repage">+repage</a> after cropping to 1655remove the page offset that will be left behind. This is especially true when 1656you are going to write to an image format such as PNG that supports an image 1657offset.</p> 1658 1659<div style="margin: auto;"> 1660 <h3 class="magick-header"><a id="cycle"></a>-cycle <var>amount</var></h3> 1661</div> 1662 1663<p class="magick-description">displace image colormap by amount.</p> 1664 1665<p><var>Amount</var> defines the number of positions each 1666colormap entry is shifted.</p> 1667 1668 1669<div style="margin: auto;"> 1670 <h3 class="magick-header"><a id="debug"></a>-debug <var>events</var></h3> 1671</div> 1672 1673<p class="magick-description">enable debug printout.</p> 1674 1675<p>The <code>events</code> parameter specifies which events are to be logged. It 1676can be either <code>None</code>, <code>All</code>, <code>Trace</code>, or 1677a comma-separated list consisting of one or more of the following domains: 1678<code>Accelerate</code>, <code>Annotate</code>, <code>Blob</code>, <code>Cache</code>, 1679<code>Coder</code>, <code>Configure</code>, <code>Deprecate</code>, 1680<code>Exception</code>, <code>Locale</code>, <code>Render</code>, 1681<code>Resource</code>, <code>Security</code>, <code>TemporaryFile</code>, 1682<code>Transform</code>, <code>X11</code>, or <code>User</code>. </p> 1683 1684 1685<p>For example, to log cache and blob events, use.</p> 1686 1687<pre> 1688convert -debug "Cache,Blob" rose: rose.png 1689</pre> 1690 1691<p>The <code>User</code> domain is normally empty, but developers can log user 1692events in their private copy of ImageMagick.</p> 1693 1694<p>To print the complete list of debug methods, use <a href="command-line-options.html#list">-list 1695debug</a>.</p> 1696 1697<p>Use the <a href="command-line-options.html#log">-log</a> option to specify the format for debugging 1698output.</p> 1699 1700<p>Use <a href="command-line-options.html#debug">+debug</a> to turn off all logging.</p> 1701 1702<p>Debugging may also be set using the <code>MAGICK_DEBUG</code> <a href="resources.html#environment">environment variable</a>. The allowed values for the <code>MAGICK_DEBUG</code> 1703environment variable are the same as for the <a href="command-line-options.html#debug">-debug</a> 1704option.</p> 1705 1706 1707<div style="margin: auto;"> 1708 <h3 class="magick-header"><a id="decipher"></a>-decipher <var>filename</var></h3> 1709</div> 1710 1711<p class="magick-description">Decipher and restore pixels that were previously transformed by <a href="command-line-options.html#encipher">-encipher</a>.</p> 1712 1713<p>Get the passphrase from the file specified by <var>filename</var>.</p> 1714 1715<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or 1716Decipher an Image</a>.</p> 1717 1718 1719<div style="margin: auto;"> 1720 <h3 class="magick-header"><a id="deconstruct"></a>-deconstruct</h3> 1721</div> 1722 1723<p class="magick-description">find areas that has changed between images </p> 1724 1725<p>Given a sequence of images all the same size, such as produced by <a href="command-line-options.html#coalesce">-coalesce</a>, replace the second and later images, with 1726a smaller image of just the area that changed relative to the previous image. 1727</p> 1728 1729<p>The resulting sequence of images can be used to optimize an animation 1730sequence, though will not work correctly for GIF animations when parts of the 1731animation can go from opaque to transparent. </p> 1732 1733<p>This option is actually equivalent to the <a href="command-line-options.html#layers">-layers</a> 1734method '<code>compare-any</code>'. </p> 1735 1736 1737<div style="margin: auto;"> 1738 <h3 class="magick-header"><a id="define"></a>-define <var>key</var>{<var>=value</var>}<var>...</var></h3> 1739</div> 1740 1741<p class="magick-description">add specific global settings generally used to control coders and image processing operations.</p> 1742 1743<p>This option creates one or more definitions for coders and decoders to use 1744while reading and writing image data. Definitions are generally used to 1745control image file format coder modules, and image processing operations, 1746beyond what is provided by normal means. Defined settings are listed in <a href="command-line-options.html#verbose">-verbose</a> information ("<code>info:</code>" output format) 1747as "Artifacts". </p> 1748 1749<p>If <var>value</var> is missing for a definition, an empty-valued 1750definition of a flag is created with that name. This used to control on/off 1751options. Use <a href="command-line-options.html#define">+define key</a> to remove definitions 1752previously created. Use <a href="command-line-options.html#define">+define "*"</a> to remove all 1753existing definitions.</p> 1754 1755<p>The same 'artifact' settings can also be defined using the <a href="command-line-options.html#set">-set "option:<var>key</var>" "<var>value</var>"</a> option, which also allows the use of <a href="escape.html">Format and Print Image 1756Properties</a> in the defined value. </p> 1757 1758<p>The <var>option</var> and <var>key</var> are case-independent (they are 1759converted to lowercase for use within the decoders) while the <var>value</var> 1760is case-dependent.</p> 1761 1762<p>Such settings are global in scope, and affect all images and operations. </p> 1763 1764<p>The following definitions are just some of the artifacts that are 1765available:</p> 1766 1767<table class="table table-condensed table-striped"> 1768 <tr> 1769 <td>bmp:format=<var>value</var></td> 1770 <td> valid values are <var>bmp2</var>, <var>bmp3</var>, 1771 and <var>bmp4</var>. This option can be useful when the 1772 method of prepending "BMP2:" to the output filename is inconvenient or 1773 is not available, such as when using the <a href="mogrify.html">mogrify</a> utility.</td> 1774 </tr> 1775 1776 <tr> 1777 <td>complex:snr=<var>value</var></td> 1778 <td>Set the divide SNR constant<a href="command-line-options.html#complex">-complex</a></td> 1779 </tr> 1780 1781 <tr> 1782 <td>compose:args=<var>arguments</var></td> 1783 <td>Sets certain compose argument values when using convert ... -compose ... 1784 -composite. See <a href="compose.html">Image Composition</a></td> 1785 </tr> 1786 1787 <tr> 1788 <td>convolve:scale=<var>{kernel_scale}[!^] [,{origin_addition}] [%]</var></td> 1789 <td>Defines the kernel scaling. The special flag ! automatically scales to 1790 full dynamic range. The ! flag can be used in combination with a factor or 1791 percent. The factor or percent is then applied after the automatic scaling. 1792 An example is 50%!. This produces a result 50% darker than full dynamic 1793 range scaling. The ^ flag assures the kernel is 'zero-summing', for 1794 example when some values are positive and some are negative as in edge 1795 detection kernels. The origin addition adds that value to the center 1796 pixel of the kernel. This produces and effect that is like adding the image 1797 that many times to the result of the filtered image. The typical value 1798 is 1 so that the original image is added to the result of the convolution. 1799 The default is 0.</td> 1800 </tr> 1801 1802 <tr> 1803 <td>convolve:showkernel=<var>1</var></td> 1804 <td>Outputs (to 'standard error') all the information about a specified <a href="command-line-options.html#morphology">-morphology convolve</a> kernel.</td> 1805 </tr> 1806 1807 <tr> 1808 <td>dcm:display-range=<var>reset</var></td> 1809 <td>Sets the display range to the minimum and maximum pixel values for the 1810 DCM image format.</td> 1811 </tr> 1812 1813 <tr> 1814 <td>dds:cluster-fit=<var>true|false</var></td> 1815 <td>Enables the dds cluster-fit.</td> 1816 </tr> 1817 1818 <tr> 1819 <td>dds:compression=<var>dxt1|dxt5|none</var></td> 1820 <td>Sets the dds compression.</td> 1821 </tr> 1822 1823 <tr> 1824 <td>dds:mipmaps=<var>value</var></td> 1825 <td>Sets the dds number of mipmaps.</td> 1826 </tr> 1827 1828 <tr> 1829 <td>dds:weight-by-alpha=<var>true|false</var></td> 1830 <td>Enables the dds alpha weighting.</td> 1831 </tr> 1832 1833 <tr> 1834 <td>delegate:bimodal=<var>true</var></td> 1835 <td>Specifies direct conversion from Postscript to PDF.</td> 1836 </tr> 1837 1838 <tr> 1839 <td>distort:scale=<var>value</var></td> 1840 <td>Sets the output scaling factor for use with <a href="command-line-options.html#distort">-distort</a></td> 1841 </tr> 1842 1843 <tr> 1844 <td>distort:viewport=<var>WxH+X+Y</var></td> 1845 <td>Sets the viewport for use with <a href="command-line-options.html#distort">-distort</a></td> 1846 </tr> 1847 1848 <tr> 1849 <td>dot:layout-engine=<var>value</var></td> 1850 <td>Specifies the layout engine for the DOT image format (e.g. 1851 <code>neato</code>).</td> 1852 </tr> 1853 1854 <tr> 1855 <td>filter:option=<var>value</var></td> 1856 <td>Set a filter option for use with <a href="command-line-options.html#resize">-resize</a>. 1857 See <a href="command-line-options.html#filter">-filter</a> for details.</td> 1858 </tr> 1859 1860 <tr> 1861 <td>fourier:normalize=<var>inverse</var></td> 1862 <td>Sets the location for the FFT/IFT normalization as use by 1863 <a href="command-line-options.html#fft">+-fft</a> and <a href="command-line-options.html#ift">+-ift</a>. The default is 1864 forward.</td> 1865 </tr> 1866 1867 <tr> 1868 <td>icon:auto-resize</td> 1869 <td>Automatically stores multiple sizes when writing an ico image 1870 (requires a 256x256 input image).</td> 1871 </tr> 1872 1873 <tr> 1874 <td>jp2:layer-number=<var>value</var></td> 1875 <td>Sets the maximum number of quality layers to decode. Same for JPT, JC2, 1876 and J2K</td> 1877 </tr> 1878 1879 <tr> 1880 <td>jp2:number-resolutions=<var>value</var></td> 1881 <td>Sets the number of resolutions to encode.Same for JPT, JC2, and J2K</td> 1882 </tr> 1883 1884 <tr> 1885 <td>jp2:progression-order=<var>value</var></td> 1886 <td>choose from LRCP, RLCP, RPCL, PCRL or CPRL. Same for JPT, JC2, and 1887 J2K</td> 1888 </tr> 1889 1890 <tr> 1891 <td>jp2:quality=<var>value,value...</var></td> 1892 <td>Sets the quality layer PSNR, given in dB. The order is from left to 1893 right in ascending order. The default is a single lossless quality layer. 1894 Same for JPT, JC2, and J2K</td> 1895 </tr> 1896 1897 <tr> 1898 <td>jp2:rate=<var>value</var></td> 1899 <td>Specify the compression factor to use while writing JPEG-2000 files. The 1900 compression factor is the reciprocal of the compression ratio. The valid 1901 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined, 1902 this value overrides the -quality setting. A quality setting of 75 1903 results in a rate value of 0.06641. Same for JPT, JC2, and J2K</td> 1904 </tr> 1905 1906 <tr> 1907 <td>jp2:reduce-factor=<var>value</var></td> 1908 <td>Sets the number of highest resolution levels to be discarded.Same for 1909 JPT, JC2, and J2K</td> 1910 </tr> 1911 1912 <tr> 1913 <td>jpeg:block-smoothing=<var>on|off</var></td> 1914 1915 </tr><tr> 1916 <td>jpeg:colors=<var>value</var></td> 1917 <td>Set the desired number of colors and let the JPEG encoder do the 1918 quantizing.</td> 1919 </tr> 1920 1921 <tr> 1922 <td>jpeg:dct-method=<var>value</var></td> 1923 <td>Choose from <code>default</code>, <code>fastest</code>, 1924 <code>float</code>, <code>ifast</code>, and <code>islow</code>.</td> 1925 </tr> 1926 1927 <tr> 1928 <td>jpeg:extent=<var>value</var></td> 1929 <td>Restrict the maximum JPEG file size, for example <code>-define 1930 jpeg:extent=400KB</code>. The JPEG encoder will search for the highest 1931 compression quality level that results in an output file that does not 1932 exceed the value. The <code>-quality</code> option is ignored if it 1933 is also present.</td> 1934 </tr> 1935 1936 <tr> 1937 <td>jpeg:fancy-upsampling=<var>on|off</var></td> 1938 1939 </tr><tr> 1940 <td>jpeg:optimize-coding=<var>on|off</var></td> 1941 1942 </tr><tr> 1943 <td>jpeg:q-table=<var>table</var></td> 1944 1945 </tr><tr> 1946 <td>jpeg:sampling-factor=<var>sampling-factor-string</var></td> 1947 1948 </tr><tr> 1949 <td>jpeg:size=<var>geometry</var></td> 1950 <td>Set the size hint of a JPEG image, for 1951 example, <code>-define jpeg:size=128x128</code>. 1952 It is most useful for increasing performance and reducing the memory 1953 requirements when reducing the size of a large JPEG image.</td> 1954 </tr> 1955 1956 <tr> 1957 <td>json:features</td> 1958 <td>includes features in verbose information</td> 1959 </tr> 1960 1961 <tr> 1962 <td>json:limit</td> 1963 1964 </tr><tr> 1965 <td>json:locate</td> 1966 1967 </tr><tr> 1968 <td>json:moments</td> 1969 <td>includes image moments in verbose information</td> 1970 </tr> 1971 1972 <tr> 1973 <td>mng:need-cacheoff</td> 1974 <td>turn playback caching off for streaming MNG.</td> 1975 </tr> 1976 1977 <tr> 1978 <td>morphology:compose=<var>compose-method</var></td> 1979 <td>Specifies how to merge results generated by multiple<a href="command-line-options.html#morphology">-morphology</a> kernel. The default is none. One 1980 typical value is 'lighten' as used, for example, with the sobel edge 1981 kernels. </td> 1982 </tr> 1983 1984 <tr> 1985 <td>morphology:showkernel=<var>1</var></td> 1986 <td>Outputs (to 'standard error') all the information about a generated <a href="command-line-options.html#morphology">-morphology</a> kernel.</td> 1987 </tr> 1988 1989 <tr> 1990 <td>pcl:fit-to-page=<var>true</var></td> 1991 1992 </tr><tr> 1993 <td>pdf:fit-page=<var>geometry</var></td> 1994 <td> geometry specifies the scaling dimensions for resizing when the PDF is 1995 being read. The geometry is either WxH{%} or page size. No offsets are 1996 allowed. (introduced in IM 6.8.8-8)</td> 1997 </tr> 1998 1999 <tr> 2000 <td>pdf:fit-to-page=<var>true</var></td> 2001 2002 </tr><tr> 2003 <td>pdf:use-cropbox=<var>true</var></td> 2004 2005 </tr><tr> 2006 <td>pdf:use-trimbox=<var>true</var></td> 2007 2008 </tr><tr> 2009 <td>png:bit-depth=<var>value</var></td> 2010 </tr><tr> 2011 <td>png:color-type=<var>value</var></td> 2012 <td>desired bit-depth and color-type for PNG output. You can force the PNG 2013 encoder to use a different bit-depth and color-type than it would have 2014 normally selected, but only if this does not cause any loss of image 2015 quality. Any attempt to reduce image quality is treated as an error and no 2016 PNG file is written. E.g., if you have a 1-bit black-and-white image, you 2017 can use these "defines" to cause it to be written as an 8-bit grayscale, 2018 indexed, or even a 64-bit RGBA. But if you have a 16-million color image, 2019 you cannot force it to be written as a grayscale or indexed PNG. If you 2020 wish to do this, you must use the appropriate <a href="command-line-options.html#depth">-depth</a>, 2021 <a href="command-line-options.html#colors">-colors</a>, or <a href="command-line-options.html#type">-type</a> directives to 2022 reduce the image quality prior to using the PNG encoder. Note that in 2023 indexed PNG files, "bit-depth" refers to the number of bits per index, 2024 which can be 1, 2, 4, or 8. In such files, the color samples always have 2025 8-bit depth.</td> 2026 </tr> 2027 2028 <tr> 2029 <td>png:compression-filter=<var>value</var></td> 2030 <td> valid values are 0 through 9. 0-4 are the corresponding PNG filters, 2031 5 means adaptive filtering except for images with a colormap, 6 means 2032 adaptive filtering for all images, 7 means MNG "loco" compression, 8 means 2033 Z_RLE strategy with adaptive filtering, and 9 means Z_RLE strategy with no 2034 filtering.</td> 2035 </tr> 2036 2037 <tr> 2038 <td>png:compression-level=<var>value</var></td> 2039 <td> valid values are 0 through 9, with 0 providing the least but fastest 2040 compression and 9 usually providing the best and always the slowest.</td> 2041 </tr> 2042 2043 <tr> 2044 <td>png:compression-strategy=<var>value</var></td> 2045 <td> valid values are 0 through 4, meaning default, filtered, huffman_only, 2046 rle, and fixed ZLIB compression strategy. If you are using an old zlib 2047 that does not support Z_RLE (before 1.2.0) or Z_FIXED (before 1.2.2.2), 2048 values 3 and 4, respectively, will use the zlib default strategy 2049 instead.</td> 2050 </tr> 2051 2052 <tr> 2053 <td>png:format=<var>value</var></td> 2054 <td> valid values are <var>png8</var>, <var>png24</var>, 2055 <var>png32</var>, <var>png48</var>, 2056 <var>png64</var>, and <var>png00</var>. 2057 This property can be useful for specifying 2058 the specific PNG format to be used, when the usual method of prepending the 2059 format name to the output filename is inconvenient, such as when writing 2060 a PNG-encoded ICO file or when using <a href="mogrify.html">mogrify</a>. 2061 Value = <var>png8</var> reduces the number of colors to 256, 2062 only one of which may be fully transparent, if necessary. The other 2063 values do not force any reduction of quality; it is an error to request 2064 a format that cannot represent the image data without loss (except that 2065 it is allowed to reduce the bit-depth from 16 to 8 for all formats). 2066 Value = <var>png24</var> and <var>png48</var> 2067 allow transparency, only if a single color is fully transparent and that 2068 color does not also appear in an opaque pixel; such transparency is 2069 written in a PNG <code>tRNS</code> chunk. 2070 Value = <var>png00</var> causes the image to inherit its 2071 color-type and bit-depth from the input image, if the input was also 2072 a PNG.</td> 2073 </tr> 2074 2075 <tr> 2076 <td>png:exclude-chunk=<var>value</var></td> 2077 2078 </tr><tr> 2079 <td>png:include-chunk=<var>value</var></td> 2080 <td>ancillary chunks to be excluded from or included in PNG output. 2081 2082 <p>The <var>value</var> can be the name of a PNG chunk-type such 2083 as <var>bKGD</var>, a comma-separated list of chunk-names 2084 (which can include the word <var>date</var>, the word 2085 <var>all</var>, or the word <var>none</var>). 2086 Although PNG chunk-names are case-dependent, you can use all lowercase 2087 names if you prefer.</p> 2088 2089 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior 2090 of the PNG encoder and have no effect on the PNG decoder.</p> 2091 2092 <p>As a special case, if the <code>sRGB</code> chunk is excluded and 2093 the <code>gAMA</code> chunk is included, the <code>gAMA</code> chunk will 2094 only be written if gamma is not 1/2.2, since most decoders assume 2095 sRGB and gamma=1/2.2 when no colorspace information is included in 2096 the PNG file. Because the list is processed from left to right, you 2097 can achieve this with a single define:</p> 2098 2099<pre> 2100-define png:include-chunk=none,gAMA 2101</pre> 2102 2103 <p>As a special case, if the <code>sRGB</code> chunk is not excluded and 2104 the PNG encoder recognizes that the image contains the sRGB ICC profile, 2105 the PNG encoder will write the <code>sRGB</code> chunk instead of the 2106 entire ICC profile. To force the PNG encoder to write the sRGB 2107 profile as an <code>iCCP</code> chunk in the output PNG instead of the 2108 <code>sRGB</code> chunk, exclude the <code>sRGB</code> chunk.</p> 2109 2110 <p>The critical PNG chunks <code>IHDR</code>, <code>PLTE</code>, 2111 <code>IDAT</code>, and <code>IEND</code> cannot be excluded. Any such 2112 entries appearing in the list will be ignored.</p> 2113 2114 <p>If the ancillary PNG <code>tRNS</code> chunk is excluded and the 2115 image has transparency, the PNG colortype is forced to be 4 or 6 2116 (GRAY_ALPHA or RGBA). If the image is not transparent, then the 2117 <code>tRNS</code> chunk isn't written anyhow, and there is no effect 2118 on the PNG colortype of the output image.</p> 2119 2120 <p>The <a href="command-line-options.html#strip">-strip</a> option does the equivalent of the 2121 following for PNG output:</p> 2122 2123<pre> 2124-define png:exclude-chunk=EXIF,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date 2125</pre> 2126 2127 <p>The default behavior is to include all known PNG ancillary chunks 2128 plus ImageMagick's private <code>vpAg</code> ("virtual page") chunk, 2129 and to exclude all PNG chunks that are unknown to ImageMagick, 2130 regardless of their PNG "copy-safe" status as described in the 2131 PNG specification.</p> 2132 2133 <p>Any chunk names that are not known to ImageMagick are ignored 2134 if they appear in either the "include-chunk" or "exclude-chunk" list. 2135 The ancillary chunks currently known to ImageMagick are 2136 <code>bKGD</code>, <code>cHRM</code>, <code>gAMA</code>, <code>iCCP</code>, 2137 <code>oFFs</code>, <code>pHYs</code>, <code>sRGB</code>, <code>tEXt</code>, 2138 <code>tRNS</code>, <code>vpAg</code>, and <code>zTXt</code>.</p> 2139 2140 <p>You can also put <code>date</code> in the list to include or exclude 2141 the "Date:create" and "Date:modify" text chunks that ImageMagick normally 2142 inserts in the output PNG.</p></td> 2143 </tr> 2144 2145 <tr> 2146 <td>png:preserve-colormap[=<var>true</var>]</td> 2147 <td>Use the existing image->colormap. Normally the PNG encoder will 2148 try to optimize the palette, eliminating unused entries and putting 2149 the transparent colors first. If this flag is set, that behavior 2150 is suppressed.</td> 2151 </tr> 2152 2153 <tr> 2154 <td>png:preserve-iCCP[=<var>true</var>]</td> 2155 <td>By default, the PNG decoder and encoder examine any ICC profile 2156 that is present, either from an <code>iCCP</code> chunk in the PNG 2157 input or supplied via an option, and if the profile is recognized 2158 to be the sRGB profile, converts it to the <code>sRGB</code> chunk. 2159 You can use <code>-define png:preserve-iCCP</code> to prevent 2160 this from happening; in such cases the <code>iCCP</code> chunk 2161 will be read or written and no <code>sRGB</code> chunk will be 2162 written. There are some ICC profiles that claim to be sRGB but 2163 have various errors that cause them to be rejected by libpng16; such 2164 profiles are recognized anyhow and converted to the <code>sRGB</code> 2165 chunk, but are rejected if the <code>-define png:preserve-iCCP</code> 2166 is present. Note that not all "sRGB" ICC profiles are recognized 2167 yet; we will add them to the list as we encounter them.</td> 2168 </tr> 2169 2170 <tr> 2171 <td>png:swap-bytes[=<var>true</var>]</td> 2172 <td>The PNG specification requires that any multi-byte integers be stored in 2173 network byte order (MSB-LSB endian). This option allows you to 2174 fix any invalid PNG files that have 16-bit samples stored incorrectly 2175 in little-endian order (LSB-MSB). The "-define png:swap-bytes" option 2176 must appear before the input filename on the commandline. The swapping 2177 is done during the libpng decoding operation.</td> 2178 </tr> 2179 2180 <tr> 2181 <td>profile:skip=<var>name1,name2,...</var></td> 2182 <td>Skip the named profile[s] when reading the image. Use skip="*" to 2183 skip all named profiles in the image. Many named profiles exist, 2184 including ICC, EXIF, APP1, IPTC, XMP, and others.</td> 2185 </tr> 2186 2187 <tr> 2188 <td>ps:imagemask</td> 2189 <td>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create 2190 Postscript files that render bilevel images with the Postscript imagemask 2191 operator instead of the image operator.</td> 2192 </tr> 2193 2194 <tr> 2195 <td>quantum:format=<var>type</var></td> 2196 <td>Set the type to <code>floating-point</code> to specify a floating-point 2197 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode 2198 to preserve negative values. If <a href="command-line-options.html#depth">-depth</a> 16 is 2199 included, the result is a single precision floating point format. 2200 If <a href="command-line-options.html#depth">-depth</a> 32 is included, the result is 2201 double precision floating point format.</td> 2202 </tr> 2203 2204 <tr> 2205 <td>quantum:polarity=<var>photometric-interpretation</var></td> 2206 <td>Set the photometric-interpretation of an image (typically for TIFF image 2207 file format) to either <code>min-is-black</code> (default) or 2208 <code>min-is-white</code>.</td> 2209 </tr> 2210 2211 <tr> 2212 <td>sample:offset=<var>geometry</var></td> 2213 <td>Location of the sampling point within the sub-region being sampled, 2214 expressed as percentages (see <a href="command-line-options.html#sample">-sample</a>).</td> 2215 </tr> 2216 2217 <tr> 2218 <td>showkernel=<var>1</var></td> 2219 <td>Outputs (to 'standard error') all the information about a generated <a href="command-line-options.html#morphology">-morphology</a> kernel.</td> 2220 </tr> 2221 2222 <tr> 2223 <td>stream:buffer-size=<var>value</var></td> 2224 <td>Set the stream buffer size. Select 0 for unbuffered I/O.</td> 2225 </tr> 2226 2227 <tr> 2228 <td>tiff:alpha=<var>associated|unassociated|unspecified</var></td> 2229 <td>Specify the alpha extra samples as associated, unassociated or unspecified </td> 2230 </tr> 2231 2232 <tr> 2233 <td>tiff:endian=<var>msb|lsb</var></td> 2234 2235 </tr><tr> 2236 <td>tiff:exif-properties=<var>false</var></td> 2237 <td>Skips reading the EXIF properties.</td> 2238 </tr> 2239 2240 <tr> 2241 <td>tiff:fill-order=<var>msb|lsb</var></td> 2242 2243 </tr><tr> 2244 <td>tiff:ignore-tags=<var>comma-separate-list-of-tag-IDs</var></td> 2245 <td>Allows one or more tag ID values to be ignored.</td> 2246 </tr> 2247 2248 <tr> 2249 <td>tiff:rows-per-strip=<var>value</var></td> 2250 <td>Sets the number of rows per strip</td> 2251 </tr> 2252 2253 <tr> 2254 <td>tiff:tile-geometry=<var>WxH</var></td> 2255 <td>Sets the tile size for pyramid tiffs. Requires the suffix 2256 PTIF: before the outputname</td> 2257 </tr> 2258</table> 2259 2260<p>For example, to create a postscript file that will render only the black 2261pixels of a bilevel image, use:</p> 2262 2263<pre> 2264convert bilevel.tif -define ps:imagemask eps3:stencil.ps 2265</pre> 2266 2267<p>Set attributes of the image registry by prefixing the value with 2268<code>registry:</code>. For example, to set a temporary path to put work files, 2269use:</p> 2270 2271<pre> 2272-define registry:temporary-path=/data/tmp 2273</pre> 2274 2275<div style="margin: auto;"> 2276 <h3 class="magick-header"><a id="delay"></a>-delay <var>ticks</var> <br>-delay <var>ticks</var>x<var>ticks-per-second</var> {<var><</var>} {<var>></var>}</h3> 2277</div> 2278 2279<p class="magick-description">display the next image after pausing.</p> 2280 2281<p>This option is useful for regulating the animation of image sequences 2282<var>ticks/ticks-per-second</var> seconds must expire before the display of the 2283next image. The default is no delay between each showing of the image 2284sequence. The default ticks-per-second is 100.</p> 2285 2286<p>Use <code>></code> to change the image delay <var>only</var> if its current 2287value exceeds the given delay. <code><</code> changes the image delay 2288<var>only</var> if current value is less than the given delay. For example, if 2289you specify <code>30></code> and the image delay is 20, the image delay does 2290not change. However, if the image delay is 40 or 50, the delay it is changed 2291to 30. Enclose the given delay in quotation marks to prevent the 2292<code><</code> or <code>></code> from being interpreted by your shell as 2293a file redirection.</p> 2294 2295 2296<div style="margin: auto;"> 2297 <h3 class="magick-header"><a id="delete"></a>-delete <var>indexes</var></h3> 2298</div> 2299 2300<p class="magick-description">delete the images specified by index, from the image sequence.</p> 2301 2302<p>Specify the image by its index in the sequence. The first image is index 23030. Negative indexes are relative to the end of the sequence, for example, -1 2304represents the last image of the sequence. Specify a range of images with 2305a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use 2306<code>+delete</code> to delete the last image in the current image sequence.</p> 2307 2308 2309<div style="margin: auto;"> 2310 <h3 class="magick-header"><a id="density"></a>-density <var>width</var><br>-density <var>width</var>x<var>height</var></h3> 2311</div> 2312 2313<p class="magick-description">Set the horizontal and vertical resolution of an image for rendering to devices.</p> 2314 2315<p>This option specifies the image resolution to store while encoding a raster 2316image or the canvas resolution while rendering (reading) vector formats such 2317as Postscript, PDF, WMF, and SVG into a raster image. Image resolution 2318provides the unit of measure to apply when rendering to an output device or 2319raster image. The default unit of measure is in dots per inch (DPI). The <a href="command-line-options.html#units">-units</a> option may be used to select dots per centimeter 2320instead.</p> 2321 2322<p>The default resolution is 72 dots per inch, which is equivalent to one 2323point per pixel (Macintosh and Postscript standard). Computer screens are 2324normally 72 or 96 dots per inch, while printers typically support 150, 300, 2325600, or 1200 dots per inch. To determine the resolution of your display, use 2326a ruler to measure the width of your screen in inches, and divide by the 2327number of horizontal pixels (1024 on a 1024x768 display).</p> 2328 2329<p>If the file format supports it, this option may be used to update the 2330stored image resolution. Note that Photoshop stores and obtains image 2331resolution from a proprietary embedded profile. If this profile is not 2332stripped from the image, then Photoshop will continue to treat the image using 2333its former resolution, ignoring the image resolution specified in the standard 2334file header.</p> 2335 2336<p>The <a href="command-line-options.html#density">-density</a> option sets an <var>attribute</var> and 2337does not alter the underlying raster image. It may be used to adjust the 2338rendered size for desktop publishing purposes by adjusting the scale applied 2339to the pixels. To resize the image so that it is the same size at a different 2340resolution, use the <a href="command-line-options.html#resample">-resample</a> option.</p> 2341 2342<div style="margin: auto;"> 2343 <h3 class="magick-header"><a id="depth"></a>-depth <var>value</var></h3> 2344</div> 2345 2346<p class="magick-description">depth of the image.</p> 2347 2348<p>This the number of bits in a color sample within a pixel. Use this option 2349to specify the depth of raw images whose depth is unknown such as GRAY, RGB, 2350or CMYK, or to change the depth of any image after it has been read.</p> 2351 2352<div style="margin: auto;"> 2353 <h3 class="magick-header"><a id="descend"></a>-descend</h3> 2354</div> 2355 2356<p class="magick-description">obtain image by descending window hierarchy.</p> 2357 2358<div style="margin: auto;"> 2359 <h3 class="magick-header"><a id="deskew"></a>-deskew <var>threshold</var></h3> 2360</div> 2361 2362<p class="magick-description">straighten an image. A threshold of 40% works for most images.</p> 2363 2364<p>Use <a href="command-line-options.html#set">-set</a> <code>option:deskew:auto-crop 2365<var>width</var></code> to auto crop the image. The set argument is the pixel 2366width of the image background (e.g 40).</p> 2367 2368<div style="margin: auto;"> 2369 <h3 class="magick-header"><a id="despeckle"></a>-despeckle</h3> 2370</div> 2371 2372<p class="magick-description">reduce the speckles within an image.</p> 2373 2374<div style="margin: auto;"> 2375 <h3 class="magick-header"><a id="direction"></a>-direction <var>type</var></h3> 2376</div> 2377 2378<p class="magick-description">render text right-to-left or left-to-right.</p> 2379 2380<div style="margin: auto;"> 2381 <h3 class="magick-header"><a id="displace"></a>-displace <var>horizontal-scale</var><br>-displace <var>horizontal-scale</var>x<var>vertical-scale</var></h3> 2382</div> 2383 2384<p class="magick-description">shift image pixels as defined by a displacement map.</p> 2385 2386<p>With this option, the 'overlay' image, and optionally the 'mask' image, 2387is used as a displacement map, which is used to displace the lookup of 2388what part of the 'background' image is seen at each point of the overlaid 2389area. Much like the displacement map is a 'lens' that redirects light shining 2390through it so as to present a distorted view the original 'background' image 2391behind it. </p> 2392 2393<p>Any perfect grey areas of the displacement map produce a zero 2394displacement of the image. Black areas produce the given maximum negative 2395displacement of the lookup point, while white produce a maximum positive 2396displacement of the lookup. </p> 2397 2398<p>Note that it is the lookup of the 'background' that is displaced, not a 2399displacement of the image itself. As such an area of the displacement map 2400containing 'white' will have the lookup point 'shifted' by a positive amount, 2401and thus generating a copy of the destination image to the right/downward from 2402the correct position. That is the image will look like it may have been 2403'shifted' in a negative left/upward direction. Understanding this is a very 2404important in understanding how displacement maps work. </p> 2405 2406<p>The given arguments define the maximum amount of displacement in pixels 2407that a particular map can produce. If the displacement scale is large enough 2408it is also possible to lookup parts of the 'background' image that lie well 2409outside the bounds of the displacement map itself. That is you could very 2410easily copy a section of the original image from outside the overlay area 2411into the overlay area. </p> 2412 2413<p>The '%' flag makes the displacement scale relative to the size of the 2414overlay image (100% = half width/height of image). Using '!' switches 2415percentage arguments to refer to the destination image size instead. 2416these flags were added as of IM v6.5.3-5.</p> 2417 2418<p>Normally a single grayscale displacement map is provided, which with the 2419given scaling values will determine a single direction (vector) in which 2420displacements can occur (positively or negatively). However, if you also 2421specify a third image which is normally used as a <var>mask</var>, 2422the <var>composite image</var> is used for horizontal X 2423displacement, while the <var>mask image</var> is used for vertical Y 2424displacement. This allows you to define completely different displacement 2425values for the X and Y directions, and allowing you to lookup any point within 2426the <var>scale</var> bounds. In other words each pixel can lookup 2427any other nearby pixel, producing complex 2 dimensional displacements, rather 2428than a simple 1 dimensional vector displacements. </p> 2429 2430<p>Alternatively rather than supplying two separate images, as of IM v6.4.4-0, 2431you can use the 'red' channel of the overlay image to specify the horizontal 2432or X displacement, and the 'green' channel for the vertical or Y displacement. 2433</p> 2434 2435<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a 2436mask the transparency of the destination image. However areas outside the 2437overlaid areas will not be effected. </p> 2438 2439 2440<div style="margin: auto;"> 2441 <h3 class="magick-header"><a id="display"></a>-display <var>host:display[.screen]</var></h3> 2442</div> 2443 2444<p class="magick-description">Specifies the X server to contact.</p> 2445 2446<p>This option is used with convert for obtaining image or font from this 2447X server. See <var>X(1)</var>.</p> 2448 2449<div style="margin: auto;"> 2450 <h3 class="magick-header"><a id="dispose"></a>-dispose <var>method</var></h3> 2451</div> 2452 2453<p class="magick-description">define the GIF disposal image setting for images that are being created or read in. </p> 2454 2455<p>The layer disposal method defines the way each the displayed image is to be 2456modified after the current 'frame' of an animation has finished being 2457displayed (after its 'delay' period), but before the next frame on an 2458animation is to be overlaid onto the display. </p> 2459 2460<p>Here are the valid methods:</p> 2461 2462<dl class="dl-horizontal"> 2463<dt>Undefined</dt><dd>0: No disposal specified (equivalent to '<code>none</code>').</dd> 2464<dt>None</dt><dd>1: Do not dispose, just overlay next frame image.</dd> 2465<dt>Background</dt><dd>2: Clear the frame area with the background color.</dd> 2466<dt>Previous</dt><dd>3: Clear to the image prior to this frames overlay.</dd> 2467</dl> 2468 2469<p>You can also use the numbers given above, which is what the GIF format 2470uses internally to represent the above settings. </p> 2471 2472<p>To print a complete list of dispose methods, use <a href="command-line-options.html#list">-list dispose</a>.</p> 2473 2474<p>Use <a href="command-line-options.html#dispose">+dispose</a>, turn off the setting and prevent 2475resetting the layer disposal methods of images being read in. </p> 2476 2477<p>Use <a href="command-line-options.html#set">-set</a> '<code>dispose</code>' method to set the image 2478disposal method for images already in memory.</p> 2479 2480<div style="margin: auto;"> 2481 <h3 class="magick-header"><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <var>value</var></h3> 2482</div> 2483 2484<p class="magick-description">maximum RMSE for subimage match (default 0.2).</p> 2485 2486 2487<div style="margin: auto;"> 2488 <h3 class="magick-header"><a id="dissolve"></a>-dissolve <var>src_percent</var>[x<var>dst_percent</var>]</h3> 2489</div> 2490 2491<p class="magick-description">dissolve an image into another by the given percent.</p> 2492 2493<p>The opacity of the composite image is multiplied by the given percent, then 2494it is composited 'over' the main image. If <var>src_percent</var> 2495is greater than 100, start dissolving the main image so it becomes 2496transparent at a value of '<code>200</code>'. If both percentages 2497are given, each image are dissolved to the percentages given. </p> 2498 2499<p>Note that dissolve percentages do not add, two opaque images dissolved 2500'50,50', produce a 75% transparency. For a 50% + 50% blending of the two 2501images, you would need to use dissolve values of '50,100'. </p> 2502 2503<div style="margin: auto;"> 2504 <h3 class="magick-header"><a id="distort"></a>-distort <var>method arguments</var></h3> 2505</div> 2506 2507<p class="magick-description">distort an image, using the given <var>method</var> and its required <var>arguments</var>.</p> 2508 2509<p>The <var>arguments</var> is a single string containing a list 2510of floating point numbers separated by commas or spaces. The number of 2511and meaning of the floating point values depends on the distortion <var>method</var> being used. </p> 2512 2513<p>Choose from these distortion types:</p> 2514 2515<table class="table table-condensed table-striped"> 2516 <tr> 2517 <th style="width: 8%">Method</th> 2518 <th>Description</th> 2519 </tr> 2520 2521 <tr> 2522 <td><code>ScaleRotateTranslate</code> 2523 <br>or <code>SRT</code></td> 2524 <td> 2525 Distort image by first scaling and rotating about a given 'center', 2526 before translating that 'center' to the new location, in that order. It 2527 is an alternative method of specifying a '<code>Affine</code>' type of 2528 distortion, but without shearing effects. It also provides a good way 2529 of rotating and displacing a smaller image for tiling onto a larger 2530 background (IE 2-dimensional animations). <br> 2531 2532 The number of arguments determine the specific meaning of each 2533 argument for the scales, rotation, and translation operations. <br> 2534 2535 <table class="table table-condensed table-striped"> 2536 <tr><td>2:</td><td><var>Scale Angle</var></td></tr> 2537 <tr><td>3:</td><td><var>X,Y Angle</var></td></tr> 2538 <tr><td>4:</td><td><var>X,Y Scale Angle</var></td></tr> 2539 <tr><td>5:</td> 2540 <td><var>X,Y ScaleX,ScaleY Angle</var></td></tr> 2541 <tr><td>6:</td> 2542 <td><var>X,Y Scale Angle NewX,NewY</var></td></tr> 2543 <tr><td>7:</td> 2544 <td><var>X,Y ScaleX,ScaleY Angle 2545 NewX,NewY</var></td></tr> 2546 </table> 2547 2548 This is actually an alternative way of specifying a 2 dimensional linear 2549 '<code>Affine</code>' or '<code>AffineProjection</code>' distortion. </td> </tr> 2550 2551 <tr> 2552 <td><code>Affine</code></td> 2553 <td> 2554 Distort the image linearly by moving a list of at least 3 or more sets 2555 of control points (as defined below). Ideally 3 sets or 12 floating 2556 point values are given allowing the image to be linearly scaled, 2557 rotated, sheared, and translated, according to those three points. See 2558 also the related '<code>AffineProjection</code>' and '<code>SRT</code>' 2559 distortions. <br> 2560 2561 More than 3 sets given control point pairs (12 numbers) is least 2562 squares fitted to best match a linear affine distortion. If only 2 2563 control point pairs (8 numbers) are given a two point image translation 2564 rotation and scaling is performed, without any possible shearing, 2565 flipping or changes in aspect ratio to the resulting image. If only one 2566 control point pair is provides the image is only translated, (which may 2567 be a floating point non-integer translation). <br> 2568 2569 This distortion does not include any form of perspective distortion. 2570 </td> 2571 2572 </tr> 2573 2574 <tr> 2575 <td><code>AffineProjection</code></td> 2576 <td> 2577 Linearly distort an image using the given Affine Matrix of 6 2578 pre-calculated coefficients forming a set of Affine Equations to map 2579 the source image to the destination image. 2580 2581 <div style="text-align: center"><var> 2582 s<sub>x</sub>, r<sub>x</sub>, 2583 r<sub>y</sub>, s<sub>y</sub>, 2584 t<sub>x</sub>, t<sub>y</sub> 2585 </var></div> 2586 2587 See <a href="command-line-options.html#affine">-affine</a> setting for more detail, and 2588 meanings of these coefficients. <br> 2589 2590 The distortions '<code>Affine</code>' and '<code>SRT</code>' provide 2591 alternative methods of defining this distortion, with ImageMagick doing 2592 the calculations needed to generate the required coefficients. You can 2593 see the internally generated coefficients, by using a <a href="command-line-options.html#verbose">-verbose</a> setting with those other variants. </td> 2594 2595 </tr> 2596 2597 <tr> 2598 <td><code>BilinearForward</code><br> 2599 <code>BilinearReverse</code></td> 2600 <td> 2601 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or 2602 16 values (see below). Not that lines may not appear straight after 2603 distortion, though the distance between coordinates will remain 2604 consistent. <br> 2605 2606 The '<code>BilinearForward</code>' is used to map rectangles to any 2607 quadrilateral, while the '<code>BilinearReverse</code>' form maps any 2608 quadrilateral to a rectangle, while preserving the straight line edges 2609 in each case. <br> 2610 2611 Note that '<code>BilinearForward</code>' can generate invalid pixels 2612 which will be colored using the <a href="command-line-options.html#mattecolor">-mattecolor</a> 2613 color setting. Also if the quadrilateral becomes 'flipped' the image 2614 may disappear. <br> 2615 2616 There are future plans to produce a true Bilinear distortion that will 2617 attempt to map any quadrilateral to any other quadrilateral, while 2618 preserving edges (and edge distance ratios). 2619 2620 </td> 2621 </tr> 2622 2623 <tr> 2624 <td><code>Perspective</code></td> 2625 <td> 2626 Perspective distort the images, using a list of 4 or more sets of 2627 control points (as defined below). More that 4 sets (16 numbers) of 2628 control points provide least squares fitting for more accurate 2629 distortions (for the purposes of image registration and panorama 2630 effects). Less than 4 sets will fall back to a '<code>Affine</code>' 2631 linear distortion. <br> 2632 2633 Perspective Distorted images ensures that straight lines remain 2634 straight, but the scale of the distorted image will vary. The horizon 2635 is anti-aliased, and the 'sky' color may be set using the 2636 <a href="command-line-options.html#mattecolor">-mattecolor</a> setting. </td> 2637 </tr> 2638 2639 <tr> 2640 <td><code>PerspectiveProjection</code> </td> 2641 <td> 2642 Do a '<code>Perspective</code>' distortion biased on a set of 8 2643 pre-calculated coefficients. You can get these coefficients by looking 2644 at the <a href="command-line-options.html#verbose">-verbose</a> output of a 2645 '<code>Perspective</code>' distortion, or by calculating them yourself. 2646 If the last two perspective scaling coefficients are zero, the 2647 remaining 6 represents a transposed 'Affine Matrix'. </td> 2648 2649 </tr> 2650 2651 <tr> 2652 <td><code>Arc</code></td> 2653 <td> 2654 Arc the image (variation of polar mapping) over the angle given around 2655 a circle. <br> 2656 <table class="table table-condensed table-striped"> 2657 <tr><td>Argument</td> 2658 <td>Meaning</td></tr> 2659 <tr><td><var>arc_angle</var></td> 2660 <td>The angle over which to arc the image side-to-side</td></tr> 2661 <tr><td><var>rotate_angle</var></td> 2662 <td>Angle to rotate resulting image from vertical center</td></tr> 2663 <tr><td><var>top_radius</var></td> 2664 <td>Set top edge of source image at this radius</td></tr> 2665 <tr><td><var>bottom_radius</var> </td> 2666 <td>Set bottom edge to this radius (radial scaling)</td></tr> 2667 </table> 2668 2669 The resulting image is always resized to best fit the resulting image, 2670 (as if using <a href="command-line-options.html#distort">+distort</a>) while attempting to 2671 preserve scale and aspect ratio of the original image as much as 2672 possible with the arguments given by the user. All four arguments will 2673 be needed to change the overall aspect ratio of an 'Arc'ed image. <br> 2674 2675 This a variation of a polar distortion designed to try to preserve the 2676 aspect ratio of the image rather than direct Cartesian to Polar 2677 conversion. </td> 2678 </tr> 2679 2680 <tr> 2681 <td><code>Polar</code></td> 2682 <td> 2683 Like '<code>Arc</code>' but do a complete Cartesian to Polar mapping of 2684 the image. that is the height of the input image is mapped to the 2685 radius limits, while the width is wrapped around between the 2686 angle limits. <br> 2687 2688 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br> 2689 2690 All arguments are optional. With <var>Rmin</var> defaulting to zero, the 2691 center to the center of the image, and the angles going from -180 (top) 2692 to +180 (top). If <var>Rmax</var> is given the special value of 2693 '<code>0</code>', the the distance from the center to the nearest edge 2694 is used for the radius of the output image, which will ensure the whole 2695 image is visible (though scaled smaller). However a special value of 2696 '<code>-1</code>' will use the distance from the center to the furthest 2697 corner, This may 'clip' the corners from the input rectangular image, 2698 but will generate the exact reverse of a '<code>DePolar</code>' with 2699 the same arguments. <br> 2700 2701 If the plus form of distort (<a href="command-line-options.html#distort">+distort</a>) is used 2702 output image center will default to <code>0,0</code> of the virtual 2703 canvas, and the image size adjusted to ensure the whole input image is 2704 made visible in the output image on the virtual canvas. </td> 2705 2706 </tr> 2707 2708 <tr> 2709 <td><code>DePolar</code></td> 2710 <td> 2711 Uses the same arguments and meanings as a '<code>Polar</code>' distortion 2712 but generates the reverse Polar to Cartesian distortion. <br> 2713 2714 The special <var>Rmax</var> setting of '<code>0</code>' may however clip 2715 the corners of the input image. However using the special 2716 <var>Rmax</var> setting of '<code>-1</code>' (maximum center to corner 2717 distance) will ensure the whole distorted image is preserved in the 2718 generated result, so that the same argument to '<code>Polar</code>' will 2719 reverse the distortion re-producing the original. 2720 2721 Note that as this distortion requires the area resampling of a circular 2722 arc, which can not be handled by the builtin EWA resampling function. 2723 As such the normal EWA filters are turned off. It is recommended some 2724 form of 'super-sampling' image processing technique be used to produce 2725 a high quality result. </td> 2726 2727 </tr> 2728 2729 <tr> 2730 <td><code>Barrel</code></td> 2731 <td> 2732 Given the four coefficients (A,B,C,D) as defined by <a href="http://wiki.panotools.org/Lens_correction_model">Helmut 2733 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to 2734 correct radial lens distortions. That is in photographs, make straight 2735 lines straight again. <br> 2736 2737 Arguments: <var>A B C</var> [ <var>D</var> [ 2738 <var>X</var> , <var>Y</var> ] ] <br> 2739 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 2740 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var> 2741 [ <var>X</var> , <var>Y</var> ] <br> 2742 So that it forms the function <br> 2743 Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> + 2744 <var>C</var>*r + <var>D</var> )<br> 2745 2746 Where <var>X</var>,<var>Y</var> is the optional center of the distortion 2747 (defaulting to the center of the image). <br> 2748 The second form is typically used to distort images, rather than 2749 correct lens distortions. <br> 2750 </td> 2751 2752 </tr> 2753 2754 <tr> 2755 <td><code>BarrelInverse</code></td> 2756 <td> 2757 This is very similar to '<code>Barrel</code>' with the same set of 2758 arguments, and argument handling. However it uses the inverse 2759 of the radial polynomial, 2760 so that it forms the function <br> 2761 Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> + 2762 <var>C</var>*r + <var>D</var> )<br> 2763 Note that this is not the reverse of the '<code>Barrel</code>' 2764 distortion, just a different barrel-like radial distortion method. 2765 2766 </td> 2767 </tr> 2768 2769 <tr> 2770 <td><code>Shepards</code></td> 2771 <td> 2772 Distort the given list control points (any number) using an Inverse 2773 Squared Distance Interpolation Method (<a href="http://en.wikipedia.org/wiki/Shepard%27s_method">Shepards 2774 Method</a>). The control points in effect do 'localized' displacement 2775 of the image around the given control point (preserving the look and 2776 the rotation of the area near the control points. For best results 2777 extra control points should be added to 'lock' the positions of the 2778 corners, edges and other unchanging parts of the image, to prevent 2779 their movement. <br> 2780 2781 The distortion has been likened to 'taffy pulling' using nails, or 2782 pins' stuck in a block of 'jelly' which is then moved to the new 2783 position, distorting the surface of the jelly. <br> 2784 2785 Internally it is equivalent to generating a displacement map (see <a href="command-line-options.html#displace">-displace</a>) for source image color look-up using 2786 the <a href="command-line-options.html#sparse-color">-sparse-color</a> method of the same name. 2787 2788 </td> 2789 </tr> 2790 2791</table> 2792 2793<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list 2794distort</a>.</p> 2795 2796<p>Many of the above distortion methods such as '<code>Affine</code>', 2797'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points 2798defining how these points in the given image should be distorted in the 2799destination image. Each set of four floating point values represent a source 2800image coordinate, followed immediately by the destination image coordinate. 2801This produces a list of values such as...</p> 2802<div style="text-align: center"><var> 2803 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 2804 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 2805 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 2806 ... 2807 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 2808</var></div> 2809<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the 2810destination image. </p> 2811 2812<p>For example, to warp an image using '<code>perspective</code>' distortion, 2813needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 2814perspective distortion of the built-in "rose:" image. Note how spaces were 2815used to group the 4 sets of coordinate pairs, to make it easier to read and 2816understand.</p> 2817 2818<pre> 2819convert rose: -virtual-pixel black \ 2820 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \ 2821 rose_3d_rotated.gif" 2822</pre> 2823 2824<p>If more that the required number of coordinate pairs are given for 2825a distortion, the distortion method is 'least squares' fitted to produce the 2826best result for all the coordinate pairs given. If less than the ideal number 2827of points are given, the distort will generally fall back to a simpler form of 2828distortion that can handles the smaller number of coordinates (usually a linear 2829'<code>Affine</code>' distortion). </p> 2830 2831<p>By using more coordinates you can make use of image registration tool to 2832find matching coordinate pairs in overlapping images, so as to improve the 2833'fit' of the distortion. Of course a bad coordinate pair can also make the 2834'fit' worse. Caution is always advised. </p> 2835 2836<p>Colors are acquired from the source image according to a cylindrical 2837resampling <a href="command-line-options.html#filter">-filter</a>, using a special technique known as 2838EWA resampling. This produces very high quality results, especially when 2839images become smaller (minified) in the output, which is very common when 2840using '<code>perspective</code>' distortion. For example here we view 2841a infinitely tiled 'plane' all the way to the horizon. </p> 2842 2843<pre> 2844convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \ 2845 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \ 2846 checks_tiled.jpg 2847</pre> 2848 2849<p>Note that a infinitely tiled perspective images involving the horizon can 2850be very slow, because of the number of pixels that are compressed to generate 2851each individual pixel close to the 'horizon'. You can turn off EWA 2852resampling, by specifing the special <a href="command-line-options.html#filter">-filter</a> setting of 2853'<code>point</code>' (recommended if you plan to use super-sampling instead). 2854</p> 2855 2856<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 2857example, <a href="command-line-options.html#distort">-distort</a> will use the current <a href="command-line-options.html#mattecolor">-mattecolor</a> setting for these pixels. If you do not 2858what these pixels to be visible, set the color to match the rest of the 2859ground. </p> 2860 2861<p>The output image size will by default be the same as the input image. This 2862means that if the part of the distorted image falls outside the viewed area of 2863the 'distorted space', those parts is clipped and lost. However if you use 2864the plus form of the operator (<a href="command-line-options.html#distort">+distort</a>) the operator 2865will attempt (if possible) to show the whole of the distorted image, while 2866retaining a correct 'virtual canvas' offset, for image layering. This offset 2867may need to be removed using <a href="command-line-options.html#repage">+repage</a>, to remove if it 2868is unwanted. </p> 2869 2870<p>Setting <a href="command-line-options.html#verbose">-verbose</a> setting, will cause <a href="command-line-options.html#distort">-distort</a> to attempt to output the internal coefficients, 2871and the <a href="command-line-options.html#fx">-fx</a> equivalent to the distortion, for expert study, 2872and debugging purposes. This many not be available for all distorts. </p> 2873 2874<p>You can alternatively specify a special "<code><a href="command-line-options.html#define">-define</a> distort:viewport={geometry_string}</code>" setting which will 2875specify the size and the offset of the generated 'viewport' image of the 2876distorted image space.</p> 2877 2878<p>Setting a "<code><a href="command-line-options.html#define">-define</a> 2879distort:scale={scale_factor}</code>" will scale the output image (viewport or 2880otherwise) by that factor without changing the viewed contents of the 2881distorted image. This can be used either for 'super-sampling' the image for 2882a higher quality result, or for panning and zooming around the image (with 2883appropriate viewport changes, or post-distort cropping and resizing). </p> 2884 2885<p>Setting "<code><a href="command-line-options.html#define">-define</a> resample:verbose=1</code>" 2886will output the cylindrical filter lookup table created by the EWA (Elliptical 2887Weighted Average) resampling algorithm. Note this table uses a squared radius 2888lookup value. This is typically only used for debugging EWA resampling. </p> 2889 2890 2891<div style="margin: auto;"> 2892 <h3 class="magick-header"><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3> 2893</div> 2894 2895<p class="magick-description">launch a distributed pixel cache server. </p> 2896 2897<div style="margin: auto;"> 2898 <h3 class="magick-header"><a id="dither"></a>-dither <var>method</var></h3> 2899</div> 2900 2901<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to 2902images when general color reduction is applied via an option, or automagically 2903when saving to specific formats. This enabled by default.</p> 2904 2905<p>Dithering places two or more colors in neighboring pixels so that to the 2906eye a closer approximation of the images original color is reproduced. This 2907reduces the number of colors needed to reproduce the image but at the cost of 2908a lower level pattern of colors. Error diffusion dithers can use any set of 2909colors (generated or user defined) to an image. </p> 2910 2911<p>Dithering is turned on by default, to turn it off use the plus form of the 2912setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript 2913without text or graphic aliasing. Disabling dithering often (but not always) 2914leads to faster process, a smaller number of colors, but more cartoon like 2915image coloring. Generally resulting in 'color banding' effects in areas with 2916color gradients. </p> 2917 2918<p>The color reduction operators <a href="command-line-options.html#colors">-colors</a>, <a href="command-line-options.html#monochrome">-monochrome</a>, <a href="command-line-options.html#remap%20">-remap</a>, and <a href="command-line-options.html#posterize">-posterize</a>, apply dithering to images using the reduced 2919color set they created. These operators are also used as part of automatic 2920color reduction when saving images to formats with limited color support, such 2921as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used 2922in these cases. </p> 2923 2924<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a> 2925to generate purely random dither. Or use <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to apply threshold mapped dither 2926patterns, using uniform color maps, rather than specific color maps. </p> 2927 2928 2929<div style="margin: auto;"> 2930 <h3 class="magick-header"><a id="draw"></a>-draw <var>string</var></h3> 2931</div> 2932 2933<p class="magick-description">Annotate an image with one or more graphic primitives.</p> 2934 2935<p>Use this option to annotate or decorate an image with one or more graphic 2936primitives. The primitives include shapes, text, transformations, and pixel 2937operations.</p> 2938 2939<p>The shape primitives:</p> 2940 2941<pre> 2942point x,y 2943line x0,y0 x1,y1 2944rectangle x0,y0 x1,y1 2945roundRectangle x0,y0 x1,y1 wc,hc 2946arc x0,y0 x1,y1 a0,a1 2947ellipse x0,y0 rx,ry a0,a1 2948circle x0,y0 x1,y1 2949polyline x0,y0 ... xn,yn 2950polygon x0,y0 ... xn,yn 2951bezier x0,y0 ... xn,yn 2952path specification 2953image operator x0,y0 w,h filename 2954</pre> 2955 2956<p>The text primitive:</p> 2957 2958<pre> 2959text x0,y0 string 2960</pre> 2961<p>The text gravity primitive:</p> 2962 2963<pre> 2964gravity NorthWest, North, NorthEast, West, Center, 2965 East, SouthWest, South, or SouthEast 2966</pre> 2967 2968<p>The text gravity primitive only affects the placement of text and does not 2969interact with the other primitives. It is equivalent to using the <a href="command-line-options.html#gravity">-gravity</a> command-line option, except that it is limited in 2970scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p> 2971 2972<p>The transformation primitives:</p> 2973 2974<pre> 2975rotate degrees 2976translate dx,dy 2977scale sx,sy 2978skewX degrees 2979skewY degrees 2980</pre> 2981 2982<p>The pixel operation primitives:</p> 2983 2984<pre> 2985color x0,y0 method 2986matte x0,y0 method 2987</pre> 2988 2989<p>The shape primitives are drawn in the color specified by the preceding <a href="command-line-options.html#fill">-fill</a> setting. For unfilled shapes, use <a href="command-line-options.html#fill">-fill none</a>. You can optionally control the stroke (the 2990"outline" of a shape) with the <a href="command-line-options.html#stroke">-stroke</a> and <a href="command-line-options.html#strokewidth">-strokewidth</a> settings.</p> 2991 2992<p>A <code>point</code> primitive is specified by a single <var>point</var> in the 2993pixel plane, that is, by an ordered pair of integer coordinates, 2994<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code> 2995primitive is not affected by <a href="command-line-options.html#stroke">-stroke</a> or <a href="command-line-options.html#strokewidth">-strokewidth</a>.)</p> 2996 2997<p>A <code>line</code> primitive requires a start point and end point.</p> 2998 2999<p>A <code>rectangle</code> primitive is specified by the pair of points at the 3000upper left and lower right corners.</p> 3001 3002<p>A <code>roundRectangle</code> primitive takes the same corner points as 3003a <code>rectangle</code> followed by the width and height of the rounded corners 3004to be removed.</p> 3005 3006<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled). 3007Give the center and any point on the perimeter (boundary).</p> 3008 3009<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in 3010to a given rectangle. An <code>arc</code> requires the two corners used for 3011<code>rectangle</code> (see above) followed by the start and end angles of the 3012arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end 3013points produced are then joined with a line segment and the resulting segment 3014of an ellipse is filled.</p> 3015 3016<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the 3017center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of 3018the ellipse) and start and end angles in degrees (e.g. 100,100 100,150 30190,360).</p> 3020 3021<p>The <code>polyline</code> and <code>polygon</code> primitives require three or 3022more points to define their perimeters. A <code>polyline</code> is simply 3023a <code>polygon</code> in which the final point is not stroked to the start 3024point. When unfilled, this is a <var>polygonal line</var>. If the <a href="command-line-options.html#stroke">-stroke</a> setting is <code>none</code> (the default), then 3025a <code>polyline</code> is identical to a <code>polygon</code>. </p> 3026 3027<p>A <var>coordinate</var> is a pair of integers separated by a space or 3028optional comma. </p> 3029 3030<p>As an example, to define a circle centered at 100,100 that extends to 3031150,150 use:</p> 3032 3033<pre> 3034-draw 'circle 100,100 150,150' 3035</pre> 3036 3037<p>The <code>Bezier</code> primitive creates a spline curve and requires three 3038or points to define its shape. The first and last points are the 3039<var>knots</var> and these points are attained by the curve, while any 3040intermediate coordinates are <var>control points</var>. If two control points 3041are specified, the line between each end knot and its sequentially respective 3042control point determines the tangent direction of the curve at that end. If 3043one control point is specified, the lines from the end knots to the one 3044control point determines the tangent directions of the curve at each end. If 3045more than two control points are specified, then the additional control points 3046act in combination to determine the intermediate shape of the curve. In order 3047to draw complex curves, it is highly recommended either to use the 3048<code>path</code> primitive or to draw multiple four-point bezier segments with 3049the start and end knots of each successive segment repeated. For example:</p> 3050 3051<pre> 3052-draw 'bezier 20,50 45,100 45,0 70,50' 3053-draw 'bezier 70,50 95,100 95,0 120,50' 3054</pre> 3055 3056<p>A <code>path</code> represents an outline of an object, defined in terms of 3057moveto (set a new current point), lineto (draw a straight line), curveto (draw 3058a Bezier curve), arc (elliptical or circular arc) and closepath (close the 3059current shape by drawing a line to the last moveto) elements. Compound paths 3060(i.e., a path with subpaths, each consisting of a single moveto followed by 3061one or more line or curve operations) are possible to allow effects such as 3062<var>donut holes</var> in objects. (See <a href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p> 3063 3064<p>Use <code>image</code> to composite an image with another image. Follow the 3065image keyword with the composite operator, image location, image size, and 3066filename:</p> 3067 3068<pre> 3069-draw 'image SrcOver 100,100 225,225 image.jpg' 3070</pre> 3071 3072<p>You can use 0,0 for the image size, which means to use the actual 3073dimensions found in the image header. Otherwise, it is scaled to the given 3074dimensions. See <a href="compose.html">Alpha Compositing</a> for 3075a detailed discussion of alpha composition methods that are available. </p> 3076 3077<p>The "special augmented compose operators" such as "dissolve" that require 3078arguments cannot be used at present with the <code>-draw image</code> option. 3079 </p> 3080 3081<p>Use <code>text</code> to annotate an image with text. Follow the text 3082coordinates with a string. If the string has embedded spaces, enclose it in 3083single or double quotes.</p> 3084 3085<p>For example, the following annotates the image with <code>Works like 3086magick!</code> for an image titled <code>bird.miff</code>. </p> 3087 3088<pre> 3089-draw "text 100,100 'Works like magick!' " 3090</pre> 3091 3092<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way 3093to annotate an image with text.</p> 3094 3095<p>The <code>rotate</code> primitive rotates subsequent shape primitives and 3096text primitives about the origin of the main image. If the <a href="command-line-options.html#region">-region</a> option precedes the <a href="command-line-options.html#draw">-draw</a> 3097option, the origin for transformations is the upper left corner of the 3098region.</p> 3099 3100<p>The <code>translate</code> primitive translates subsequent shape and text 3101primitives.</p> 3102 3103<p>The <code>scale</code> primitive scales them.</p> 3104 3105<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect 3106to the origin of the main image or the region.</p> 3107 3108<p>The transformations modify the current affine matrix, which is initialized 3109from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a> 3110option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a> 3111option. The initial affine matrix is not affected; that matrix is only changed 3112by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another 3113<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is 3114reinitialized from the initial affine matrix.</p> 3115 3116<p>Use the <code>color</code> primitive to change the color of a pixel to the 3117fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with 3118a method:</p> 3119 3120<pre> 3121point 3122replace 3123floodfill 3124filltoborder 3125reset 3126</pre> 3127 3128<p>Consider the target pixel as that specified by your coordinate. The 3129<code>point</code> method recolors the target pixel. The <code>replace</code> 3130method recolors any pixel that matches the color of the target pixel. 3131<code>Floodfill</code> recolors any pixel that matches the color of the target 3132pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor 3133pixel that is not the border color. Finally, <code>reset</code> recolors all 3134pixels.</p> 3135 3136<p>Use <code>matte</code> to the change the pixel matte value to transparent. 3137Follow the pixel coordinate with a method (see the <code>color</code> primitive 3138for a description of methods). The <code>point</code> method changes the matte 3139value of the target pixel. The <code>replace</code> method changes the matte 3140value of any pixel that matches the color of the target pixel. 3141<code>Floodfill</code> changes the matte value of any pixel that matches the 3142color of the target pixel and is a neighbor, whereas <code>filltoborder</code> 3143changes the matte value of any neighbor pixel that is not the border color (<a href="command-line-options.html#bordercolor">-bordercolor</a>). Finally <code>reset</code> changes the 3144matte value of all pixels.</p> 3145 3146<p>You can set the primitive color, font, and font bounding box color with <a href="command-line-options.html#fill">-fill</a>, <a href="command-line-options.html#font">-font</a>, and <a href="command-line-options.html#box">-box</a> 3147respectively. Options are processed in command line order so be sure to use 3148these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p> 3149 3150<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather 3151than 1.png).</p> 3152 3153<p>Drawing primitives conform to the <a href="magick-vector-graphics.html">Magick 3154Vector Graphics</a> format.</p> 3155 3156 3157<div style="margin: auto;"> 3158 <h3 class="magick-header"><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3> 3159</div> 3160 3161<p class="magick-description">duplicate an image one or more times.</p> 3162 3163<p>Specify the count and the image to duplicate by its index in the sequence. 3164The first image is index 0. Negative indexes are relative to the end of the 3165sequence, for example, -1 represents the last image of the sequence. Specify 3166a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g. 31670,2). Use <code>+duplicate</code> to duplicate the last image in the current 3168image sequence.</p> 3169 3170<div style="margin: auto;"> 3171 <h3 class="magick-header"><a id="edge"></a>-edge <var>radius</var></h3> 3172</div> 3173 3174<p class="magick-description">detect edges within an image.</p> 3175 3176<div style="margin: auto;"> 3177 <h3 class="magick-header"><a id="emboss"></a>-emboss <var>radius</var></h3> 3178</div> 3179 3180<p class="magick-description">emboss an image.</p> 3181 3182<div style="margin: auto;"> 3183 <h3 class="magick-header"><a id="encipher"></a>-encipher <var>filename</var></h3> 3184</div> 3185 3186<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p> 3187 3188<p>Get the passphrase from the file specified by <var>filename</var>.</p> 3189 3190<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or 3191Decipher an Image</a>.</p> 3192 3193 3194 3195<div style="margin: auto;"> 3196 <h3 class="magick-header"><a id="encoding"></a>-encoding <var>type</var></h3> 3197</div> 3198 3199<p class="magick-description">specify the text encoding.</p> 3200 3201<p>Choose from <code>AdobeCustom</code>, <code>AdobeExpert</code>, 3202<code>AdobeStandard</code>, <code>AppleRoman</code>, <code>BIG5</code>, 3203<code>GB2312</code>, <code>Latin 2</code>, <code>None</code>, <code>SJIScode</code>, 3204<code>Symbol</code>, <code>Unicode</code>, <code>Wansung</code>.</p> 3205 3206<div style="margin: auto;"> 3207 <h3 class="magick-header"><a id="endian"></a>-endian <var>type</var></h3> 3208</div> 3209 3210<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p> 3211 3212<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p> 3213 3214<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p> 3215 3216 3217<div style="margin: auto;"> 3218 <h3 class="magick-header"><a id="enhance"></a>-enhance</h3> 3219</div> 3220 3221<p class="magick-description">Apply a digital filter to enhance a noisy image.</p> 3222 3223 3224<div style="margin: auto;"> 3225 <h3 class="magick-header"><a id="equalize"></a>-equalize</h3> 3226</div> 3227 3228<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p> 3229 3230<p>To perform histogram equalization on all channels in concert, transform the 3231image into some other color space, such as HSL, OHTA, YIQ or YUV, then 3232equalize the appropriate intensity-like channel, then convert back to RGB.</p> 3233 3234<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness 3235-equalize -colorspace RGB</code> ...</p> 3236 3237<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal 3238components transformation that puts most of the information in the first 3239channel. Here we have ... <code>-colorspace OHTA -channel red -equalize 3240-colorspace RGB</code> ...</p> 3241 3242<div style="margin: auto;"> 3243 <h3 class="magick-header"><a id="evaluate"></a>-evaluate <var>operator value</var></h3> 3244</div> 3245 3246<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p> 3247 3248<p>(See the <a href="command-line-options.html#function">-function</a> operator for some 3249multi-parameter functions. See the <a href="command-line-options.html#fx">-fx</a> operator if more 3250elaborate calculations are needed.)</p> 3251 3252<p>The behaviors of each <var>operator</var> are summarized in the 3253following list. For brevity, the numerical value of a "pixel" referred to 3254below is the value of the corresponding channel of that pixel, while 3255a "normalized pixel" is that number divided by the maximum 3256(installation-dependent) value <var>QuantumRange</var>. (If 3257normalized pixels are used, they are restored, following the other 3258calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p> 3259 3260<table class="table table-condensed table-striped"> 3261 <tr><td># </td><td>arguments meaning</td></tr> 3262 <tr><td>1:</td><td><var>Angle_of_Rotation</var></td></tr> 3263 <tr><td>2:</td><td><var>Scale Angle</var></td></tr> 3264 <tr><td>3:</td><td><var>X,Y Angle</var></td></tr> 3265 <tr><td>4:</td><td><var>X,Y Scale Angle</var></td></tr> 3266 <tr><td>5:</td> 3267 <td><var>X,Y ScaleX,ScaleY Angle</var></td></tr> 3268 <tr><td>6:</td> 3269 <td><var>X,Y Scale Angle NewX,NewY</var></td></tr> 3270 <tr><td>7:</td> 3271 <td><var>X,Y ScaleX,ScaleY Angle 3272 NewX,NewY</var></td></tr> 3273 </table> 3274 3275 This is actually an alternative way of specifying a 2 dimensional linear 3276 '<code>Affine</code>' or '<code>AffineProjection</code>' distortion. 3277 3278 <tr> 3279 <td><code>Affine</code></td> 3280 <td> 3281 Distort the image linearly by moving a list of at least 3 or more sets 3282 of control points (as defined below). Ideally 3 sets or 12 floating 3283 point values are given allowing the image to be linearly scaled, 3284 rotated, sheared, and translated, according to those three points. See 3285 also the related '<code>AffineProjection</code>' and '<code>SRT</code>' 3286 distortions. <br> 3287 3288 More than 3 sets given control point pairs (12 numbers) is least 3289 squares fitted to best match a linear affine distortion. If only 2 3290 control point pairs (8 numbers) are given a two point image translation 3291 rotation and scaling is performed, without any possible shearing, 3292 flipping or changes in aspect ratio to the resulting image. If only one 3293 control point pair is provides the image is only translated, (which may 3294 be a floating point non-integer translation). <br> 3295 3296 This distortion does not include any form of perspective distortion. 3297 </td> 3298 3299 </tr> 3300 3301 <tr> 3302 <td><code>AffineProjection</code></td> 3303 <td> 3304 Linearly distort an image using the given Affine Matrix of 6 3305 pre-calculated coefficients forming a set of Affine Equations to map 3306 the source image to the destination image. 3307 3308 <div style="text-align: center"><var> 3309 s<sub>x</sub>, r<sub>x</sub>, 3310 r<sub>y</sub>, s<sub>y</sub>, 3311 t<sub>x</sub>, t<sub>y</sub> 3312 </var></div> 3313 3314 See <a href="command-line-options.html#affine">-affine</a> setting for more detail, and 3315 meanings of these coefficients. <br> 3316 3317 The distortions '<code>Affine</code>' and '<code>SRT</code>' provide 3318 alternative methods of defining this distortion, with ImageMagick doing 3319 the calculations needed to generate the required coefficients. You can 3320 see the internally generated coefficients, by using a <a href="command-line-options.html#verbose">-verbose</a> setting with those other variants. </td> 3321 3322 </tr> 3323 3324 <tr> 3325 <td><code>BilinearForward</code><br> 3326 <code>BilinearReverse</code></td> 3327 <td> 3328 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or 3329 16 values (see below). Not that lines may not appear straight after 3330 distortion, though the distance between coordinates will remain 3331 consistent. <br> 3332 3333 The '<code>BilinearForward</code>' is used to map rectangles to any 3334 quadrilateral, while the '<code>BilinearReverse</code>' form maps any 3335 quadrilateral to a rectangle, while preserving the straight line edges 3336 in each case. <br> 3337 3338 Note that '<code>BilinearForward</code>' can generate invalid pixels 3339 which will be colored using the <a href="command-line-options.html#mattecolor">-mattecolor</a> 3340 color setting. Also if the quadrilateral becomes 'flipped' the image 3341 may disappear. <br> 3342 3343 There are future plans to produce a true Bilinear distortion that will 3344 attempt to map any quadrilateral to any other quadrilateral, while 3345 preserving edges (and edge distance ratios). 3346 3347 </td> 3348 </tr> 3349 3350 <tr> 3351 <td><code>Perspective</code></td> 3352 <td> 3353 Perspective distort the images, using a list of 4 or more sets of 3354 control points (as defined below). More that 4 sets (16 numbers) of 3355 control points provide least squares fitting for more accurate 3356 distortions (for the purposes of image registration and panorama 3357 effects). Less than 4 sets will fall back to a '<code>Affine</code>' 3358 linear distortion. <br> 3359 3360 Perspective Distorted images ensures that straight lines remain 3361 straight, but the scale of the distorted image will vary. The horizon 3362 is anti-aliased, and the 'sky' color may be set using the 3363 <a href="command-line-options.html#mattecolor">-mattecolor</a> setting. </td> 3364 </tr> 3365 3366 <tr> 3367 <td><code>PerspectiveProjection</code> </td> 3368 <td> 3369 Do a '<code>Perspective</code>' distortion biased on a set of 8 3370 pre-calculated coefficients. You can get these coefficients by looking 3371 at the <a href="command-line-options.html#verbose">-verbose</a> output of a 3372 '<code>Perspective</code>' distortion, or by calculating them yourself. 3373 If the last two perspective scaling coefficients are zero, the 3374 remaining 6 represents a transposed 'Affine Matrix'. </td> 3375 3376 </tr> 3377 3378 <tr> 3379 <td><code>Arc</code></td> 3380 <td> 3381 Arc the image (variation of polar mapping) over the angle given around 3382 a circle. <br> 3383 <table class="table table-condensed table-striped"> 3384 <tr><td>Argument</td> 3385 <td>Meaning</td></tr> 3386 <tr><td><var>arc_angle</var></td> 3387 <td>The angle over which to arc the image side-to-side</td></tr> 3388 <tr><td><var>rotate_angle</var></td> 3389 <td>Angle to rotate resulting image from vertical center</td></tr> 3390 <tr><td><var>top_radius</var></td> 3391 <td>Set top edge of source image at this radius</td></tr> 3392 <tr><td><var>bottom_radius</var> </td> 3393 <td>Set bottom edge to this radius (radial scaling)</td></tr> 3394 </table> 3395 3396 The resulting image is always resized to best fit the resulting image, 3397 (as if using <a href="command-line-options.html#distort">+distort</a>) while attempting to 3398 preserve scale and aspect ratio of the original image as much as 3399 possible with the arguments given by the user. All four arguments will 3400 be needed to change the overall aspect ratio of an 'Arc'ed image. <br> 3401 3402 This a variation of a polar distortion designed to try to preserve the 3403 aspect ratio of the image rather than direct Cartesian to Polar 3404 conversion. </td> 3405 </tr> 3406 3407 <tr> 3408 <td><code>Polar</code></td> 3409 <td> 3410 Like '<code>Arc</code>' but do a complete Cartesian to Polar mapping of 3411 the image. that is the height of the input image is mapped to the 3412 radius limits, while the width is wrapped around between the 3413 angle limits. <br> 3414 3415 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br> 3416 3417 All arguments are optional. With <var>Rmin</var> defaulting to zero, the 3418 center to the center of the image, and the angles going from -180 (top) 3419 to +180 (top). If <var>Rmax</var> is given the special value of 3420 '<code>0</code>', the the distance from the center to the nearest edge 3421 is used for the radius of the output image, which will ensure the whole 3422 image is visible (though scaled smaller). However a special value of 3423 '<code>-1</code>' will use the distance from the center to the furthest 3424 corner, This may 'clip' the corners from the input rectangular image, 3425 but will generate the exact reverse of a '<code>DePolar</code>' with 3426 the same arguments. <br> 3427 3428 If the plus form of distort (<a href="command-line-options.html#distort">+distort</a>) is used 3429 output image center will default to <code>0,0</code> of the virtual 3430 canvas, and the image size adjusted to ensure the whole input image is 3431 made visible in the output image on the virtual canvas. </td> 3432 3433 </tr> 3434 3435 <tr> 3436 <td><code>DePolar</code></td> 3437 <td> 3438 Uses the same arguments and meanings as a '<code>Polar</code>' distortion 3439 but generates the reverse Polar to Cartesian distortion. <br> 3440 3441 The special <var>Rmax</var> setting of '<code>0</code>' may however clip 3442 the corners of the input image. However using the special 3443 <var>Rmax</var> setting of '<code>-1</code>' (maximum center to corner 3444 distance) will ensure the whole distorted image is preserved in the 3445 generated result, so that the same argument to '<code>Polar</code>' will 3446 reverse the distortion re-producing the original. 3447 3448 Note that as this distortion requires the area resampling of a circular 3449 arc, which can not be handled by the builtin EWA resampling function. 3450 As such the normal EWA filters are turned off. It is recommended some 3451 form of 'super-sampling' image processing technique be used to produce 3452 a high quality result. </td> 3453 3454 </tr> 3455 3456 <tr> 3457 <td><code>Barrel</code></td> 3458 <td> 3459 Given the four coefficients (A,B,C,D) as defined by <a href="http://wiki.panotools.org/Lens_correction_model">Helmut 3460 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to 3461 correct radial lens distortions. That is in photographs, make straight 3462 lines straight again. <br> 3463 3464 Arguments: <var>A B C</var> [ <var>D</var> [ 3465 <var>X</var> , <var>Y</var> ] ] <br> 3466 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 3467 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var> 3468 [ <var>X</var> , <var>Y</var> ] <br> 3469 So that it forms the function <br> 3470 Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> + 3471 <var>C</var>*r + <var>D</var> )<br> 3472 3473 Where <var>X</var>,<var>Y</var> is the optional center of the distortion 3474 (defaulting to the center of the image). <br> 3475 The second form is typically used to distort images, rather than 3476 correct lens distortions. <br> 3477 </td> 3478 3479 </tr> 3480 3481 <tr> 3482 <td><code>BarrelInverse</code></td> 3483 <td> 3484 This is very similar to '<code>Barrel</code>' with the same set of 3485 arguments, and argument handling. However it uses the inverse 3486 of the radial polynomial, 3487 so that it forms the function <br> 3488 Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> + 3489 <var>C</var>*r + <var>D</var> )<br> 3490 Note that this is not the reverse of the '<code>Barrel</code>' 3491 distortion, just a different barrel-like radial distortion method. 3492 3493 </td> 3494 </tr> 3495 3496 <tr> 3497 <td><code>Shepards</code></td> 3498 <td> 3499 Distort the given list control points (any number) using an Inverse 3500 Squared Distance Interpolation Method (<a href="http://en.wikipedia.org/wiki/Shepard%27s_method">Shepards 3501 Method</a>). The control points in effect do 'localized' displacement 3502 of the image around the given control point (preserving the look and 3503 the rotation of the area near the control points. For best results 3504 extra control points should be added to 'lock' the positions of the 3505 corners, edges and other unchanging parts of the image, to prevent 3506 their movement. <br> 3507 3508 The distortion has been likened to 'taffy pulling' using nails, or 3509 pins' stuck in a block of 'jelly' which is then moved to the new 3510 position, distorting the surface of the jelly. <br> 3511 3512 Internally it is equivalent to generating a displacement map (see <a href="command-line-options.html#displace">-displace</a>) for source image color look-up using 3513 the <a href="command-line-options.html#sparse-color">-sparse-color</a> method of the same name. 3514 3515 </td> 3516 </tr> 3517 3518 3519 3520<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list 3521distort</a>.</p> 3522 3523<p>Many of the above distortion methods such as '<code>Affine</code>', 3524'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points 3525defining how these points in the given image should be distorted in the 3526destination image. Each set of four floating point values represent a source 3527image coordinate, followed immediately by the destination image coordinate. 3528This produces a list of values such as...</p> 3529<div style="text-align: center"><var> 3530 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 3531 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 3532 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 3533 ... 3534 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 3535</var></div> 3536<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the 3537destination image. </p> 3538 3539<p>For example, to warp an image using '<code>perspective</code>' distortion, 3540needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 3541perspective distortion of the built-in "rose:" image. Note how spaces were 3542used to group the 4 sets of coordinate pairs, to make it easier to read and 3543understand.</p> 3544 3545<pre> 3546convert rose: -virtual-pixel black \ 3547 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \ 3548 rose_3d_rotated.gif" 3549</pre> 3550 3551<p>If more that the required number of coordinate pairs are given for 3552a distortion, the distortion method is 'least squares' fitted to produce the 3553best result for all the coordinate pairs given. If less than the ideal number 3554of points are given, the distort will generally fall back to a simpler form of 3555distortion that can handles the smaller number of coordinates (usually a linear 3556'<code>Affine</code>' distortion). </p> 3557 3558<p>By using more coordinates you can make use of image registration tool to 3559find matching coordinate pairs in overlapping images, so as to improve the 3560'fit' of the distortion. Of course a bad coordinate pair can also make the 3561'fit' worse. Caution is always advised. </p> 3562 3563<p>Colors are acquired from the source image according to a cylindrical 3564resampling <a href="command-line-options.html#filter">-filter</a>, using a special technique known as 3565EWA resampling. This produces very high quality results, especially when 3566images become smaller (minified) in the output, which is very common when 3567using '<code>perspective</code>' distortion. For example here we view 3568a infinitely tiled 'plane' all the way to the horizon. </p> 3569 3570<pre> 3571convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \ 3572 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \ 3573 checks_tiled.jpg 3574</pre> 3575 3576<p>Note that a infinitely tiled perspective images involving the horizon can 3577be very slow, because of the number of pixels that are compressed to generate 3578each individual pixel close to the 'horizon'. You can turn off EWA 3579resampling, by specifing the special <a href="command-line-options.html#filter">-filter</a> setting of 3580'<code>point</code>' (recommended if you plan to use super-sampling instead). 3581</p> 3582 3583<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 3584example, <a href="command-line-options.html#distort">-distort</a> will use the current <a href="command-line-options.html#mattecolor">-mattecolor</a> setting for these pixels. If you do not 3585what these pixels to be visible, set the color to match the rest of the 3586ground. </p> 3587 3588<p>The output image size will by default be the same as the input image. This 3589means that if the part of the distorted image falls outside the viewed area of 3590the 'distorted space', those parts is clipped and lost. However if you use 3591the plus form of the operator (<a href="command-line-options.html#distort">+distort</a>) the operator 3592will attempt (if possible) to show the whole of the distorted image, while 3593retaining a correct 'virtual canvas' offset, for image layering. This offset 3594may need to be removed using <a href="command-line-options.html#repage">+repage</a>, to remove if it 3595is unwanted. </p> 3596 3597<p>Setting <a href="command-line-options.html#verbose">-verbose</a> setting, will cause <a href="command-line-options.html#distort">-distort</a> to attempt to output the internal coefficients, 3598and the <a href="command-line-options.html#fx">-fx</a> equivalent to the distortion, for expert study, 3599and debugging purposes. This many not be available for all distorts. </p> 3600 3601<p>You can alternatively specify a special "<code><a href="command-line-options.html#define">-define</a> distort:viewport={geometry_string}</code>" setting which will 3602specify the size and the offset of the generated 'viewport' image of the 3603distorted image space.</p> 3604 3605<p>Setting a "<code><a href="command-line-options.html#define">-define</a> 3606distort:scale={scale_factor}</code>" will scale the output image (viewport or 3607otherwise) by that factor without changing the viewed contents of the 3608distorted image. This can be used either for 'super-sampling' the image for 3609a higher quality result, or for panning and zooming around the image (with 3610appropriate viewport changes, or post-distort cropping and resizing). </p> 3611 3612<p>Setting "<code><a href="command-line-options.html#define">-define</a> resample:verbose=1</code>" 3613will output the cylindrical filter lookup table created by the EWA (Elliptical 3614Weighted Average) resampling algorithm. Note this table uses a squared radius 3615lookup value. This is typically only used for debugging EWA resampling. </p> 3616 3617 3618<div style="margin: auto;"> 3619 <h3 class="magick-header"><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3> 3620</div> 3621 3622<p class="magick-description">launch a distributed pixel cache server. </p> 3623 3624<div style="margin: auto;"> 3625 <h3 class="magick-header"><a id="dither"></a>-dither <var>method</var></h3> 3626</div> 3627 3628<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to 3629images when general color reduction is applied via an option, or automagically 3630when saving to specific formats. This enabled by default.</p> 3631 3632<p>Dithering places two or more colors in neighboring pixels so that to the 3633eye a closer approximation of the images original color is reproduced. This 3634reduces the number of colors needed to reproduce the image but at the cost of 3635a lower level pattern of colors. Error diffusion dithers can use any set of 3636colors (generated or user defined) to an image. </p> 3637 3638<p>Dithering is turned on by default, to turn it off use the plus form of the 3639setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript 3640without text or graphic aliasing. Disabling dithering often (but not always) 3641leads to faster process, a smaller number of colors, but more cartoon like 3642image coloring. Generally resulting in 'color banding' effects in areas with 3643color gradients. </p> 3644 3645<p>The color reduction operators <a href="command-line-options.html#colors">-colors</a>, <a href="command-line-options.html#monochrome">-monochrome</a>, <a href="command-line-options.html#remap%20">-remap</a>, and <a href="command-line-options.html#posterize">-posterize</a>, apply dithering to images using the reduced 3646color set they created. These operators are also used as part of automatic 3647color reduction when saving images to formats with limited color support, such 3648as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used 3649in these cases. </p> 3650 3651<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a> 3652to generate purely random dither. Or use <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to apply threshold mapped dither 3653patterns, using uniform color maps, rather than specific color maps. </p> 3654 3655 3656<div style="margin: auto;"> 3657 <h3 class="magick-header"><a id="draw"></a>-draw <var>string</var></h3> 3658</div> 3659 3660<p class="magick-description">Annotate an image with one or more graphic primitives.</p> 3661 3662<p>Use this option to annotate or decorate an image with one or more graphic 3663primitives. The primitives include shapes, text, transformations, and pixel 3664operations.</p> 3665 3666<p>The shape primitives:</p> 3667 3668<pre> 3669point x,y 3670line x0,y0 x1,y1 3671rectangle x0,y0 x1,y1 3672roundRectangle x0,y0 x1,y1 wc,hc 3673arc x0,y0 x1,y1 a0,a1 3674ellipse x0,y0 rx,ry a0,a1 3675circle x0,y0 x1,y1 3676polyline x0,y0 ... xn,yn 3677polygon x0,y0 ... xn,yn 3678bezier x0,y0 ... xn,yn 3679path specification 3680image operator x0,y0 w,h filename 3681</pre> 3682 3683<p>The text primitive:</p> 3684 3685<pre> 3686text x0,y0 string 3687</pre> 3688<p>The text gravity primitive:</p> 3689 3690<pre> 3691gravity NorthWest, North, NorthEast, West, Center, 3692 East, SouthWest, South, or SouthEast 3693</pre> 3694 3695<p>The text gravity primitive only affects the placement of text and does not 3696interact with the other primitives. It is equivalent to using the <a href="command-line-options.html#gravity">-gravity</a> command-line option, except that it is limited in 3697scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p> 3698 3699<p>The transformation primitives:</p> 3700 3701<pre> 3702rotate degrees 3703translate dx,dy 3704scale sx,sy 3705skewX degrees 3706skewY degrees 3707</pre> 3708 3709<p>The pixel operation primitives:</p> 3710 3711<pre> 3712color x0,y0 method 3713matte x0,y0 method 3714</pre> 3715 3716<p>The shape primitives are drawn in the color specified by the preceding <a href="command-line-options.html#fill">-fill</a> setting. For unfilled shapes, use <a href="command-line-options.html#fill">-fill none</a>. You can optionally control the stroke (the 3717"outline" of a shape) with the <a href="command-line-options.html#stroke">-stroke</a> and <a href="command-line-options.html#strokewidth">-strokewidth</a> settings.</p> 3718 3719<p>A <code>point</code> primitive is specified by a single <var>point</var> in the 3720pixel plane, that is, by an ordered pair of integer coordinates, 3721<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code> 3722primitive is not affected by <a href="command-line-options.html#stroke">-stroke</a> or <a href="command-line-options.html#strokewidth">-strokewidth</a>.)</p> 3723 3724<p>A <code>line</code> primitive requires a start point and end point.</p> 3725 3726<p>A <code>rectangle</code> primitive is specified by the pair of points at the 3727upper left and lower right corners.</p> 3728 3729<p>A <code>roundRectangle</code> primitive takes the same corner points as 3730a <code>rectangle</code> followed by the width and height of the rounded corners 3731to be removed.</p> 3732 3733<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled). 3734Give the center and any point on the perimeter (boundary).</p> 3735 3736<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in 3737to a given rectangle. An <code>arc</code> requires the two corners used for 3738<code>rectangle</code> (see above) followed by the start and end angles of the 3739arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end 3740points produced are then joined with a line segment and the resulting segment 3741of an ellipse is filled.</p> 3742 3743<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the 3744center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of 3745the ellipse) and start and end angles in degrees (e.g. 100,100 100,150 37460,360).</p> 3747 3748<p>The <code>polyline</code> and <code>polygon</code> primitives require three or 3749more points to define their perimeters. A <code>polyline</code> is simply 3750a <code>polygon</code> in which the final point is not stroked to the start 3751point. When unfilled, this is a <var>polygonal line</var>. If the <a href="command-line-options.html#stroke">-stroke</a> setting is <code>none</code> (the default), then 3752a <code>polyline</code> is identical to a <code>polygon</code>. </p> 3753 3754<p>A <var>coordinate</var> is a pair of integers separated by a space or 3755optional comma. </p> 3756 3757<p>As an example, to define a circle centered at 100,100 that extends to 3758150,150 use:</p> 3759 3760<pre> 3761-draw 'circle 100,100 150,150' 3762</pre> 3763 3764<p>The <code>Bezier</code> primitive creates a spline curve and requires three 3765or points to define its shape. The first and last points are the 3766<var>knots</var> and these points are attained by the curve, while any 3767intermediate coordinates are <var>control points</var>. If two control points 3768are specified, the line between each end knot and its sequentially respective 3769control point determines the tangent direction of the curve at that end. If 3770one control point is specified, the lines from the end knots to the one 3771control point determines the tangent directions of the curve at each end. If 3772more than two control points are specified, then the additional control points 3773act in combination to determine the intermediate shape of the curve. In order 3774to draw complex curves, it is highly recommended either to use the 3775<code>path</code> primitive or to draw multiple four-point bezier segments with 3776the start and end knots of each successive segment repeated. For example:</p> 3777 3778<pre> 3779-draw 'bezier 20,50 45,100 45,0 70,50' 3780-draw 'bezier 70,50 95,100 95,0 120,50' 3781</pre> 3782 3783 3784<p>A <code>path</code> represents an outline of an object, defined in terms of 3785moveto (set a new current point), lineto (draw a straight line), curveto (draw 3786a Bezier curve), arc (elliptical or circular arc) and closepath (close the 3787current shape by drawing a line to the last moveto) elements. Compound paths 3788(i.e., a path with subpaths, each consisting of a single moveto followed by 3789one or more line or curve operations) are possible to allow effects such as 3790<var>donut holes</var> in objects. (See <a href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p> 3791 3792<p>Use <code>image</code> to composite an image with another image. Follow the 3793image keyword with the composite operator, image location, image size, and 3794filename:</p> 3795 3796<pre> 3797-draw 'image SrcOver 100,100 225,225 image.jpg' 3798</pre> 3799 3800<p>You can use 0,0 for the image size, which means to use the actual 3801dimensions found in the image header. Otherwise, it is scaled to the given 3802dimensions. See <a href="compose.html">Alpha Compositing</a> for 3803a detailed discussion of alpha composition methods that are available. </p> 3804 3805<p>The "special augmented compose operators" such as "dissolve" that require 3806arguments cannot be used at present with the <code>-draw image</code> option. 3807 </p> 3808 3809<p>Use <code>text</code> to annotate an image with text. Follow the text 3810coordinates with a string. If the string has embedded spaces, enclose it in 3811single or double quotes.</p> 3812 3813<p>For example, the following annotates the image with <code>Works like 3814magick!</code> for an image titled <code>bird.miff</code>. </p> 3815 3816<pre> 3817-draw "text 100,100 'Works like magick!' " 3818</pre> 3819 3820<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way 3821to annotate an image with text.</p> 3822 3823<p>The <code>rotate</code> primitive rotates subsequent shape primitives and 3824text primitives about the origin of the main image. If the <a href="command-line-options.html#region">-region</a> option precedes the <a href="command-line-options.html#draw">-draw</a> 3825option, the origin for transformations is the upper left corner of the 3826region.</p> 3827 3828<p>The <code>translate</code> primitive translates subsequent shape and text 3829primitives.</p> 3830 3831<p>The <code>scale</code> primitive scales them.</p> 3832 3833<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect 3834to the origin of the main image or the region.</p> 3835 3836<p>The transformations modify the current affine matrix, which is initialized 3837from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a> 3838option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a> 3839option. The initial affine matrix is not affected; that matrix is only changed 3840by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another 3841<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is 3842reinitialized from the initial affine matrix.</p> 3843 3844<p>Use the <code>color</code> primitive to change the color of a pixel to the 3845fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with 3846a method:</p> 3847 3848<pre> 3849point 3850replace 3851floodfill 3852filltoborder 3853reset 3854</pre> 3855 3856<p>Consider the target pixel as that specified by your coordinate. The 3857<code>point</code> method recolors the target pixel. The <code>replace</code> 3858method recolors any pixel that matches the color of the target pixel. 3859<code>Floodfill</code> recolors any pixel that matches the color of the target 3860pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor 3861pixel that is not the border color. Finally, <code>reset</code> recolors all 3862pixels.</p> 3863 3864<p>Use <code>matte</code> to the change the pixel matte value to transparent. 3865Follow the pixel coordinate with a method (see the <code>color</code> primitive 3866for a description of methods). The <code>point</code> method changes the matte 3867value of the target pixel. The <code>replace</code> method changes the matte 3868value of any pixel that matches the color of the target pixel. 3869<code>Floodfill</code> changes the matte value of any pixel that matches the 3870color of the target pixel and is a neighbor, whereas <code>filltoborder</code> 3871changes the matte value of any neighbor pixel that is not the border color (<a href="command-line-options.html#bordercolor">-bordercolor</a>). Finally <code>reset</code> changes the 3872matte value of all pixels.</p> 3873 3874<p>You can set the primitive color, font, and font bounding box color with <a href="command-line-options.html#fill">-fill</a>, <a href="command-line-options.html#font">-font</a>, and <a href="command-line-options.html#box">-box</a> 3875respectively. Options are processed in command line order so be sure to use 3876these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p> 3877 3878<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather 3879than 1.png).</p> 3880 3881<p>Drawing primitives conform to the <a href="magick-vector-graphics.html">Magick 3882Vector Graphics</a> format.</p> 3883 3884 3885<div style="margin: auto;"> 3886 <h3 class="magick-header"><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3> 3887</div> 3888 3889<p class="magick-description">duplicate an image one or more times.</p> 3890 3891<p>Specify the count and the image to duplicate by its index in the sequence. 3892The first image is index 0. Negative indexes are relative to the end of the 3893sequence, for example, -1 represents the last image of the sequence. Specify 3894a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g. 38950,2). Use <code>+duplicate</code> to duplicate the last image in the current 3896image sequence.</p> 3897 3898<div style="margin: auto;"> 3899 <h3 class="magick-header"><a id="edge"></a>-edge <var>radius</var></h3> 3900</div> 3901 3902<p class="magick-description">detect edges within an image.</p> 3903 3904<div style="margin: auto;"> 3905 <h3 class="magick-header"><a id="emboss"></a>-emboss <var>radius</var></h3> 3906</div> 3907 3908<p class="magick-description">emboss an image.</p> 3909 3910<div style="margin: auto;"> 3911 <h3 class="magick-header"><a id="encipher"></a>-encipher <var>filename</var></h3> 3912</div> 3913 3914<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p> 3915 3916<p>Get the passphrase from the file specified by <var>filename</var>.</p> 3917 3918<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or 3919Decipher an Image</a>.</p> 3920 3921 3922 3923<div style="margin: auto;"> 3924 <h3 class="magick-header"><a id="encoding"></a>-encoding <var>type</var></h3> 3925</div> 3926 3927<p class="magick-description">specify the text encoding.</p> 3928 3929<p>Choose from <code>AdobeCustom</code>, <code>AdobeExpert</code>, 3930<code>AdobeStandard</code>, <code>AppleRoman</code>, <code>BIG5</code>, 3931<code>GB2312</code>, <code>Latin 2</code>, <code>None</code>, <code>SJIScode</code>, 3932<code>Symbol</code>, <code>Unicode</code>, <code>Wansung</code>.</p> 3933 3934<div style="margin: auto;"> 3935 <h3 class="magick-header"><a id="endian"></a>-endian <var>type</var></h3> 3936</div> 3937 3938<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p> 3939 3940<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p> 3941 3942<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p> 3943 3944 3945<div style="margin: auto;"> 3946 <h3 class="magick-header"><a id="enhance"></a>-enhance</h3> 3947</div> 3948 3949<p class="magick-description">Apply a digital filter to enhance a noisy image.</p> 3950 3951 3952<div style="margin: auto;"> 3953 <h3 class="magick-header"><a id="equalize"></a>-equalize</h3> 3954</div> 3955 3956<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p> 3957 3958<p>To perform histogram equalization on all channels in concert, transform the 3959image into some other color space, such as HSL, OHTA, YIQ or YUV, then 3960equalize the appropriate intensity-like channel, then convert back to RGB.</p> 3961 3962<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness 3963-equalize -colorspace RGB</code> ...</p> 3964 3965<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal 3966components transformation that puts most of the information in the first 3967channel. Here we have ... <code>-colorspace OHTA -channel red -equalize 3968-colorspace RGB</code> ...</p> 3969 3970<div style="margin: auto;"> 3971 <h3 class="magick-header"><a id="evaluate"></a>-evaluate <var>operator value</var></h3> 3972</div> 3973 3974<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p> 3975 3976<p>(See the <a href="command-line-options.html#function">-function</a> operator for some 3977multi-parameter functions. See the <a href="command-line-options.html#fx">-fx</a> operator if more 3978elaborate calculations are needed.)</p> 3979 3980<p>The behaviors of each <var>operator</var> are summarized in the 3981following list. For brevity, the numerical value of a "pixel" referred to 3982below is the value of the corresponding channel of that pixel, while 3983a "normalized pixel" is that number divided by the maximum 3984(installation-dependent) value <var>QuantumRange</var>. (If 3985normalized pixels are used, they are restored, following the other 3986calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p> 3987 3988<table class="table table-condensed table-striped"> 3989 <col width="25%"> 3990 <col width="75%"> 3991 <thead> 3992 <tr> 3993 <th><var>operator</var></th> 3994 <th>Summary (see further below for details)</th> 3995 </tr> 3996 </thead> 3997 <tbody> 3998 3999 <tr><td>Abs </td> <td>Add <var>value</var> to pixels and return absolute value. </td></tr> 4000 <tr><td>Add </td> <td>Add <var>value</var> to pixels. </td></tr> 4001 <tr><td>AddModulus </td> <td>Add <var>value</var> to pixels modulo <var>QuantumRange</var>.</td></tr> 4002 <tr><td>And </td> <td>Binary AND of pixels with <var>value</var>.</td></tr> 4003 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <var>value</var> with 50% bias added.</td></tr> 4004 <tr><td>Divide </td> <td>Divide pixels by <var>value</var>.</td></tr> 4005 <tr><td>Exp </td> <td>base-e exponential function</td></tr> 4006 <tr><td>Exponential </td> <td>base-e exponential function</td></tr> 4007 <tr><td>LeftShift </td> <td>Shift the pixel values left by <var>value</var> bits (i.e., multiply pixels by 2<sup><var>value</var></sup>).</td></tr> 4008 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr> 4009 <tr><td>Max </td> <td>Clip pixels at lower bound <var>value</var>.</td></tr> 4010 <tr><td>Mean </td> <td>Add the <var>value</var> and divide by 2.</td></tr> 4011 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr> 4012 <tr><td>Min </td> <td>Clip pixels at upper bound <var>value</var>.</td></tr> 4013 <tr><td>Multiply </td> <td>Multiply pixels by <var>value</var>.</td></tr> 4014 <tr><td>Or </td> <td>Binary OR of pixels with <var>value</var>.</td></tr> 4015 <tr><td>Pow </td> <td>Raise normalized pixels to the power <var>value</var>.</td></tr> 4016 <tr><td>RightShift </td> <td>Shift the pixel values right by <var>value</var> bits (i.e., divide pixels by 2<sup><var>value</var></sup>).</td></tr> 4017 <tr><td>RMS</td> <td>Square the pixel and add the <var>value</var>.</td></tr> 4018 <tr><td>RootMeanSquare</td> <td>Square the pixel and add the <var>value</var>.</td></tr> 4019 <tr><td>Set </td> <td>Set pixel equal to <var>value</var>.</td></tr> 4020 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <var>value</var> with 50% bias added.</td></tr> 4021 <tr><td>Subtract </td> <td>Subtract <var>value</var> from pixels.</td></tr> 4022 <tr><td>Xor </td> <td>Binary XOR of pixels with <var>value.</var></td></tr> 4023 4024 <tr><td> </td></tr> 4025 4026 <tr><td>Gaussian-noise</td><td> </td></tr> 4027 <tr><td>Impulse-noise</td><td> </td></tr> 4028 <tr><td>Laplacian-noise</td><td> </td></tr> 4029 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="command-line-options.html#noise">-noise</a> operators.)</td></tr> 4030 <tr><td>PoissonNoise</td><td> </td></tr> 4031 <tr><td>Uniform-noise</td><td> </td></tr> 4032 4033 <tr><td> </td></tr> 4034 4035 <tr><td>Threshold </td> <td>Threshold pixels larger than <var>value</var>.</td></tr> 4036 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <var>value</var>.</td></tr> 4037 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <var>value</var>. </td></tr> 4038 </tbody> 4039 </table> 4040 4041<p>The specified functions are applied only to each previously set <a href="command-line-options.html#channel">-channel</a> in the image. If necessary, the results of the 4042calculations are truncated (clipped) to fit in the interval [0, <var>QuantumRange</var>]. The transparency channel of the image is 4043represented as a 'alpha' values (0 = fully transparent), so, for example, a 4044<code>Divide</code> by 2 of the alpha channel will make the image 4045semi-transparent. Append the percent symbol '<code>%</code>' to specify a value 4046as a percentage of the <var>QuantumRange</var>.</p> 4047 4048<p>To print a complete list of <a href="command-line-options.html#evaluate">-evaluate</a> operators, use 4049<a href="command-line-options.html#list">-list evaluate</a>.</p> 4050 4051<p>The results of the <code>Add</code>, <code>Subtract</code> and 4052<code>Multiply</code> methods can also be achieved using either the <a href="command-line-options.html#level">-level</a> or the <a href="command-line-options.html#level">+level</a> operator, with 4053appropriate argument, to linearly modify the overall range of color values. 4054Please note, however, that <a href="command-line-options.html#level">-level</a> treats transparency as 4055'matte' values (0 = opaque), while <a href="command-line-options.html#level">-evaluate</a> works with 4056'alpha' values.</p> 4057 4058<p><code>AddModulus</code> has been added as of ImageMagick 6.4.8-4 and provides 4059addition modulo the <var>QuantumRange</var>. It is therefore 4060equivalent to <code>Add</code> unless the resulting pixel value is outside the 4061interval [0, <var>QuantumRange</var>]. </p> 4062 4063<p><code>Exp or Exponential</code> has been added as of ImageMagick 6.6.5-1 and 4064works on normalized pixel values. The <var>value</var> used with 4065<code>Exp</code> should be negative so as to produce a decaying exponential 4066function. Non-negative values will always produce results larger unity and 4067thus outside the interval [0, <var>QuantumRange</var>]. The 4068formula is expressed below. </p> 4069 4070 <div style="text-align:center;"> 4071 exp(<var>value</var> × <b><var>u</var></b>) 4072 </div> 4073 4074<p> If the input image is squared, for example, using <a href="command-line-options.html#-function">-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be 4075the result.</p> 4076 4077<p><code>Log</code> has been added as of ImageMagick 6.4.2-1 and works on 4078normalized pixel values. This a <var>scaled</var> log function. The <var>value</var> used with <code>Log</code> provides a <var>scaling 4079factor</var> that adjusts the curvature in the graph of the log function. The 4080formula applied to a normalized value <b><var>u</var></b> is below. </p> 4081 4082 <div style="text-align:center;"> 4083 log(<var>value</var> × <b><var>u</var></b> + 1) / log(<var>value</var> + 1) 4084 </div> 4085 4086<p><code>Pow</code> has been added as of ImageMagick 6.4.1-9, and works on 4087normalized pixel values. Note that <code>Pow</code> is related to the <a href="command-line-options.html#gamma">-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent 4088to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used 4089with <a href="command-line-options.html#gamma">-gamma</a> is simply the reciprocal of the value used 4090with <code>Pow</code>.</p> 4091 4092<p><code>Cosine</code> and <code>Sine</code> was added as of IM v6.4.8-8 and 4093converts the image values into a value according to a (co)sine wave function. 4094The synonyms <code>Cos</code> and <code>Sin</code> may also be used. The output 4095is biased 50% and normalized by 50% so as to fit in the respective color value 4096range. The <var>value</var> scaling of the <var>period</var> of the 4097function (its frequency), and thus determines the number of 'waves' that will 4098be generated over the input color range. For example, if the <var>value</var> is 1, the effective period is simply the <var>QuantumRange</var>; but if the <var>value</var> is 2, 4099then the effective period is the <var>half</var> the <var>QuantumRange</var>.</p> 4100 4101 <div style="text-align:center;"> 4102 0.5 + 0.5 × cos(2 π <b><var>u</var></b> × <var>value</var>). 4103 </div> 4104 4105<p>See also the <a href="command-line-options.html#function">-function</a> operator, which is a 4106multi-value version of evaluate. </p> 4107 4108<div style="margin: auto;"> 4109 <h3 class="magick-header"><a id="evaluate-sequence"></a>-evaluate-sequence <var>operator</var></h3> 4110</div> 4111 4112<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or 4113logical expression over a sequence of images.</p> 4114 4115<p>To print a complete list of <a href="command-line-options.html#evaluate-sequence">-evaluate-sequence</a> operators, use <a href="command-line-options.html#list">-list evaluate</a>.</p> 4116 4117<div style="margin: auto;"> 4118 <h3 class="magick-header"><a id="extent"></a>-extent <var>geometry</var></h3> 4119</div> 4120 4121<p class="magick-description">Set the image size and offset.</p> 4122 4123<p>If the image is enlarged, unfilled areas are set to the background color. 4124To position the image, use offsets in the <var>geometry</var> 4125specification or precede with a <a href="command-line-options.html#gravity">-gravity</a> setting. To 4126specify how to compose the image with the background, use <a href="command-line-options.html#compose">-compose</a>.</p> 4127 4128<p>This command reduces or expands a JPEG image to fit on an 800x600 4129display. If the aspect ratio of the input image isn't exactly 4:3, then the 4130image is centered on an 800x600 black canvas: </p> 4131 4132<pre> 4133convert input.jpg -resize 800x600 -background black -compose Copy \ 4134 -gravity center -extent 800x600 -quality 92 output.jpg 4135</pre> 4136 4137<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4138 4139<div style="margin: auto;"> 4140 <h3 class="magick-header"><a id="extract"></a>-extract <var>geometry</var></h3> 4141</div> 4142 4143<p class="magick-description">Extract the specified area from image.</p> 4144 4145<p>This option is most useful for extracting a subregion of a very large raw 4146image. Note that these two commands are equivalent:</p> 4147 4148<pre> 4149convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \ 4150 image.rgb image.png", 4151convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \ 4152 image.rgb image.png" 4153</pre> 4154 4155<p>If you omit the offsets, as in</p> 4156 4157<pre> 4158convert -size 16000x16000 -depth 8 -extract 640x480 \ 4159 image.rgb image.png 4160</pre> 4161 4162<p>the image is <var>resized</var> to the specified dimensions instead, 4163equivalent to:</p> 4164 4165<pre> 4166convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png 4167</pre> 4168 4169<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4170 4171<div style="margin: auto;"> 4172 <h3 class="magick-header"><a id="family"></a>-family <var>fontFamily</var></h3> 4173</div> 4174 4175<p class="magick-description">Set a font family for text.</p> 4176 4177<p>This setting suggests a font family that ImageMagick should try to use for 4178rendering text. If the family can be found it is used; if not, a default font 4179(e.g., "Arial") or a family known to be similar is substituted (e.g., 4180"Courier" might be used if "System" is requested but not found). </p> 4181 4182<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p> 4183 4184<div style="margin: auto;"> 4185 <h3 class="magick-header"><a id="features"></a>-features <var>distance</var></h3> 4186</div> 4187 4188<p class="magick-description">display (cooccurrence matrix) texture measure features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</p> 4189 4190<pre> 4191Angular Second Moment 4192Contrast 4193Correlation 4194Sum of Squares Variance 4195Inverse Difference Moment 4196Sum Average 4197Sum Variance 4198Sum Entropy 4199Entropy 4200Difference Variance 4201Difference Entropy 4202Information Measure of Correlation 1 4203Information Measure of Correlation 2 4204Maximum Correlation Coefficient 4205</pre> 4206 4207 4208<div style="margin: auto;"> 4209 <h3 class="magick-header"><a id="fft"></a>-fft</h3> 4210</div> 4211 4212<p class="magick-description">implements the forward discrete Fourier transform (DFT).</p> 4213 4214<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows 4215users in ImageMagick 6.6.0-9). It transforms an image from the normal 4216(spatial) domain to the frequency domain. In the frequency domain, an image is 4217represented as a superposition of complex sinusoidal waves of varying 4218amplitudes. The image x and y coordinates are the possible frequencies along 4219the x and y directions, respectively, and the pixel intensity values are 4220complex numbers that correspond to the sinusoidal wave amplitudes. See for 4221example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier 4222Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier 4223Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier 4224Transform</a>.</p> 4225 4226<p>A single image name is provided as output for this option. However, the 4227output result will have two components. It is either a two-frame image or two 4228separate images, depending upon whether the image format specified supports 4229multi-frame images. The reason that we get a dual output result is because the 4230frequency domain represents an image using complex numbers, which cannot be 4231visualized directly. Therefore, the complex values are automagically separated 4232into a two-component image representation. The first component is the 4233magnitude of the complex number and the second is the phase of the complex 4234number. See for example, <a href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p> 4235 4236<p>The magnitude and phase component images must be specified using image 4237formats that do not limit the color or compress the image. Thus, MIFF, TIF, 4238PFM, EXR and PNG are the recommended image formats to use. All of these 4239formats, except PNG support multi-frame images. So for example,</p> 4240 4241<pre> 4242convert image.png -fft fft_image.miff 4243</pre> 4244 4245<p>generates a magnitude image as <code>fft_image.miff[0]</code> and a phase 4246image as <code>fft_image.miff[1]</code>. Similarly,</p> 4247 4248<pre> 4249convert image.png -fft fft_image.png 4250</pre> 4251 4252<p>generates a magnitude image as <code>fft_image-0.png</code> and a phase image 4253as <code>fft_image-1.png</code>. If you prefer this representation, then you can 4254force any of the other formats to produce two output images by including <a href="command-line-options.html#adjoin">+adjoin</a> following -fft in the command line.</p> 4255 4256<p>The input image can be any size, but if not square and even-dimensioned, it 4257is padded automagically to the larger of the width or height of the input 4258image and to an even number of pixels. The padding will occur at the bottom 4259and/or right sides of the input image. The resulting output magnitude and 4260phase images is square at this size. The kind of padding relies on the <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting.</p> 4261 4262<p>Both output components will have dynamic ranges that fit within 4263[0, <var>QuantumRange</var>], so that HDRI need not be enabled. 4264Phase values nominally range from 0 to 2*π, but is scaled to span the full 4265dynamic range. (The first few releases had non-HDRI scaled but HDRI not 4266scaled). The magnitude image is not scaled and thus generally will contain 4267very small values. As such, the image normally will appear totally black. In 4268order to view any detail, the magnitude image typically is enhanced with a log 4269function into what is usually called the spectrum. A log function is used to 4270enhance the darker values more in comparison to the lighter values. This can 4271be done, for example, as follows:</p> 4272 4273<pre> 4274convert fft_image.miff[0] -contrast-stretch 0 \ 4275 -evaluate log 1000 fft_image_spectrum.png" 4276</pre> 4277 4278<p>where either <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> 0 or <a href="command-line-options.html#auto-level">-auto-level</a> is used to scale the image to full dynamic 4279range, first. The argument to the <a href="command-line-options.html#evaluate">-evaluate</a> log 4280typically is specified between 100 and 10,000, depending upon the amount of 4281detail that one wants to bring out in the spectrum. Larger values produce more 4282visible detail. Too much detail, however, may hide the important features.</p> 4283 4284<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to 4285use <a href="command-line-options.html#fft">-fft</a>.</p> 4286 4287<p>Use <a href="command-line-options.html#fft">+fft</a> to produce two output images that are the real 4288and imaginary components of the complex valued Fourier transform.</p> 4289 4290<p>However, as the real and imaginary components can contain negative values, 4291this requires that IM be configured with HDRI enabled. In this case, you must 4292use either MIFF, TIF, PFM or MPC formats for the real and imaginary component 4293results, since they are formats that preserve both negative and fractional 4294values without clipping them or truncating the fractional part. With either 4295MIFF or TIF, one should add -define quantum:format=32, to allow those image 4296types to work properly in HDRI mode without clipping.</p> 4297 4298<p>The real and imaginary component images resulting from <a href="command-line-options.html#fft">+fft</a> are also square, even dimensioned images due to the same 4299padding that was discussed above for the magnitude and phase component 4300images.</p> 4301 4302<p>See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High Dynamic-Range Images</a>. For more 4303about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages, <a href="http://www.fmwconcepts.com/imagemagick/fourier_transforms/fourier.html">Fred's Fourier Processing With ImageMagick page</a> or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 4304 entry. </p> 4305 4306<p>By default the FFT is normalized (and the IFT is not). Use "<code><a href="command-line-options.html#define">-define</a> fourier:normalize=forward</code> to explicityly normalize the FFT and unnormalize the IFT.</p> 4307 4308 4309<div style="margin: auto;"> 4310 <h3 class="magick-header"><a id="fill"></a>-fill <var>color</var></h3> 4311</div> 4312 4313<p class="magick-description">color to use when filling a graphic primitive.</p> 4314 4315<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA, 4316HSL, HSLA, CMYK, or CMYKA specification. See <a href="color.html">Color Names</a> for 4317a description of how to properly specify the color argument.</p> 4318 4319<p>Enclose the color specification in quotation marks to prevent the "#" or 4320the parentheses from being interpreted by your shell.</p> 4321 4322<p>For example,</p> 4323 4324<pre> 4325-fill blue 4326-fill "#ddddff" 4327-fill "rgb(255,255,255)" 4328</pre> 4329 4330<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p> 4331 4332<p>To print a complete list of color names, use the <a href="command-line-options.html#list">-list color</a> option.</p> 4333 4334<div style="margin: auto;"> 4335 <h3 class="magick-header"><a id="filter"></a>-filter <var>type</var></h3> 4336</div> 4337 4338<p class="magick-description">Use this <var>type</var> of filter when resizing or distorting an image.</p> 4339 4340<p>Use this option to affect the resizing operation of an image during 4341operations such as <a href="command-line-options.html#resize">-resize</a> and <a href="command-line-options.html#distort">-distort</a>. For example you can use a simple resize filter such as:</p> 4342 4343<pre> 4344Point Hermite Cubic 4345Box Gaussian Catrom 4346Triangle Quadratic Mitchell 4347</pre> 4348 4349<p>The <code>Bessel</code> and <code>Sinc</code> filter is also provided (as well 4350as a faster <code>SincFast</code> equivalent form). However these filters are 4351generally useless on their own as they are infinite filters that are being 4352clipped to the filters support size. Their direct use is not recommended 4353except via expert settings (see below). </p> 4354 4355<p>Instead these special filter functions are typically windowed by a windowing 4356function that the <a href="command-line-options.html#filter">-filter</a> setting defines. That is 4357using these functions will define a 'Windowed' filter, appropriate to the 4358operator involved. Windowed filters include: </p> 4359 4360<pre> 4361Lanczos Hamming Parzen 4362Blackman Kaiser Welsh 4363Hanning Bartlett Bohman 4364</pre> 4365 4366<p>Also one special self-windowing filter is also provided 4367<code>Lagrange</code>, which will automagically re-adjust its function depending 4368on the current 'support' or 'lobes' expert settings (see below).</p> 4369 4370<p>If you do not select a filter with this option, the filter defaults to 4371<code>Mitchell</code> for a colormapped image, an image with a matte channel, or 4372if the image is enlarged. Otherwise the filter default to 4373<code>Lanczos</code>.</p> 4374 4375<p>To print a complete list of resize filters, use the <a href="command-line-options.html#list">-list 4376filter</a> option.</p> 4377 4378<p>You can modify how the filter behaves as it scales your image through the 4379use of these expert settings (see also <a href="command-line-options.html#define">-define</a> and <a href="command-line-options.html#set">-set</a>):-</p> 4380 4381<table class="table table-condensed table-striped"> 4382 <tr> 4383 <td>-define filter:blur=<var>factor</var></td> 4384 <td>Scale the X axis of the filter (and its window). Use > 1.0 for 4385 blurry or < 1.0 for sharp. This should only be used with Gaussian and 4386 Gaussian-like filters simple filters, or you may not get the expected 4387 results. </td> 4388 </tr> 4389 4390 <tr> 4391 <td>-define filter:support=<var>radius</var></td> 4392 <td>Set the filter support radius. Defines how large the filter should be and 4393 thus directly defines how slow the filtered resampling process is. All 4394 filters have a default 'prefered' support size. Some filters like 4395 <code>Lagrange</code> and windowed filters adjust themselves depending on 4396 this value. With simple filters this value either does nothing (but slow 4397 the resampling), or will clip the filter function in a detrimental way. 4398 </td> 4399 </tr> 4400 4401 <tr> 4402 <td>-define filter:lobes=<var>count</var></td> 4403 <td>Set the number of lobes to use for the Sinc/Bessel filter. This an 4404 alternative way of specifying the 'support' range of the filter, that is 4405 designed to be more suited to windowed filters, especially when used for 4406 image distorts.</td> 4407 </tr> 4408 4409 <tr> 4410 <td>-define filter:sigma=<var>value</var></td> 4411 <td>The 'sigma' value used to define the <code>Gaussian</code> filter. Default 4412 sigma value is '<code>0.5</code>'. It only effects <code>Gaussian</code> but 4413 does not shrink (but may enlarge) the filter's 'support'. It can be used 4414 to generate very small blurs but without the filter 'missing' pixels due 4415 to using a small support setting. A larger value of '<code>0.707</code>' 4416 (a value of '1/sqrt(2)') is another common setting. </td> 4417 </tr> 4418 4419 <tr> 4420 <td>-define filter:b=<var>b-spline_factor</var></td> 4421 </tr><tr> 4422 <td>-define filter:c=<var>keys_alpha_factor</var></td> 4423 <td>Redefine the values used for cubic filters such as <code>Cubic</code>, 4424 <code>Catrom</code>, <code>Mitchel</code>, and <code>Hermite</code>, as well as 4425 the <code>Parzen</code> cubic windowing function. If only one of the values 4426 are defined, the other is set so as to generate a 'Cubic-Keys' filter. 4427 The values meaning was defined by a research paper by 4428 Mitchell-Netravali.</td> 4429 </tr> 4430 4431 <tr> 4432 <td>-define filter:kaiser-beta=<var>value</var></td> 4433 <td>The 'alpha' value used to as part of the Kaiser Windowing function. 4434 Default value is '6.5'. It only effects Kaiser windowing function, and 4435 does not effect any other attributes. 4436 Before ImageMagick v6.7.6-10, this option was known as "filter:alpha", (an 4437 inheritance from the very old "zoom" program). It was changed to bring the 4438 function in line with more modern academic research usage, and better 4439 assign it be more definitive. </td> 4440 </tr> 4441 4442 <tr> 4443 <td>-define filter:kaiser-alpha=<var>value</var></td> 4444 <td>This value when multiplied by 'PI' is equivalent to "kaiser-beta", and 4445 will override that setting. It only effects Kaiser windowing function, 4446 and does not effect any other attributes. </td> 4447 </tr> 4448 4449 <tr> 4450 <td>-define filter:filter=<var>filter_function</var></td> 4451 <td>Use this function directly as the weighting filter. This will allow 4452 you to directly use a windowing function such as <code>Blackman</code>, 4453 as a resampling filter, rather than as its normal usage as a windowing 4454 function. If defined, no windowing function also defined, the window function is set 4455 to <code>Box</code>). Directly specifying <code>Sinc</code> or <code>Jinc</code> 4456 as a filter will also do this. </td> 4457 </tr> 4458 4459 <tr> 4460 <td>-define filter:window=<var>filter_function</var></td> 4461 <td>The IIR (infinite impulse response) filters <code>Sinc</code> and 4462 <code>Jinc</code> are windowed (brought down to zero over the defined 4463 support range) with the given filter. This allows you to specify a filter 4464 function to be used as a windowing function for these IIR filters. 4465 Many of the defined filters are actually windowing functions for these IIR 4466 filters. A typical choices is <code>Box</code>, (which effectively turns 4467 off the windowing function). </td> 4468 </tr> 4469 4470 <tr> 4471 <td>-define filter:win-support=<var>radius</var></td> 4472 <td>Scale windowing function to this size instead. This causes the windowing 4473 (or self-windowing Lagrange filter) to act is if the support window is 4474 larger than what is actually supplied to the calling operator. The filter 4475 however is still clipped to the real support size given. If unset this 4476 will equal the normal filter support size. </td> 4477 </tr> 4478 4479 <tr> 4480 <td>-define filter:verbose=<var>1</var></td> 4481 <td>This causes IM to print information on the final internal filter 4482 selection to standard output. This includes a commented header on the 4483 filter settings being used, and data allowing the filter weights to be 4484 easily graphed. Note however that some filters are internally defined in terms of other filters. The <code>Lanczos</code> filter for example is defined in terms of 4485 a <code>SincFast</code> windowed <code>SincFast</code> filter, while 4486 <code>Mitchell</code> is defined as a general <code>Cubic</code> family filter 4487 with specific 'B' and 'C' settings. </td> 4488 </tr> 4489 4490</table> 4491 4492<p>For example, to get a 8 lobe jinc windowed sinc filter (Genseng filter?):</p> 4493 4494<pre> 4495convert image.png \ 4496 -filter sinc \ 4497 -set filter:window=jinc \ 4498 -set filter:lobes=8 \ 4499 -resize 150% image.jpg" 4500</pre> 4501 4502<p>Or a raw un-windowed Sinc filter with 4 lobes:</p> 4503 4504<pre> 4505convert image.png \ 4506 -set filter:filter=sinc \ 4507 -set filter:lobes=4 \ 4508 -resize 150% image.jpg" 4509</pre> 4510 4511<p>To extract the data for a raw windowing function, combine it with 4512a '<code>Box</code>' filter. For example the '<code>Welch</code> parabolic 4513windowing function. </p> 4514 4515<pre> 4516convert null: -define filter:filter=Box \ 4517 -define filter:window=Welch \ 4518 -define filter:support=1.0 \ 4519 -define filter:verbose=1 \ 4520 -resize 2 null: > window_welch.dat 4521gnuplot 4522 set grid 4523 plot \"window_welch.dat\" with lines 4524</pre> 4525 4526<p>Note that the use of expert options is provided for image processing experts 4527who have studied and understand how resize filters work. Without this 4528knowledge, and an understanding of the definition of the actual filters 4529involved, using expert settings are more likely to be detrimental to your image 4530resizing.</p> 4531 4532 4533<div style="margin: auto;"> 4534 <h3 class="magick-header"><a id="flatten"></a>-flatten</h3> 4535</div> 4536 4537<p class="magick-description">This is a simple alias for the <a href="command-line-options.html#layers">-layers</a> method "flatten".</p> 4538 4539 4540<div style="margin: auto;"> 4541 <h3 class="magick-header"><a id="flip"></a>-flip</h3> 4542</div> 4543 4544<p class="magick-description">create a <var>mirror image</var></p> 4545 4546<p>reflect the scanlines in the vertical direction. The image will be mirrored 4547upside-down. </p> 4548 4549 4550<div style="margin: auto;"> 4551 <h3 class="magick-header"><a id="floodfill"></a>-floodfill {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var> <var>color</var></h3> 4552</div> 4553 4554<p class="magick-description">floodfill the image with color at the specified offset.</p> 4555 4556<p>Flood fill starts from the given 'seed point' which is not gravity effected. 4557Any color that matches within <a href="command-line-options.html#fuzz">-fuzz</a> color distance of the 4558given <var>color</var> argument, connected to that 'seed point' 4559will be replaced with the current <a href="command-line-options.html#fill">-fill</a> color. </p> 4560 4561<p>Note that if the pixel at the 'seed point' does not itself match the given 4562<var>color</var> (according to <a href="command-line-options.html#fuzz">-fuzz</a>), then no 4563action will be taken. </p> 4564 4565<p>This operator works more like the <a href="command-line-options.html#opaque">-opaque</a> option, than 4566a more general flood fill that reads the matching color directly at the 'seed 4567point'. For this form of flood fill, look at <a href="command-line-options.html#draw">-draw</a> and 4568its 'color floodfill' drawing method. </p> 4569 4570 4571<div style="margin: auto;"> 4572 <h3 class="magick-header"><a id="flop"></a>-flop</h3> 4573</div> 4574 4575<p class="magick-description">create a <var>mirror image</var>.</p> 4576 4577<p>Reflect the scanlines in the horizontal direction, just like the image in 4578a vertical mirror. </p> 4579 4580 4581<div style="margin: auto;"> 4582 <h3 class="magick-header"><a id="font"></a>-font <var>name</var></h3> 4583</div> 4584 4585<p class="magick-description">set the font to use when annotating images with text, or creating labels.</p> 4586 4587<p>To print a complete list of fonts, use the <a href="command-line-options.html#list">-list font</a> 4588option (for versions prior to 6.3.6, use 'type' instead of 'font').</p> 4589 4590<p>In addition to the fonts specified by the above pre-defined list, you can 4591also specify a font from a specific source. For example <code>Arial.ttf</code> 4592is a TrueType font file, <code>ps:helvetica</code> is PostScript font, and 4593<code>x:fixed</code> is X11 font.</p> 4594 4595<p>For other settings that affect fonts, see the options <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p> 4596 4597 4598<div style="margin: auto;"> 4599 <h3 class="magick-header"><a id="foreground"></a>-foreground <var>color</var></h3> 4600</div> 4601 4602<p class="magick-description">Define the foreground color for menus.", "display</p> 4603 4604<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 4605 4606<p>The default foreground color is black.</p> 4607 4608<div style="margin: auto;"> 4609 <h3 class="magick-header"><a id="format"></a>-format <var>type</var></h3> 4610</div> 4611 4612<p class="magick-description">the image format type.</p> 4613 4614<p>When used with the <code>mogrify</code> utility, this option converts any 4615image to the image <a href="formats.html">format</a> you specify. 4616For a list of image format types supported by ImageMagick, use <a href="command-line-options.html#list">-list format</a>.</p> 4617 4618<p>By default the file is written to its original name. However, if the 4619filename extension matches a supported format, the extension is replaced with 4620the image format type specified with <a href="command-line-options.html#format">-format</a>. For 4621example, if you specify <var>tiff</var> as the format type and the 4622input image filename is <var>image.gif</var>, the output image 4623filename becomes <var>image.tiff</var>.</p> 4624 4625<div style="margin: auto;"> 4626 <h3 class="magick-header"><a id="format_identify_"></a>-format <var>string</var></h3> 4627</div> 4628 4629<p class="magick-description">output formatted image characteristics.</p> 4630 4631<p>See <a href="escape.html">Format and Print Image 4632Properties</a> for an explanation on how to specify the argument to this 4633option.</p> 4634 4635<div style="margin: auto;"> 4636 <h3 class="magick-header"><a id="frame"></a>-frame <var>geometry</var></h3> 4637</div> 4638 4639<p class="magick-description">Surround the image with a border or beveled frame.</p> 4640 4641<p>The color of the border is specified with the <a href="command-line-options.html#mattecolor">-mattecolor</a> command line option. </p> 4642 4643<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>size</var> portion of the <var>geometry</var> argument indicates the amount of extra width and 4644height that is added to the dimensions of the image. If no offsets are given 4645in the <var>geometry</var> argument, then the border added is 4646a solid color. Offsets <var>x</var> and <var>y</var>, if present, specify that 4647the width and height of the border is partitioned to form an outer bevel of 4648thickness <var>x</var> pixels and an inner bevel of thickness 4649<var>y</var> pixels. Negative offsets make no sense as frame arguments. 4650</p> 4651 4652<p>The <a href="command-line-options.html#frame">-frame</a> option is affected by the current <a href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default 4653'<code>Over</code>' composition method. It generates an image of the appropriate 4654size with the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting, and then 4655draws the frame of four distinct colors close to the current <a href="command-line-options.html#mattecolor">-mattecolor</a>. The original image is then overlaid onto 4656center of this image. This means that with the default compose method of 4657'<code>Over</code>' any transparent parts may be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p> 4658 4659<p>The image composition is not 4660affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p> 4661 4662 4663<div style="margin: auto;"> 4664 <h3 class="magick-header"><a id="frame_import_"></a>-frame</h3> 4665</div> 4666 4667<p class="magick-description">include the X window frame in the imported image. </p> 4668<div style="margin: auto;"> 4669 <h3 class="magick-header"><a id="function"></a>-function <var>function</var> <var>parameters</var></h3> 4670</div> 4671 4672<p class="magick-description">Apply a function to channel values.</p> 4673 4674<p>This operator performs calculations based on the given arguments to modify 4675each of the color values for each previously set <a href="command-line-options.html#channel">-channel</a> in the image. See <a href="command-line-options.html#evaluate">-evaluate</a> for details concerning how the results of the 4676calculations are handled.</p> 4677 4678<p>This is can be considered a multi-argument version of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. (Added in 4679ImageMagick 6.4.8−8.)</p> 4680 4681<p>Here, <var>parameters</var> is a comma-separated list of 4682numerical values. The number of values varies depending on which <var>function</var> is selected. Choose the <var>function</var> from:</p> 4683 4684<pre> 4685Polynomial 4686Sinusoid 4687Arcsin 4688Arctan 4689</pre> 4690 4691<p>To print a complete list of <a href="command-line-options.html#function">-function</a> operators, 4692use <a href="command-line-options.html#list">-list function</a>. Descriptions follow.</p> 4693 4694<dl class="dl-horizontal"> 4695 <dt>Polynomial</dt> 4696 <dd><p>The <code>Polynomial</code> function takes an arbitrary number of parameters, 4697these being the coefficients of a polynomial, in decreasing order of degree. 4698That is, entering</p> 4699 4700<pre> 4701-function Polynomial <var>a</var><sub><var>n</var></sub>,<var>a</var><sub><var>n</var>-1</sub>,...<var>a</var><sub>1</sub>,<var>a</var><sub>0</sub> 4702</pre> 4703 4704<p>will invoke a polynomial function given by</p> 4705 4706<pre> 4707<var>a</var><sub><var>n</var></sub> <b><var>u</var></b><sup><var>n</var></sup> + <var>a</var><sub><var>n</var>-1</sub> <b><var>u</var></b><sup><var>n</var>-1</sup> + ··· <var>a</var><sub>1</sub> <b><var>u</var></b> + <var>a</var><sub>0</sub>, 4708</pre> 4709 4710<p>where <b><var>u</var></b> is pixel's original normalized channel value.</p> 4711 4712<p>The <code>Polynomial</code> function can be used in place of <code>Set</code> 4713(the <var>constant</var> polynomial) and <code>Add</code>, <code>Divide</code>, 4714<code>Multiply</code>, and <code>Subtract</code> (some <var>linear</var> 4715polynomials) of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. The <a href="command-line-options.html#level">-level</a> operator also affects channels linearly. Some 4716correspondences follow.</p> 4717 4718<table class="table table-condensed table-striped"> 4719 <tr> 4720 <td>-evaluate Set <var>value</var> </td> 4721 <td>-function Polynomial <var>value</var></td> 4722 <td>(Constant functions; set <var>value</var>×100% gray when channels are RGB.)</td> 4723 </tr> 4724 <tr> 4725 <td>-evaluate Add <var>value</var> </td> 4726 <td>-function Polynomial 1,<var>value</var></td> 4727 </tr> 4728 <tr> 4729 <td>-evaluate Subtract <var>value</var> </td> 4730 <td>-function Polynomial 1,−<var>value</var></td> 4731 </tr> 4732 <tr> 4733 <td>-evaluate Multiply <var>value</var> </td> 4734 <td>-function Polynomial <var>value</var>,0</td> 4735 </tr> 4736 <tr> 4737 <td>+level black% x white%</td> 4738 <td>-function Polynomial A,B</td> 4739 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td> 4740 </tr> 4741</table> 4742 4743<p>The <code>Polynomial</code> function gives great versatility, since 4744polynomials can be used to fit any continuous curve to any degree of accuracy 4745desired.</p> 4746 4747</dd> 4748<dt>Sinusoid</dt> 4749<dd> 4750<p>The <code>Sinusoid</code> function can be used to vary the channel values 4751sinusoidally by setting frequency, phase shift, amplitude, and a bias. These 4752values are given as one to four parameters, as follows,</p> 4753 4754<pre> 4755-function <code>Sinusoid</code> <var>freq</var>,[<var>phase</var>,[<var>amp</var>,[<var>bias</var>]]] 4756</pre> 4757 4758<p>where <var>phase</var> is in degrees. (The domain [0,1] of the function 4759corresponds to 0 through <var>freq</var>×360 degrees.) 4760The result is that if a pixel's normalized channel value is originally 4761<b><var>u</var></b>, its resulting normalized value is given by </p> 4762 4763<pre> 4764<var>amp</var> * sin(2*π* (<var>freq</var> * <b><var>u</var></b> + <var>phase</var> / 360)) + <var>bias</var> 4765</pre> 4766 4767<p> For example, the following generates a curve that starts and ends at 0.9 4768(when <b><var>u</var></b>=0 and 1, resp.), oscillating three times between 4769.7−.2=.5 and .7+.2=.9. </p> 4770 4771<pre> 4772-function Sinusoid 3,-90,.2,.7 4773</pre> 4774 4775<p>The default values of <var>amp</var> and <var>bias</var> are both .5. The default for <var>phase</var> 4776is 0.</p> 4777 4778<p>The <code>Sinusoid</code> function generalizes <code>Sin</code> and 4779<code>Cos</code> of the <a href="command-line-options.html#evaluate">-evaluate</a> operator by allowing 4780varying amplitude, phase and bias. The correspondence is as follows.</p> 4781 4782<table class="table table-condensed table-striped"> 4783 <tr> 4784 <td>-evaluate Sin <var>freq</var> </td> 4785 <td>-function Sinusoid <var>freq</var>,0 </td> 4786 </tr> 4787 <tr> 4788 <td>-evaluate Cos <var>freq</var> </td> 4789 <td>-function Sinusoid <var>freq</var>,90 </td> 4790 </tr> 4791</table> 4792 </dd> 4793<dt>ArcSin</dt> 4794<dd> 4795<p>The <code>ArcSin</code> function generates the inverse curve of a Sinusoid, 4796and can be used to generate cylindrical distortion and displacement maps. 4797The curve can be adjusted relative to both the input values and output range 4798of values.</p> 4799 4800<pre> 4801-function <code>ArcSin</code> <var>width</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]] 4802</pre> 4803 4804<p>with all values given in terms of normalized color values (0.0 for black, 48051.0 for white). Defaulting to values covering the full range from 0.0 to 1.0 4806for bout input (<var>width</var>), and output (<var>width</var>) values. '<code>1.0,0.5,1.0,0.5</code>' </p> 4807 4808<pre> 4809<var>range</var>/π * asin( 2/<var>width</var> * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var> 4810</pre> 4811 4812</dd> 4813<dt>ArcTan</dt> 4814<dd> 4815<p>The <code>ArcTan</code> function generates a curve that smooth crosses from 4816limit values at infinities, though a center using the given slope value. 4817All these values can be adjusted via the arguments.</p> 4818 4819<pre> 4820-function <code>ArcTan</code> <var>slope</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]] 4821</pre> 4822 4823<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'. 4824</p> 4825 4826<pre> 4827<var>range</var>/π * atan( <var>slope</var>*π * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var> 4828</pre> 4829 </dd> 4830 4831</dl> 4832 4833 4834 4835<div style="margin: auto;"> 4836 <h3 class="magick-header"><a id="fuzz"></a>-fuzz <var>distance</var>{<var>%</var>}</h3> 4837</div> 4838 4839<p class="magick-description">Colors within this <var>distance</var> are considered equal.</p> 4840 4841<p>A number of algorithms search for a target color. By default the color must 4842be exact. Use this option to match colors that are close to the target color 4843in RGB space. For example, if you want to automagically trim the edges of an 4844image with <a href="command-line-options.html#trim">-trim</a> but the image was scanned and the target 4845background color may differ by a small amount. This option can account for 4846these differences.</p> 4847 4848<p>The <var>distance</var> can be in absolute intensity units or, by 4849appending <code>%</code> as a percentage of the maximum possible intensity (255, 485065535, or 4294967295).</p> 4851 4852<p>Use <a href="command-line-options.html#fuzz">+fuzz</a> to reset the fuzz value to 0.</p> 4853 4854 4855<div style="margin: auto;"> 4856 <h3 class="magick-header"><a id="fx"></a>-fx <var>expression</var></h3> 4857</div> 4858 4859<p class="magick-description">apply a mathematical expression to an image or image channels.</p> 4860 4861<p>If the first character of <var>expression</var> is <code>@</code>, 4862the expression is read from a file titled by the remaining characters in the 4863string.</p> 4864 4865<p>See <a href="fx.html">FX, 4866The Special Effects Image Operator</a> for a detailed discussion of this 4867option.</p> 4868 4869 4870<div style="margin: auto;"> 4871 <h3 class="magick-header"><a id="gamma"></a>-gamma <var>value</var></h3> 4872</div> 4873 4874<p class="magick-description">level of gamma correction.</p> 4875 4876<p>The same color image displayed on two different workstations may look 4877different due to differences in the display monitor. Use gamma correction to 4878adjust for this color difference. Reasonable values extend from 4879<code>0.8</code> to <code>2.3</code>. Gamma less than 1.0 darkens the image and 4880gamma greater than 1.0 lightens it. Large adjustments to image gamma may 4881result in the loss of some image information if the pixel quantum size is only 4882eight bits (quantum range 0 to 255).</p> 4883 4884<p>Gamma adjusts the image's channel values pixel-by-pixel according to 4885a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the 4886normalized or 0 to 1 color value. For example, using a value of gamma=2 is the 4887same as taking the square root of the image.</p> 4888 4889<p>You can apply separate gamma values to the red, green, and blue channels of 4890the image with a gamma value list delimited with commas (e.g., 4891<code>1.7,2.3,1.2</code>).</p> 4892 4893<p>Use <a href="command-line-options.html#gamma">+gamma <var>value</var></a> to set the 4894image gamma level without actually adjusting the image pixels. This option 4895is useful if the image is of a known gamma but not set as an image attribute 4896(e.g. PNG images). Write the "file gamma" which is the reciprocal of the 4897display gamma; e.g., if your image is sRGB and you want to write a PNG gAMA 4898chunk, use</p> 4899 4900<pre> 4901convert input.png +gamma .45455 output.png 4902</pre> 4903 4904<p>(0.45455 is 1/2.2)</p> 4905 4906<p>Note that gamma adjustments are also available via the <a href="command-line-options.html#level">-level</a> operator.</p> 4907 4908<div style="margin: auto;"> 4909 <h3 class="magick-header"><a id="gaussian-blur"></a>-gaussian-blur <var>radius</var><br>-gaussian-blur <var>radius</var>x<var>sigma</var></h3> 4910</div> 4911 4912<p class="magick-description">Blur the image with a Gaussian operator.</p> 4913 4914<p>Convolve the image with a Gaussian or normal distribution using the given 4915<var>Sigma</var> value. The formula is:</p> 4916 4917<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"> 4918</div> 4919 4920<p>The <var>Sigma</var> value is the important argument, and 4921determines the actual amount of blurring that will take place. </p> 4922 4923<p>The <var>Radius</var> is only used to determine the size of the 4924array which will hold the calculated Gaussian distribution. It should be an 4925integer. If not given, or set to zero, IM will calculate the largest possible 4926radius that will provide meaningful results for the Gaussian distribution. 4927</p> 4928 4929<p>The larger the <var>Radius</var> the radius the slower the 4930operation is. However too small a <var>Radius</var>, and sever 4931aliasing effects may result. As a guideline, <var>Radius</var> 4932should be at least twice the <var>Sigma</var> value, though three 4933times will produce a more accurate result. </p> 4934 4935<p>This differs from the faster <a href="command-line-options.html#blur">-blur</a> operator in that a 4936full 2-dimensional convolution is used to generate the weighted average of the 4937neighboring pixels. </p> 4938 4939<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how 4940pixels which are outside the image proper are blurred into the final result. 4941</p> 4942 4943 4944<div style="margin: auto;"> 4945 <h3 class="magick-header"><a id="geometry"></a>-geometry <var>geometry</var></h3> 4946</div> 4947 4948<p class="magick-description">Set the preferred size and location of the image.</p> 4949 4950<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4951 4952<div style="margin: auto;"> 4953 <h3 class="magick-header"><a id="gravity"></a>-gravity <var>type</var></h3> 4954</div> 4955 4956<p class="magick-description">Sets the current gravity suggestion for various other settings and options.</p> 4957 4958<p>Choices include: <code>NorthWest</code>, <code>North</code>, 4959<code>NorthEast</code>, <code>West</code>, <code>Center</code>, <code>East</code>, 4960<code>SouthWest</code>, <code>South</code>, <code>SouthEast</code>. Use <a href="command-line-options.html#list">-list gravity</a> to get a complete list of <a href="command-line-options.html#gravity">-gravity</a> settings available in your ImageMagick 4961installation.</p> 4962 4963<p>The direction you choose specifies where to position text or subimages. For 4964example, a gravity of <code>Center</code> forces the text to be centered within 4965the image. By default, the image gravity is <code>NorthWest</code>. See <a href="command-line-options.html#draw">-draw</a> for more details about graphic primitives. Only the 4966text primitive of <a href="command-line-options.html#draw">-draw</a> is affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p> 4967 4968<p>The <a href="command-line-options.html#gravity">-gravity</a> option is also used in concert with the 4969<a href="command-line-options.html#geometry">-geometry</a> setting and other settings or options that 4970take <var>geometry</var> as an argument, such as the <a href="command-line-options.html#crop">-crop</a> option. </p> 4971 4972<p>If a <a href="command-line-options.html#gravity">-gravity</a> setting occurs before another option 4973or setting having a <var>geometry</var> argument that specifies an 4974offset, the offset is usually applied to the point within the image suggested 4975by the <a href="command-line-options.html#gravity">-gravity</a> argument. Thus, in the following 4976command, for example, suppose the file <code>image.png</code> has dimensions 4977200x100. The offset specified by the argument to <a href="command-line-options.html#region">-region</a> 4978is (−40,+20). The argument to <a href="command-line-options.html#gravity">-gravity</a> is 4979<code>Center</code>, which suggests the midpoint of the image, at the point 4980(100,50). The offset (−40,20) is applied to that point, giving 4981(100−40,50+20)=(60,70), so the specified 10x10 region is located at 4982that point. (In addition, the <a href="command-line-options.html#gravity">-gravity</a> affects the 4983region itself, which is <var>centered</var> at the pixel 4984coordinate (60,70). (See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.)</p> 4985 4986<pre> 4987convert image.png -gravity Center -region 10x10-40+20 \ 4988 -negate output.png 4989</pre> 4990 4991<p>When used as an option to <a href="composite.html">composite</a>, <a href="command-line-options.html#gravity">-gravity</a> gives the direction that the image gravitates 4992within the composite.</p> 4993 4994<p>When used as an option to <a href="montage.html">montage</a>, <a href="command-line-options.html#gravity">-gravity</a> gives the direction that an image gravitates 4995within a tile. The default gravity is <code>Center</code> for this purpose.</p> 4996 4997 4998<div style="margin: auto;"> 4999 <h3 class="magick-header"><a id="grayscale"></a>-grayscale <var>method</var></h3> 5000</div> 5001 5002<p class="magick-description">convert image to grayscale.</p> 5003 5004<p>This will use one of the <a href="command-line-options.html#intensity">-intensity</a> methods to 5005convert the given image into a linear-grayscale image. </p> 5006 5007<p>For example, to convert an image to (linear) Rec709Luminance grayscale, type:</p> 5008 5009<pre> 5010convert in.png -grayscale Rec709Luminance out.png 5011</pre> 5012 5013<p>which is equivalent to:</p> 5014 5015<pre> 5016convert in.png -colorspace gray out.png 5017</pre> 5018 5019<p>Similarly, to convert an image to (non-linear) Rec709Luma grayscale, type:</p> 5020 5021<pre> 5022convert in.png -grayscale Rec709Luma out.png 5023</pre> 5024 5025<p>which is equivalent to:</p> 5026 5027<pre> 5028convert in.png -set colorspace RGB -colorspace gray out.png 5029</pre> 5030 5031<p>Note that a 'colorspace' intensity method will produce the same result 5032regardless of the current colorpsace of the image. But a 'mathematical' 5033intensity method will depend on the current colorspace the image is currently 5034using. </p> 5035 5036<p>While this operation uses an <a href="command-line-options.html#intensity">-intensity</a> method, 5037it does not use or set the <a href="command-line-options.html#intensity">-intensity</a> setting, so 5038will not effect other operations that may use that setting.</p> 5039 5040 5041<div style="margin: auto;"> 5042 <h3 class="magick-header"><a id="green-primary"></a>-green-primary <var>x,y</var></h3> 5043</div> 5044 5045<p class="magick-description">green chromaticity primary point.</p> 5046 5047 5048<div style="margin: auto;"> 5049 <h3 class="magick-header"><a id="hald-clut"></a>-hald-clut</h3> 5050</div> 5051 5052<p class="magick-description">apply a Hald color lookup table to the image.</p> 5053 5054<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2 5055dimensions. Create it with the <code>HALD:</code> prefix (e.g. HALD:8). You 5056can apply any color transformation to the Hald image and then use this option 5057to apply the transform to the image. </p> 5058 5059<pre> 5060convert image.png hald.png -hald-clut transform.png 5061</pre> 5062 5063<p>This option provides a convenient method for you to use Gimp or Photoshop 5064to make color corrections to the Hald CLUT image and subsequently apply them 5065to multiple images using an ImageMagick script. </p> 5066 5067<p>Note that the representation is only of the normal RGB color space and that 5068the whole color value triplet is used for the interpolated lookup of the 5069represented Hald color cube image. Because of this the operation is not <a href="command-line-options.html#channel">-channel</a> setting effected, nor can it adjust or modify an 5070images transparency or alpha/matte channel.</p> 5071 5072<p>See also <a href="command-line-options.html#clut">-clut</a> which provides color value replacement 5073of the individual color channels, usually involving a simpler gray-scale 5074image. E.g: gray-scale to color replacement, or modification by a histogram 5075mapping. </p> 5076 5077 5078<div style="margin: auto;"> 5079 <h3 class="magick-header"><a id="help"></a>-help</h3> 5080</div> 5081 5082<p class="magick-description">print usage instructions.</p> 5083 5084<div style="margin: auto;"> 5085 <h3 class="magick-header"><a id="highlight-color"></a>-highlight-color <var>color</var></h3> 5086</div> 5087 5088<p class="magick-description">when comparing images, emphasize pixel differences with this color.</p> 5089 5090<div style="margin: auto;"> 5091 <h3 class="magick-header"><a id="hough-lines"></a>-hough-lines <var>width</var>x<var>height</var>{<var>+threshold</var>}</h3> 5092</div> 5093 5094<p class="magick-description">identify straight lines in the image (e.g. -hough-lines 9x9+195).</p> 5095 5096<p>Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds.</p> 5097 5098<p>The process accumulates counts for every white pixel in the binary edge image for every possible orientation (for angles from 0 to 179 in 1 deg increments) and distance from the center of the image to the corners (in 1 px increments). It stores the counts in an accumulator matrix of angle vs distance. The size of the accumulator will be 180x(diagonal/2). Next it searches the accumulator for peaks in counts and converts the locations of the peaks to slope and intercept in the normal x,y input image space. The algorithm uses slope/intercepts to find the endpoints clipped to the bounds of the image. The lines are drawn from the given endpoints. The counts are a measure of the length of the lines.</p>. 5099 5100<p>The WxH arguments specify the filter size for locating the peaks in the Hough accumulator. The threshold excludes lines whose counts are less than the threshold value.</p> 5101 5102<p>Use <code><a href="command-line-options.html#background">-background</a></code> to specify the color of the background onto which the lines will be drawn. The default is black.</p> 5103 5104<p>Use <code><a href="command-line-options.html#fill">-fill</a></code> to specify the color of the lines. The default is black.</p> 5105 5106<p>Use <code><a href="command-line-options.html#stroke">-stroke</a></code> and <code><a href="command-line-options.html#strokewidth">-strokewidth</a></code> to specify the thickness of the lines. The default is black and no strokewidth.</p> 5107 5108<p>A text file listing the endpoints and counts may be created by using the suffix, .mvg, for the output image.</p> 5109 5110<p>Use <code><a href="command-line-options.html#define">-define</a> hough-lines:accumulator=true</code> to return the accumulator image in addition to the lines image.</p> 5111 5112<div style="margin: auto;"> 5113 <h3 class="magick-header"><a id="iconGeometry"></a>-iconGeometry <var>geometry</var></h3> 5114</div> 5115 5116<p class="magick-description">specify the icon geometry.</p> 5117 5118<p>Offsets, if present in the geometry specification, are handled in the same 5119manner as the <a href="command-line-options.html#geometry">-geometry</a> option, using X11 style to 5120handle negative offsets.</p> 5121 5122<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5123 5124<div style="margin: auto;"> 5125 <h3 class="magick-header"><a id="iconic"></a>-iconic</h3> 5126</div> 5127 5128<p class="magick-description">start in icon mode in X Windows", 'animate', 'display</p> 5129 5130<div style="margin: auto;"> 5131 <h3 class="magick-header"><a id="identify"></a>-identify</h3> 5132</div> 5133 5134<p class="magick-description">identify the format and characteristics of the image.</p> 5135 5136<p>This information is printed: image scene number; image name; image size; 5137the image class (<var>DirectClass</var> or <var>PseudoClass</var>); the total number of unique colors; and the 5138number of seconds to read and transform the image. Refer to <a href="miff.html">MIFF</a> for 5139a description of the image class.</p> 5140 5141<p>If <a href="command-line-options.html#colors">-colors</a> is also specified, the total unique colors 5142in the image and color reduction error values are printed. Refer to <a href="quantize.html">color 5143reduction algorithm</a> for a description of these values.</p> 5144 5145<p>If <a href="command-line-options.html#verbose">-verbose</a> precedes this option, copious 5146amounts of image properties are displayed including image statistics, profiles, 5147image histogram, and others.</p> 5148 5149<div style="margin: auto;"> 5150 <h3 class="magick-header"><a id="ift"></a>-ift</h3> 5151</div> 5152 5153<p class="magick-description">implements the inverse discrete Fourier transform (DFT).</p> 5154 5155<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows 5156users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase 5157images from the frequency domain to a single image in the normal or spatial 5158domain. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>, 5159<a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and 5160<a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p> 5161 5162<p>For example, depending upon the image format used to store the result of 5163the <a href="command-line-options.html#fft">-fft</a>, one would use either</p> 5164 5165<pre> 5166convert fft_image.miff -ift fft_image_ift.png 5167</pre> 5168 5169<p>or</p> 5170 5171<pre> 5172convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png 5173</pre> 5174 5175<p>The resulting image may need to be cropped due to padding introduced when 5176the original image, prior to the <a href="command-line-options.html#fft">-fft</a> or <a href="command-line-options.html#fft">+fft</a>, was not square or even dimensioned. Any padding is at 5177the right and/or bottom sides of the image.</p> 5178 5179<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to 5180use <a href="command-line-options.html#ift">-ift</a>.</p> 5181 5182<p>Use <a href="command-line-options.html#ift">+ift</a> (with HDRI enabled) to transform a pair of real 5183and imaginary images from the frequency domain to a single image in the normal 5184(spatial) domain.</p> 5185 5186<p>By default the IFT is not normalized (and the FFT is). Use "<code><a href="command-line-options.html#define">-define</a> fourier:normalize=inverse</code> to explictly normalize the IFT and unnormalize the FFT.</p> 5187 5188<div style="margin: auto;"> 5189 <h3 class="magick-header"><a id="immutable"></a>-immutable</h3> 5190</div> 5191 5192<p class="magick-description">make image immutable.</p> 5193 5194<div style="margin: auto;"> 5195 <h3 class="magick-header"><a id="implode"></a>-implode <var>factor</var></h3> 5196</div> 5197 5198<p class="magick-description">implode image pixels about the center.</p> 5199 5200<div style="margin: auto;"> 5201 <h3 class="magick-header"><a id="insert"></a>-insert <var>index</var></h3> 5202</div> 5203 5204<p class="magick-description">insert the last image into the image sequence.</p> 5205 5206<p>This option takes last image in the current image sequence and inserts it 5207at the given index. If a negative index is used, the insert position is 5208calculated before the last image is removed from the sequence. As such 5209<code>-insert -1</code> will result in no change to the image sequence.</p> 5210 5211<p>The <code>+insert</code> option is equivalent to <code>-insert -1</code>. In 5212other words, insert the last image, at the end of the current image sequence. 5213Consequently this has no effect on the image sequence order.</p> 5214 5215<div style="margin: auto;"> 5216 <h3 class="magick-header"><a id="intensity"></a>-intensity <var>method</var></h3> 5217</div> 5218 5219<p class="magick-description">method to generate intensity value from pixel.</p> 5220 5221<p>ImageMagick provides a number of methods used in situations where an 5222operatory needs to determine a single grayscale value for some purpose, from 5223an image with red, green, and blue pixel components. Typically the linear 5224<code>Rec709Luminance</code> formula is used, which is the same formula used when 5225converting images to <code>-colorspace gray</code>. </p> 5226 5227<p>The following formulas are currently provided, and will first convert 5228the pixel values to linear-RGB or non-linear sRGB colorspace before 5229being applied to calulate the final greyscale value. </p> 5230 5231<pre> 5232 Rec601Luma 0.298839R' + 0.586811G'+ 0.114350B' 5233 Rec601Luminance 0.298839R + 0.586811G + 0.114350B 5234 Rec709Luma 0.212656R' + 0.715158G' + 0.072186B' 5235 Rec709Luminance 0.212656R + 0.715158G + 0.072186B 5236 Brightness max(R', G', B') 5237 Lightness (min(R', G', B') + max(R', G', B')) / 2.0 5238</pre> 5239<p>Note that the above R,G,B values is the image's linear-RGB values, while 5240R',G',B' are sRGB non-linear values. </p> 5241 5242<p>These intensity methods are mathematical in nature and will use the 5243current value in the images respective R,G,B channel regardless of 5244what that is, or what colorspace the image is currently using.</p> 5245 5246<pre> 5247 Average (R + G + B) / 3.0 5248 MS (R^2 + G^2 + B^2) / 3.0 5249 RMS sqrt( (R^2 + G^2 + B^2) / 3.0 ) 5250</pre> 5251 5252<p>These methods are often used for other purposes, such as generating a 5253grayscale difference image between two color images (using <a href="command-line-options.html#compose">-compose</a> '<code>Difference</code>' composition. </p> 5254 5255<p> For example The 'MS' (Mean Squared) setting is good for minimizing color 5256error comparisions. While... The method 'RMS' (Root Mean Squared) for 5257example is appropriate for calculating color vector distance, from a color 5258difference image. This is equivalent to the color only component of the <a href="command-line-options.html#fuzz">-fuzz</a> factor color compare setting. </p> 5259 5260<p>See also <a href="command-line-options.html#grayscale">-grayscale</a> which applies one of the above 5261grayscaling formula directly to an image without setting the <a href="command-line-options.html#intensity">-intensity</a> setting.</p> 5262 5263<p>The <a href="command-line-options.html#colorspace">-colorspace gray</a> image conversion also uses 5264the current intensity setting, but will always convert the image to the 5265appropriate sRGB or linear-RGB colorspace before appling the above 5266function.</p> 5267 5268<p>To print a complete list of posible pixel intensity setting methods, use <a href="command-line-options.html#list">-list intensity</a>.</p> 5269 5270<p>Operators affected by the <a href="command-line-options.html#intensity">-intensity</a> setting include:</p> 5271 5272<pre> 5273-adaptive-blur 5274-adaptive-sharpen 5275-black-threshold 5276-clut (when mapping greyscale CLUT image to alpha channel if set by -channels) 5277-colors for gray colorspace 5278-compose {LightenIntensity, DarkenIntensity, CopyOpacity, CopyBlack} 5279-contrast-stretch 5280-distort {ErodeIntensity, DilateIntensity} 5281-normalize 5282-random-threshold 5283-selective-blur 5284-shade 5285-threshold 5286-tint 5287-white-threshold 5288</pre> 5289 5290<div style="margin: auto;"> 5291 <h3 class="magick-header"><a id="intent"></a>-intent <var>type</var></h3> 5292</div> 5293 5294<p class="magick-description">use this type of rendering intent when managing the image color.</p> 5295 5296<p>Use this option to affect the color management operation of an image (see 5297<a href="command-line-options.html#profile">-profile</a>). Choose from these intents: <code>Absolute, 5298Perceptual, Relative, Saturation</code>.</p> 5299 5300<p>The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces.</p> 5301 5302<p>To print a complete list of rendering intents, use <a href="command-line-options.html#list">-list intent</a>.</p> 5303 5304<div style="margin: auto;"> 5305 <h3 class="magick-header"><a id="interlace"></a>-interlace <var>type</var></h3> 5306</div> 5307 5308<p class="magick-description">the type of interlacing scheme.</p> 5309 5310<p>Choose from:</p> 5311 5312<pre> 5313 none 5314 line 5315 plane 5316 partition 5317 JPEG 5318 GIF 5319 PNG 5320</pre> 5321 5322<p>This option is used to specify the type of interlacing scheme for raw image 5323formats such as <code>RGB</code> or <code>YUV</code>.</p> 5324 5325<p><code>None</code> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p> 5326 5327<p><code>Line</code> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p> 5328 5329<p><code>Plane</code> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p> 5330 5331<p><code>Partition</code> is like plane except the different planes are saved to 5332individual files (e.g. image.R, image.G, and image.B).</p> 5333 5334<p>Use <code>Line</code> or <code>Plane</code> to create an <code>interlaced 5335PNG</code> or <code>GIF</code> or <code>progressive JPEG</code> image.</p> 5336 5337<p>To print a complete list of interlacing schemes, use <a href="command-line-options.html#list">-list 5338interlace</a>.</p> 5339 5340<div style="margin: auto;"> 5341 <h3 class="magick-header"><a id="interpolate"></a>-interpolate <var>type</var></h3> 5342</div> 5343 5344<p class="magick-description">Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.</p> 5345 5346<p>When looking up the color of a pixel using a non-integer floating point 5347value, you typically fall in between the pixel colors defined by the source 5348image. This setting determines how the color is determined from the colors of 5349the pixels surrounding that point. That is how to determine the color of a 5350point that falls between two, or even four different colored pixels. </p> 5351 5352<dl class="dl-horizontal"> 5353 <dt>integer</dt> 5354 <dd>The color of the top-left pixel (floor function)</dd> 5355 <dt>nearest-neighbor</dt> 5356 <dd>The nearest pixel to the lookup point (rounded function)</dd> 5357 <dt>average</dt> 5358 <dd>The average color of the surrounding four pixels</dd> 5359 <dt>bilinear</dt> 5360 <dd>A double linear interpolation of pixels (the default)</dd> 5361 <dt>mesh</dt> 5362 <dd>Divide area into two flat triangular interpolations</dd> 5363 <dt>bicubic</dt> 5364 <dd>Fitted bicubic-spines of surrounding 16 pixels</dd> 5365 <dt>spline</dt> 5366 <dd>Direct spline curves (colors are blurred)</dd> 5367 <dt>filter</dt> 5368 <dd>Use resize <a href="command-line-options.html#filter">-filter</a> settings</dd> 5369</dl> 5370 5371<p>This most important for distortion operators such as <a href="command-line-options.html#distort">-distort</a>, <a href="command-line-options.html#implode">-implode</a>, <a href="command-line-options.html#transform">-transform</a> and <a href="command-line-options.html#fx">-fx</a>. </p> 5372 5373<p>To print a complete list of interpolation methods, use <a href="command-line-options.html#list">-list interpolate</a>.</p> 5374 5375<p>See also <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a>, for control of the 5376lookup for positions outside the boundaries of the image. </p> 5377 5378 5379<div style="margin: auto;"> 5380 <h3 class="magick-header"><a id="interline-spacing"></a>-interline-spacing <var>value</var></h3> 5381</div> 5382 5383<p class="magick-description">the space between two text lines.</p> 5384 5385<div style="margin: auto;"> 5386 <h3 class="magick-header"><a id="interword-spacing"></a>-interword-spacing <var>value</var></h3> 5387</div> 5388 5389<p class="magick-description">the space between two words.</p> 5390 5391<div style="margin: auto;"> 5392 <h3 class="magick-header"><a id="kerning"></a>-kerning <var>value</var></h3> 5393</div> 5394 5395<p class="magick-description">the space between two letters.</p> 5396 5397<div style="margin: auto;"> 5398 <h3 class="magick-header"><a id="kuwahara"></a>-kuwahara <var>radius</var><br>-kuwahara <var>radius</var>x<var>sigma</var></h3> 5399</div> 5400 5401<p class="magick-description">edge preserving noise reduction filter.</p> 5402 5403<p>The <var>radius</var> is more important than the <var>sigma</var>. If <var>sigma</var> is left off, it will be computed automatically from the <var>radius</var> as <var>sigma</var>=<var>radius</var>-0.5. The <var>sigma</var> provides a bit of additional smoothing control.</p> 5404 5405 5406<div style="margin: auto;"> 5407 <h3 class="magick-header"><a id="label"></a>-label <var>name</var></h3> 5408</div> 5409 5410<p class="magick-description">assign a label to an image.</p> 5411 5412<p>Use this option to assign a specific label to the image, as it is read in 5413or created. You can use the <a href="command-line-options.html#set">-set</a> operation to re-assign 5414a the labels of images already read in. Image formats such as TIFF, PNG, 5415MIFF, supports saving the label information with the image.</p> 5416 5417<p>When saving an image to a <var>PostScript</var> file, any label 5418assigned to an image is used as a header string to print above the postscript 5419image. </p> 5420 5421<p>You can include the image filename, type, width, height, or other image 5422attribute by embedding special format character. See <a href="escape.html">Format and Print Image 5423Properties</a> for details of the percent escape codes.</p> 5424 5425<p>For example,</p> 5426 5427<pre> 5428-label "%m:%f %wx%h" bird.miff 5429</pre> 5430 5431<p>assigns an image label of <code>MIFF:bird.miff 512x480</code> to the 5432"<code>bird.miff</code>" image and whose width is 512 and height is 480, as it 5433is read in. If a <a href="command-line-options.html#label">+label</a> option was used instead, any 5434existing label present in the image would be used. You can remove all labels 5435from an image by assigning the empty string. </p> 5436 5437<p>A label is not drawn on the image, but is embedded in the image datastream 5438via <var>Label</var> tag or similar mechanism. If you want the label to be 5439visible on the image itself, use the <a href="command-line-options.html#draw">-draw</a> option, or 5440during the final processing in the creation of an image montage.</p> 5441 5442<p>If the first character of <var>string</var> is <var>@</var>, the image label is read from a file titled by the 5443remaining characters in the string. Labels in a file are literal, no embedded 5444formatting characters are recognized.</p> 5445 5446 5447<div style="margin: auto;"> 5448 <h3 class="magick-header"><a id="lat"></a>-lat <var>width</var><br>-lat <var>width</var>x<var>height</var>{<var>+-</var>}<var>offset</var>{<var>%</var>}</h3> 5449</div> 5450 5451<p class="magick-description">perform local adaptive threshold.</p> 5452 5453<p>Adaptively threshold each pixel based on the value of pixels in a 5454surrounding window. If the current pixel is lighter than this average plus 5455the optional <code>offset</code>, then it is made white, otherwise it is made 5456black. Small variations in pixel values such as found in scanned documents 5457can be ignored if offset is positive. A negative offset will make it more 5458sensitive to those small variations. </p> 5459 5460<p>This is commonly used to threshold images with an uneven background. It is 5461based on the assumption that average color of the small window is the 5462the local background color, from which to separate the foreground color. </p> 5463 5464 5465<div style="margin: auto;"> 5466 <h3 class="magick-header"><a id="layers"></a>-layers <var>method</var></h3> 5467</div> 5468 5469<p class="magick-description">handle multiple images forming a set of image layers or animation frames.</p> 5470 5471<p>Perform various image operation methods to a ordered sequence of images 5472which may represent either a set of overlaid 'image layers', a GIF disposal 5473animation, or a fully-'coalesced' animation sequence. </p> 5474 5475<table class="table table-condensed table-striped"> 5476 <tbody> 5477 <tr> 5478 <th style="width: 8%">Method</th> 5479 <th>Description</th> 5480 </tr> 5481 5482 <tr> 5483 <td>compare-any</td> 5484 <td>Crop the second and later frames to the smallest rectangle 5485 that contains all the differences between the two images. No GIF <a href="command-line-options.html#dispose">-dispose</a> methods are taken into account. </td> 5486 </tr> 5487 5488 <tr><td></td><td>This exactly the same as the <a href="command-line-options.html#deconstruct">-deconstruct</a> operator, and does not preserve animations normal 5489 working, especially when animation used layer disposal methods such as 5490 '<code>Previous</code>' or '<code>Background</code>'. </td> 5491 </tr> 5492 5493 <tr> 5494 <td>compare-clear</td> 5495 <td>As '<code>compare-any</code>' but crop to the bounds of any 5496 opaque pixels which become transparent in the second frame. That is the 5497 smallest image needed to mask or erase pixels for the next frame. </td> 5498 </tr> 5499 5500 <tr> 5501 <td>compare-overlay</td> 5502 <td>As '<code>compare-any</code>' but crop to pixels that add 5503 extra color to the next image, as a result of overlaying color pixels. 5504 That is the smallest single overlaid image to add or change colors. </td> 5505 </tr> 5506 5507 <tr><td></td><td>This can be used with the <a href="command-line-options.html#compose">-compose</a> alpha 5508 composition method '<code>change-mask</code>', to reduce the image to 5509 just the pixels that need to be overlaid. </td> 5510 </tr> 5511 5512 <tr> 5513 <td>coalesce</td> 5514 <td>Equivalent to a call to the <a href="command-line-options.html#coalesce">-coalesce</a> operator. Apply the layer disposal methods set in the 5515 current image sequence to form a fully defined animation sequence, as 5516 it should be displayed. Effectively converting a GIF animation into a 5517 'film strip'-like animation. </td> 5518 </tr> 5519 5520 <tr> 5521 <td>composite</td> 5522 <td>Alpha Composition of two image lists, separated by a 5523 "<code>null:</code>" image, with the destination image list first, and 5524 the source images last. An image from each list are composited 5525 together until one list is finished. The separator image and source 5526 image lists are removed. </td> 5527 </tr> 5528 5529 5530 <tr><td></td> 5531 <td>The <a href="command-line-options.html#geometry">-geometry</a> offset is adjusted according 5532 to <a href="command-line-options.html#gravity">-gravity</a> in accordance of the virtual 5533 canvas size of the first image in each list. Unlike a normal <a href="command-line-options.html#composite">-composite</a> operation, the canvas offset is also 5534 added to the final composite positioning of each image. </td> </tr> 5535 5536 <tr><td></td> 5537 <td>If one of the image lists only contains one image, that image is 5538 applied to all the images in the other image list, regardless of which 5539 list it is. In this case it is the image meta-data of the list which 5540 preserved. </td> 5541 </tr> 5542 5543 5544 <tr> 5545 <td>dispose</td> 5546 <td>This like '<code>coalesce</code>' but shows the look of 5547 the animation after the layer disposal method has been applied, before 5548 the next sub-frame image is overlaid. That is the 'dispose' image that 5549 results from the application of the GIF <a href="command-line-options.html#dispose">-dispose</a> method. This allows you to check what 5550 is going wrong with a particular animation you may be developing. 5551 </td> 5552 </tr> 5553 5554 <tr> 5555 <td>flatten</td> 5556 <td>Create a canvas the size of the first images virtual 5557 canvas using the current <a href="command-line-options.html#background">-background</a> color, 5558 and <a href="command-line-options.html#compose">-compose</a> each image in turn onto that 5559 canvas. Images falling outside that canvas is clipped. Final 5560 image will have a zero virtual canvas offset. </td> 5561 </tr> 5562 5563 <tr><td></td> 5564 <td>This usually used as one of the final 'image layering' operations 5565 overlaying all the prepared image layers into a final image. </td> 5566 </tr> 5567 5568 <tr><td></td> 5569 <td>For a single image this method can also be used to fillout a virtual 5570 canvas with real pixels, or to underlay an opaque color to remove 5571 transparency from an image.</td> 5572 </tr> 5573 5574 5575 <tr> 5576 <td>merge</td> 5577 <td>As 'flatten' method but merging all the given image 5578 layers to create a new layer image just large enough to hold all the 5579 image without clipping or extra space. The new images virtual offset 5580 will preserve the position of the new layer, even if this offset is 5581 negative. The virtual canvas size of the first image is preserved. 5582 </td> 5583 </tr> 5584 5585 <tr><td></td><td>Caution is advised when handling image layers with 5586 negative offsets as few image file formats handle them correctly. 5587 Following this operation method with <a href="command-line-options.html#repage">+repage</a> 5588 will remove the layer offset, and create an image in which all the 5589 overlaid image positions relative to each other is preserved, though 5590 not necessarily exactly where you specified them. 5591 </td> 5592 </tr> 5593 5594 <tr><td></td><td>See also 'trim-bounds' below which is closely related but 5595 without doing the'flatten' to merge the images together. </td> 5596 </tr> 5597 5598 <tr> 5599 <td>mosaic</td> 5600 <td>As 'flatten' method but expanding the initial canvas size 5601 of the first image in a positive direction only so as to hold all the 5602 image layers. However as a virtual canvas is 'locked' to the origin, 5603 by its own definition, image layers with a negative offsets will still 5604 become clipped by the top and left edges. See 'merge' or 'trim-bounds' 5605 if this could be a problem. </td> 5606 5607 </tr> 5608 5609 <tr><td></td><td>This method is commonly used to layout individual image 5610 using various offset but without knowing the final canvas size. The 5611 resulting image will, like 'flatten' not have any virtual offset, so 5612 can be saved to any image file format. </td> 5613 </tr> 5614 5615 5616 <tr> 5617 <td>optimize</td> 5618 <td>Optimize a coalesced animation, into GIF animation using 5619 a number of general techniques. This currently a short cut to 5620 apply both the '<code>optimize-frame</code>', and 5621 '<code>optimize-transparency</code>' methods but may be expanded to 5622 include other optimization methods as they are developed. </td> 5623 </tr> 5624 5625 <tr> 5626 <td>optimize-frame</td> 5627 <td>Optimize a coalesced animation, into GIF animation by 5628 reducing the number of pixels per frame as much as possible by 5629 attempting to pick the best layer disposal method to use, while ensuring 5630 the result will continue to animate properly. </td> 5631 </tr> 5632 5633 <tr><td></td><td> There is no guarantee that the best optimization is found. 5634 But then no reasonably fast GIF optimization algorithm can do this. 5635 However this does seem to do better than most other GIF frame 5636 optimizers seen. </td> 5637 </tr> 5638 5639 <tr> 5640 <td>optimize-plus</td> 5641 <td>As '<code>optimize-frame</code>' but attempt to improve the 5642 overall optimization by adding extra frames to the animation, without 5643 changing the final look or timing of the animation. The frames are 5644 added to attempt to separate the clearing of pixels from the 5645 overlaying of new additional pixels from one animation frame to the 5646 next. If this does not improve the optimization (for the next frame 5647 only), it will fall back to the results of the previous normal 5648 '<code>optimize-frame</code>' technique. </td> 5649 </tr> 5650 5651 <tr><td></td><td>There is the possibility that the change in the disposal 5652 style will result in a worsening in the optimization of later frames, 5653 though this is unlikely. In other words there no guarantee that it is 5654 better than the normal '<code>optimize-frame</code>' technique. For some 5655 animations however you can get a vast improvement in the final 5656 animation size. </td> 5657 </tr> 5658 5659 <tr> 5660 <td>optimize-transparency</td> 5661 <td>Given a GIF animation, replace any pixel in the sub-frame 5662 overlay images with transparency, if it does not change the resulting 5663 animation by more than the current <a href="command-line-options.html#fuzz">-fuzz</a> factor. 5664 </td> 5665 </tr> 5666 5667 <tr><td></td><td>This should allow a existing frame optimized GIF animation 5668 to compress into a smaller file size due to larger areas of one 5669 (transparent) color rather than a pattern of multiple colors repeating 5670 the current disposed image of the last frame. </td> 5671 </tr> 5672 5673 <tr> 5674 <td>remove-dups</td> 5675 <td>Remove (and merge time delays) of duplicate consecutive 5676 images, so as to simplify layer overlays of coalesced animations. 5677 </td> 5678 </tr> 5679 5680 <tr><td></td><td>Usually this a result of using a constant time delay 5681 across the whole animation, or after a larger animation was split into 5682 smaller sub-animations. The duplicate frames could also have been 5683 used as part of some frame optimization methods. </td> 5684 </tr> 5685 5686 <tr> 5687 <td>remove-zero</td> 5688 <td>Remove any image with a zero time delay, unless ALL the 5689 images have a zero time delay (and is not a proper timed animation, a 5690 warning is then issued). </td> 5691 </tr> 5692 5693 <tr><td></td><td>In a GIF animation, such images are usually frames which 5694 provide partial intermediary updates between the frames that are 5695 actually displayed to users. These frames are usually added for 5696 improved frame optimization in GIF animations. </td> 5697 </tr> 5698 5699 <tr> 5700 <td>trim-bounds</td> 5701 <td>Find the bounds of all the images in the current 5702 image sequence, then adjust the offsets so all images are contained on 5703 a minimal positive canvas. None of the image data is modified or 5704 merged, only the individual image virtual canvas size and offset. 5705 All the images is given the same canvas size, and and will have 5706 a positive offset, but will remain in the same position relative to 5707 each other. As a result of the minimal canvas size at least one image 5708 will touch every edge of that canvas. The image data touching those 5709 edges however may be transparent. </td> 5710 </tr> 5711 5712 <tr><td></td><td>The result is much like if you used 'merge' followed by a 5713 <a href="command-line-options.html#repage">+repage</a> option, except that all the images 5714 have been kept separate. If 'flatten' is used after using 5715 'trim-bounds' you will get the same result. </td> 5716 </tr> 5717 5718 </tbody> 5719</table> 5720 5721<p>To print a complete list of layer types, use <a href="command-line-options.html#list">-list layers</a>.</p> 5722 5723<p>The operators <a href="command-line-options.html#coalesce">-coalesce</a>, <a href="command-line-options.html#deconstruct">-deconstruct</a>, <a href="command-line-options.html#flatten">-flatten</a>, and <a href="command-line-options.html#mosaic">-mosaic</a> are only aliases for the above methods and may be depreciated in 5724the future. Also see <a href="command-line-options.html#page">-page</a>, <a href="command-line-options.html#repage">-repage</a> operators, the <a href="command-line-options.html#compose">-compose</a> setting, and the 5725GIF <a href="command-line-options.html#dispose">-dispose</a> and <a href="command-line-options.html#delay">-delay</a> 5726settings. </p> 5727 5728 5729<div style="margin: auto;"> 5730 <h3 class="magick-header"><a id="level"></a>-level <var>black_point</var>{,<var>white_point</var>}{<var>%</var>}{,<var>gamma</var>}</h3> 5731</div> 5732 5733<p class="magick-description">adjust the level of image channels.</p> 5734 5735<p>Given one, two or three values delimited with commas: black-point, 5736white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and 5737white points range from 0 to <var>QuantumRange</var>, or from 0 to 5738100%; if the white point is omitted it is set to (<var>QuantumRange</var> - black_point), so as to center contrast changes. 5739If a <code>%</code> sign is present anywhere in the string, both black and white 5740points are percentages of the full color range. Gamma will do a <a href="command-line-options.html#gamma">-gamma</a> adjustment of the values. If it is omitted, the 5741default of 1.0 (no gamma correction) is assumed.</p> 5742 5743<p>In normal usage (<code>-level</code>) the image values are stretched so that 5744the given '<code>black_point</code>' value in the original image is set to zero 5745(or black), while the given '<code>white_point</code>' value is set to <var>QuantumRange</var> (or white). This provides you with direct 5746contrast adjustments to the image. The '<code>gamma</code>' of the resulting 5747image will then be adjusted. </p> 5748 5749<p>From ImageMagick v6.4.1-9 using the plus form of the operator 5750(<code>+level</code>) or adding the special '!' flag anywhere in the argument 5751list, will cause the operator to do the reverse of the level adjustment. That 5752is a zero, or <var>QuantumRange</var> value (black, and white, resp.) 5753in the original image, is adjusted to the given level values, allowing you to 5754de-contrast, or compress the channel values within the image. The 5755'<code>gamma</code>' is adjusted before the level adjustment to de-contrast the 5756image is made. </p> 5757 5758<p>Only the channels defined by the current <a href="command-line-options.html#channel">-channel</a> 5759setting are adjusted (defaults to RGB color channels only), allowing you to 5760limit the effect of this operator. </p> 5761 5762<p>Please note that the transparency channel is treated as 'matte' 5763values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 5764 5765 5766<div style="margin: auto;"> 5767 <h3 class="magick-header"><a id="level-colors"></a>-level-colors {<var>black_color</var>}{,}{<var>white_color</var>}</h3> 5768</div> 5769 5770<p class="magick-description">adjust the level of an image using the provided dash separated colors.</p> 5771 5772<p>This function is exactly like <a href="command-line-options.html#level">-level</a>, except that the 5773value value for each color channel is determined by the 5774'<code>black_color</code>' and '<code>white_color</code>' colors given (as 5775described under the <a href="command-line-options.html#fill">-fill</a> option). </p> 5776 5777<p>This effectually means the colors provided to <code>-level-colors</code> 5778is mapped to become 'black' and 'white' respectively, with all the other 5779colors linearly adjusted (or clipped) to match that change. Each channel is 5780adjusted separately using the channel values of the colors specified. </p> 5781 5782<p>On the other hand the plus form of the operator (<code>+level-colors</code>) 5783will map the image color 'black' and 'white' to the given colors 5784respectively, resulting in a gradient (de-contrasting) tint of the image to 5785those colors. This can also be used to convert a plain gray-scale image into a 5786one using the gradient of colors specified. </p> 5787 5788<p>By supplying a single color with a comma separator either before or after 5789that color, will just replace the respective 'black' or 'white' point 5790respectively. But if no comma separator is provided, the given color is 5791used for both the black and white color points, making the operator either 5792threshold the images around that color (- form) or set all colors to that 5793color (+ form). </p> 5794 5795 5796<div style="margin: auto;"> 5797 <h3 class="magick-header"><a id="limit"></a>-limit <var>type value</var></h3> 5798</div> 5799 5800<p class="magick-description">Set the pixel cache resource limit.</p> 5801 5802<p>Choose from: <code>area</code>, <code>disk</code>, <code>file</code>, 5803<code>map</code>, <code>memory</code>, <code>thread</code>, or <code>time</code>.</p> 5804 5805<p>The value for <code>file</code> is in number of files. The other limits are 5806in bytes. Define arguments for the memory, map, area, and disk resource limits 5807with SI prefixes (.e.g 100MB).</p> 5808 5809<p>By default the limits are 768 files, 3GB of image area, 1.5GiB memory, 3GiB 5810memory map, and 18.45EB of disk. These limits are adjusted relative to the 5811available resources on your computer if this information is available. When 5812any limit is reached, ImageMagick fails in some fashion but attempts to take 5813compensating actions, if possible. For example, the following limits 5814memory:</p> 5815 5816<pre> 5817-limit memory 32MiB -limit map 64MiB 5818</pre> 5819 5820<p>Use <a href="command-line-options.html#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p> 5821 5822<pre> 5823-> identify -list resource 5824Resource limits: 5825 Width: 100MP 5826 Height: 100MP 5827 Area: 25.181GB 5828 Memory: 11.726GiB 5829 Map: 23.452GiB 5830 Disk: unlimited 5831 File: 768 5832 Thread: 12 5833 Throttle: 0 5834 Time: unlimited 5835</pre> 5836 5837<p>Requests for pixel storage to keep intermediate images are satisfied by one 5838of three resource categories: in-memory pool, memory-mapped files pool, and 5839disk pool (in that order) depending on the <a href="command-line-options.html#limit">‑limit</a> settings 5840and whether the system honors a resource request. If the total size of 5841allocated pixel storage in the given pool reaches the corresponding limit, the 5842request is passed to the next pool. Additionally, requests that exceed the 5843<code>area</code> limit automagically are allocated on disk.</p> 5844 5845<p>To illustrate how ImageMagick utilizes resource limits, consider a typical 5846image resource request. First, ImageMagick tries to allocate the pixels in 5847memory. The request might be denied if the resource request exceeds the 5848<code>memory</code> limit or if the system does not honor the request. If 5849a memory request is not honored, the pixels are allocated to disk and the file 5850is memory-mapped. However, if the allocation request exceeds the 5851<code>map</code> limit, the resource allocation goes to disk. In all cases, if 5852the resource request exceeds the <code>area</code> limit, the pixels are 5853automagically cached to disk. If the disk has a hard limit, the program 5854fails.</p> 5855 5856<p>In most cases you simply do not need to concern yourself with resource 5857limits. ImageMagick chooses reasonable defaults and most images do not tax 5858your computer resources. Where limits do come in handy is when you process 5859images that are large or on shared systems where ImageMagick can consume all 5860or most of the available memory. In this case, the ImageMagick workflow slows 5861other processes or, in extreme cases, brings the system to a halt. Under 5862these circumstances, setting limits give some assurances that the ImageMagick 5863workflow will not interfere with other concurrent uses of the computer. For 5864example, assume you have a web interface that processes images uploaded from 5865the Internet. To assure ImageMagick does not exceed 10MiB of memory you can 5866simply set the area limit to 10MiB:</p> 5867 5868<pre> 5869-limit area 10MB 5870</pre> 5871 5872<p>Now whenever a large image is processed, the pixels are automagically 5873cached to disk instead of memory. This of course implies that large images 5874typically process very slowly, simply because pixel processing in memory can 5875be an order of magnitude faster than on disk. Because your web site users 5876might inadvertently upload a huge image to process, you should set a disk 5877limit as well:</p> 5878 5879<pre> 5880-limit area 10MB -limit disk 500MB 5881</pre> 5882 5883<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p> 5884 5885<p>In addition to command-line resource limit option, resources can be set 5886with <a href="resources.html#environment">environment variables</a>. Set the 5887environment variables <code>MAGICK_AREA_LIMIT</code>, 5888<code>MAGICK_DISK_LIMIT</code>, <code>MAGICK_FILE_LIMIT</code>, 5889<code>MAGICK_MEMORY_LIMIT</code>, <code>MAGICK_MAP_LIMIT</code>, 5890<code>MAGICK_THREAD_LIMIT</code>, <code>MAGICK_TIME_LIMIT</code> for limits of 5891image area, disk space, open files, heap memory, memory map, number of threads 5892of execution, and maximum elapsed time in seconds respectively.</p> 5893 5894<p> Inquisitive users can try adding <a href="command-line-options.html#debug">-debug cache</a> to 5895their commands and then scouring the generated output for references to the 5896pixel cache, in order to determine how the pixel cache was allocated and how 5897resources were consumed. Advanced Unix/Linux users can pipe that output 5898through <code>grep memory|open|destroy|disk</code> for more readable sifting. 5899</p> 5900 5901<p>For more about ImageMagick's use of resources, see the section <b>Cache 5902Storage and Resource Requirements</b> on the <a href="architecture.html#cache%0A">Architecture</a> page. </p> 5903 5904<div style="margin: auto;"> 5905 <h3 class="magick-header"><a id="linear-stretch"></a>-linear-stretch <var>black-point</var><br>-linear-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}}</h3> 5906</div> 5907 5908<p class="magick-description">Linear with saturation stretch.</p> 5909 5910<p>This is very similar to <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>, 5911and uses a 'histogram bin' to determine the range of color values that needs to 5912be stretched. However it then stretches those colors using the <a href="command-line-options.html#level">-level</a> operator.</p> 5913 5914<p>As such while the initial determination may have 'binning' round off 5915effects, the image colors are stretched mathematically, rather than using the 5916histogram bins. This makes the operator more accurate. </p> 5917 5918<p>note however that a <a href="command-line-options.html#linear-stretch">-linear-stretch</a> of 5919'<code>0</code>' does nothing, while a value of '<code>1</code>' does a near 5920perfect stretch of the color range. </p> 5921 5922<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect' 5923normalization of mathematical images. </p> 5924 5925<p>This operator is under review for re-development. </p> 5926 5927 5928<div style="margin: auto;"> 5929 <h3 class="magick-header"><a id="linewidth"></a>-linewidth</h3> 5930</div> 5931 5932<p class="magick-description">the line width for subsequent draw operations.</p> 5933 5934<div style="margin: auto;"> 5935 <h3 class="magick-header"><a id="liquid-rescale"></a>-liquid-rescale <var>geometry</var></h3> 5936</div> 5937 5938<p class="magick-description">rescale image with seam-carving.</p> 5939 5940<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5941 5942<div style="margin: auto;"> 5943 <h3 class="magick-header"><a id="list"></a>-list <var>type</var></h3> 5944</div> 5945 5946<p class="magick-description">Print a list of supported arguments for various options or settings. Choose from these list types:</p> 5947 5948<pre> 5949 Align Alpha Boolean Channel 5950 Class ClipPath Coder Color 5951 Colorspace Command Compose Compress 5952 Configure DataType Debug Decoration 5953 Delegate Direction Dispose Distort 5954 Dither Endian Evaluate FillRule 5955 Filter Font Format Function 5956 Gravity ImageList Intent Interlace 5957 Interpolate Kernel Layers LineCap 5958 LineJoin List Locale LogEvent 5959 Log Magic Method Metric 5960 Mime Mode Morphology Module 5961 Noise Orientation Policy PolicyDomain 5962 PolicyRights Preview Primitive QuantumFormat 5963 Resource SparseColor Storage Stretch 5964 Style Threshold Type Units 5965 Validate VirtualPixel 5966</pre> 5967 5968<p>These lists vary depending on your version of ImageMagick. Use "<code>-list 5969list</code>" to get a complete listing of all the "<code>-list</code>" arguments 5970available:</p> 5971 5972<pre> 5973identify -list list 5974</pre> 5975 5976<div style="margin: auto;"> 5977 <h3 class="magick-header"><a id="log"></a>-log <var>string</var></h3> 5978</div> 5979 5980<p class="magick-description">Specify format for debug log.</p> 5981 5982<p>This option specifies the format for the log printed when the <a href="command-line-options.html#debug">-debug</a> option is active.</p> 5983 5984<p>You can display the following components by embedding special format 5985characters:</p> 5986 5987<pre> 5988%d domain 5989%e event 5990%f function 5991%l line 5992%m module 5993%p process ID 5994%r real CPU time 5995%t wall clock time 5996%u user CPU time 5997%% percent sign 5998\n newline 5999\r carriage return 6000</pre> 6001 6002<p>For example:</p> 6003 6004<pre> 6005convert -debug coders -log "%u %m:%l %e" in.gif out.png 6006</pre> 6007 6008<p>The default behavior is to print all of the components.</p> 6009 6010<div style="margin: auto;"> 6011 <h3 class="magick-header"><a id="loop"></a>-loop <var>iterations</var></h3> 6012</div> 6013 6014<p class="magick-description">add Netscape loop extension to your GIF animation.</p> 6015 6016<p>Set iterations to zero to repeat the animation an infinite number of times, 6017otherwise the animation repeats itself up to <var>iterations</var> 6018times.</p> 6019 6020<div style="margin: auto;"> 6021 <h3 class="magick-header"><a id="lowlight-color"></a>-lowlight-color <var>color</var></h3> 6022</div> 6023 6024<p class="magick-description">when comparing images, de-emphasize pixel differences with this color.</p> 6025 6026<div style="margin: auto;"> 6027 <h3 class="magick-header"><a id="magnify"></a>-magnify</h3> 6028</div> 6029 6030<p class="magick-description">double the size of the image with pixel art scaling.</p> 6031 6032 6033<div style="margin: auto;"> 6034 <h3 class="magick-header"><a id="map"></a>-map <var>type</var></h3> 6035</div> 6036 6037<p class="magick-description">Display image using this <var>type</var>.</p> 6038 6039<p>Choose from these <var>Standard Colormap</var> types:</p> 6040 6041<pre> 6042best 6043default 6044gray 6045red 6046green 6047blue 6048</pre> 6049 6050<p>The <var>X server</var> must support the <var>Standard 6051Colormap</var> you choose, otherwise an error occurs. Use <code>list</code> as 6052the type and <code>display</code> searches the list of colormap types in 6053<code>top-to-bottom</code> order until one is located. See <var>xstdcmap(1)</var> for one way of creating Standard Colormaps.</p> 6054 6055 6056<div style="margin: auto;"> 6057 <h3 class="magick-header"><a id="map_stream_"></a>-map <var>components</var></h3> 6058</div> 6059 6060<p class="magick-description">pixel map.</p> 6061 6062<p>Here are the valid components of a map:</p> 6063 6064<pre> 6065r red pixel component 6066g green pixel component 6067b blue pixel component 6068a alpha pixel component (0 is transparent) 6069o opacity pixel component (0 is opaque) 6070i grayscale intensity pixel component 6071c cyan pixel component 6072m magenta pixel component 6073y yellow pixel component 6074k black pixel component 6075p pad component (always 0) 6076</pre> 6077 6078<p>You can specify as many of these components as needed in any order (e.g. 6079bgr). The components can repeat as well (e.g. rgbr).</p> 6080 6081 6082<div style="margin: auto;"> 6083 <h3 class="magick-header"><a id="mask"></a>-mask 6084<var>filename</var></h3> 6085</div> 6086 6087<p class="magick-description">Prevent updates to image pixels specified by the mask.</p> 6088 6089<p>This the same as using a mask used for composite masking operations, with 6090grayscale values causing blended updates of the image the mask is attached to. 6091</p> 6092 6093<p>Use <a href="command-line-options.html#mask">+mask</a> to remove the mask from images.</p> 6094 6095<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way, 6096but with strict boolean masking. </p> 6097 6098<div style="margin: auto;"> 6099 <h3 class="magick-header"><a id="mattecolor"></a>-mattecolor <var>color</var></h3> 6100</div> 6101 6102<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p> 6103 6104<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 6105 6106<p>The default matte color is <code>#BDBDBD</code>, <span style="background-color: #bdbdbd;">this shade of gray</span>.</p> 6107 6108<div style="margin: auto;"> 6109 <h3 class="magick-header"><a id="maximum"></a>-maximum</h3> 6110</div> 6111 6112<p class="magick-description">return the maximum intensity of an image sequence.</p> 6113 6114<p>Select the 'maximum' value from all the surrounding pixels. </p> 6115 6116<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same 6117name. </p> 6118 6119<div style="margin: auto;"> 6120 <h3 class="magick-header"><a id="median"></a>-median <var>geometry</var></h3> 6121</div> 6122 6123<p class="magick-description">apply a median filter to the image.</p> 6124 6125<p>Select the 'middle' value from all the surrounding pixels. </p> 6126 6127<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same 6128name. </p> 6129 6130<div style="margin: auto;"> 6131 <h3 class="magick-header"><a id="mean-shift"></a>-mean-shift <var>width</var>x<var>height</var>{<var>+distance</var>{%}}</h3> 6132</div> 6133 6134<p class="magick-description">image noise removal and color reduction/segmentation (e.g. -mean-shift 7x7+10%).</p> 6135 6136<p><var>width</var>x<var>height</var> is the window size and <var>distance</var> is the color distance measured in the range 0 to 1 or 0 to 100%</p> 6137 6138<p>The mean shift algorithm is iterative and thus slower the larger the window size. For each pixel, it gets all the pixels in the window centered at the pixel and excludes those that are outside the radius=sqrt((width-1)(height-1)/4) surrounding the pixel. From those pixels, it finds which of them are within the specified squared color distance from the current mean. It then computes a new x,y centroid from those coordinates and a new mean. This new x,y centroid is used as the center for a new window. This process is iterated until it converges and the final mean is then used to replace the original pixel value. It repeats this process for the next pixel, etc, until it processes all pixels in the image. Results are better when using other colorspaces rather than RGB. Recommend YIQ, YUV or YCbCr, which seem to give equivalent results.</p> 6139 6140<div style="margin: auto;"> 6141 <h3 class="magick-header"><a id="metric"></a>-metric <var>type</var></h3> 6142</div> 6143 6144<p class="magick-description">Output to STDERR a measure of the differences between images according to the <var>type</var> given metric.</p> 6145 6146<p>Choose from:</p> 6147 6148<dl class="dl-horizontal"> 6149<dt>AE</dt><dd> absolute error count, number of different pixels (-fuzz effected)</dd> 6150<dt>FUZZ</dt><dd> mean color distance</dd> 6151<dt>MAE</dt><dd> mean absolute error (normalized), average channel error distance</dd> 6152<dt>MEPP</dt><dd> mean error per pixel (normalized mean error, normalized peak error)</dd> 6153<dt>MSE</dt><dd> mean error squared, average of the channel error squared</dd> 6154<dt>NCC</dt><dd> normalized cross correlation</dd> 6155<dt>PAE</dt><dd> peak absolute (normalized peak absolute)</dd> 6156<dt>PHASH</dt><dd> perceptual hash</dd> 6157<dt>PSNR</dt><dd> peak signal to noise ratio</dd> 6158<dt>RMSE</dt><dd> root mean squared (normalized root mean squared)</dd> 6159</dl> 6160 6161<p>Control the '<code>AE</code>', or absolute count of pixels that are different, 6162with the <a href="command-line-options.html#fuzz">-fuzz</a> factor (ignore pixels which 6163only changed by a small amount). Use '<code>PAE</code>' to find the 6164size of the <a href="command-line-options.html#fuzz">-fuzz</a> factor needed to make all pixels 6165'similar', while '<code>MAE</code>' determines the factor needed 6166for about half the pixels to be similar. </p> 6167 6168<p>The '<code>MEPP</code>' metric returns three different metrics 6169('<code>MAE</code>', '<code>MAE</code>' normalized, and '<code>PAE</code>' 6170normalized) from a single comparison run. </p> 6171 6172<p>To print a complete list of metrics, use the <a href="command-line-options.html#list">-list 6173metric</a> option.</p> 6174 6175 6176<div style="margin: auto;"> 6177 <h3 class="magick-header"><a id="minimum"></a>-minimum</h3> 6178</div> 6179 6180<p class="magick-description">return the minimum intensity of an image sequence.</p> 6181 6182<p>Select the 'minimal' value from all the surrounding pixels. </p> 6183 6184<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same 6185name. </p> 6186 6187 6188 6189<div style="margin: auto;"> 6190 <h3 class="magick-header"><a id="mode"></a>-mode <var>geometry</var></h3> 6191</div> 6192 6193<p class="magick-description">make each pixel the \'predominant color\' of the neighborhood.'</p> 6194 6195<div style="margin: auto;"> 6196 <h3 class="magick-header">-mode <var>value</var></h3> 6197</div> 6198 6199<p class="magick-description">Mode of operation.</p> 6200 6201<p>Choose the <var>value</var> from these styles: <code>Frame, 6202Unframe, or Concatenate</code></p> 6203 6204<p>Use the <a href="command-line-options.html#list">-list</a> option with a '<code>Mode</code>' argument 6205for a list of <a href="command-line-options.html#mode">-mode</a> arguments available in your 6206ImageMagick installation.</p> 6207 6208 6209<div style="margin: auto;"> 6210 <h3 class="magick-header"><a id="modulate"></a>-modulate <var>brightness</var>[,<var>saturation</var>,<var>hue</var>]</h3> 6211</div> 6212 6213<p class="magick-description">Vary the <var>brightness</var>, <var>saturation</var>, and <var>hue</var> of an image.</p> 6214 6215<p>The arguments are given as a percentages of variation. A value of 100 means 6216no change, and any missing values are taken to mean 100.</p> 6217 6218<p>The <var>brightness</var> is a multiplier of the overall 6219brightness of the image, so 0 means pure black, 50 is half as bright, 200 is 6220twice as bright. To invert its meaning <a href="command-line-options.html#negate">-negate</a> the image 6221before and after. </p> 6222 6223<p>The <var>saturation</var> controls the amount of color in an 6224image. For example, 0 produce a grayscale image, while a large value such as 6225200 produce a very colorful, 'cartoonish' color.</p> 6226 6227<p>The <var>hue</var> argument causes a "rotation" of the colors 6228within the image by the amount specified. For example, 50 results in 6229a counter-clockwise rotation of 90, mapping red shades to purple, and so on. 6230A value of either 0 or 200 results in a complete 180 degree rotation of the 6231image. Using a value of 300 is a 360 degree rotation resulting in no change to 6232the original image. </p> 6233 6234<p>For example, to increase the color brightness by 20% and decrease the color 6235saturation by 10% and leave the hue unchanged, use <a href="command-line-options.html#modulate">-modulate 120,90</a>.</p> 6236 6237<p>Use <a href="command-line-options.html#set">-set</a> attribute of '<code>option:modulate:colorspace</code>' to specify which colorspace to 6238modulate. Choose from <code>HCL</code>, <code>HCLp</code>, <code>HSB</code>, <code>HSI</code>, <code>HSL</code> (the default), <code>HSV</code>, <code>HWB</code>, or <code>LCH</code> (LCHuv). For example,</p> 6239 6240<pre> 6241convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png 6242</pre> 6243 6244<div style="margin: auto;"> 6245 <h3 class="magick-header"><a id="moments"></a>-moments</h3> 6246</div> 6247 6248<p class="magick-description">report image moments and perceptual hash.</p> 6249 6250 6251<div style="margin: auto;"> 6252 <h3 class="magick-header"><a id="monitor"></a>-monitor</h3> 6253</div> 6254 6255<p class="magick-description">monitor progress.</p> 6256 6257 6258<div style="margin: auto;"> 6259 <h3 class="magick-header"><a id="monochrome"></a>-monochrome</h3> 6260</div> 6261 6262<p class="magick-description">transform the image to black and white.</p> 6263 6264<div style="margin: auto;"> 6265 <h3 class="magick-header"><a id="morph"></a>-morph <var>frames</var></h3> 6266</div> 6267 6268<p class="magick-description">morphs an image sequence.</p> 6269 6270<p>Both the image pixels and size are linearly interpolated to give the 6271appearance of a metamorphosis from one image to the next, over all the images 6272in the current image list. The added images are the equivalent of a <a href="command-line-options.html#blend">-blend</a> composition. The <var>frames</var> 6273argument determine how many images to interpolate between each image. </p> 6274 6275 6276<div style="margin: auto;"> 6277 <h3 class="magick-header"><a id="morphology"></a>-morphology</h3> 6278 <h3 class="magick-header">-morphology <var>method</var> <var>kernel</var></h3> 6279</div> 6280 6281<p class="magick-description">apply a morphology method to the image.</p> 6282 6283<p>Until I get around to writing an option summary for this, see <a href="http://www.imagemagick.org/Usage/morphology/">IM Usage Examples, 6284Morphology</a>. </p> 6285 6286 6287<div style="margin: auto;"> 6288 <h3 class="magick-header"><a id="mosaic"></a>-mosaic</h3> 6289</div> 6290 6291<p class="magick-description">an simple alias for the <a href="command-line-options.html#layers">-layers</a> method "mosaic"</p> 6292 6293 6294<div style="margin: auto;"> 6295 <h3 class="magick-header"><a id="motion-blur"></a>-motion-blur <var>radius</var><br>-motion-blur <var>radius</var>x<var>sigma</var>+<var>angle</var></h3> 6296</div> 6297 6298<p class="magick-description">simulate motion blur.</p> 6299 6300<p>Blur with the given radius, standard deviation (sigma), and angle. The 6301angle given is the angle toward which the image is blurred. That is the 6302direction people would consider the object is coming from. </p> 6303 6304<p>Note that the blur is not uniform distribution, giving the motion a 6305definite sense of direction of movement. </p> 6306 6307<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how 6308pixels which are outside the image proper are blurred into the final result. 6309</p> 6310 6311<div style="margin: auto;"> 6312 <h3 class="magick-header"><a id="name"></a>-name</h3> 6313</div> 6314 6315<p class="magick-description">name an image.</p> 6316<div style="margin: auto;"> 6317 <h3 class="magick-header"><a id="negate"></a>-negate</h3> 6318</div> 6319 6320<p class="magick-description">replace each pixel with its complementary color.</p> 6321 6322<p>The red, green, and blue intensities of an image are negated. White becomes 6323black, yellow becomes blue, etc. Use <a href="command-line-options.html#negate">+negate</a> to only 6324negate the grayscale pixels of the image.</p> 6325 6326<div style="margin: auto;"> 6327 <h3 class="magick-header"><a id="noise"></a>-noise <var>geometry</var><br> 6328 +noise <var>type</var></h3> 6329</div> 6330 6331<p class="magick-description">Add or reduce noise in an image.</p> 6332 6333<p>The principal function of noise peak elimination filter is to smooth the 6334objects within an image without losing edge information and without creating 6335undesired structures. The central idea of the algorithm is to replace a pixel 6336with its next neighbor in value within a pixel window, if this pixel has been 6337found to be noise. A pixel is defined as noise if and only if this pixel is 6338a maximum or minimum within the pixel window.</p> 6339 6340<p>Use <code><a href="command-line-options.html#noise">-noise</a> <var>radius</var></code> to 6341specify the width of the neighborhood when reducing noise. This is equivalent 6342to using a <code><a href="command-line-options.html#statistic">-statistic</a> NonPeak</code> operation, 6343which should be used in preference.</p> 6344 6345<p>Use <a href="command-line-options.html#noise">+noise</a> followed by a noise <var>type</var> to add noise to an image. Choose from these noise 6346types:</p> 6347 6348<pre> 6349Gaussian 6350Impulse 6351Laplacian 6352Multiplicative 6353Poisson 6354Random 6355Uniform 6356</pre> 6357 6358<p>The amount of noise added can be controled by the <code><a href="command-line-options.html#attunuuate">-attenuate</a></code> setting. If unset the value is 6359equivalent to 1.0, or a maximum noise addition.</p> 6360 6361<p>Note that Random will replace the image with noise rather than add noise to the image. Use Uniform, if you wish to add random noise to the image.</p> 6362 6363<p>To print a complete list of noises, use the <a href="command-line-options.html#list">-list noise</a> option.</p> 6364 6365<p>Also see the <a href="command-line-options.html#evaluate">-evaluate</a> noise functions that allows 6366the use of a controlling value to specify the amount of noise that should be 6367added to an image. </p> 6368 6369 6370<div style="margin: auto;"> 6371 <h3 class="magick-header"><a id="normalize"></a>-normalize</h3> 6372</div> 6373 6374<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p> 6375 6376<p>The intensity values are stretched to cover the entire range of possible 6377values. While doing so, black-out at most <var>2%</var> of the pixels and 6378white-out at most <var>1%</var> of the pixels.</p> 6379 6380<p>Note that as of ImageMagick 6.4.7-0, <a href="command-line-options.html#normalize">-normalize</a> 6381is equivalent to <a href="command-line-options.html#contrast-stretch">-contrast-stretch 2%x1%</a>. 6382(Before this version, it was equivalent to <a href="command-line-options.html#contrast-stretch">-contrast-stretch 2%x99%</a>).</p> 6383 6384<p>All the channels are normalized in concert by the came amount so as to 6385preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a> 6386setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a> 6387setting will normalize the RGB channels independently.</p> 6388 6389<p>See <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> for more details. 6390Also see <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect' normalization 6391that is better suited to mathematically generated images. </p> 6392 6393<p>This operator is under review for re-development. </p> 6394 6395 6396<div style="margin: auto;"> 6397 <h3 class="magick-header"><a id="opaque"></a>-opaque <var>color</var></h3> 6398</div> 6399 6400<p class="magick-description">change this color to the fill color within the image.</p> 6401 6402<p>The <var>color</var> argument is defined using the format 6403described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz">-fuzz</a> setting can be used to match and replace colors similar to the one 6404given.</p> 6405 6406<p>Use <a href="command-line-options.html#opaque">+opaque</a> to paint any pixel that does not match 6407the target color. </p> 6408 6409<p>The <a href="command-line-options.html#transparent">-transparent</a> operator is exactly the same 6410as <a href="command-line-options.html#opaque">-opaque</a> but replaces the matching color with 6411transparency rather than the current <a href="command-line-options.html#fill">-fill</a> color setting. 6412To ensure that it can do this it also ensures that the image has an alpha 6413channel enabled, as per "<code><a href="command-line-options.html#alpha">-alpha</a> set</code>", for 6414the new transparent colors, and does not require you to modify the <a href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p> 6415 6416 6417<div style="margin: auto;"> 6418 <h3 class="magick-header"><a id="ordered-dither"></a>-ordered-dither <var>threshold_map</var>{,<var>level</var>...}</h3> 6419</div> 6420 6421<p class="magick-description">dither the image using a pre-defined ordered dither <var>threshold map</var> specified, and a uniform color map with the 6422given number of <var>levels</var> per color channel.</p> 6423 6424<p>You can choose from these standard threshold maps:</p> 6425 6426<pre> 6427threshold 1x1 Threshold 1x1 (non-dither) 6428checks 2x1 Checkerboard 2x1 (dither) 6429o2x2 2x2 Ordered 2x2 (dispersed) 6430o3x3 3x3 Ordered 3x3 (dispersed) 6431o4x4 4x4 Ordered 4x4 (dispersed) 6432o8x8 8x8 Ordered 8x8 (dispersed) 6433h3x4a 4x1 Halftone 4x4 (angled) 6434h6x6a 6x1 Halftone 6x6 (angled) 6435h8x8a 8x1 Halftone 8x8 (angled) 6436h3x4o Halftone 4x4 (orthogonal) 6437h6x6o Halftone 6x6 (orthogonal) 6438h8x8o Halftone 8x8 (orthogonal) 6439h36x16o Halftone 16x16 (orthogonal) 6440c5x5b c5x5 Circles 5x5 (black) 6441c5x5w Circles 5x5 (white) 6442c6x6b c6x6 Circles 6x6 (black) 6443c6x6w Circles 6x6 (white) 6444c7x7b c7x7 Circles 7x7 (black) 6445c7x7w Circles 7x7 (white) 6446</pre> 6447 6448<p> The <code>threshold</code> generated a simple 50% threshold of the image. 6449This could be used with <var>level</var> to do the equivalent of <a href="command-line-options.html#posterize">-posterize</a> to reduce an image to basic primary colors. 6450</p> 6451 6452<p>The <code>checks</code> pattern produces a 3 level checkerboard dither 6453pattern. That is a grayscale will become a pattern of solid black, solid 6454white, and mid-tone colors into a checkerboard pattern of black and white. 6455</p> 6456 6457<p>You can define your own <var>threshold map</var> for ordered 6458dithering and halftoning your images, in either personal or system 6459<code>thresholds.xml</code> XML file. See <a href="resources.html">Resources</a> 6460for more details of configuration files. </p> 6461 6462<p>To print a complete list of the thresholds that have been defined, use the 6463<a href="command-line-options.html#list">-list threshold</a> option.</p> 6464 6465<p>Note that at this time the same threshold dithering map is used for all 6466color channels, no attempt is made to offset or rotate the map for different 6467channels is made, to create an offset printing effect. Also as the maps are 6468simple threshold levels, the halftone and circle maps will create incomplete 6469circles along the edges of a colored area. Also all the effects are purely 6470on/off boolean effects, without anti-aliasing to make the circles smooth 6471looking. Large dots can be made to look better with a small amount of blurring 6472after being created. </p> 6473 6474 6475<div style="margin: auto;"> 6476 <h3 class="magick-header"><a id="orient"></a>-orient <var>image orientation</var></h3> 6477</div> 6478 6479<p class="magick-description">specify orientation of a digital camera image.</p> 6480 6481<p>Choose from these orientations:</p> 6482 6483<pre> 6484bottom-left 6485bottom-right 6486left-bottom 6487left-top 6488right-bottom 6489right-top 6490top-left 6491top-right 6492undefined 6493</pre> 6494 6495<p>To print a complete list of orientations, use the <a href="command-line-options.html#list">-list 6496orientation</a> option.</p> 6497 6498 6499<div style="margin: auto;"> 6500 <h3 class="magick-header"><a id="page"></a>-page <var>geometry</var><br> 6501 -page <var>media</var>[<var>offset</var>][{<var>^!<></var>}]<br> 6502 +page 6503 </h3> 6504</div> 6505 6506<p class="magick-description">Set the size and location of an image on the larger virtual canvas.</p> 6507 6508<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 6509 6510<p>For convenience you can specify the page size using <var>media</var> (see below). Offsets can then be added as with other 6511<var>geometry</var> arguments (e.g. <a href="command-line-options.html#page">-page</a> <code>Letter+43+43</code>).</p> 6512 6513<p>Use <var>media</var> as shorthand to specify the dimensions (<var>width</var>x<var>height</var>) of the <var>PostScript</var> page in dots per inch or a TEXT page in pixels. 6514The choices for a PostScript page are:</p> 6515 6516<div class="table-responsive"> 6517<table class="table table-condensed table-striped"> 6518 <tr> 6519 <td><var>Media</var></td> 6520 <td align="right"><var>Width</var></td> 6521 <td align="right"><var>Height</var></td> 6522 </tr> 6523<tr><td> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr> 6524<tr><td> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr> 6525<tr><td> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr> 6526<tr><td> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 6527<tr><td> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 6528<tr><td> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr> 6529<tr><td> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr> 6530<tr><td> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr> 6531<tr><td> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr> 6532<tr><td> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr> 6533<tr><td> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr> 6534<tr><td> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr> 6535<tr><td> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr> 6536<tr><td> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr> 6537<tr><td> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 6538<tr><td> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 6539<tr><td> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr> 6540<tr><td> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr> 6541<tr><td> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr> 6542<tr><td> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr> 6543<tr><td> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr> 6544<tr><td> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr> 6545<tr><td> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr> 6546<tr><td> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr> 6547<tr><td> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr> 6548<tr><td> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr> 6549<tr><td> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr> 6550<tr><td> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr> 6551<tr><td> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr> 6552<tr><td> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr> 6553<tr><td> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr> 6554<tr><td> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr> 6555<tr><td> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr> 6556<tr><td> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr> 6557<tr><td> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr> 6558<tr><td> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 6559<tr><td> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 6560<tr><td> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr> 6561</table></div> 6562 6563<p>This option is also used to place subimages when writing to a multi-image 6564format that supports offsets, such as GIF89 and MNG. When used for this 6565purpose the offsets are always measured from the top left corner of the canvas 6566and are not affected by the <a href="command-line-options.html#gravity">-gravity</a> option. To 6567position a GIF or MNG image, use <a href="command-line-options.html#page">-page</a><var>{+-}x{+-}y</var> (e.g. -page +100+200). When writing to a MNG 6568file, a <a href="command-line-options.html#page">-page</a> option appearing ahead of the first image in 6569the sequence with nonzero width and height defines the width and height values 6570that are written in the <code>MHDR</code> chunk. Otherwise, the MNG width and 6571height are computed from the bounding box that contains all images in the 6572sequence. When writing a GIF89 file, only the bounding box method is used to 6573determine its dimensions.</p> 6574 6575<p>For a PostScript page, the image is sized as in <a href="command-line-options.html#geometry">-geometry</a> but positioned relative to the <var>lower 6576left-hand corner</var> of the page by {+-}<code>x</code><var>offset</var>{+-}<code>y</code> <var>offset</var>. Use <a href="command-line-options.html#page">-page 612x792</a>, for example, to center the image within the 6577page. If the image size exceeds the PostScript page, it is reduced to fit the 6578page. The default gravity for the <a href="command-line-options.html#page">-page</a> option is <var>NorthWest</var>, i.e., positive <code>x</code> and <code>y</code> <var>offset</var> are measured rightward and downward from the top left 6579corner of the page, unless the <a href="command-line-options.html#gravity">-gravity</a> option is 6580present with a value other than <var>NorthWest</var>.</p> 6581 6582<p>The default page dimensions for a TEXT image is 612x792.</p> 6583 6584<p>This option is used in concert with <a href="command-line-options.html#density">-density</a>.</p> 6585 6586<p>Use <a href="command-line-options.html#page">+page</a> to remove the page settings for an image.</p> 6587 6588<div style="margin: auto;"> 6589 <h3 class="magick-header"><a id="paint"></a>-paint <var>radius</var></h3> 6590</div> 6591 6592<p class="magick-description">simulate an oil painting.</p> 6593 6594<p>Each pixel is replaced by the most frequent color in a circular 6595neighborhood whose width is specified with <var>radius</var>.</p> 6596 6597<div style="margin: auto;"> 6598 <h3 class="magick-header"><a id="path"></a>-path <var>path</var></h3></div> 6599 6600<p class="magick-description">write images to this path on disk.</p> 6601 6602<div style="margin: auto;"> 6603 <h3 class="magick-header"><a id="pause_animate_"></a>-pause <var>seconds</var></h3> 6604</div> 6605 6606<p class="magick-description">Pause between animation loops</p> 6607 6608<p>Pause for the specified number of seconds before repeating the animation.</p> 6609 6610<div style="margin: auto;"> 6611 <h3 class="magick-header"><a id="pause_import_"></a>-pause <var>seconds</var></h3> 6612</div> 6613 6614<p class="magick-description">Pause between snapshots.</p> 6615 6616<p>Pause for the specified number of seconds before taking the next snapshot.</p> 6617 6618<div style="margin: auto;"> 6619 <h3 class="magick-header"><a id="perceptible"></a>-perceptible <var>epsilon</var></h3> 6620</div> 6621 6622<p class="magick-description">set each pixel whose value is less than |<var>epsilon</var>| to <var>-epsilon</var> or <var>epsilon</var> (whichever is closer) otherwise the pixel value remains unchanged.</p> 6623 6624<div style="margin: auto;"> 6625 <h3 class="magick-header"><a id="ping"></a>-ping</h3> 6626</div> 6627 6628<p class="magick-description">efficiently determine image characteristics.</p> 6629 6630<div style="margin: auto;"> 6631 <h3 class="magick-header"><a id="pointsize"></a>-pointsize <var>value</var></h3> 6632</div> 6633 6634<p class="magick-description">pointsize of the PostScript, OPTION1, or TrueType font.</p> 6635 6636<div style="margin: auto;"> 6637 <h3 class="magick-header"><a id="polaroid"></a>-polaroid <var>angle</var></h3> 6638</div> 6639 6640<p class="magick-description">simulate a Polaroid picture.</p> 6641 6642<p>Use <code>+polaroid</code> to rotate the image at a random angle between -15 and +15 degrees.</p> 6643 6644<div style="margin: auto;"> 6645 <h3 class="magick-header"><a id="poly"></a>-poly <var>"wt,exp ..."</var></h3> 6646</div> 6647 6648<p class="magick-description">combines multiple images according to a weighted sum of polynomials; one floating point weight (coefficient) and one floating point polynomial exponent (power) for each image expressed as comma separated pairs.</p> 6649 6650<p> The weights should typically be fractions between -1 and 1. But the sum of weights should be 1 or at least between 0 and 1 to avoid clamping in non-hdri mode at black and white.</p> 6651 6652<p>The exponents may be positive, negative or zero. A negative exponent is equivalent to 1 divided by the image raised to the corresponding positive exponent. A zero exponent always produces 1 scaled by quantumrange to white, i.e. wt*white, no matter what the image.</p> 6653 6654<p>The format is: output = wt1*image1^exp1 + wt2*image2^exp2 ...</p> 6655 6656<p>Some simple uses are:</p> 6657<ul> 6658<li>A weighted sum of each image provided all weights add to unity and all exponents=1. If the the weights are all equal to 1/(number of images), then this is equivalent to <a href="command-line-options.html#profile">-evaluate-sequence</a> <var>mean</var>.</li> 6659<li>The sum of squares of two or more images, provided the weights are equal (and sum to 1 to avoid clamping) and the exponents equal 2.</li> 6660</ul> 6661 6662<p>Note that one may add a constant color to the expression simply by using xc:somecolor for one of the images and specifying the desired weight and exponent equal to 0.</p> 6663 6664<p>Similarly one may add white to the expression by simply using null: (or xc:white) for one of the images with the appropriate weight and exponent equal to 0.</p> 6665 6666 6667<div style="margin: auto;"> 6668 <h3 class="magick-header"><a id="posterize"></a>-posterize <var>levels</var></h3> 6669</div> 6670 6671<p class="magick-description">reduce the image to a limited number of color levels per channel.</p> 6672 6673<p>Very low values of <var>levels</var>, e.g., 2, 3, 4, have the most 6674visible effect.</p> 6675 6676<div style="margin: auto;"> 6677 <h3 class="magick-header"><a id="precision"></a>-precision <var>value</var></h3> 6678</div> 6679 6680<p class="magick-description">set the maximum number of significant digits to be printed.</p> 6681 6682<div style="margin: auto;"> 6683 <h3 class="magick-header"><a id="preview"></a>-preview <var>type</var></h3> 6684</div> 6685 6686<p class="magick-description">image preview type.</p> 6687 6688<p>Use this option to affect the preview operation of an image (e.g. 6689<code>convert file.png -preview Gamma Preview:gamma.png</code>). Choose from 6690these previews:</p> 6691 6692<pre> 6693Rotate Shear Roll Hue 6694Saturation Brightness Gamma Spiff 6695Dull Grayscale Quantize Despeckle 6696ReduceNoise Add Noise Sharpen Blur 6697Threshold EdgeDetect Spread Shade 6698Raise Segment Solarize Swirl 6699Implode Wave OilPaint CharcoalDrawing 6700JPEG 6701</pre> 6702 6703<p>To print a complete list of previews, use the <a href="command-line-options.html#list">-list preview</a> option.</p> 6704 6705<p>The default preview is <code>JPEG</code>.</p> 6706 6707<div style="margin: auto;"> 6708 <h3 class="magick-header"><a id="print"></a>-print <var>string</var></h3> 6709</div> 6710 6711<p class="magick-description">interpret string and print to console.</p> 6712 6713<div style="margin: auto;"> 6714 <h3 class="magick-header"><a id="process"></a>-process <var>command</var></h3> 6715</div> 6716 6717<p class="magick-description">process the image with a custom image filter.</p> 6718 6719<p>The command arguments has the form <code>"module arg1 arg2 arg3 ... 6720argN"</code> where <code>module</code> is the name of the module to invoke (e.g. 6721"Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to 6722pass to the process module.</p> 6723 6724<div style="margin: auto;"> 6725 <h3 class="magick-header"><a id="profile"></a>-profile <var>filename</var><br> 6726 +profile <var>profile_name</var></h3> 6727</div> 6728 6729<p class="magick-description">Manage ICM, IPTC, or generic profiles in an image.</p> 6730 6731<p>Using <a href="command-line-options.html#profile">-profile</a> <var>filename</var> adds an 6732ICM (ICC color management), IPTC (newswire information), or a generic profile 6733to the image.</p> 6734 6735<p>Use <a href="command-line-options.html#profile">+profile <var>profile_name</var></a> to 6736remove the indicated profile. ImageMagick uses standard filename globbing, so 6737wildcard expressions may be used to remove more than one profile. Here we 6738remove all profiles from the image except for the XMP profile: <code>+profile 6739"!xmp,*"</code>. </p> 6740 6741<p>Use <code>identify -verbose</code> to find out which profiles are in the 6742image file. Use <a href="command-line-options.html#strip">-strip</a> to remove all profiles (and 6743comments).</p> 6744 6745<p>To extract a profile, the <a href="command-line-options.html#profile">-profile</a> option is not 6746used. Instead, simply write the file to an image format such as <var>APP1, 8BIM, ICM,</var> or <var>IPTC</var>.</p> 6747 6748<p>For example, to extract the Exif data (which is stored in JPEG files in the 6749<var>APP1</var> profile), use.</p> 6750 6751<pre> 6752convert cockatoo.jpg profile.exif 6753</pre> 6754 6755<p>It is important to note that results may depend on whether or not the 6756original image already has an included profile. Also, keep in mind that <a href="command-line-options.html#profile">-profile</a> is an "operator" (as opposed to a "setting") and 6757therefore a conversion is made each time it is encountered, in order, in the 6758command-line. For instance, in the following example, if the original image is 6759CMYK with profile, a CMYK-CMYK-RGB conversion results.</p> 6760 6761<pre> 6762convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff 6763</pre> 6764 6765<p>Furthermore, since ICC profiles are not necessarily symmetric, extra 6766conversion steps can yield unwanted results. CMYK profiles are often very 6767asymmetric since they involve 3−>4 and 4−>3 channel mapping. 6768</p> 6769 6770<div style="margin: auto;"> 6771 <h3 class="magick-header"><a id="quality"></a>-quality <var>value</var></h3> 6772</div> 6773 6774<p class="magick-description">JPEG/MIFF/PNG compression level.</p> 6775 6776<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and 6777highest compression) to 100 (best quality but least effective compression). 6778The default is to use the estimated quality of your input image if it can 6779be determined, otherwise 92. When the quality is greater than 90, then the 6780chroma channels are not downsampled. 6781Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to specify the 6782factors for chroma downsampling.</p> 6783 6784<p>For the MIFF image format, quality/10 is the zlib compression level, which 6785is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect 6786on the image appearance, since the compression is always lossless.</p> 6787 6788<p>For the JPEG-2000 image format, quality is mapped using a non-linear 6789equation to the compression ratio required by the Jasper library. This 6790non-linear equation is intended to loosely approximate the quality provided by 6791the JPEG v1 format. The default quality value 100, a request for non-lossy 6792compression. A quality of 75 results in a request for 16:1 compression.</p> 6793 6794<p>For the MNG and PNG image formats, the quality value sets the zlib 6795compression level (quality / 10) and filter-type (quality % 10). The default 6796PNG "quality" is 75, which means compression level 7 with adaptive PNG 6797filtering, unless the image has a color map, in which case it means 6798compression level 7 with no PNG filtering.</p> 6799 6800<p>For compression level 0 (quality value less than 10), the Huffman-only 6801strategy is used, which is fastest but not necessarily the worst 6802compression.</p> 6803 6804<p>If filter-type is 4 or less, the specified PNG filter-type is used for 6805all scanlines:</p> 6806 6807<pre> 68080: none 68091: sub 68102: up 68113: average 68124: Paeth 6813</pre> 6814 6815<p>If filter-type is 5, adaptive filtering is used when quality is greater 6816than 50 and the image does not have a color map, otherwise no filtering is 6817used.</p> 6818 6819<p>If filter-type is 6, adaptive filtering 6820with <var>minimum-sum-of-absolute-values</var> is used.</p> 6821 6822<p>Only if the output is MNG, if filter-type is 7, the LOCO color 6823transformation (intrapixel differencing) and adaptive filtering 6824with <var>minimum-sum-of-absolute-values</var> are used.</p> 6825 6826<p>If the filter-type is 8 the zlib Z_RLE compression strategy (or the 6827Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with 6828adaptive PNG filtering.</p> 6829 6830<p>If the filter-type is 9 the zlib Z_RLE compression strategy (or the 6831Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with 6832no PNG filtering.</p> 6833 6834<p>The quality setting has no effect on the appearance or signature of PNG 6835and MNG images, since the compression is always lossless.</p> 6836 6837<p>Not all combinations of compression level, strategy, and PNG filter type 6838can be obtained using the -quality option. For more precise control, 6839you can use the PNG:compression-level=N, PNG:compression-strategy=N, and 6840PNG:compression-filter=N defines, respectively, instead. 6841See <a href="command-line-options.html#define">-define</a>. Values from the defines take precedence 6842over values from the -quality option.</p> 6843 6844<p>For further information, see 6845the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p> 6846 6847<div style="margin: auto;"> 6848 <h3 class="magick-header"><a id="quantize"></a>-quantize <var>colorspace</var></h3> 6849</div> 6850 6851<p class="magick-description">reduce colors using this colorspace.</p> 6852 6853<p>This setting defines the colorspace used to sort out and reduce the number 6854of colors needed by an image (for later dithering) by operators such as <a href="command-line-options.html#colors">-colors</a>, Note that color reduction also happens 6855automatically when saving images to color-limited image file formats, such as 6856GIF, and PNG8.</p> 6857 6858 6859<div style="margin: auto;"> 6860 <h3 class="magick-header"><a id="quiet"></a>-quiet</h3> 6861</div> 6862 6863<p class="magick-description">suppress all warning messages. Error messages are still reported.</p> 6864 6865<div style="margin: auto;"> 6866 <h3 class="magick-header"><a id="radial-blur"></a>-radial-blur <var>angle</var></h3> 6867</div> 6868 6869<p class="magick-description">Blur around the center of the image.</p> 6870 6871<p>Note that this is actually a rotational blur rather than a radial and as 6872such actually mis-named. </p> 6873 6874<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how 6875pixels which are outside the image proper are blurred into the final result. 6876</p> 6877 6878 6879<div style="margin: auto;"> 6880 <h3 class="magick-header"><a id="raise"></a>-raise <var>thickness</var></h3> 6881</div> 6882 6883<p class="magick-description">Lighten or darken image edges.</p> 6884 6885<p>This will create a 3-D effect. Use <a href="command-line-options.html#raise">-raise</a> to create 6886a raised effect, otherwise use <a href="command-line-options.html#raise">+raise</a>. </p> 6887 6888<p>Unlike the similar <a href="command-line-options.html#frame">-frame</a> option, <a href="command-line-options.html#raise">-raise</a> does not alter the dimensions of the image.</p> 6889 6890<div style="margin: auto;"> 6891 <h3 class="magick-header"><a id="random-threshold"></a>-random-threshold <var>low</var>x<var>high</var></h3> 6892</div> 6893 6894<p class="magick-description">Apply a random threshold to the image.</p> 6895 6896<div style="margin: auto;"> 6897 <h3 class="magick-header"><a id="red-primary"></a>-red-primary <var>x,y</var></h3> 6898</div> 6899 6900<p class="magick-description">Set the red chromaticity primary point.</p> 6901 6902<div style="margin: auto;"> 6903 <h3 class="magick-header"><a id="regard-warnings"></a>-regard-warnings</h3> 6904</div> 6905 6906<p class="magick-description">Pay attention to warning messages.</p> 6907 6908<p>This option causes some warnings in some image formats to be treated 6909as errors. </p> 6910 6911<div style="margin: auto;"> 6912 <h3 class="magick-header"><a id="remap"></a>-remap <var>filename</var></h3> 6913</div> 6914 6915<p class="magick-description">Reduce the number of colors in an image to the colors used by this image.</p> 6916 6917<p>If the <a href="command-line-options.html#dither">-dither</a> setting is enabled (the default) then 6918the given colors are dithered over the image as necessary, otherwise the closest 6919color (in RGB colorspace) is selected to replace that pixel in the image. </p> 6920 6921<p>As a side effect of applying a <a href="command-line-options.html#remap">-remap</a> of colors across all 6922images in the current image sequence, all the images will have the same color 6923table. That means that when saved to a file format such as GIF, it will use 6924that color table as a single common or global color table, for all the images, 6925without requiring extra local color tables. </p> 6926 6927<p>Use <a href="command-line-options.html#remap">+remap</a> to reduce all images in the current image 6928sequence to use a common color map over all the images. This equivalent to 6929appending all the images together (without extra background colors) and color 6930reducing those images using <a href="command-line-options.html#colors">-colors</a> with a 256 color 6931limit, then <a href="command-line-options.html#remap">-remap</a> those colors over the original list of 6932images. This ensures all the images follow a single color map. </p> 6933 6934<p>If the number of colors over all the images is less than 256, then <a href="command-line-options.html#remap">+remap</a> should not perform any color reduction or dithering, as 6935no color changes are needed. In that case, its only effect is to force the use 6936of a global color table. This recommended after using either <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to 6937reduce the number of colors in an animated image sequence. </p> 6938 6939<p>Note, the remap image colormap has at most 8-bits of precision. Deeper color maps are automagically coalesced with other colors to meet this requirement.</p> 6940 6941<div style="margin: auto;"> 6942 <h3 class="magick-header"><a id="region"></a>-region <var>geometry</var></h3> 6943</div> 6944 6945<p class="magick-description">Set a region in which subsequent operations apply.</p> 6946 6947<p>The <var>x</var> and <var>y</var> offsets are treated 6948in the same manner as in <a href="command-line-options.html#crop">-crop</a>.</p> 6949 6950<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 6951 6952<div style="margin: auto;"> 6953 <h3 class="magick-header"><a id="remote"></a>-remote</h3> 6954</div> 6955 6956<p class="magick-description">perform a remote operation.</p> 6957 6958<p>The only command recognized is the name of an image file to load.</p> 6959 6960<p>If you have more than one <a href="display.html">display</a> application 6961running simultaneously, use the <a href="command-line-options.html#window"> window</a> option to 6962specify which application to control.</p> 6963 6964<div style="margin: auto;"> 6965 <h3 class="magick-header"><a id="render"></a>-render</h3> 6966</div> 6967 6968<p class="magick-description">render vector operations.</p> 6969 6970<p>Use <a href="command-line-options.html#render">+render</a> to turn off rendering vector operations. 6971This useful when saving the result to vector formats such as MVG or SVG.</p> 6972 6973<div style="margin: auto;"> 6974<h3 class="magick-header"><a id="repage"></a>-repage <var>geometry</var></h3> 6975</div> 6976 6977<p class="magick-description">Adjust the canvas and offset information of the image.</p> 6978 6979<p>This option is like <a href="command-line-options.html#page">-page</a> but acts as an image operator 6980rather than a setting. You can separately set the canvas size or the offset 6981of the image on that canvas by only providing those components. </p> 6982 6983<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 6984 6985<p>If a <code>!</code> flag is given the offset given is added to the existing 6986offset to move the image relative to its previous position. This useful for 6987animation sequences. </p> 6988 6989<p>A given a canvas size of zero such as '<code>0x0</code>' forces it to 6990recalculate the canvas size so the image (at its current offset) will appear 6991completely on that canvas (unless it has a negative offset).</p> 6992 6993<p>Use <a href="command-line-options.html#repage">+repage</a> to completely remove/reset the virtual 6994canvas meta-data from the images. </p> 6995 6996<p>The <a href="command-line-options.html#set">-set</a> '<code>page</code>' option can be used to 6997directly assign virtual canvas meta-data. </p> 6998 6999 7000<div style="margin: auto;"> 7001 <h3 class="magick-header"><a id="resample"></a>-resample <var>horizontal</var>x<var>vertical</var></h3> 7002</div> 7003 7004<p class="magick-description">Resample image to specified horizontal and vertical resolution.</p> 7005 7006<p>Resize the image so that its rendered size remains the same as the original 7007at the specified target resolution. For example, if a 300 DPI image renders at 70083 inches by 2 inches on a 300 DPI device, when the image has been resampled to 700972 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that 7010only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of 7011storing the image resolution. For formats which do not support an image 7012resolution, the original resolution of the image must be specified via <a href="command-line-options.html#density">-density</a> on the command line prior to specifying the 7013resample resolution.</p> 7014 7015<p>Note that Photoshop stores and obtains image resolution from a proprietary 7016embedded profile. If this profile exists in the image, then Photoshop will 7017continue to treat the image using its former resolution, ignoring the image 7018resolution specified in the standard file header.</p> 7019 7020<div style="margin: auto;"> 7021 <h3 class="magick-header"><a id="resize"></a>-resize <var>geometry</var></h3> 7022</div> 7023 7024<p class="magick-description">Resize an image.</p> 7025 7026<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are 7027ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p> 7028 7029<p>If the <a href="command-line-options.html#filter">-filter</a> option 7030or <code>-define filter:option=value</code> precedes the <a href="command-line-options.html#resize">-resize</a> option, the image is resized with the specified 7031filter.</p> 7032 7033<p>Many image processing algorithms assume your image is in a linear-light 7034coding. If your image is gamma-corrected, you can remove the nonlinear gamma 7035correction, apply the transform, then restore it like this:</p> 7036 7037<pre> 7038convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \ 7039 -quality 92 passport.jpg 7040</pre> 7041 7042<div style="margin: auto;"> 7043 <h3 class="magick-header"><a id="respect-parentheses"></a>-respect-parentheses</h3> 7044</div> 7045 7046<p class="magick-description">settings remain in effect until parenthesis boundary.</p> 7047 7048<div style="margin: auto;"> 7049 <h3 class="magick-header"><a id="reverse"></a>-reverse</h3> 7050</div> 7051 7052<p class="magick-description">Reverse the order of images in the current image list.</p> 7053 7054 7055<div style="margin: auto;"> 7056 <h3 class="magick-header"><a id="roll"></a>-roll {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3> 7057</div> 7058 7059<p class="magick-description">roll an image vertically or horizontally by the amount given.</p> 7060 7061<p>A negative <var>x</var> offset rolls the image right-to-left. 7062A negative <var>y</var> offset rolls the image bottom-to-top.</p> 7063 7064 7065<div style="margin: auto;"> 7066 <h3 class="magick-header"><a id="rotate"></a>-rotate <var>degrees</var>{<var><</var>}{<var>></var>}</h3> 7067</div> 7068 7069<p class="magick-description">Apply Paeth image rotation (using shear operations) to the image.</p> 7070 7071<p>Use <code>></code> to rotate the image only if its width exceeds the 7072height. <code><</code> rotates the image <var>only</var> if its width is less 7073than the height. For example, if you specify <code>-rotate "-90>"</code> and 7074the image size is 480x640, the image is not rotated. However, if the image is 7075640x480, it is rotated by -90 degrees. If you use <code>></code> or 7076<code><</code>, enclose it in quotation marks to prevent it from being 7077misinterpreted as a file redirection.</p> 7078 7079<p>Empty triangles in the corners, left over from rotating the image, are 7080filled with the <code>background</code> color. </p> 7081 7082<p>See also the <a href="command-line-options.html#distort">-distort</a> operator and specifically the 7083'<code>ScaleRotateTranslate</code>' distort method. </p> 7084 7085 7086<div style="margin: auto;"> 7087 <h3 class="magick-header"><a id="sample"></a>-sample <var>geometry</var></h3> 7088</div> 7089 7090<p class="magick-description">minify / magnify the image with pixel subsampling and pixel replication, respectively.</p> 7091 7092<p>Change the image size simply by directly sampling the pixels original 7093from the image. When magnifying, pixels are replicated in blocks. When 7094minifying, pixels are sub-sampled (i.e., some rows and columns are skipped 7095over). </p> 7096 7097<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with 7098a <a href="command-line-options.html#filter">-filter</a> setting of <code>point</code> (nearest 7099neighbour), though <a href="command-line-options.html#sample">-sample</a> is a lot faster, as it 7100avoids all the filter processing of the image. As such it completely ignores 7101the current <a href="command-line-options.html#filter">-filter</a> setting. </p> 7102 7103<p>The key feature of the <a href="command-line-options.html#sample">-sample</a> is that no new colors 7104will be added to the resulting image, though some colors may disappear. </p> 7105 7106<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are 7107ignored, unlike <a href="command-line-options.html#resize">-resize</a>. </p> 7108 7109 7110<p>The actual sampling point is the middle of the sub-region being sampled. 7111As such a single pixel sampling of an image will take the middle pixel, (or 7112top-left-middle if image has even dimensions). However the <a href="command-line-options.html#define">-define</a> '<code>sample:offset</code>' can be set to modify 7113this position some other location within each sub-region being sampled, as 7114a percentage offset.</p> 7115 7116<p>By default this value is '<code>50</code>' for the midpoint, but could be set 7117to '<code>0</code>' for top-left, '<code>100</code>' for bottom-right, or with 7118separate X and Y offsets such as '<code>0x50</code>' for left-middle edge of 7119sampling sub-region.</p> 7120 7121 7122<div style="margin: auto;"> 7123 <h3 class="magick-header"><a id="sampling-factor"></a>-sampling-factor <var>horizontal-factor</var>x<var>vertical-factor</var></h3> 7124</div> 7125 7126<p class="magick-description">sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</p> 7127 7128<p>This option specifies the sampling factors to be used by the JPEG encoder 7129for chroma downsampling. If this option is omitted, the JPEG library will use 7130its own default values. When reading or writing the YUV format and when 7131writing the M2V (MPEG-2) format, use <a href="command-line-options.html#sampling-factor">-sampling-factor 2x1</a> or <a href="command-line-options.html#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2 7132downsampling method.</p> 7133 7134<div style="margin: auto;"> 7135 <h3 class="magick-header"><a id="scale"></a>-scale <var>geometry</var></h3> 7136</div> 7137 7138<p class="magick-description">minify / magnify the image with pixel block averaging and pixel replication, respectively.</p> 7139 7140<p>Change the image size simply by replacing pixels by averaging pixels 7141together when minifying, or replacing pixels when magnifying. </p> 7142 7143<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with 7144a <a href="command-line-options.html#filter">-filter</a> setting of <code>box</code>. Though it is a lot 7145faster, as it avoids all the filter processing of the image. As such it 7146completely ignores the current <a href="command-line-options.html#filter">-filter</a> setting. </p> 7147 7148<p>If when shrinking (minifying) images the original image is some integer 7149multiple of the new image size, the number of pixels averaged together to 7150produce the new pixel color is the same across the whole image. This is 7151a special case known as 'binning' and is often used as a method of reducing 7152noise in image such as those generated by digital cameras, especially in low 7153light conditions. </p> 7154 7155 7156<div style="margin: auto;"> 7157 <h3 class="magick-header"><a id="scene"></a>-scene <var>value</var></h3> 7158</div> 7159 7160<p class="magick-description">set scene number.</p> 7161 7162<p>This option sets the scene number of an image or the first image in an image sequence.</p> 7163 7164<div style="margin: auto;"> 7165 <h3 class="magick-header"><a id="screen"></a>-screen</h3> 7166</div> 7167 7168<p class="magick-description">specify the screen to capture.</p> 7169 7170<p>This option indicates that the GetImage request used to obtain the image 7171should be done on the root window, rather than directly on the specified 7172window. In this way, you can obtain pieces of other windows that overlap the 7173specified window, and more importantly, you can capture menus or other popups 7174that are independent windows but appear over the specified window.</p> 7175 7176<div style="margin: auto;"> 7177 <h3 class="magick-header"><a id="seed"></a>-seed</h3> 7178</div> 7179 7180<p class="magick-description">seed a new sequence of pseudo-random numbers</p> 7181 7182<div style="margin: auto;"> 7183 <h3 class="magick-header"><a id="segment"></a>-segment <var>cluster-threshold</var>x<var>smoothing-threshold</var></h3> 7184</div> 7185 7186<p class="magick-description">segment the colors of an image.</p> 7187 7188<p>Segment an image by analyzing the histograms of the color components and 7189identifying units that are homogeneous with the fuzzy c-means technique. This 7190is part of the ImageMagick color quantization routines. </p> 7191 7192<p>Specify <var>cluster threshold</var> as the number of pixels in 7193each cluster that must exceed the cluster threshold to be considered valid. 7194<var>Smoothing threshold</var> eliminates noise in the second 7195derivative of the histogram. As the value is increased, you can expect 7196a smoother second derivative. The default is 1.5.</p> 7197 7198<p>If the <a href="command-line-options.html#verbose">-verbose</a> setting is defined, a detailed report 7199of the color clusters is returned.</p> 7200 7201 7202<div style="margin: auto;"> 7203 <h3 class="magick-header"><a id="selective-blur"></a>-selective-blur <var>radius</var><br>-selective-blur <var>radius</var>x<var>sigma</var>{<var>+threshold</var>}</h3> 7204</div> 7205 7206<p class="magick-description">Selectively blur pixels within a contrast threshold.</p> 7207 7208<p>Blurs those pixels that are less than or equal to the threshold in 7209contrast. The threshold may be expressed as a fraction of <var>QuantumRange</var> or as a percentage.</p> 7210 7211<div style="margin: auto;"> 7212 <h3 class="magick-header"><a id="separate"></a>-separate</h3> 7213</div> 7214 7215<p class="magick-description">separate an image channel into a grayscale image. Specify the channel with <a href="command-line-options.html#channel">-channel</a>.</p> 7216 7217<div style="margin: auto;"> 7218 <h3 class="magick-header"><a id="sepia-tone"></a>-sepia-tone <var>threshold</var></h3> 7219</div> 7220 7221<p class="magick-description">simulate a sepia-toned photo.</p> 7222 7223<p>Specify <var>threshold</var> as the percent threshold of the intensity (0 - 99.9%).</p> 7224 7225<p>This option applies a special effect to the image, similar to the effect 7226achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to <var>QuantumRange</var> and is a measure of the extent of the sepia 7227toning. A threshold of 80% is a good starting point for a reasonable 7228tone.</p> 7229 7230 7231 7232<div style="margin: auto;"> 7233 <h3 class="magick-header"><a id="set"></a>-set <var>key value</var></h3> 7234 <h3 class="magick-header">+set <var>key</var></h3> 7235</div> 7236 7237<p class="magick-description">sets image attributes and properties for images in the current image sequence.</p> 7238 7239<p>This will assign (or modify) specific settings attached to all the images 7240in the current image sequence. Using the <a href="command-line-options.html#set">+set</a> form of the 7241option will either remove, or reset that setting to a default state, as 7242appropriate. </p> 7243 7244<p>For example, it will modify specific well known image meta-data 7245'attributes' such as those normally overridden by: the options <a href="command-line-options.html#delay">-delay</a>, <a href="command-line-options.html#dispose">-dispose</a>, and <a href="command-line-options.html#page">-page</a>, <a href="command-line-options.html#colorspace">-colorspace</a>; generally 7246assigned before the image is read in, by using a <var>key</var> of 7247the same name. </p> 7248 7249<p>If the given <var>key</var> does not match a specific known 7250'attribute ', such as shown above, the setting is stored as a a free form 7251'property' string. Such settings are listed in <a href="command-line-options.html#verbose">-verbose</a> information ("<code>info:</code>" output format) as "Properties". 7252</p> 7253 7254<p>This includes string 'properties' that are set by and assigned to images 7255using the options <a href="command-line-options.html#comment">-comment</a>, <a href="command-line-options.html#label">-label</a>, <a href="command-line-options.html#caption">-caption</a>. These options actually assign 7256a global 'artifact' which are automatically assigned (and any <a href="escape.html">Format Percent 7257Escapes</a> expanded) to images as they are read in. For example:</p> 7258 7259<pre> 7260convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png 7261identify -format %c rose.png 7262Rose is a rose is a rose is a rose 7263</pre> 7264 7265<p>The set value can also make use of <a href="escape.html">Format and Print Image 7266Properties</a> in the defined value. For example:</p> 7267 7268<pre> 7269convert rose: -set origsize '%wx%h' -resize 50% \ 7270 -format 'Old size = %[origsize] New size = %wx%h' info: 7271Old size = 70x46 New size = 35x23 7272</pre> 7273 7274<p>Other well known 'properties' that are availible include: 7275'<code>date:create</code>' and '<code>date:modify</code>' and 7276'<code>signature</code>'. </p> 7277 7278<p>The <a href="command-line-options.html#repage">-repage</a> operator will also allow you to modify 7279the '<code>page</code>' attribute of an image for images already in memory (also 7280see <a href="command-line-options.html#repage">-page</a>). However it is designed to provide a finer 7281control of the sub-parts of this 'attribute'. The <a href="command-line-options.html#set">-set page</a> 7282option will only provide a direct, unmodified assignment of '<code>page</code>' 7283attribute. </p> 7284 7285<p>This option can also associate a colorspace or profile with your image. 7286For example,</p> 7287 7288<pre> 7289convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd 7290</pre> 7291 7292<p>Some 'properties' must be defined in a specific way to be used. For 7293example only 'properties' prefixed with "<code>filename:</code>" can be used to 7294modify the output filename of an image. For example</p> 7295 7296<pre> 7297convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png' 7298</pre> 7299 7300<p>If the setting value is prefixed with "<code>option:</code>" the setting will 7301be saved as a global "Artifact" exactly as if it was set using the <a href="command-line-options.html#define">-define</a> option. As such settings are global in scope, they 7302can be used to pass 'attributes' and 'properties' of one specific image, 7303in a way that allows you to use them in a completely different image, even if 7304the original image has long since been modified or destroyed. For example: </p> 7305 7306<pre> 7307convert rose: -set option:rosesize '%wx%h' -delete 0 \ 7308 label:'%[rosesize]' label_size_of_rose.gif" 7309</pre> 7310 7311<p>Note that <a href="escape.html">Format Percent Escapes</a> will only match 7312a 'artifact' if the given <var>key</var> does not match an existing 7313'attribute' or 'property'. </p> 7314 7315<p>You can set the attributes of the image registry by prefixing the value 7316with <code>registry:</code>.</p> 7317 7318<p>The <a href="command-line-options.html#set">-set profile</a> option can also be used to inject 7319previously-formatted ancillary chunks into the output PNG file, using 7320the commandline option as shown below or by setting the profile via a 7321programming interface:</p> 7322 7323<pre> 7324convert in.png -set profile PNG-chunk-x:<filename> out.png 7325</pre> 7326 7327<p>where <var>x</var> is a location flag and 7328<var>filename</var> is a file containing the chunk 7329name in the first 4 bytes, then a colon (":"), followed by the chunk data. 7330This encoder will compute the chunk length and CRC, so those must not 7331be included in the file.</p> 7332 7333<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT), 7334or "e" (end, i.e., after IDAT). If you want to write multiple chunks 7335of the same type, then add a short unique string after the "x" to prevent 7336subsequent profiles from overwriting the preceding ones, e.g.,</p> 7337 7338 7339<pre> 7340convert in.png -set profile PNG-chunk-b01:file01 \ 7341 -profile PNG-chunk-b02:file02 out.png 7342</pre> 7343 7344<div style="margin: auto;"> 7345 <h3 class="magick-header"><a id="shade"></a>-shade <var>azimuth</var>x<var>elevation</var></h3> 7346</div> 7347 7348<p class="magick-description">shade the image using a distant light source.</p> 7349 7350<p>Specify <var>azimuth</var> and <var>elevation</var> as 7351the position of the light source. Use <a href="command-line-options.html#shade">+shade</a> to return 7352the shading results as a grayscale image.</p> 7353 7354<div style="margin: auto;"> 7355 <h3 class="magick-header"><a id="shadow"></a>-shadow <var>percent-opacity</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3> 7356</div> 7357 7358<p class="magick-description">simulate an image shadow.</p> 7359 7360<div style="margin: auto;"> 7361 <h3 class="magick-header"><a id="shared-memory"></a>-shared-memory</h3> 7362</div> 7363 7364<p class="magick-description">use shared memory.</p> 7365 7366<p>This option specifies whether the utility should attempt to use shared 7367memory for pixmaps. ImageMagick must be compiled with shared memory support, 7368and the display must support the <var>MIT-SHM</var> extension. 7369Otherwise, this option is ignored. The default is <code>True</code>.</p> 7370 7371<div style="margin: auto;"> 7372 <h3 class="magick-header"><a id="sharpen"></a>-sharpen <var>radius</var><br>-sharpen <var>radius</var>x<var>sigma</var></h3> 7373</div> 7374 7375<p class="magick-description">sharpen the image.</p> 7376 7377<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p> 7378 7379<div style="margin: auto;"> 7380 <h3 class="magick-header"><a id="shave"></a>-shave <var>geometry</var></h3> 7381</div> 7382 7383<p class="magick-description">Shave pixels from the image edges.</p> 7384 7385<p>The <var>size</var> portion of the <var>geometry</var> 7386argument specifies the width of the region to be removed from both sides of 7387the image and the height of the regions to be removed from top and bottom. 7388Offsets are ignored.</p> 7389 7390<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 7391 7392<div style="margin: auto;"> 7393 <h3 class="magick-header"><a id="shear"></a>-shear <var>Xdegrees</var>[x<var>Ydegrees</var>]</h3> 7394</div> 7395 7396<p class="magick-description">Shear the image along the x-axis and/or y-axis.</p> 7397 7398<p>The shear angles may be positive, negative, or zero. When <var>Ydegrees</var> is omitted it defaults to 0. When both angles are 7399given, the horizontal component of the shear is performed before the vertical 7400component.</p> 7401 7402<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e., 7403horizontally or vertically, respectively),creating a parallelogram. The amount 7404of each is controlled by the respective shear angle. For horizontal shears, 7405<var>Xdegrees</var> is measured clockwise relative to "up" (the 7406negative y-axis), sliding the top edge to the right when 0°<<var>Xdegrees</var><90° and to the left when 90°<<var>Xdegrees</var><180°. For vertical shears <var>Ydegrees</var> is measured clockwise relative to "right" (the 7407positive x-axis), sliding the right edge down when 0°<<var>Ydegrees</var><90° and up when 90°<<var>Ydegrees</var><180°.</p> 7408 7409<p>Empty triangles left over from shearing the image are filled with the color 7410defined by the <a href="command-line-options.html#fill">-background</a> option. The color is specified 7411using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 7412 7413<p>The horizontal shear is performed before the vertical part. This is 7414important to note, since horizontal and vertical shears do not 7415<var>commute</var>, i.e., the order matters in a sequence of shears. For 7416example, the following two commands are not equivalent.</p> 7417 7418<pre> 7419convert logo: -shear 20x0 -shear 0x60 logo-sheared.png 7420convert logo: -shear 0x60 -shear 20x0 logo-sheared.png 7421</pre> 7422 7423<p>The first of the two commands above is equivalent to the following, except 7424for the amount of empty space created; the command that follows generates 7425a smaller image, and so is a better choice in terms of time and space.</p> 7426 7427<pre> 7428convert logo: -shear 20x60 logo-sheared.png 7429</pre> 7430 7431<div style="margin: auto;"> 7432 <h3 class="magick-header"><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <var>contrast</var>x<var>mid-point</var></h3> 7433</div> 7434 7435<p class="magick-description">increase the contrast without saturating highlights or shadows.</p> 7436 7437<p>Increase the contrast of the image using a sigmoidal transfer function 7438without saturating highlights or shadows. <var>Contrast</var> 7439indicates how much to increase the contrast. For example, 0 is none, 3 is 7440typical and 20 is a lot. 7441</p> 7442 7443<p>The <var>mid-point</var> indicates where the maximum change 7444'slope' in contrast should fall in the resultant image (0 is white; 50% is 7445middle-gray; 100% is black). </p> 7446 7447<p>By default the image contrast is increased, use <var>+sigmoidal-contrast</var> to decrease the contrast.</p> 7448 7449<p>To achieve the equivalent of a sigmoidal brightness change (similar to 7450a gamma adjustment), you would use <var>-sigmoidal-contrast 7451{brightness}x0%</var> to increase brightness and <var>+sigmoidal-contrast {brightness}x0%</var> to decrease brightness. 7452Note the use of '0' fo rthe mid-point of the sigmoidal curve. </p> 7453 7454<p>Using a very high <var>contrast</var> will produce a sort of 7455'smoothed thresholding' of the image. Not as sharp (with high aliasing 7456effects) of a true threshold, but with tapered gray-levels around the threshold 7457<var>mid-point</var>. </p> 7458 7459<div style="margin: auto;"> 7460 <h3 class="magick-header"><a id="silent"></a>-silent</h3> 7461</div> 7462 7463<p class="magick-description">operate silently.</p> 7464 7465<div style="margin: auto;"> 7466 <h3 class="magick-header"><a id="similarity-threshold"></a>-similarity-threshold <var>value</var></h3> 7467</div> 7468 7469<p class="magick-description">minimum RMSE for subimage match.</p> 7470 7471<p>If this setting is used, then the search will stop as soon as it finds a match whose metric is less than or equal to the value. A partially filled second output image will result. Using a value of zero, will cause the search to stop at the first perfect match it finds. If this setting is left off, then the search will proceed to completion or as limited by <var>-dissimilarity-threshold</var>.</p> 7472 7473<div style="margin: auto;"> 7474 <h3 class="magick-header"><a id="size"></a>-size <var>width</var>[x<var>height</var>][<var>+offset</var>]</h3> 7475</div> 7476 7477<p class="magick-description">set the width and height of the image.</p> 7478 7479<p>Use this option to specify the width and height of raw images whose 7480dimensions are unknown such as <code>GRAY</code>, <code>RGB</code>, or 7481<code>CMYK</code>. In addition to width and height, use <a href="command-line-options.html#size">-size</a> with an offset to skip any header information in the 7482image or tell the number of colors in a <code>MAP</code> image file, (e.g. -size 7483640x512+256).</p> 7484 7485<p>For Photo CD images, choose from these sizes:</p> 7486 7487<pre> 7488192x128 7489384x256 7490768x512 74911536x1024 74923072x2048 7493</pre> 7494 7495<div style="margin: auto;"> 7496 <h3 class="magick-header"><a id="sketch"></a>-sketch <var>radius</var><br>-sketch <var>radius</var>x<var>sigma</var>+<var>angle</var></h3> 7497</div> 7498 7499<p class="magick-description">simulate a pencil sketch.</p> 7500 7501<p>Sketch with the given radius, standard deviation (sigma), and angle. The 7502angle given is the angle toward which the image is sketched. That is the 7503direction people would consider the object is coming from. </p> 7504 7505<div style="margin: auto;"> 7506 <h3 class="magick-header"><a id="smush"></a>-smush <var>offset</var></h3> 7507</div> 7508 7509<p class="magick-description">smush an image sequence together.</p> 7510 7511<div style="margin: auto;"> 7512 <h3 class="magick-header"><a id="snaps"></a>-snaps <var>value</var></h3> 7513</div> 7514 7515<p class="magick-description">Set the number of screen snapshots.</p> 7516 7517<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p> 7518 7519<div style="margin: auto;"> 7520 <h3 class="magick-header"><a id="solarize"></a>-solarize <var>threshold</var></h3> 7521</div> 7522 7523<p class="magick-description">negate all pixels above the threshold level.</p> 7524 7525<p>Specify <var>factor</var> as the percent threshold of the intensity (0 - 99.9%).</p> 7526 7527<p>This option produces a <var>solarization</var> effect seen when 7528exposing a photographic film to light during the development process.</p> 7529 7530<div style="margin: auto;"> 7531 <h3 class="magick-header"><a id="sparse-color"></a>-sparse-color <var>method</var> '<var>x</var>,<var>y</var> <var>color</var> ...'</h3> 7532</div> 7533 7534<p class="magick-description"> color the given image using the specified points of color, and filling the other intervening colors using the given methods. </p> 7535 7536 7537<table class="table table-condensed table-striped"> 7538 <tbody> 7539 <tr> 7540 <th style="width: 8%">Method</th> 7541 <th>Description</th> 7542 </tr> 7543 7544 <tr> 7545 <td>barycentric</td> 7546 <td>three point triangle of color given 3 points. 7547 Giving only 2 points will form a linear gradient between those points. 7548 The gradient generated extends beyond the triangle created by those 7549 3 points. </td> 7550 </tr> 7551 7552 <tr> 7553 <td>bilinear</td> 7554 <td>Like barycentric but for 4 points. Less than 4 points 7555 fall back to barycentric. </td> 7556 </tr> 7557 <tr> 7558 <td>voronoi</td> 7559 <td>Simply map each pixel to the to nearest color point 7560 given. The result are polygonal 'cells' of solid color. </td> 7561 </tr> 7562 7563 <tr> 7564 <td>shepards</td> 7565 <td>Colors points biased on the ratio of inverse distance 7566 squared. Generating spots of color in a sea of the average of 7567 colors. </td> 7568 </tr> 7569 7570 <tr> 7571 <td>inverse</td> 7572 <td>Colors points biased on the ratio of inverse distance. 7573 This generates sharper points of color rather than rounded spots of 7574 '<code>shepards</code>' Generating spots of color in a sea of the 7575 average of colors. </td> 7576 </tr> 7577 7578 </tbody> 7579</table> 7580 7581<p>The points are placed according to the images location on the virtual 7582canvas (<a href="command-line-options.html#page">-page</a> or <a href="command-line-options.html#repage">-repage</a> 7583offset), and do not actually have to exist on the given image, but may be 7584some point beyond the edge of the image. All points are floating point values. 7585</p> 7586 7587<p>Only the color channels defined by the <a href="command-line-options.html#channel">-channel</a> are 7588modified, which means that by default matte/alpha transparency channel is not 7589effected. Typically transparency channel is turned off either before or after 7590the operation. </p> 7591 7592<p>Of course if some color points are transparent to generate a transparent 7593gradient, then the image also requires transparency enabled to store the 7594values. </p> 7595 7596<p>All the above methods when given a single point of color will replace all 7597the colors in the image with the color given, regardless of the point. This is 7598logical, and provides an alternative technique to recolor an image to some 7599default value. </p> 7600 7601 7602<div style="margin: auto;"> 7603 <h3 class="magick-header"><a id="splice"></a>-splice <var>geometry</var></h3> 7604</div> 7605 7606<p class="magick-description">Splice the current background color into the image.</p> 7607 7608<p>This will add rows and columns of the current <a href="command-line-options.html#background">-background</a> color into the given image according to the 7609given <a href="command-line-options.html#gravity">-gravity</a> geometry setting. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Essentially <a href="command-line-options.html#splice">-splice</a> will divide the 7610image into four quadrants, separating them by the inserted rows and columns. 7611</p> 7612 7613<p>If a dimension of geometry is zero no rows or columns will be added for that 7614dimension. Similarly using a zero offset with the appropriate <a href="command-line-options.html#gravity">-gravity</a> setting will add rows and columns to the edges of 7615the image, padding the image only along that one edge. Edge padding is what <a href="command-line-options.html#splice">-splice</a> is most commonly used for. </p> 7616 7617<p>If the exact same <var>geometry</var> and <a href="command-line-options.html#gravity">-gravity</a> is later used with <a href="command-line-options.html#chop">-chop</a> the 7618added added all splices removed. </p> 7619 7620<div style="margin: auto;"> 7621 <h3 class="magick-header"><a id="spread"></a>-spread <var>amount</var></h3> 7622</div> 7623 7624<p class="magick-description">displace image pixels by a random amount.</p> 7625 7626<p>The argument <var>amount</var> defines the size of the 7627neighborhood around each pixel from which to choose a candidate pixel to 7628swap.</p> 7629 7630<div style="margin: auto;"> 7631 <h3 class="magick-header"><a id="statistic"></a>-statistic <var>type</var> <var>geometry</var></h3> 7632</div> 7633 7634<p class="magick-description">replace each pixel with corresponding statistic from the neighborhood.</p> 7635 7636<p>Choose from these statistic types:</p> 7637<dl class="dl-horizontal"> 7638<dt>Gradient</dt><dd>maximum difference (max - min) value in neighborhood</dd> 7639<dt>Maximum</dt><dd>maximum value per channel in neighborhood</dd> 7640<dt>Minimum</dt><dd>minimum value per channel in neighborhood</dd> 7641<dt>Mean</dt><dd>average value per channel in neighborhood</dd> 7642<dt>Median</dt><dd>median value per channel in neighborhood</dd> 7643<dt>Mode</dt><dd>mode (most frequent) value per channel in neighborhood</dd> 7644<dt>Nonpeak</dt><dd>value just before or after the median value per channel in neighborhood</dd> 7645<dt>RMS</dt><dd>root mean square value per channel in neighborhood</dd> 7646<dt>StandardDeviation</dt><dd> standard deviation value per channel in neighborhood</dd> 7647</dl> 7648 7649<div style="margin: auto;"> 7650 <h3 class="magick-header"><a id="stegano"></a>-stegano <var>offset</var></h3> 7651</div> 7652 7653<p class="magick-description">hide watermark within an image.</p> 7654 7655<p>Use an offset to start the image hiding some number of pixels from the 7656beginning of the image. Note this offset and the image size. You will need 7657this information to recover the steganographic image (e.g. display -size 7658320x256+35 stegano:image.png).</p> 7659 7660<div style="margin: auto;"> 7661 <h3 class="magick-header"><a id="stereo"></a>-stereo <var>+x</var>{<var>+y</var>}</h3> 7662</div> 7663 7664<p class="magick-description">composite two images to create a red / cyan stereo anaglyph.</p> 7665 7666<p>The left side of the stereo pair (second image) is saved as the red channel of the output image. The right side (first image) is saved as the green and blue channels. Red-green stereo glasses are required to properly view the stereo image.</p> 7667 7668<div style="margin: auto;"> 7669 <h3 class="magick-header"><a id="storage-type"></a>-storage-type <var>type</var></h3> 7670</div> 7671 7672<p class="magick-description">pixel storage type. Here are the valid types:</p> 7673 7674<pre> 7675char unsigned characters 7676double doubles 7677float floats 7678integer integers 7679long longs 7680quantum pixels in the native depth of your ImageMagick distribution 7681short unsigned shorts 7682</pre> 7683 7684<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels 7685values range from 0 to the maximum value the storage type can support.</p> 7686 7687<div style="margin: auto;"> 7688 <h3 class="magick-header"><a id="stretch"></a>-stretch <var>fontStretch</var></h3> 7689</div> 7690 7691<p class="magick-description">Set a type of stretch style for fonts.</p> 7692 7693<p>This setting suggests a type of stretch that ImageMagick should try to 7694apply to the currently selected font family. Select <var>fontStretch</var> from the following.</p> 7695 7696<pre> 7697Any 7698Condensed 7699Expanded 7700ExtraCondensed 7701ExtraExpanded 7702Normal 7703SemiCondensed 7704SemiExpanded 7705UltraCondensed 7706UltraExpanded 7707</pre> 7708 7709<p>To print a complete list of stretch types, use <a href="command-line-options.html#list">-list 7710stretch</a>.</p> 7711 7712<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p> 7713 7714<div style="margin: auto;"> 7715 <h3 class="magick-header"><a id="strip"></a>-strip</h3> 7716</div> 7717 7718<p class="magick-description">strip the image of any profiles or comments.</p> 7719 7720<div style="margin: auto;"> 7721 <h3 class="magick-header"><a id="stroke"></a>-stroke <var>color</var></h3> 7722</div> 7723 7724<p class="magick-description">color to use when stroking a graphic primitive.</p> 7725 7726<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 7727 7728<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p> 7729 7730<div style="margin: auto;"> 7731 <h3 class="magick-header"><a id="strokewidth"></a>-strokewidth <var>value</var></h3> 7732</div> 7733 7734<p class="magick-description">set the stroke width.</p> 7735 7736<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p> 7737 7738<div style="margin: auto;"> 7739 <h3 class="magick-header"><a id="style"></a>-style <var>fontStyle</var></h3> 7740</div> 7741 7742<p class="magick-description">Set a font style for text.</p> 7743 7744<p>This setting suggests a font style that ImageMagick should try to apply to 7745the currently selected font family. Select <var>fontStyle</var> from 7746the following.</p> 7747 7748<pre> 7749Any 7750Italic 7751Normal 7752Oblique 7753</pre> 7754 7755<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#weight">-weight</a>. </p> 7756 7757<div style="margin: auto;"> 7758 <h3 class="magick-header"><a id="subimage-search"></a>-subimage-search</h3> 7759</div> 7760 7761<p class="magick-description">search for subimage.</p> 7762 7763<p>This option is required to have compare search for the best match location 7764of a small image within a larger image. This search will produce two images 7765(or two frames). The first is the "difference" image and the second will 7766be the "match score" image.</p> 7767 7768<p>The "match-score" image is smaller containing a pixel for ever possible 7769position of the top-left corner of the given sub-image. that is its size will 7770be the size of the larger_image - sub_image + 1. The brightest location in 7771this image is the location s the locate on the best match that is also 7772reported. Note that this may or may not be a perfect match, and the actual 7773brightness will reflect this. Other bright 'peaks' can be used to locate other 7774possible matching locations. </p> 7775 7776<p>Note that the search will try to compare the sub-image at every possible 7777location in the larger image, as such it can be very slow. The smaller the 7778sub-image the faster this search is. </p> 7779 7780 7781<div style="margin: auto;"> 7782 <h3 class="magick-header"><a id="swap"></a>-swap <var>index,index</var></h3> 7783</div> 7784 7785<p class="magick-description">Swap the positions of two images in the image sequence.</p> 7786 7787<p>For example, <a href="command-line-options.html#swap">-swap 0,2</a> swaps the first and the third 7788images in the current image sequence. Use <a href="command-line-options.html#swap">+swap</a> to switch 7789the last two images in the sequence.</p> 7790 7791<div style="margin: auto;"> 7792 <h3 class="magick-header"><a id="swirl"></a>-swirl <var>degrees</var></h3> 7793</div> 7794 7795<p class="magick-description">swirl image pixels about the center.</p> 7796 7797<p><var>Degrees</var> defines the tightness of the swirl.</p> 7798 7799<div style="margin: auto;"> 7800 <h3 class="magick-header"><a id="synchronize"></a>-synchronize</h3> 7801</div> 7802 7803<p class="magick-description">synchronize image to storage device.</p> 7804 7805<p>Set to "true" to ensure all image data is fully flushed and synchronized 7806to disk. There is a performance penalty, but the benefits include ensuring a 7807valid image file in the event of a system crash and early reporting if there 7808is not enough disk space for the image pixel cache.</p> 7809 7810<div style="margin: auto;"> 7811 <h3 class="magick-header"><a id="taint"></a>-taint</h3> 7812</div> 7813 7814<p class="magick-description">Mark the image as modified.</p> 7815 7816<div style="margin: auto;"> 7817 <h3 class="magick-header"><a id="text-font"></a>-text-font <var>name</var></h3> 7818</div> 7819 7820<p class="magick-description">font for writing fixed-width text.</p> 7821 7822<p>Specifies the name of the preferred font to use in fixed (typewriter style) 7823formatted text. The default is 14 point <var>Courier</var>.</p> 7824 7825<p>You can tag a font to specify whether it is a PostScript, TrueType, or 7826OPTION1 font. For example, <code>Courier.ttf</code> is a TrueType font and 7827<code>x:fixed</code> is OPTION1.</p> 7828 7829<div style="margin: auto;"> 7830 <h3 class="magick-header"><a id="texture"></a>-texture <var>filename</var></h3> 7831</div> 7832 7833<p class="magick-description">name of texture to tile onto the image background.</p> 7834 7835<div style="margin: auto;"> 7836 <h3 class="magick-header"><a id="threshold"></a>-threshold <var>value</var>{<var>%</var>}</h3> 7837</div> 7838 7839<!-- {<var>green,blue,opacity</var>} 7840<p>If the green or blue value is omitted, these channels use the same value as 7841the first one provided. If all three color values are the same, the result is 7842a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used 7843and any partially transparent pixel becomes fully transparent.</p> 7844--> 7845 7846<p class="magick-description">Apply simultaneous black/white threshold to the image.</p> 7847 7848<p>Any pixel values (more specifically, those channels set using <a href="command-line-options.html#channel">‑channel</a>) that exceed the specified threshold are reassigned the 7849maximum channel value, while all other values are assigned the minimum.</p> 7850 7851<p> The threshold value can be given as a percentage or as an absolute integer 7852value corresponding to the desired channel value. When given as an integer, 7853the minimum attainable value is 0 (corresponding to black when all channels 7854are affected), but the maximum value (corresponding to white) is that of the 7855<code>quantum depth</code> of the particular build of ImageMagick, and is 7856therefore dependent on the installation. For that reason, a reasonable 7857recommendation for most applications is to specify the threshold values as 7858a percentage. </p> 7859 7860<p> The following would force pixels with red values above 50% to have 100% 7861red values, while those at or below 50% red would be set to 0 in the red 7862channel. The green, blue, and alpha channels (if present) would be unchanged. 7863</p> 7864 7865<pre> 7866convert in.png -channel red -threshold 50% out.png 7867</pre> 7868 7869<p>As (possibly) impractical but instructive examples, the following would 7870generate an all-black and an all-white image with the same dimensions as the 7871input image.</p> 7872 7873 7874<pre> 7875convert in.png -threshold 100% black.png 7876convert in.png -threshold -1 white.png 7877</pre> 7878 7879<p>Note that the values of the transparency channel is treated as 'matte' 7880values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 7881 7882<p> See also <a href="command-line-options.html#black-threshold">‑black‑threshold</a> and <a href="command-line-options.html#white-threshold">‑white‑threshold</a>. 7883</p> 7884 7885<div style="margin: auto;"> 7886 <h3 class="magick-header"><a id="thumbnail"></a>-thumbnail <var>geometry</var></h3> 7887</div> 7888 7889<p class="magick-description">Create a thumbnail of the image.</p> 7890 7891<p>This is similar to <a href="command-line-options.html#resize">-resize</a>, except it is optimized 7892for speed and any image profile, other than a color profile, is removed to 7893reduce the thumbnail size. To strip the color profiles as well, add <a href="command-line-options.html#strip">-strip</a> just before of after this option.</p> 7894 7895<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 7896 7897<div style="margin: auto;"> 7898 <h3 class="magick-header"><a id="tile"></a>-tile <var>filename</var></h3> 7899</div> 7900 7901<p class="magick-description">Set the tile image used for filling a subsequent graphic primitive.</p> 7902 7903<div style="margin: auto;"> 7904 <h3 class="magick-header">-tile <var>geometry</var></h3> 7905</div> 7906 7907<p class="magick-description">Specify the layout of images.</p> 7908 7909<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 7910 7911<div style="margin: auto;"> 7912 <h3 class="magick-header">-tile</h3> 7913</div> 7914 7915<p class="magick-description">Specifies that a subsequent composite operation is repeated across and down image.</p> 7916 7917<div style="margin: auto;"> 7918 <h3 class="magick-header"><a id="tile-offset"></a>-tile-offset {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3> 7919</div> 7920 7921<p class="magick-description">Specify the offset for tile images, relative to the background image it is tiled on.</p> 7922 7923<p>This should be set before the tiling image is set by <a href="command-line-options.html#tile">-tile</a> or <a href="command-line-options.html#texture">-texture</a>, or directly applied for 7924creating a tiled canvas using <code>TILE:</code> or <code>PATTERN:</code> input 7925formats. </p> 7926 7927<p>Internally ImageMagick does a <a href="command-line-options.html#roll">-roll</a> of the tile image 7928by the arguments given when the tile image is set. </p> 7929 7930<div style="margin: auto;"> 7931 <h3 class="magick-header"><a id="tint"></a>-tint <var>value</var></h3> 7932</div> 7933 7934<p class="magick-description">Tint the image with the fill color.</p> 7935 7936<p>Tint the image with the fill color.</p> 7937 7938<p>Specify the amount of tinting as a percentage. Pure colors like black, 7939white red, yellow, will not be affected by -tint. Only mid-range colors such 7940as the various shades of grey.</p> 7941 7942<div style="margin: auto;"> 7943 <h3 class="magick-header"><a id="title"></a>-title <var>string</var></h3> 7944</div> 7945 7946<p class="magick-description">Assign a title to displayed image.", "animate", "display", "montage</p> 7947 7948<p>Use this option to assign a specific title to the image. This assigned to 7949the image window and is typically displayed in the window title bar. 7950Optionally you can include the image filename, type, width, height, Exif data, 7951or other image attribute by embedding special format characters described 7952under the <a href="command-line-options.html#format">-format</a> option.</p> 7953 7954<p>For example,</p> 7955 7956<pre> 7957-title "%m:%f %wx%h" 7958</pre> 7959 7960<p>produces an image title of <code>MIFF:bird.miff 512x480</code> for an image 7961titled <code>bird.miff</code> and whose width is 512 and height is 480.</p> 7962 7963 7964<div style="margin: auto;"> 7965 <h3 class="magick-header"><a id="transform"></a>-transform</h3> 7966</div> 7967 7968<p class="magick-description">transform the image.</p> 7969 7970<p>This option applies the transformation matrix from a previous <a href="command-line-options.html#affine">-affine</a> option.</p> 7971 7972<pre> 7973convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg 7974</pre> 7975 7976 7977<p>This operator has been now been superseded by the <a href="command-line-options.html#distort">-distort</a> '<code>AffineProjection</code>' method. </p> 7978 7979 7980<div style="margin: auto;"> 7981 <h3 class="magick-header"><a id="transparent"></a>-transparent <var>color</var></h3> 7982</div> 7983 7984<p class="magick-description">Make this color transparent within the image.</p> 7985 7986<p>The <var>color</var> argument is defined using the format 7987described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz">-fuzz</a> setting can be used to match and replace colors similar to the one 7988given. </p> 7989 7990<p>Use <a href="command-line-options.html#transparent">+transparent</a> to invert the pixels matched. 7991that is make all non-matching colors transparent. </p> 7992 7993<p>The <a href="command-line-options.html#opaque">-opaque</a> operator is exactly the same as <a href="command-line-options.html#transparent">-transparent</a> but replaces the matching color with the 7994current <a href="command-line-options.html#fill">-fill</a> color setting, rather than transparent. 7995However the <a href="command-line-options.html#transparent">-transparent</a> operator also ensures 7996that the image has an alpha channel enabled, as per "<code><a href="command-line-options.html#alpha">-alpha</a> set</code>", and does not require you to modify the <a href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p> 7997 7998<p>Note that this does not define the color as being the 'transparency color' 7999used for color-mapped image formats, such as GIF. For that use <a href="command-line-options.html#transparent-color">-transparent-color</a> </p> 8000 8001 8002<div style="margin: auto;"> 8003 <h3 class="magick-header"><a id="transparent-color"></a>-transparent-color <var>color</var></h3> 8004</div> 8005 8006<p class="magick-description">Set the transparent color.</p> 8007 8008<p>Sometimes this is used for saving to image formats such as 8009GIF and PNG8 which uses this color to represent boolean transparency. This 8010does not make a color transparent, it only defines what color the transparent 8011color is in the color palette of the saved image. Use <a href="command-line-options.html#transparent">-transparent</a> to make an opaque color transparent.</p> 8012 8013<p>This option allows you to have both an opaque visible color, as well as a 8014transparent color of the same color value without conflict. That is, you can 8015use the same color for both the transparent and opaque color areas within an 8016image. This, in turn, frees to you to select a transparent color that is 8017appropriate when an image is displayed by an application that does not handle a 8018transparent color index, while allowing ImageMagick to correctly handle images of this 8019type. </p> 8020 8021<p>The default transparent color is <code>#00000000</code>, which is fully transparent black.</p> 8022 8023<div style="margin: auto;"> 8024 <h3 class="magick-header"><a id="transpose"></a>-transpose</h3> 8025</div> 8026 8027<p class="magick-description">Mirror the image along the top-left to bottom-right diagonal.</p> 8028 8029<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <code>-flip -rotate 90</code>. 8030</p> 8031 8032<div style="margin: auto;"> 8033 <h3 class="magick-header"><a id="transverse"></a>-transverse</h3> 8034</div> 8035 8036<p class="magick-description">Mirror the image along the images bottom-left top-right diagonal. Equivalent to the operations <code>-flop -rotate 90</code>.</p> 8037 8038 8039<div style="margin: auto;"> 8040 <h3 class="magick-header"><a id="treedepth"></a>-treedepth <var>value</var></h3> 8041</div> 8042 8043<p class="magick-description">tree depth for the color reduction algorithm.</p> 8044 8045<p>Normally, this integer value is zero or one. A value of zero or one causes 8046the use of an optimal tree depth for the color reduction algorithm.</p> 8047 8048<p>An optimal depth generally allows the best representation of the source 8049image with the fastest computational speed and the least amount of memory. 8050However, the default depth is inappropriate for some images. To assure the 8051best representation, try values between 2 and 8 for this parameter. Refer to 8052the <a href="quantize.html">color reduction algorithm</a> for more details.</p> 8053 8054<p>The <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#monochrome">-monochrome</a> 8055option, or writing to an image format which requires color reduction, is 8056required for this option to take effect.</p> 8057 8058<div style="margin: auto;"> 8059 <h3 class="magick-header"><a id="trim"></a>-trim</h3> 8060</div> 8061 8062<p class="magick-description">trim an image.</p> 8063 8064<p>This option removes any edges that are exactly the same color as the corner 8065pixels. Use <a href="command-line-options.html#fuzz">-fuzz</a> to make <a href="command-line-options.html#trim">-trim</a> remove 8066edges that are nearly the same color as the corner pixels.</p> 8067 8068<p>The page or virtual canvas information of the image is preserved allowing 8069you to extract the result of the <a href="command-line-options.html#trim">-trim</a> operation from the 8070image. Use a <a href="command-line-options.html#repage">+repage</a> to remove the virtual canvas page 8071information if it is unwanted.</p> 8072 8073<p>If the trimmed image 'disappears' an warning is produced, and a special 8074single pixel transparent 'missed' image is returned, in the same way as when a 8075<a href="command-line-options.html#crop">-crop</a> operation 'misses' the image proper. </p> 8076 8077 8078<div style="margin: auto;"> 8079 <h3 class="magick-header"><a id="type"></a>-type <var>type</var></h3> 8080</div> 8081 8082<p class="magick-description">the image type.</p> <p>Choose from: <code>Bilevel</code>, 8083<code>Grayscale</code>, <code>GrayscaleMatte</code>, <code>Palette</code>, 8084<code>PaletteMatte</code>, <code>TrueColor</code>, <code>TrueColorMatte</code>, 8085<code>ColorSeparation</code>, or <code>ColorSeparationMatte</code>.</p> 8086 8087<p>Normally, when a format supports different subformats such as grayscale and 8088truecolor, the encoder will try to choose an efficient subformat. The <a href="command-line-options.html#type">-type</a> option can be used to override this behavior. For 8089example, to prevent a JPEG from being written in grayscale format even though 8090only gray pixels are present, use.</p> 8091 8092<pre> 8093convert bird.png -type TrueColor bird.jpg 8094</pre> 8095 8096<p>Similarly, use <a href="command-line-options.html#type">-type TrueColorMatte</a> to force the 8097encoder to write an alpha channel even though the image is opaque, if the 8098output format supports transparency.</p> 8099 8100<p>Use <a href="command-line-options.html#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p> 8101 8102<div style="margin: auto;"> 8103 <h3 class="magick-header"><a id="undercolor"></a>-undercolor <var>color</var></h3> 8104</div> 8105 8106<p class="magick-description">set the color of the annotation bounding box.</p> 8107 8108<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p> 8109 8110<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p> 8111 8112 8113<div style="margin: auto;"> 8114 <h3 class="magick-header"><a id="update"></a>-update <var>seconds</var></h3> 8115</div> 8116 8117<p class="magick-description">detect when image file is modified and redisplay.</p> 8118 8119<p>Suppose that while you are displaying an image the file that is currently 8120displayed is over-written. <code>display</code> will automagically detect that 8121the input file has been changed and update the displayed image 8122accordingly.</p> 8123 8124 8125<div style="margin: auto;"> 8126 <h3 class="magick-header"><a id="unique-colors"></a>-unique-colors</h3> 8127</div> 8128 8129<p class="magick-description">discard all but one of any pixel color.</p> 8130 8131 8132<div style="margin: auto;"> 8133 <h3 class="magick-header"><a id="units"></a>-units <var>type</var></h3> 8134</div> 8135 8136<p class="magick-description">the units of image resolution.</p> 8137 8138<p>Choose from: <code>Undefined</code>, <code>PixelsPerInch</code>, or 8139<code>PixelsPerCentimeter</code>. This option is normally used in conjunction 8140with the <a href="command-line-options.html#density">-density</a> option.</p> 8141 8142 8143<div style="margin: auto;"> 8144 <h3 class="magick-header"><a id="unsharp"></a>-unsharp <var>radius</var><br>-unsharp <var>radius</var>x<var>sigma</var>{<var>+gain</var>}{<var>+threshold</var>}</h3> 8145</div> 8146 8147<p class="magick-description">sharpen the image with an unsharp mask operator.</p> 8148 8149<p>The <a href="command-line-options.html#unsharp">-unsharp</a> option sharpens an image. The image is 8150convolved with a Gaussian operator of the given radius and standard deviation 8151(sigma). For reasonable results, radius should be larger than sigma. Use 8152a radius of 0 to have the method select a suitable radius.</p> 8153 8154<p>The parameters are:</p> 8155 8156<pre> 8157 radius The radius of the Gaussian, in pixels, not counting the center 8158 pixel (default 0). 8159 sigma The standard deviation of the Gaussian, in pixels (default 1.0). 8160 gain The fraction of the difference between the original and the blur 8161 image that is added back into the original (default 1.0). 8162 threshold The threshold, as a fraction of <var>QuantumRange</var>, needed to apply the 8163 difference amount (default 0.05). 8164</pre> 8165 8166 8167<div style="margin: auto;"> 8168 <h3 class="magick-header"><a id="verbose"></a>-verbose</h3> 8169</div> 8170 8171<p class="magick-description">print detailed information about the image when this option precedes the <a href="command-line-options.html#identify">-identify</a> option or <code>info:</code>.</p> 8172 8173 8174<div style="margin: auto;"> 8175 <h3 class="magick-header"><a id="version"></a>-version</h3> 8176</div> 8177 8178<p class="magick-description">print ImageMagick version string and exit.</p> 8179 8180 8181<div style="margin: auto;"> 8182 <h3 class="magick-header"><a id="view"></a>-view <var>string</var></h3> 8183</div> 8184 8185<p class="magick-description">FlashPix viewing parameters.</p> 8186 8187 8188<div style="margin: auto;"> 8189 <h3 class="magick-header"><a id="vignette"></a>-vignette <var>radius</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3> 8190</div> 8191 8192<p class="magick-description">soften the edges of the image in vignette style.</p> 8193 8194<p>The vignette effect rolloff is controlled by radiusxsigma. For nominal rolloff, this would be set to 0xsigma. A value of 0x0 will produce a circle/ellipse with no rolloff. The arguments x and y control the size of the circle. Larger values decrease the radii and smaller values increase the radii. Values of +0+0 will generate a circle/ellipse the same size as the image. The default values for x and y are 10% of the corresponding image dimension. Thus, the radii will be decreased by 10%, i.e., the diameters of the circle/ellipse will be 80% of the corresponding image dimension.</p> 8195 8196<div style="margin: auto;"> 8197 <h3 class="magick-header"><a id="virtual-pixel"></a>-virtual-pixel <var>method</var></h3> 8198</div> 8199 8200<p class="magick-description">Specify contents of <var>virtual pixels</var>.</p> 8201 8202<p>This option defines what color source should be used if and when a color 8203lookup completely 'misses' the source image. The color(s) that appear to 8204surround the source image. Generally this color is derived from the source 8205image, but could also be set to a specify background color. </p> 8206 8207<p>Choose from these methods:</p> 8208 8209<dl class="dl-horizontal"> 8210<dt>background</dt><dd>the area surrounding the image is the background color</dd> 8211<dt>black</dt><dd>the area surrounding the image is black</dd> 8212<dt>checker-tile</dt><dd>alternate squares with image and background color</dd> 8213<dt>dither</dt><dd>non-random 32x32 dithered pattern</dd> 8214<dt>edge</dt><dd>extend the edge pixel toward infinity</dd> 8215<dt>gray</dt><dd>the area surrounding the image is gray</dd> 8216<dt>horizontal-tile</dt><dd>horizontally tile the image, background color above/below</dd> 8217<dt>horizontal-tile-edge</dt><dd>horizontally tile the image and replicate the side edge pixels</dd> 8218<dt>mirror</dt><dd>mirror tile the image</dd> 8219<dt>random</dt><dd>choose a random pixel from the image</dd> 8220<dt>tile</dt><dd>tile the image (default)</dd> 8221<dt>transparent</dt><dd>the area surrounding the image is transparent blackness</dd> 8222<dt>vertical-tile</dt><dd>vertically tile the image, sides are background color</dd> 8223<dt>vertical-tile-edge</dt><dd>vertically tile the image and replicate the side edge pixels</dd> 8224<dt>white</dt><dd>the area surrounding the image is white</dd> 8225</dl> 8226 8227<p>The default value is "edge".</p> 8228 8229<p>This most important for distortion operators such as <a href="command-line-options.html#distort">-distort</a>, <a href="command-line-options.html#implode">-implode</a>, and <a href="command-line-options.html#fx">-fx</a>. 8230However it also effects operations that may access pixels just outside the 8231image proper, such as <a href="command-line-options.html#convolve">-convolve</a>, <a href="command-line-options.html#blur">-blur</a>, and <a href="command-line-options.html#sharpen">-sharpen</a>. </p> 8232 8233<p>To print a complete list of virtual pixel types, use the <a href="command-line-options.html#list">-list virtual-pixel</a> option.</p> 8234 8235 8236<div style="margin: auto;"> 8237 <h3 class="magick-header"><a id="visual"></a>-visual <var>type</var></h3> 8238</div> 8239 8240<p class="magick-description">Animate images using this X visual type.", 'animate', 'display'</p> 8241 8242<p>Choose from these visual classes:</p> 8243 8244<pre> 8245StaticGray 8246GrayScale 8247StaticColor 8248PseudoColor 8249TrueColor 8250DirectColor 8251default 8252visual id 8253</pre> 8254 8255<p>The X server must support the visual you choose, otherwise an error occurs. 8256If a visual is not specified, the visual class that can display the most 8257simultaneous colors on the default screen is chosen.</p> 8258 8259 8260<div style="margin: auto;"> 8261 <h3 class="magick-header"><a id="watermark"></a>-watermark <var>brightness</var>x<var>saturation</var></h3> 8262</div> 8263 8264<p class="magick-description">Watermark an image using the given percentages of brightness and saturation.</p> 8265 8266<p>Take a grayscale image (with alpha mask) and modify the destination image's 8267brightness according to watermark image's grayscale value and the 8268<var>brightness</var> percentage. The destinations color saturation 8269attribute is just direct modified by the <var>saturation</var> 8270percentage, which defaults to 100 percent (no color change). </p> 8271 8272 8273<div style="margin: auto;"> 8274 <h3 class="magick-header"><a id="wave"></a>-wave <var>amplitude</var><br>-wave <var>amplitude</var>x<var>wavelength</var></h3> 8275</div> 8276 8277<p class="magick-description">Shear the columns of an image into a sine wave.</p> 8278 8279<p>Specify <var>amplitude</var> and <var>wavelength</var> 8280of the wave.</p> 8281 8282<div style="margin: auto;"> 8283 <h3 class="magick-header"><a id="weight"></a>-weight <var>fontWeight</var></h3> 8284</div> 8285 8286<p class="magick-description">Set a font weight for text.</p> 8287 8288<p>This setting suggests a font weight that ImageMagick should try to apply to 8289the currently selected font family. Use a positive integer for 8290<var>fontWeight</var> or select from the following.</p> 8291 8292<table class="table table-condensed table-striped"> 8293 <col width="25%"> 8294 <col width="75%"> 8295 <thead> 8296 <tr> 8297 <th><var>fontWeight</var></th> 8298 <th>Description</th> 8299 </tr> 8300 </thead> 8301 <tbody> 8302 <tr><td>All </td> 8303 <td>No effect. </td></tr> 8304 <tr><td>Bold </td> 8305 <td>Same as <var>fontWeight</var> = 700.</td></tr> 8306 <tr><td>Bolder </td> 8307 <td>Add 100 to font weight if currently ≤ 800.</td></tr> 8308 <tr><td>Lighter </td> 8309 <td>Subtract 100 to font weight if currently ≤ 100.</td></tr> 8310 <tr><td>Normal </td> 8311 <td>Same as <var>fontWeight</var> = 400.</td></tr> 8312 </tbody> 8313 </table> 8314 8315<p>To print a complete list of weight types, use <a href="command-line-options.html#list">-list 8316weight</a>.</p> 8317 8318<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#style">-style</a>. </p> 8319 8320<div style="margin: auto;"> 8321 <h3 class="magick-header"><a id="white-point"></a>-white-point <var>x,y</var></h3> 8322</div> 8323 8324<p class="magick-description">chromaticity white point.</p> 8325 8326<div style="margin: auto;"> 8327 <h3 class="magick-header"><a id="white-threshold"></a>-white-threshold <var>value</var>{<var>%</var>}</h3> 8328</div> 8329 8330<p class="magick-description">Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</p> 8331 8332<p> The threshold value can be given as a percentage or as an absolute integer 8333value within [0, <var>QuantumRange</var>] corresponding to the 8334desired <a href="command-line-options.html#channel">‑channel</a> value. See <a href="command-line-options.html#threshold">‑threshold</a>for more details on thresholds and resulting values. </p> 8335 8336<div style="margin: auto;"> 8337 <h3 class="magick-header"><a id="window"></a>-window <var>id</var></h3> 8338</div> 8339 8340<p class="magick-description">Make the image the background of a window.", 'animate', 'display'</p> 8341 8342<p><var>id</var> can be a window id or name. Specify <code>root</code> 8343to select X's root window as the target window.</p> 8344 8345<p>By default the image is tiled onto the background of the target window. If 8346<code>backdrop</code> or <a href="command-line-options.html#geometry">-resize</a> are specified, the 8347image is surrounded by the background color. Refer to <code>X RESOURCES</code> 8348for details.</p> 8349 8350<p>The image will not display on the root window if the image has more unique 8351colors than the target window colormap allows. Use <a href="command-line-options.html#colors">-colors</a> to reduce the number of colors.</p> 8352 8353<div style="margin: auto;"> 8354 <h3 class="magick-header"><a id="window-group"></a>-window-group</h3> 8355</div> 8356 8357<p class="magick-description">specify the window group.</p> 8358 8359<div style="margin: auto;"> 8360 <h3 class="magick-header"><a id="write"></a>-write <var>filename</var></h3> 8361</div> 8362 8363<p class="magick-description">write an image sequence.</p> 8364 8365<p>The image sequence preceding the <a href="command-line-options.html#write">-write</a> <var>filename</var> option is written out, and processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the <a href="command-line-options.html#write">+write</a> <var>filename</var> option.</p> 8366 8367<p>Use <a href="command-line-options.html#compress">-compress</a> to specify the type of image compression.</p> 8368</div> 8369</div> 8370 <footer class="magick-footer"> 8371 <div class="magick-nav-item pull-left"> 8372 <a href="support.html">Donate</a> 8373 </div> 8374 <p><a href="sitemap.html">Sitemap</a> • 8375 <a href="links.html">Related</a> • 8376 <a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi">Image Studio</a> • 8377 <a href="http://jqmagick.imagemagick.org/">JqMagick</a> • 8378 <a href="http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> 8379</p> 8380 <p><a href="command-line-options.html#">Back to top</a> • 8381 <a href="http://www.imagemagick.org/script/contact.php">Contact Us</a></p> 8382 <p class="small">© 1999-2015 ImageMagick Studio LLC</p> 8383 </footer> 8384</div><!-- /.container --> 8385 8386 <script src="https://localhost/ajax/libs/jquery/1.11.2/jquery.min.js"></script> 8387 <script src="/js/bootstrap.min.js"></script> 8388 <script type="text/javascript"> 8389 /* <![CDATA[ */ 8390 (function() { 8391 var s = document.createElement('offline-script'), t = document.getElementsByTagName('offline-script')[0]; 8392 s.type = 'text/javascript'; 8393 s.async = true; 8394 s.src = 'http://api.flattr.com/js/0.6/load.js?mode=auto'; 8395 t.parentNode.insertBefore(s, t); 8396 })(); 8397 /* ]]> */ 8398 </script> 8399</div> 8400</body> 8401</html> 8402
