command-line-options.html revision 2e2662acb3a60d153d3fde97541a19db62f7dd84
1 2 3 4 5<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 6 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 7<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" dir="ltr"> 8<head> 9 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> 10 <meta name="verify-v1" content="g222frIIxcQTrvDR3NBRUSKP3AnMNoqxOkIniCEkV7U="/> 11 <title>ImageMagick: Command-line Options</title/> 12 <meta http-equiv="Content-Language" content="en-US"/> 13 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> 14 <meta http-equiv="Reply-to" content="magick-users@imagemagick.org"/> 15 <meta name="Application-name" content="ImageMagick"/> 16 <meta name="Description" content="ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves. ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you can freely use, copy, modify, and distribute. Its license is compatible with the GPL. It runs on all major operating systems. The functionality of ImageMagick is typically utilized from the command line or you can use the features from programs written in your favorite programming language. Choose from these interfaces: MagickCore (C), MagickWand (C), ChMagick (Ch), Magick++ (C++), JMagick (Java), L-Magick (Lisp), PascalMagick (Pascal), PerlMagick (Perl), MagickWand for PHP (PHP), PythonMagick (Python), RMagick (Ruby), or TclMagick (Tcl/TK). With a language interface, use ImageMagick to modify or create images automagically and dynamically."/> 17 <meta name="Application-url" content="http://www.imagemagick.org"/> 18 <meta name="Generator" content="PHP"/> 19 <meta name="Keywords" content="command-line, options, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand, ImageMagickObject, Swiss, Army, Knife, Image, Processing"/> 20 <meta name="Rating" content="GENERAL"/> 21 <meta name="Robots" content="INDEX, FOLLOW"/> 22 <meta name="Generator" content="ImageMagick Studio LLC"/> 23 <meta name="Author" content="ImageMagick Studio LLC"/> 24 <meta name="Revisit-after" content="2 DAYS"/> 25 <meta name="Resource-type" content="document"/> 26 <meta name="Copyright" content="Copyright (c) 1999-2010 ImageMagick Studio LLC"/> 27 <meta name="Distribution" content="Global"/> 28 <link rel="icon" href="/images/wand.png" sizes="32x32"/> 29 <link rel="shortcut icon" href="/images/wand.ico" type="images/x-icon"/> 30 <link rel="meta" type="application/rdf+xml" title="ICI" href="http://imagemagick.org/ici.rdf"/> 31 <style type="text/css" media="all"> 32 @import url("/www/magick.css"); 33 </style> 34</head> 35 36<body id="www-imagemagick-org"> 37<div class="titlebar"> 38<a href="/index.html"> 39 <img src="/images/script.png" alt="[ImageMagick]" 40 style="width: 350px; height: 60px; margin: 28px auto; float: left;" /></a> 41<a href="http://www.networkredux.com"> 42 <img src="/images/networkredux.png" alt="[sponsor]" 43 style="margin: 45px auto; border: 0px; float: left;" /></a> 44<a href="http://www.imagemagick.org/discourse-server/"> 45 <img src="/images/logo.jpg" alt="" 46 style="width: 114px; height: 118px; border: 0px; float: right;" /></a> 47<a href="/index.html"> 48 <img src="/images/sprite.jpg" alt="" 49 style="width: 114px; height: 118px; border: 0px; float: right;" /></a> 50</div> 51 52<div class="westbar"> 53 54<div class="menu"> 55 <a title="About ImageMagick" href="/index.html">About ImageMagick</a> 56</div> 57<div class="sep"></div> 58<div class="menu"> 59 <a title="Binary Releases" href="/www/binary-releases.html">Binary Releases</a> 60</div> 61<div class="sub"> 62 <a title="Binary Release: Unix" href="/www/binary-releases.html#unix">Unix</a> 63</div> 64<div class="sub"> 65 <a title="Binary Release: MacOS X" href="/www/binary-releases.html#macosx">Mac OS X</a> 66</div> 67<div class="sub"> 68 <a title="Binary Release: Windows" href="/www/binary-releases.html#windows">Windows</a> 69</div> 70<div class="sep"></div> 71<div class="menu"> 72 <a title="Command-line Tools" href="/www/command-line-tools.html">Command-line Tools</a> 73</div> 74<div class="sub"> 75 <a title="Command-line Tools: Processing" href="/www/command-line-processing.html">Processing</a> 76</div> 77<div class="sub"> 78 <a title="Command-line Tools: Options" href="/www/command-line-options.html">Options</a> 79</div> 80<div class="sub"> 81 <a title="Command-line Tools: Usage" href="http://www.imagemagick.org/Usage/">Usage</a> 82</div> 83<div class="menu"> 84 <a title="Program Interfaces" href="/www/api.html">Program Interfaces</a> 85</div> 86<div class="sub"> 87 <a title="Program Interface: MagickWand" href="/www/magick-wand.html">MagickWand</a> 88</div> 89<div class="sub"> 90 <a title="Program Interface: MagickCore" href="/www/magick-core.html">MagickCore</a> 91</div> 92<div class="sub"> 93 <a title="Program Interface: PerlMagick" href="/www/perl-magick.html">PerlMagick</a> 94</div> 95<div class="sub"> 96 <a title="Program Interface: Magick++" href="/Magick++/">Magick++</a> 97</div> 98<div class="sep"></div> 99<div class="menu"> 100 <a title="Install from Source" href="/www/install-source.html">Install from Source</a> 101</div> 102<div class="sub"> 103 <a title="Install from Source: Unix" href="/www/install-source.html#unix">Unix</a> 104</div> 105<div class="sub"> 106 <a title="Install from Source: Windows" href="/www/install-source.html#windows">Windows</a> 107 </div> 108<div class="menu"> 109 <a title="Resources" href="/www/resources.html">Resources</a> 110</div> 111<div class="menu"> 112 <a title="Architecture" href="/www/architecture.html">Architecture</a> 113</div> 114<div class="menu"> 115 <a title="Download" href="/www/download.html">Download</a> 116</div> 117<div class="sep"></div> 118<div class="menu"> 119 <a title="Search" href="http://www.imagemagick.org/script/search.php">Search</a> 120</div> 121<div class="sep"></div> 122<div class="menu"> 123 <a title="Site Map"href="/www/sitemap.html">Site Map</a> 124</div> 125<div class="sub"> 126 <a title="Site Map: Links"href="/www/links.html">Links</a> 127</div> 128<div class="sep"></div> 129<div class="menu"> 130 <a title="Sponsors" href="/www/sponsors.html">Sponsors:</a> 131 132<div class="sponsbox"> 133<div class="sponsor"> 134 <a title="Sponsor: Online-Magazin" href="http://www.unkostenbeitrag.de/">Online-Magazin</a><!-- 20101101000200 --> 135</div> 136<div class="sponsor"> 137 <a title="Sponsor: Druckerei" href="http://print24.com/de/">Druckerei</a><!-- 201110010720 --> 138</div> 139<div class="sponsor"> 140 <a title="Sponsor: Image Converter" href="http://www.batchphoto.com">Image Converter</a><!-- 201103010900 Bits Coffee--> 141</div> 142<div class="sponsor"> 143 <a title="Sponsor: Flyer drucken" href="http://www.online-druck.biz">Flyer drucken</a><!-- 201109010900 Floeter--> 144</div> 145<div class="sponsor"> 146 <a title="Sponsor: Webdesign Agentur" href="http://www.ventzke-partner.de">Webdesign Agentur</a><!-- 201101010480 invendio.de--> 147</div> 148<div class="sponsor"> 149 <a title="Sponsor: LVM Versicherung" href="http://www.neu-reich.de">LVM Versicherung</a><!-- 201101010480 --> 150</div> 151<div class="sponsor"> 152 <a title="Sponsor: Diamonds are a Girls Best Friend" href="http://www.schmuck.org">Diamonds are a Girls Best Friend</a><!-- 201101010600 Peterssen--> 153</div> 154<div class="sponsor"> 155 <a title="Sponsor: Druckerei Online" href="http://www.allesdruck.de">Druckerei Online</a><!-- 201012011200 allesdruck.de--> 156</div> 157</div> 158</div> 159</div> 160 161<div class="eastbar"> 162 <script type="text/javascript"> 163 <!-- 164 google_ad_client = "pub-3129977114552745"; 165 google_ad_slot = "0574824969"; 166 google_ad_width = 160; 167 google_ad_height = 600; 168 //--> 169 </script> 170 <script type="text/javascript" 171 src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> 172 </script> 173</div> 174 175<div class="main"> 176 177<p class="navigation-index"> 178[ <a href="/www/command-line-options.html#adaptive-blur">‑adaptive‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#adaptive-resize">‑adaptive‑resize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#adaptive-sharpen">‑adaptive‑sharpen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#adjoin">‑adjoin</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#affine">‑affine</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#alpha">‑alpha</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#annotate">‑annotate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#antialias">‑antialias</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#append">‑append</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#attenuate">‑attenuate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#authenticate">‑authenticate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-gamma">‑auto‑gamma</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-level">‑auto‑level</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-orient">‑auto‑orient</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#backdrop">‑backdrop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#background">‑background</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bench">‑bench</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bias">‑bias</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blackpoint-compensation">‑blackpoint‑compensation</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#black-threshold">‑black‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blend">‑blend</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blue-primary">‑blue‑primary</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blue-shift">‑blue‑shift</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blur">‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#border">‑border</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bordercolor">‑bordercolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#borderwidth">‑borderwidth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#brightness-contrast">‑brightness‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cache">‑cache</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#caption">‑caption</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cdl">‑cdl</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#channel">‑channel</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#charcoal">‑charcoal</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#chop">‑chop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clamp">‑clamp</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clip">‑clip</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clip-mask">‑clip‑mask</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clip-path">‑clip‑path</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clone">‑clone</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clut">‑clut</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#coalesce">‑coalesce</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#colorize">‑colorize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#colormap">‑colormap</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#color-matrix">‑color‑matrix</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#colors">‑colors</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#colorspace">‑colorspace</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#combine">‑combine</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#comment">‑comment</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#compose">‑compose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#composite">‑composite</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#compress">‑compress</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#contrast">‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#contrast-stretch">‑contrast‑stretch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#convolve">‑convolve</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#crop">‑crop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cycle">‑cycle</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#debug">‑debug</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#decipher">‑decipher</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#deconstruct">‑deconstruct</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#define">‑define</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#delay">‑delay</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#delete">‑delete</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#density">‑density</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#depth">‑depth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#descend">‑descend</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#deskew">‑deskew</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#despeckle">‑despeckle</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#direction">‑direction</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#displace">‑displace</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#display">‑display</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#dispose">‑dispose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#dissimilarity-threshold">‑dissimilarity‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#dissolve">‑dissolve</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#distort">‑distort</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#dither">‑dither</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#draw">‑draw</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#edge">‑edge</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#emboss">‑emboss</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#encipher">‑encipher</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#encoding">‑encoding</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#endian">‑endian</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#enhance">‑enhance</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#equalize">‑equalize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#evaluate">‑evaluate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#evaluate-sequence">‑evaluate‑sequence</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#extent">‑extent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#extract">‑extract</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#family">‑family</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#features">‑features</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#fft">‑fft</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#fill">‑fill</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#filter">‑filter</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#flatten">‑flatten</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#flip">‑flip</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#floodfill">‑floodfill</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#flop">‑flop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#font">‑font</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#foreground">‑foreground</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#format">‑format</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#format_identify_">‑format[identify]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#frame">‑frame</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#frame_import_">‑frame[import]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#function">‑function</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#fuzz">‑fuzz</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#fx">‑fx</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#gamma">‑gamma</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#gaussian-blur">‑gaussian‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#geometry">‑geometry</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#gravity">‑gravity</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#green-primary">‑green‑primary</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#hald-clut">‑hald‑clut</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#help">‑help</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#highlight-color">‑highlight‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#iconGeometry">‑iconGeometry</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#iconic">‑iconic</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#identify">‑identify</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#ift">‑ift</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#immutable">‑immutable</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#implode">‑implode</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#insert">‑insert</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#intent">‑intent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#interlace">‑interlace</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#interpolate">‑interpolate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#interline-spacing">‑interline‑spacing</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#interword-spacing">‑interword‑spacing</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#kerning">‑kerning</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#label">‑label</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#lat">‑lat</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#layers">‑layers</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#level">‑level</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#level-colors">‑level‑colors</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#limit">‑limit</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#linear-stretch">‑linear‑stretch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#linewidth">‑linewidth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#liquid-rescale">‑liquid‑rescale</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#list">‑list</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#log">‑log</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#loop">‑loop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#lowlight-color">‑lowlight‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#magnify">‑magnify</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#map">‑map</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#map_stream_">‑map[stream]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mask">‑mask</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mattecolor">‑mattecolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#median">‑median</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#metric">‑metric</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mode">‑mode</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#modulate">‑modulate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#monitor">‑monitor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#monochrome">‑monochrome</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#morph">‑morph</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#morphology">‑morphology</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mosaic">‑mosaic</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#motion-blur">‑motion‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#name">‑name</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#negate">‑negate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#noise">‑noise</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#normalize">‑normalize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#opaque">‑opaque</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#ordered-dither">‑ordered‑dither</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#orient">‑orient</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#page">‑page</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#paint">‑paint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#path">‑path</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pause_animate_">‑pause[animate]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pause_import_">‑pause[import]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pen">‑pen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#ping">‑ping</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pointsize">‑pointsize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#polaroid">‑polaroid</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#posterize">‑posterize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#precision">‑precision</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#preview">‑preview</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#print">‑print</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#process">‑process</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#profile">‑profile</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quality">‑quality</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quantize">‑quantize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quiet">‑quiet</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#radial-blur">‑radial‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#raise">‑raise</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#random-threshold">‑random‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#red-primary">‑red‑primary</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#regard-warnings">‑regard‑warnings</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#region">‑region</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#remap">‑remap</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#remote">‑remote</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#render">‑render</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#repage">‑repage</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#resample">‑resample</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#resize">‑resize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#respect-parentheses">‑respect‑parentheses</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#reverse">‑reverse</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#roll">‑roll</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#rotate">‑rotate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sample">‑sample</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sampling-factor">‑sampling‑factor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#scale">‑scale</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#scene">‑scene</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#screen">‑screen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#seed">‑seed</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#segment">‑segment</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#selective-blur">‑selective‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#separate">‑separate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sepia-tone">‑sepia‑tone</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#set">‑set</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shade">‑shade</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shadow">‑shadow</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shared-memory">‑shared‑memory</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sharpen">‑sharpen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shave">‑shave</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shear">‑shear</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sigmoidal-contrast">‑sigmoidal‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#silent">‑silent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#size">‑size</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sketch">‑sketch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#snaps">‑snaps</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#solarize">‑solarize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sparse-color">‑sparse‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#splice">‑splice</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#spread">‑spread</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stegano">‑stegano</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stereo">‑stereo</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stretch">‑stretch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#strip">‑strip</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stroke">‑stroke</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#strokewidth">‑strokewidth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#style">‑style</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#subimage-search">‑subimage‑search</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#swap">‑swap</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#swirl">‑swirl</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#taint">‑taint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#text-font">‑text‑font</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#texture">‑texture</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#threshold">‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#thumbnail">‑thumbnail</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tile">‑tile</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tile-offset">‑tile‑offset</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tint">‑tint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#title">‑title</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transform">‑transform</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transparent">‑transparent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transparent-color">‑transparent‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transpose">‑transpose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transverse">‑transverse</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#treedepth">‑treedepth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#trim">‑trim</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#type">‑type</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#undercolor">‑undercolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#unique-colors">‑unique‑colors</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#units">‑units</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#unsharp">‑unsharp</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#update">‑update</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#verbose">‑verbose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#version">‑version</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#view">‑view</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#vignette">‑vignette</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#virtual-pixel">‑virtual‑pixel</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#visual">‑visual</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#watermark">‑watermark</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#wave">‑wave</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#weight">‑weight</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#white-point">‑white‑point</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#white-threshold">‑white‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#window">‑window</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#window-group">‑window‑group</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#write">‑write</a> ] </p> 179 180<p>Below is list of command-line options recognized by the ImageMagick <a 181href="/www/command-line-tools.html">command-line 182tools</a>. If you want a description of a particular option, click on the 183option name in the navigation bar above and you will go right to it. Unless 184otherwise noted, each option is recognized by the commands <a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>.</p> 185 186<div style="margin: auto;"> 187 <h4><a name="adaptive-blur" id="adaptive-blur"></a>-adaptive-blur <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 188</div> 189 190<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adaptively blur pixels, with decreasing effect near edges.</td><td style='text-align:right;'></td></tr></table> 191 "direction", 192<p>A Gaussian operator of the given radius and standard deviation (<em class="arg">sigma</em>) is used. If <em class="arg">sigma</em> is not given it defaults to 1.</p> 193 194<div style="margin: auto;"> 195 <h4><a name="adaptive-resize" id="adaptive-resize"></a>-adaptive-resize <em class="arg">geometry</em></h4> 196</div> 197 198<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resize the image using data-dependent triangulation.</td><td style='text-align:right;'></td></tr></table> 199 200<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <a href="#adaptive-resize">-adaptive-resize</a> option defaults to data-dependent triangulation. Use the <a href="#filter">-filter</a> to choose a different resampling algorithm. Offsets, if present in the geometry string, are ignored, and the <a href="#gravity">-gravity</a> option has no effect.</p> 201 202<div style="margin: auto;"> 203 <h4><a name="adaptive-sharpen" id="adaptive-sharpen"></a>-adaptive-sharpen <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 204</div> 205 206<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adaptively sharpen pixels, with increasing effect near edges.</td><td style='text-align:right;'></td></tr></table> 207 208<p>A Gaussian operator of the given radius and standard deviation (<em class="arg">sigma</em>) is used. If <em class="arg">sigma</em> is not given it defaults to 1.</p> 209 210<div style="margin: auto;"> 211 <h4><a name="adjoin" id="adjoin"></a>-adjoin</h4> 212</div> 213 214<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Join images into a single multi-image file.</td><td style='text-align:right;'></td></tr></table> 215 216<p>This option is enabled by default. An attempt is made to save all 217images of an image sequence into the given output file. 218However, some formats, such as JPEG and PNG, do not support more than one 219image per file, and in that case ImageMagick is forced to write each image as a separate file. As 220such, if more than one image needs to be written, the filename given is 221modified by adding a <a href="#scene">-scene</a> number before the 222suffix, in order to make distinct names for each image. </p> 223 224<p>Use <a href="#adjoin">+adjoin</a> to force each image to be written 225to separate files, whether or not the file format allows multiple images 226per file (for example, GIF, MIFF, and TIFF). </p> 227 228<p>Including a C-style integer format string in the output filename will automagically enable <a href="#adjoin">+adjoin</a> and are used to specify where the <a href="#scene">-scene</a> number is placed in the filenames. These strings, such as '<kbd>%d</kbd>' or '<kbd>%03d</kbd>', are familiar to those who have used the standard <kbd>printf()</kbd>' C-library function. As an example, the command</p> 229 230<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: rose: -morph 15 my%02dmorph.jpg</span></p> 231<p>will create a sequence of 17 images named my00morph.jpg, my01morph.jpg, my02morph.jpg, ..., my16morph.jpg. 232</p> 233 234<p>In summary, ImageMagick tries to write all images to one file, but will use 235multiple files if either (1) the output image's file format does not allow multi-image files, 236(2) the <a href="#adjoin">+adjoin</a> option is given, or (3) a C-style integer format string is 237present in the output filename. </p> 238 239 240<div style="margin: auto;"> 241 <h4><a name="affine" id="affine"></a>-affine <em class="arg">s<sub>x</sub></em>,<em class="arg">r<sub>x</sub></em>,<em class="arg">r<sub>y</sub></em>,<em class="arg">s<sub>y</sub></em>,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em><br/> 242 -affine <em class="arg">s<sub>x</sub></em>,<em class="arg">r<sub>x</sub></em>,<em class="arg">r<sub>y</sub></em>,<em class="arg">s<sub>y</sub></em></h4> 243</div> 244 245<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the drawing transformation matrix for combined rotating and scaling.</td><td style='text-align:right;'></td></tr></table> 246 247<p>This option sets a transformation matrix, encoded as (<em class="arg">s<sub>x</sub></em>, <em class="arg">r<sub>x</sub></em>, <em class="arg">r<sub>y</sub></em>, <em class="arg">s<sub>y</sub></em>, <em class="arg">t<sub>x</sub></em>, <em class="arg">t<sub>y</sub></em>), for use by subsequent <a href="#draw">-draw</a> or <a href="#transform">-transform</a> options.</p> 248 249<p>The matrix entries are entered as comma-separated numeric values <i>with no spaces</i>. </p> 250 251<p>Internally, the transformation matrix has 3x3 elements, but three of them are omitted from the input because they are constant. The new (transformed) coordinates (<em class="arg">x'</em>, <em class="arg">y'</em>) of a pixel at position (<em class="arg">x</em>, <em class="arg">y</em>) in the original image are calculated using the following matrix equation.</p> 252 253<div class="eqn"> 254<img alt="affine transformation" src="/images/affine.png"/> 255</div> 256 257<p> 258The size of the resulting image is that of the smallest rectangle that contains the transformed source image. The parameters <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> subsequently shift the image pixels so that those that are moved out of the image area are cut off.</p> 259 260<p>The transformation matrix complies with the left-handed pixel coordinate system: positive <em class="arg">x</em> and <em class="arg">y</em> directions are rightward and downward, resp.; positive rotation is clockwise.</p> 261 262<p> If the translation coefficients <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are omotted they default to 0,0. Therefore, four parameters suffice for rotation and scaling without translation.</p> 263 264<p>Scaling by the factors <em class="arg">s<sub>x</sub></em> and <em class="arg">s<sub>y</sub></em> in the <em>x</em> and <em>y</em> directions, respectively, is accomplished with the following.</p> 265 266<p class="crtsnip"> 267 -affine <em class="arg">s<sub>x</sub></em>,0,0,<em class="arg">s<sub>y</sub></em> 268</p> 269 270<p>Translation by a displacement (<em class="arg">t<sub>x</sub></em>, <em class="arg">t<sub>y</sub></em>) is accomplished like so:</p> 271 272<p class="crtsnip"> 273 -affine 1,0,0,1,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em> 274</p> 275 276<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle <em>a</em> by letting 277<em>c</em> = cos(<em>a</em>), <em>s</em> = sin(<em>a</em>), and using the following.</p> 278 279<p class="crtsnip"> 280 -affine <em>c</em>,<em>s</em>,-<em>s</em>,<em>c</em> 281</p> 282 283<p>The cumulative effect of a sequence of <a href="#affine" >-affine</a> transformations can be accomplished by instead by a single <a href="#affine" >-affine</a> operation using the matrix equal to the product of the matrices of the individual transformations.</p> 284 285<p>An attempt is made to detect near-singular transformation matrices. If the matrix determinant has a sufficiently small absolute value it is rejected.</p> 286 287<div style="margin: auto;"> 288 <h4><a name="alpha" id="alpha"></a>-alpha <em class="arg">type</em></h4> 289</div> 290 291<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Gives control of the alpha/matte channel of an image.</td><td style='text-align:right;'></td></tr></table> 292 293<p>Used to set a flag on an image indicating whether or not to use existing alpha 294channel data, to create an alpha channel, or to perform other operations on the alpha channel. Choose the argument <em class="arg">type</em> from the list below.</p> 295 296 297<table class="doc"> 298 <tbody> 299 <tr valign="top"> 300 <th align="left" style="width: 8%">type</th> 301 <th align="left">Description</th> 302 </tr> 303 304 <tr valign="top"> 305 <td valign="top"><kbd>Activate</kbd> or <kbd>On</kbd></td> 306 <td valign="top"> 307 Enable the image's transparency channel. Note normally <kbd>Set</kbd> 308 should be used instead of this, unless you specifically need to 309 preserve existing (but specifically turned <kbd>Off</kbd>) transparency 310 channel. </td></tr> 311 312 <tr valign="top"> 313 <td valign="top"><kbd>Deactivate</kbd> or <kbd>Off</kbd></td> 314 <td valign="top"> 315 Disables the image's transparency channel. Does not delete or change the 316 existing data, just turns off the use of that data.</td></tr> 317 318 <tr valign="top"> 319 <td valign="top"><kbd>Set</kbd></td> 320 <td valign="top"> 321 Activates the alpha/matte channel. If it was previously turned off 322 then it also resets the channel to opaque. If the image already had 323 the alpha channel turned on, it will have no effect.</td></tr> 324 325 <tr valign="top"> 326 <td valign="top"><kbd>Opaque</kbd></td> 327 <td valign="top"> 328 Enables the alpha/matte channel and forces it to be fully opaque. 329 </td></tr> 330 331 <tr valign="top"> 332 <td valign="top"><kbd>Transparent</kbd></td> 333 <td valign="top"> 334 Activates the alpha/matte channel and forces it to be fully 335 transparent. This effectively creates a fully transparent image the 336 same size as the original and with all its original RGB data still 337 intact, but fully transparent. </td></tr> 338 339 <tr valign="top"> 340 <td valign="top"><kbd>Extract</kbd></td> 341 <td valign="top"> 342 Copies the alpha channel values into all the color channels and turns 343 '<kbd>Off</kbd>' the the image's transparency, so as to generate 344 a gray-scale mask of the image's shape. The alpha channel data is left 345 intact just deactivated. This is the inverse of '<kbd>Copy</kbd>'. 346 </td></tr> 347 348 <tr valign="top"> 349 <td valign="top"><kbd>Copy</kbd></td> 350 <td valign="top"> 351 Turns '<kbd>On</kbd>' the alpha/matte channel, then copies the 352 gray-scale intensity of the image, into the alpha channel, converting 353 a gray-scale mask into a transparent shaped mask ready to be colored 354 appropriately. The color channels are not modified. </td></tr> 355 356 <tr valign="top"> 357 <td valign="top"><kbd>Shape</kbd></td> 358 <td valign="top"> 359 As per '<kbd>Copy</kbd>' but also colors the resulting shape mask with 360 the current background color. That is the RGB color channels is 361 replaced, with appropriate alpha shape. 362 </td></tr> 363 364 <tr valign="top"> 365 <td valign="top"><kbd>Background</kbd></td> 366 <td valign="top"> 367 Set any fully-transparent pixel to the background color, while leaving 368 it fully-transparent. This can make some image file formats, such as 369 PNG, smaller as the RGB values of transparent pixels are more uniform, 370 and thus can compress better. 371 </td></tr> 372 </tbody> 373</table> 374 375<p>Note that while the <a href="#matte" >+matte</a> operation is the same as 376"<kbd><a href="#alpha" >-alpha</a> Off</kbd>", the <a href="#matte" 377>-matte</a> operation is the same as "<kbd><a href="#alpha" >-alpha</a> 378Set</kbd>" and not "<kbd><a href="#alpha" >-alpha</a> On</kbd>". </p> 379 380 381<div style="margin: auto;"> 382 <h4><a name="annotate" id="annotate"></a> 383 -annotate <em class="arg">degrees</em> <em class="arg">text</em><br /> 384 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> <em class="arg">text</em><br /> 385 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> {+-}<em class="arg">t<sub>x</sub></em>{+-}<em class="arg">t<sub>y</sub></em> <em class="arg">text</em></h4> 386</div> 387 388<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Annotate an image with text.</td><td style='text-align:right;'></td></tr></table> 389 390<p>This is a convenience for annotating an image with text. For more precise control over text annotations, use <a href="#draw">-draw</a>.</p> 391 392 393<p>The values <em class="arg">Xdegrees</em> and <em class="arg">Ydegrees</em> control the shears with respect to the , respectively, applied to the text, while <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are offsets that give the location of the text relative to the upper left corner of the image.</p> 394 395<p>Using <a href="#annotate">-annotate</a> <em class="arg">degrees</em> or <a href="#annotate">-annotate</a> <em class="arg">degrees</em>x<em class="arg">degrees</em> produces an unsheared rotation of the text. The direction of the rotation is positive, which means a clockwise rotation if <em class="arg">degrees</em> is positive. (This conforms to the usual mathematical convention once it is realized that the positive <em>y</em>–direction is conventionally considered to be <em>downward</em> for images.)</p> 396 397<p>The new (transformed) coordinates (<em class="arg">x'</em>, <em class="arg">y'</em>) of a pixel at position (<em class="arg">x</em>, <em class="arg">y</em>) in the image are calculated using the following matrix equation.</p> 398<div class="eqn"><img alt="annotate transformation" src="/images/annotate.png"/></div> 399 400<p>If <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are omitted, they default to 0. This makes the bottom-left of the text becomes the upper-left corner of the image, which is probably undesirable. Adding a <a href="#gravity" >-gravity</a> option in this case leads to nice results.</p> 401 402<p>Text is any UTF-8 encoded character sequence. If <em class="arg">text</em> is of the form '@mytext.txt', the text is read from the file <kbd>mytext.txt</kbd>. Text in a file is taken literally; no embedded formatting characters are recognized.</p> 403 404<div style="margin: auto;"> 405 <h4><a name="antialias" id="antialias"></a>-antialias</h4> 406</div> 407 408<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Enable/Disable of the rendering of anti-aliasing pixels when 409drawing fonts and lines.</td><td style='text-align:right;'></td></tr></table> 410 411<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when 412drawn. Use <a href="#antialias">+antialias</a> to disable the addition of 413antialiasing edge pixels. This will then reduce the number of colors added to 414an image to just the colors being directly drawn. That is, no mixed colors 415are added when drawing such objects. </p> 416 417<div style="margin: auto;"> 418 <h4><a name="append" id="append"></a>-append</h4> 419</div> 420 421<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Join current images vertically or horizontally.</td><td style='text-align:right;'></td></tr></table> 422 423<p>This option creates a single longer image image, by joining all the current 424images in sequence top-to-bottom. Use <a href="#append">+append</a> to 425stack images left-to-right. </p> 426 427<p>If they are not of the same width, narrower images are padded with the 428current <a href="#background">-background</a> color setting, and their 429position relative to each other can be controlled by the current <a 430href="#gravity">-gravity</a> setting. </p> 431 432 433<div style="margin: auto;"> 434 <h4><a name="attenuate" id="attenuate"></a>-attenuate <em class="arg">value</em></h4> 435</div> 436 437<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Lessen (or intensify) when adding noise to an image.</td><td style='text-align:right;'></td></tr></table> 438 439 440<div style="margin: auto;"> 441 <h4><a name="authenticate" id="authenticate"></a>-authenticate <em class="arg">password</em></h4> 442</div> 443 444<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Decrypt a PDF with a password.</td><td style='text-align:right;'></td></tr></table> 445 446<p>Use this option to supply a <em class="arg">password</em> for decrypting a PDF that has been encrypted using Microsoft Crypto API (MSC API). The encrypting using the MSC API is not supported.</p> 447 448<p>For a different encryption method, see <a href="#encipher">-encipher</a> and <a href="#decipher">-decipher</a>. </p> 449 450 451 452<div style="margin: auto;"> 453 <h4><a name="auto-gamma" id="auto-gamma"></a>-auto-gamma</h4> 454</div> 455 456<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically adjust gamma level of image.</td><td style='text-align:right;'></td></tr></table> 457 458<p>This calculates the mean values of an image, then applies a calculated <a 459href="#gamma" >-gamma</a> adjustment so that is the mean color exists in the 460image it will get a have a value of 50%. </p> 461 462<p>This means that any solid 'gray' image becomes 50% gray. </p> 463 464<p>This works well for real-life images with little or no extreme dark and 465light areas, but tend to fail for images with large amounts of bright sky or 466dark shadows. It also does not work well for diagrams or cartoon like images. 467</p> 468 469<p>It uses the <a href="#channel" >-channel</a> setting, (including the 470'<CODE>sync</CODE>' flag for channel syncronization), to determine which color 471values is used and modified. As the default <a href="#channel" 472>-channel</a> setting is '<CODE>RGB,sync</CODE>', channels are modified 473together by the same gamma value, preserving colors. </p> 474 475 476 477<div style="margin: auto;"> 478 <h4><a name="auto-level" id="auto-level"></a>-auto-level</h4> 479</div> 480 481<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically adjust color levels of image.</td><td style='text-align:right;'></td></tr></table> 482 483<p>This is a 'perfect' image normalization operator. It finds the exact 484minimum and maximum color values in the image and then applies a <a 485href="#level" >-level</a> operator to stretch the values to the full range of 486values. </p> 487 488<p>The operator is not typically used for real-life images, image scans, or 489JPEG format images, as a single 'out-rider' pixel can set a bad min/max values 490for the <a href="#level" >-level</a> operation. On the other hand it is the 491right operator to use for color stretching gradient images being used to 492generate Color lookup tables, distortion maps, or other 'mathematically' 493defined images. </p> 494 495<p>The operator is very similar to the <a href="#normalize">-normalize</a>, <a 496href="#contrast-stretch" >-contrast-stretch</a>, and <a href="#linear-stretch" 497>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping' 498problems that these operators may have. That is <a href="#auto-level" 499>-auto-level</a> is the perfect or ideal version these operators. </p> 500 501<p>It uses the <a href="#channel" >-channel</a> setting, (including the 502special '<CODE>sync</CODE>' flag for channel syncronization), to determine 503which color values are used and modified. As the default <a 504href="#channel" >+channel</a> setting is '<CODE>RGB,sync</CODE>', the 505'<CODE>sync</CODE>' ensures that the color channels will are modified 506together by the same gamma value, preserving colors, and ignoring 507transparency. </p> 508 509 510<div style="margin: auto;"> 511 <h4><a name="auto-orient" id="auto-orient"></a>-auto-orient</h4> 512</div> 513 514<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically orient (rotate) an image created by a digital camera.</td><td style='text-align:right;'></td></tr></table> 515 516<p>This operator reads and resets the EXIF image profile setting 'Orientation' 517and then performs the appropriate 90 degree rotation on the image to orient 518the image, for correct viewing. </p> 519 520<p>This EXIF profile setting is usually set using a gravity sensor in digital 521camara, however photos taken directly downward or upward may not have an 522appropriate value. Also images that have been orientation 'corrected' without 523reseting this setting, may be 'corrected' again resulting in a incorrect 524result. If the he EXIF profile was previously stripped, the <a 525href="#auto-orient" >-auto-orient</a> operator will do nothing. </p> 526 527 528<div style="margin: auto;"> 529 <h4><a name="average" id="average"></a>-average</h4> 530</div> 531 532<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Average a set of images.</td><td style='text-align:right;'></td></tr></table> 533 534<p>An error results if the images are not identically sized.</p> 535 536 537<div style="margin: auto;"> 538 <h4><a name="backdrop" id="backdrop"></a>-backdrop</h4> 539</div> 540 541<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Display the image centered on a backdrop.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 542 543<p>This backdrop covers the entire workstation screen and is useful for hiding other X window activity while viewing the image. The color of the backdrop is specified as the background color. The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 544 545<div style="margin: auto;"> 546 <h4><a name="background" id="background"></a>-background <em class="arg">color</em></h4> 547</div> 548 549<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the background color.</td><td style='text-align:right;'></td></tr></table> 550 551<p>The color is specified using the format described under the <a href="#fill">-fill</a> option. The default background color (if none is specified or found in the image) is white.</p> 552 553<div style="margin: auto;"> 554 <h4><a name="bench" id="bench"></a>-bench <em class="arg">iterations</em></h4> 555</div> 556 557<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Measure performance.</td><td style='text-align:right;'></td></tr></table> 558 559<p>Repeat the entire command for the given number of <em class="arg">iterations</em> and report the user-time and elapsed time. For instance, consider the following command and its output. Modify the benchmark with the -duration to run the benchmark for a fixed number of seconds and -concurrent to run the benchmark in parallel (requires the OpenMP feature).</p> 560 561<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -resize 1000% -bench 5 logo.png</span><span class='crtout'>Performance: 5i 0.875657ips 6.880u 0:05.710</span></p> 562<p>In this example, 5 iterations were completed at 0.875657 iterations per second, using 6.88 seconds of the user's allotted time, for a total elapsed time of 5.71 seconds.</p> 563 564<div style="margin: auto;"> 565 <h4><a name="bias" id="bias"></a>-bias <em class="arg">value</em>{<em class="arg">%</em>}</h4> 566</div> 567 568<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Add bias when convolving an image.</td><td style='text-align:right;'></td></tr></table> 569 570<p>This option shifts the output of <a href="/www/command-line-options.html#convolve">‑convolve</a> so that positive and negative results are relative to the specified bias value. </p> 571 572<p>This is important for non-HDRI compilations of ImageMagick when dealing with convolutions that contain negative as well as positive values. This is especially the case with convolutions involving high pass filters or edge detection. Without an output bias, the negative values are clipped at zero.</p> 573 574<p>When using an ImageMagick with the HDRI compile-time setting, <a href="/www/command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 575negative results without clipping to the color value range 576(0..QuantumRange).</p> 577 578<p>See the discussion on HDRI implementations of ImageMagick on the page 579<a href="/www/high-dynamic-range.html">High Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> entry. 580</p> 581 582<div style="margin: auto;"> 583 <h4><a name="black-point-compensation" id="black-point-compensation"></a>-black-point-compensation</h4> 584</div> 585 586<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use black point compensation.</td><td style='text-align:right;'></td></tr></table> 587 588<div style="margin: auto;"> 589 <h4><a name="black-threshold" id="black-threshold"></a>-black-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 590</div> 591 592<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</td><td style='text-align:right;'></td></tr></table> 593 594<p> The threshold value can be given as a percentage or as an absolute integer value within [0, <em class="QR">QuantumRange</em>] corresponding to the desired <a href="/www/command-line-options.html#channel">‑channel</a> value. See <a href="/www/command-line-options.html#threshold">‑threshold</a> for more details on thresholds and resulting values. 595</p> 596 597 598<div style="margin: auto;"> 599 <h4><a name="blend" id="blend"></a>-blend <em class="arg">geometry</em></h4> 600</div> 601 602<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>blend an image into another by the given absolute value or percent.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 603 604<p>Blend will average the images together ('plus') according to the 605percentages given and each pixels transparency. If only a single percentage 606value is given it sets the weight of the composite or 'source' image, while 607the background image is weighted by the exact opposite amount. That is a 608<kbd>-blend 30%</kbd> merges 30% of the 'source' image with 70% of the 609'destination' image. Thus it is equivalent to <kbd>-blend 30x70%</kbd>.</p> 610 611 612<div style="margin: auto;"> 613 <h4><a name="blue-primary" id="blue-primary"></a>-blue-primary <em class="arg">x</em>,<em class="arg">y</em></h4> 614</div> 615 616<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the blue chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 617 618<div style="margin: auto;"> 619 <h4><a name="blue-shift" id="blue-shift"></a>-blue-shift <em class="arg">factor</em></h4> 620</div> 621 622<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</td><td style='text-align:right;'></td></tr></table> 623 624<div style="margin: auto;"> 625 626<div style="margin: auto;"> 627 <h4><a name="blur" id="blur"></a>-blur <em class="arg">radius</em><br />-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 628</div> 629 630<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reduce image noise and reduce detail levels.</td><td style='text-align:right;'></td></tr></table> 631 632<p>Convolve the image with a Gaussian or normal distribution using the given 633<em class="arg" >Sigma</em> value. The formula is:</p> 634 635<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 636</div> 637 638<p>The <em class="arg" >Sigma</em> value is the important argument, and 639determines the actual amount of bluring that will take place. </p> 640 641<p>The <em class="arg" >Radius</em> is only used to determine the size of the 642array which will hold the calculated gaussian distribution. It should be an 643integer. If not given, or set to zero, IM will calculate the largest possible 644radius that will provide meaningful results for the Gaussian distribution. 645</p> 646 647<p>The larger the <em class="arg" >Radius</em> the radius the slower the 648operation is. However too small a <em class="arg" >Radius</em>, and sever 649aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 650should be at least twice the <em class="arg" >Sigma</em> value, though three 651times will produce a more accurite result. </p> 652 653<p>This option differs from <a href="#gaussian-blur">-gaussian-blur</a> simply 654by taking advantage of the separability properties of the distribution. Here 655we apply a single-dimensional Gaussian matrix in the horizontal direction, 656then repeat the process in the vertical direction.</p> 657 658<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 659pixels which are outside the image proper are blurred into the final result. 660</p> 661 662 663<div style="margin: auto;"> 664 <h4><a name="blur-composite" id="blur"></a>-blur <em class="arg">Width</em>[x<em class="arg">Height</em>[+<em class="arg">Angle</em>]]</h4> 665</div> 666 667<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Variably blur and image according to the overlay mapping.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 668 669<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted 670Average (EWA) of the source image, scaled according to the grayscale 671mapping. </p> 672 673<p>The ellipse is weighted with sigma set to the given <em class="arg" 674>Width</em> and <em class="arg" >Height</em>. The <em class="arg" >Height</em> 675defaults to the <em class="arg" >Width</em> for a normal circular Guassian 676weighting. The <em class="arg" >Angle</em> will rotate the ellipse from 677horizontal clock-wise. </p> 678 679<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 680pixels which are outside the image proper are blurred into the final result. 681</p> 682 683 684<div style="margin: auto;"> 685 <h4><a name="border" id="border"></a>-border <em class="arg">geometry</em></h4> 686</div> 687 688<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Surround the image with a border of color. </td><td style='text-align:right;'></td></tr></table> 689 690<p>Set the width and height using the <em class="arg">size</em> portion of the 691<em class="arg">gravity</em> argument. See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets are 692ignored. </p> 693 694<p>Set the border color by preceding with the <a 695href="#bordercolor">-bordercolor</a> setting.</p> 696 697<p>The <a href="#border">-border</a> operation is affected by the current <a 698href="#compose">-compose</a> setting and assumes that this is using the default 699'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 700size colors by the current <a href="#bordercolor">-bordercolor</a> before 701overlaying the original image in the center of this net image. This means that 702with the default compose method of '<kbd>Over</kbd>' any transparent parts may 703be replaced by the current <a href="#bordercolor">-bordercolor</a> setting.</p> 704<p>See also the <a href="#frame">-frame</a> option, which has more 705functionality.</p> 706 707<div style="margin: auto;"> 708 <h4><a name="bordercolor" id="bordercolor"></a>-bordercolor <em class="arg">color</em></h4> 709</div> 710 711<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the border color.</td><td style='text-align:right;'></td></tr></table> 712 713<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 714 715<p>The default border color is <kbd>#DFDFDF</kbd>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p> 716 717<div style="margin: auto;"> 718 <h4><a name="borderwidth" id="borderwidth"></a>-borderwidth <em class="arg">geometry</em> </h4> 719</div> 720 721<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the border width.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 722 723<div style="margin: auto;"> 724 <h4><a name="brightness-contrast" id="brightness-contrast"></a>-brightness-contrast <em class="arg">brightness</em><br />-brightness-contrast <em class="arg">brightness</em>{x<em class="arg">contrast</em>}{<em class="arg">%</em>}}</h4> 725</div> 726 727<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adjust the brightness and/or contrast of the image.</td><td style='text-align:right;'></td></tr></table> 728 729<p>Brightness and Contrast values apply changes to the input image. They are not absolute settings. A brightness or contrast value of zero means no change. The range of values is -100 to +100 on each. Positive values increase the brightness or contrast and negative values decrease the brightness or contrast. To control only contrast, set the brightness=0. To control only brightness, set contrast=0 or just leave it off.</p> 730 731<p>You may also use <a href="#fill">-channel</a> to control which channels to apply the brightness and/or contrast change. The default is to apply the same transformation to all channels.</p> 732 733<p>Brightness and Contrast arguments are converted to offset and slope of a linear transform and applied using <a href="#fill">-function polynomial "slope,offset"</a>.</p> 734 735<p>The slope varies from 0 at contrast=-100 to almost vertical at contrast=+100. For brightness=0 and contrast=-100, the result are totally midgray. For brightness=0 and contrast=+100, the result will approach but not quite reach a threshold at midgray; that is the linear transformation is a very steep vertical line at mid gray.</p> 736 737<p>Negative slopes, i.e. negating the image, are not possible with this function. All achievable slopes are zero or positive.</p> 738 739<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5 at brightness=+100. Thus, when contrast=0 and brightness=100, the result is totally white. Similarly, when contrast=0 and brightness=-100, the result is totally black.</p> 740 741<p>As the range of values for the arguments are -100 to +100, adding the '%' symbol is no different than leaving it off.</p> 742 743<div style="margin: auto;"> 744 <h4><a name="cache" id="cache"></a>-cache <em class="arg">threshold</em></h4> 745</div> 746 747<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>(This option has been replaced by the <a href='#limit'>-limit</a> option.)</td><td style='text-align:right;'></td></tr></table> 748 749<div style="margin: auto;"> 750 <h4><a name="caption" id="caption"></a>-caption <em class="arg">string</em></h4> 751</div> 752 753<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Assign a caption to an image.</td><td style='text-align:right;'></td></tr></table> 754 755<p>This option sets the caption meta-data of an image read in after this 756option has been given. To modify a caption of images already in memory use 757"<kbd><a href="#set">-set</a> caption</kbd>". </p> 758 759<p>The caption can contain special format characters listed in the <a 760href="/www/escape.html">Format and 761Print Image Properties</a>. These attributes are expanded when the caption 762is finally assigned to the individual images. </p> 763 764<p>If the first character of <em class="arg">string</em> is <em 765class="arg">@</em>, the image caption is read from a file titled by the 766remaining characters in the string. Comments read in from a file are literal; 767no embedded formatting characters are recognized.</p> 768 769<p>Caption meta-data ais not visible on the image itself. To do that use the 770<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 771instead.</p> 772 773<p>For example,</p> 774 775<p class="crtsnip"> 776 -caption "%m:%f %wx%h" bird.miff 777</p> 778 779<p>produces an image caption of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 780that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 781480.</p> 782 783 784<div style="margin: auto;"> 785 <h4><a name="cdl" id="cdl"></a>-cdl <em class="arg">filename</em></h4> 786</div> 787 788<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color correct with a color decision list.</td><td style='text-align:right;'></td></tr></table> 789 790<p>Here is an example color correction collection:</p> 791 792<pre class="text"> 793<?xml version="1.0" encoding="UTF-8"?> 794<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 795 <ColorCorrection id="cc06668"> 796 <SOPNode> 797 <Slope> 0.9 1.2 0.5 </Slope> 798 <Offset> 0.4 -0.5 0.6 </Offset> 799 <Power> 1.0 0.8 1.5 </Power> 800 </SOPNode> 801 <SATNode> 802 <Saturation> 0.85 </Saturation> 803 </SATNode> 804 </ColorCorrection> 805</ColorCorrectionCollection> 806</pre> 807 808<div style="margin: auto;"> 809 <h4><a name="channel" id="channel"></a>-channel <em class="arg">type</em></h4> 810</div> 811 812<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify those image color channels to which subsequent operators are limited.</td><td style='text-align:right;'></td></tr></table> 813 814<p>Choose from: <kbd>Red</kbd>, <kbd>Green</kbd>, <kbd>Blue</kbd>, <kbd>Alpha</kbd>, <kbd>Cyan</kbd>, <kbd>Magenta</kbd>, <kbd>Yellow</kbd>, <kbd>Black</kbd>, <kbd>Opacity</kbd>, <kbd>Index</kbd>, <kbd>RGB</kbd>, <kbd>RGBA</kbd>, <kbd>CMYK</kbd>, or <kbd>CMYKA</kbd>.</p> 815 816<p>The channels above can also be specified as a comma-separated list or can be 817abbreviated as a concatenation of the letters '<kbd>R</kbd>', '<kbd>G</kbd>', 818'<kbd>B</kbd>', '<kbd>A</kbd>', '<kbd>O</kbd>', '<kbd>C</kbd>', 819'<kbd>M</kbd>', '<kbd>Y</kbd>', '<kbd>K</kbd>'. 820 821For example, to only select the <kbd>Red</kbd> and <kbd>Blue</kbd> channels 822you can either use </p> 823<p class="crtsnip"> 824 -channel Red,Blue 825</p> 826<p>or you can use the short hand form</p> 827<p class="crtsnip"> 828 -channel RB 829</p> 830 831<p>All the channels that is present in an image can be specified using the 832special channel type <kbd>All</kbd>. Not all operators are 'channel capable', 833but generally any operators that are generally 'grey-scale' image operators, 834will understand this setting. See individual operator documentation. </p> 835 836<br> 837 838<p>On top of the normal channel selection a extra flag can be specified, 839'<kbd>Sync</kbd>'. This is turned on by default and if set means that 840operators that understand this flag should perform: cross-channel 841syncronization of the channels. If not specified, then most grey-scale 842operators will apply their image processing operations to each individual 843channel (as specified by the rest of the <a href="#channel">-channel</a> 844setting) completely independently from each other. </p> 845 846<p>For example for operators such as <a href="#auto-level">-auto-level</a> and 847<a href="#auto-gamma">-auto-gamma</a> the color channels are modified 848together in exactly the same way so that colors will remain in-sync. Without 849it being set, then each channel is modified separately and 850independently, which may produce color distortion. </p> 851 852<p>The <a href="#morphology">-morphology</a> '<kdb>Convolve</kdb>' method 853and the <a href="#compose">-compose</a> mathematical methods, also understands 854the '<kbd>Sync</kbd>' flag to modify the behaviour of pixel colors according 855to the alpha channel (if present). That is to say it will modify the image 856processing with the understanding that fully-transparent colors should not 857contribute to the final result. </p> 858 859Basically, by default, operators work with color channels in syncronous, and 860treats transparency as special, unless the <a href="#channel">-channel</a> 861setting is modified so as to remove the effect of the '<kbd>Sync</kbd>' flag. 862How each operator does this depends on that operators current implementation. 863Not all operators understands this flag at this time, but that is changing. 864</p> 865 866<p>To print a complete list of channel types, use <a href="#list">-list 867channel</a>.</p> 868 869<br> 870 871<p>By default, ImageMagick sets <a href="#channel">-channel</a> to the value 872'<kbd>RGBK,sync</kbd>', which specifies that operators act on all color 873channels except the transparency channel, and that all the color channels are 874to be modified in exactly the same way, with a understanding of transprancy 875(depending on the operation being applied). The 'plus' form <a 876href="#channel" >+channel</a> will reset the value back to this default. </p> 877 878<p>Options that are affected by the <a href="#channel" >-channel</a> setting 879include the following. 880 881<a href="#auto-gamma">-auto-gamma</a>, 882<a href="#auto-level">-auto-level</a>, 883<a href="#black-threshold">-black-threshold</a>, 884<a href="#blur">-blur</a>, 885<a href="#clamp">-clamp</a>, 886<a href="#clut">-clut</a>, 887<a href="#combine">-combine</a>, 888<a href="#composite">-composite</a> (Mathematical compose methods only), 889<a href="#convolve">-convolve</a>, 890<a href="#contrast-stretch">-contrast-stretch</a>, 891<a href="#evaluate">-evaluate</a>, 892<a href="#function">-function</a>, 893<a href="#fx">-fx</a>, 894<a href="#gaussian-blur">-gaussian-blur</a>, 895<a href="#hald-clut">-hald-clut</a>, 896<a href="#motion-blur">-motion-blur</a>, 897<a href="#morphology">-morphology</a>, 898<a href="#negate">-negate</a>, 899<a href="#normalize">-normalize</a>, 900<a href="#ordered-dither">-ordered-dither</a>, 901<a href="#radial-blur">-radial-blur</a>, 902<a href="#random-threshold">-random-threshold</a>, 903<a href="#separate">-separate</a>, 904<a href="#threshold">-threshold</a>, and 905<a href="#white-threshold">-white-threshold</a>. 906</p> 907 908<p>Warning, some operators behave differently when the <a href="#channel" 909>+channel</a> default setting is in effect, verses ANY user defined <a 910href="#channel" >-channel</a> setting (including the equivalent of the 911default). These operators have yet to be made to understand the newer 'Sync' 912flag. </p> 913 914<p>For example <a href="#threshold">-threshold</a> will by default gray-scale 915the image before thresholding, if no <a href="#channel" >-channel</a> setting 916has been defined. This is not 'Sync flag controlled, yet. </p> 917 918<p>Also some operators such as <a href="#blur">-blur</a>, <a 919href="#gaussian-blur">-gaussian-blur</a>, will modify their handling of the 920color channels if the '<kbd>alpha</kbd>' channel is also enabled by <a 921href="#channel" >-channel</a>. Generally this done to ensure that 922fully-transparent colors are treated as being fully-transparent, and thus any 923underlying 'hidden' color has no effect on the final results. Typically 924resulting in 'halo' effects. The newer <a href="#morphology">-morphology</a> 925convolution equivalents however does have a understanding of the 'Sync' flag 926and will thus handle transparency correctly by default. </p> 927 928<p>As a alpha channel is optional within images, some operators will read the 929color channels of an image as a greyscale alpha mask, when the image has no 930alpha channel present, and the <a href="#channel" >-channel</a> setting tells 931the operator to apply the operation using alpha channels. The <a 932href="#clut">-clut</a> operator is a good example of this. </p> 933 934 935<div style="margin: auto;"> 936 <h4><a name="clamp" id="clamp"></a>-clamp</h4> 937</div> 938 939<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Restrict image colors from 0 to the quantum depth.</td><td style='text-align:right;'></td></tr></table> 940 941<div style="margin: auto;"> 942 <h4><a name="charcoal" id="charcoal"></a>-charcoal <em class="arg">factor</em></h4> 943</div> 944 945<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Simulate a charcoal drawing.</td><td style='text-align:right;'></td></tr></table> 946 947<div style="margin: auto;"> 948 <h4><a name="chop" id="chop"></a>-chop <em class="arg">geometry</em></h4> 949</div> 950 951<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Remove pixels from the interior of an image.</td><td style='text-align:right;'></td></tr></table> 952 953<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <em class="arg">width</em> and <em class="arg">height</em> given in the of the <em class="arg">size</em> portion of the <em class="arg">geometry</em> argument give the number of columns and rows to remove. The <em class="arg">offset</em> portion of the <em class="arg">geometry</em> argument is influenced by a <a href="#gravity">-gravity</a> setting, if present.</p> 954 955<p>The <a href="#chop">-chop</a> option removes entire rows and columns, and moves the remaining corner blocks leftward and upward to close the gaps.</p> 956 957<div style="margin: auto;"> 958 <h4><a name="clip" id="clip"></a>-clip</h4> 959</div> 960 961<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply the clipping path if one is present.</td><td style='text-align:right;'></td></tr></table> 962 963<p>If a clipping path is present, it is applied to subsequent operations.</p> 964 965<p>For example, in the command</p> 966 967<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -clip -negate cockatoo.tif negated.tif</span></p> 968<p>only the pixels within the clipping path are negated.</p> 969 970<p>The <a href="#clip">-clip</a> feature requires the XML library. If the XML library is not present, the option is ignored.</p> 971 972<div style="margin: auto;"> 973 <h4><a name="clip-mask" id="clip-mask"></a>-clip-mask</h4> 974</div> 975 976<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Clip the image as defined by this mask.</td><td style='text-align:right;'></td></tr></table> 977 978<div style="margin: auto;"> 979 <h4><a name="clip-path" id="clip-path"></a>-clip-path <em class="arg">id</em></h4> 980</div> 981 982<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Clip along a named path from the 8BImageMagick profile.</td><td style='text-align:right;'></td></tr></table> 983 984<div style="margin: auto;"> 985 <h4><a name="clone" id="clone"></a>-clone <em class="arg">index(s)</em></h4> 986</div> 987 988<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make a copy of an image (or images).</td><td style='text-align:right;'></td></tr></table> 989 990<p>Specify the image by its index in the sequence. The first image is index 9910. Negative indexes are relative to the end of the sequence; for example, −1 992represents the last image of the sequence. Specify a range of images with a 993dash (e.g. 0−4). Separate multiple indexes with commas but no spaces (e.g. 0,2,5). Use <a 994href="#clone">+clone</a> make a copy of the last image in the image 995sequence.</p> 996 997<div style="margin: auto;"> 998 <h4><a name="clut" id="clut"></a>-clut</h4> 999</div> 1000 1001<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Replace the channel values in the first image using each 1002corresponding channel in the second image as a <b>c</b>olor 1003<b>l</b>ook<b>u</b>p <b>t</b>able.</td><td style='text-align:right;'></td></tr></table> 1004 1005<p>The second (LUT) image is ordinarily a gradient image containing the 1006histogram mapping of how each channel should be modified. Typically it is a 1007either a single row or column image of replacement color values. If larger 1008than a single row or column, values are taken from a diagonal line from 1009top-left to bottom-right corners.</p> 1010 1011<p>The lookup is further controlled by the <a 1012href="#interpolate">-interpolate</a> setting, which is especially handy for an 1013LUT which is not the full length needed by the ImageMagick installed Quality 1014(Q) level. Good settings for this are the '<kbd>bilinear</kbd>' and 1015'<kbd>bicubic</kbd>' interpolation settings, which give smooth color 1016gradients, and the '<kbd>integer</kbd>' setting for a direct, unsmoothed 1017lookup of color values. </p> 1018 1019<p>This operator is especially suited to replacing a grayscale image with a 1020specific color gradient from the CLUT image. </p> 1021 1022<p>Only the channel values defined by the <a href="#channel">-channel</a> 1023setting will have their values replaced. In particular, since the default <a 1024href="#channel">-channel</a> setting is <kbd>RGB</kbd>, this means that 1025transparency (alpha/matte channel) is not affected, unless the <a 1026href="#channel">-channel</a> setting is modified. When the alpha channel is 1027set, it is treated by the <a href="#clut" >-clut</a> operator in the same way 1028as the other channels, implying that alpha/matte values are replaced using the 1029alpha/matte values of the original image. </p> 1030 1031<p>If either the image being modified, or the lookup image, contains no 1032transparency (i.e. <a href="#alpha" >-alpha</a> is turned 'off') but the <a 1033href="#channel">-channel</a> setting includes alpha replacement, then it is 1034assumed that image represents a gray-scale gradient which is used for the 1035replacement alpha values. That is you can use a gray-scale CLUT image to 1036adjust a existing images alpha channel, or you can color a gray-scale image 1037using colors form CLUT containing the desired colors, including transparency. 1038</p> 1039 1040<p>See also <a href="#hald-clut" >-hald-clut</a> which replaces colors according 1041the lookup of the full color RGB value from a 2D representation of a 3D color 1042cube. </p> 1043 1044 1045<div style="margin: auto;"> 1046 <h4><a name="coalesce" id="coalesce"></a>-coalesce</h4> 1047</div> 1048 1049<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</td><td style='text-align:right;'></td></tr></table> 1050 1051<p>Overlay each image in an image sequence according to its <a href="#dispose">-dispose</a> meta-data, to reproduce the look of an animation at each point in the animation sequence. All images should be the same size, and are assigned appropriate GIF disposal settings for the animation to continue working as expected as a GIF animation. Such frames are more easily viewed and processed than the highly optimized GIF overlay images. </p> 1052 1053<p>The animation can be re-optimized after processing using the <a href="#layers">-layers</a> method '<kbd>optimize</kbd>', though there is no guarantee that the restored GIF animation optimization is better than the original. </p> 1054 1055 1056<div style="margin: auto;"> 1057 <h4><a name="colorize" id="colorize"></a>-colorize <em class="arg">value</em></h4> 1058</div> 1059 1060<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Colorize the image by an amount specified by <em class="arg">value</em> using the color specified by the most recent <a href="#fill" >-fill</a> setting.</td><td style='text-align:right;'></td></tr></table> 1061 1062<p>Specify the amount of colorization as a percentage. Separate colorization values can be applied to the red, green, and blue channels of the image with a comma-delimited list of colorization values (e.g., <kbd>-colorize 0,0,50</kbd>).</p> 1063 1064<div style="margin: auto;"> 1065 <h4><a name="colormap" id="colormap"></a>-colormap <em class="arg">type</em></h4> 1066</div> 1067 1068<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Define the colormap type.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 1069 1070<p>The <em class="arg">type</em> can be <kbd>shared</kbd> or <kbd>private</kbd>.</p> 1071 1072<p>This option only applies when the default X server visual is <kbd>PseudoColor</kbd> or <kbd>GrayScale</kbd>. Refer to <a href="#visual">-visual</a> for more details. By default, a shared colormap is allocated. The image shares colors with other X clients. Some image colors could be approximated, therefore your image may look very different than intended. If <kbd>private</kbd> is chosen, the image colors appear exactly as they are defined. However, other clients may go <em>technicolor</em> when the image colormap is installed.</p> 1073 1074<div style="margin: auto;"> 1075 <h4><a name="colors" id="colors"></a>-colors <em class="arg">value</em></h4> 1076</div> 1077 1078<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the preferred number of colors in the image.</td><td style='text-align:right;'></td></tr></table> 1079 1080<p>The actual number of colors in the image may be less than your request, but never more. Note that this a color reduction option. Images with fewer unique colors than specified by <em class="arg">value</em> will have any duplicate or unused colors removed. The ordering of an existing color palette may be altered. When converting an image from color to grayscale, it is more efficient to convert the image to the gray colorspace before reducing the number of colors. Refer to the <a href="/www/quantize.html">color reduction algorithm</a> for more details.</p> 1081 1082<div style="margin: auto;"> 1083 <h4><a name="color-matrix" id="color-matrix"></a>-color-matrix <em class="arg">matrix</em></h4> 1084</div> 1085 1086<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply color correction to the image.</td><td style='text-align:right;'></td></tr></table> 1087 1088<p>This option permits saturation changes, hue rotation, luminance to alpha, and various other effects. Although variable-sized transformation matrices can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 for CMYKA (or RGBA with offsets). The matrix is similar to those used by Adobe Flash except offsets are in column 6 rather than 5 (in support of CMYKA images) and offsets are normalized (divide Flash offset by 255).</p> 1089 1090<p>As an example, to add contrast to an image with offsets, try this command:</p> 1091 1092<pre class="text"> 1093convert kittens.jpg -color-matrix \ 1094 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \ 1095 0.0 1.5 0.0 0.0, 0.0, -0.157 \ 1096 0.0 0.0 1.5 0.0, 0.0, -0.157 \ 1097 0.0 0.0 0.0 1.0, 0.0, 0.0 \ 1098 0.0 0.0 0.0 0.0, 1.0, 0.0 \ 1099 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png 1100</pre> 1101<div style="margin: auto;"> 1102 <h4><a name="colorspace" id="colorspace"></a>-colorspace <em class="arg">value</em></h4> 1103</div> 1104 1105<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the image colorspace.</td><td style='text-align:right;'></td></tr></table> 1106 1107<p>Choices are:</p> 1108 1109<pre class="text"> 1110 CMY 1111 CMYK 1112 Gray 1113 HSB 1114 HSL 1115 HWB 1116 Lab 1117 Log 1118 OHTA 1119 Rec601Luma 1120 Rec601YCbCr 1121 Rec709Luma 1122 Rec709YCbCr 1123 RGB 1124 sRGB 1125 Transparent 1126 XYZ 1127 YCbCr 1128 YCC 1129 YIQ 1130 YPbPr 1131 YUV 1132</pre> 1133 1134<p>To print a complete list of colorspaces, use <a href="#list">-list colorspace</a>.</p> 1135 1136<p>For a more accurate color conversion to or from the RGB, CMYK, or grayscale colorspaces, use the <a href="#profile">-profile</a> option.</p> 1137 1138<table class="doc"> 1139 <caption>Conversion Of RGB To Other Color Spaces</caption> 1140 <tr><th align="left" valign="middle">CMY</th></tr> 1141 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>−R</td></tr> 1142 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>−G</td></tr> 1143 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>−B</td></tr> 1144 <tr><th align="left" valign="middle">CMYK — starts with CMY from above</th></tr> 1145 <tr><td align="left" valign="middle">K=min(C,Y,M)</td></tr> 1146 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>*(C−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1147 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>*(M−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1148 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>*(Y−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1149 1150 <tr><th align="left" valign="middle">Gray</th></tr> 1151 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1152 1153 <tr><th align="left" valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr> 1154 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1155 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1156 <tr><td align="left" valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <em>intensity-like</em></td></tr> 1157 1158 <tr><th align="left" valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr> 1159 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1160 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1161 <tr><td align="left" valign="middle">L=distance along axis from bottom upward; L=0.5*max(R,G,B) + 0.5*min(R,G,B); <em>intensity-like</em></td></tr> 1162 1163 <tr><th align="left" valign="middle">HWB — Hue, Whiteness, Blackness</th></tr> 1164 <tr><td align="left" valign="middle">Hue (complicated equation)</td></tr> 1165 <tr><td align="left" valign="middle">Whiteness (complicated equation)</td></tr> 1166 <tr><td align="left" valign="middle">Blackness (complicated equation)</td></tr> 1167 1168 <tr><th align="left" valign="middle">LAB</th></tr> 1169 <tr><td align="left" valign="middle">L (complicated equation relating X,Y,Z)</td></tr> 1170 <tr><td align="left" valign="middle">A (complicated equation relating X,Y,Z)</td></tr> 1171 <tr><td align="left" valign="middle">B (complicated equation relating X,Y,Z)</td></tr> 1172 1173 <tr><th align="left" valign="middle">LOG</th></tr> 1174 <tr><td align="left" valign="middle">I1 (complicated equation involving logarithm of R)</td></tr> 1175 <tr><td align="left" valign="middle">I2 (complicated equation involving logarithm of G)</td></tr> 1176 <tr><td align="left" valign="middle">I3 (complicated equation involving logarithm of B)</td></tr> 1177 1178 <tr><th align="left" valign="middle">OHTA — approximates principal components transformation</th></tr> 1179 <tr><td align="left" valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <em>intensity-like</em></td></tr> 1180 <tr><td align="left" valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1181 <tr><td align="left" valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1182 1183 <tr><th align="left" valign="middle">Rec601Luma</th></tr> 1184 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1185 1186 <tr><th align="left" valign="middle">Rec601YCbCr</th></tr> 1187 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1188 <tr><td align="left" valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1189 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1190 1191 <tr><th align="left" valign="middle">Rec709Luma</th></tr> 1192 <tr><td align="left" valign="middle">Gray=0.21260*R+0.71520*G+0.07220*B</td></tr> 1193 1194 <tr><th align="left" valign="middle">Rec709YCbCr</th></tr> 1195 <tr><td align="left" valign="middle">Y=0.212600*R+0.715200*G+0.072200*B; <em>intensity-like</em></td></tr> 1196 <tr><td align="left" valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1197 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1198 1199 <tr><th align="left" valign="middle">sRGB</th></tr> 1200 <tr><td align="left" valign="middle">if Rs ≤ .03928 then Rs=R/12.92 else Rs=((R+.055)/1.055)^2.4</td></tr> 1201 <tr><td align="left" valign="middle">if Gs ≤ .03928 then Gs=B/12.92 else Gs=((G+.055)/1.055)^2.4</td></tr> 1202 <tr><td align="left" valign="middle">if Bs ≤ .03928 then Bs=B/12.92 else Bs=((B+.055)/1.055)^2.4</td></tr> 1203 1204 <tr><th align="left" valign="middle">XYZ</th></tr> 1205 <tr><td align="left" valign="middle">X=0.4124240*R+0.3575790*G+0.1804640*B</td></tr> 1206 <tr><td align="left" valign="middle">Y=0.2126560*R+0.7151580*G+0.0721856*B</td></tr> 1207 <tr><td align="left" valign="middle">Z=0.0193324*R+0.1191930*G+0.9504440*B</td></tr> 1208 1209 <tr><th align="left" valign="middle">YCC</th></tr> 1210 <tr><td align="left" valign="middle">Y=(0.29900*R+0.58700*G+0.11400*B) (with complicated scaling); <em>intensity-like</em></td></tr> 1211 <tr><td align="left" valign="middle">C1=(−0.29900*R−0.58700*G+0.88600*B) (with complicated scaling)</td></tr> 1212 <tr><td align="left" valign="middle">C2=(0.70100*R−0.58700*G−0.11400*B) (with complicated scaling)</td></tr> 1213 1214 <tr><th align="left" valign="middle">YCbCr</th></tr> 1215 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1216 <tr><td align="left" valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1217 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1218 1219 <tr><th align="left" valign="middle">YIQ</th></tr> 1220 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1221 <tr><td align="left" valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1222 <tr><td align="left" valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1223 1224 <tr><th align="left" valign="middle">YPbPr</th></tr> 1225 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1226 <tr><td align="left" valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1227 <tr><td align="left" valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1228 1229 <tr><th align="left" valign="middle">YUV</th></tr> 1230 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1231 <tr><td align="left" valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1232 <tr><td align="left" valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1233</table> 1234 1235<div style="margin: auto;"> 1236 <h4><a name="combine" id="combine"></a>-combine</h4> 1237</div> 1238 1239<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Combine one or more images into a single image.</td><td style='text-align:right;'></td></tr></table> 1240 1241<p>The channels (previously set by <a href="#channel">-channel</a>) of the combined image are taken from the grayscale values of each image in the sequence, in order. For the default -channel setting of <kbd>RGB</kbd>, this means the first image is assigned to the <kbd>Red</kbd> channel, the second to the <kbd>Green</kbd> channel, the third to the <kbd>Blue</kbd>.</p> 1242 1243<p>This option can be thought of as the inverse to <a href="#separate">-separate</a>, so long as the channel settings are the same. Thus, in the following example, the final image should be a copy of the original. 1244</p> 1245 1246<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert original.png -channel RGB -separate sepimage.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \ <br/> -combine imagecopy.png</span></p> 1247<div style="margin: auto;"> 1248 <h4><a name="comment" id="comment"></a>-comment <em class="arg">string</em></h4> 1249</div> 1250 1251<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Embed a comment in an image.</td><td style='text-align:right;'></td></tr></table> 1252 1253<p>This option sets the comment meta-data of an image read in after this 1254option has been given. To modify a comment of images already in memory use 1255"<kbd><a href="#set">-set</a> comment</kbd>". </p> 1256 1257<p>The comment can contain special format characters listed in the <a 1258href="/www/escape.html">Format and 1259Print Image Properties</a>. These attributes are expanded when the comment 1260is finally assigned to the individual images. </p> 1261 1262<p>If the first character of <em class="arg">string</em> is <em 1263class="arg">@</em>, the image comment is read from a file titled by the 1264remaining characters in the string. Comments read in from a file are literal; 1265no embedded formatting characters are recognized.</p> 1266 1267<p>Comment meta-data are not visible on the image itself. To do that use the 1268<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 1269instead.</p> 1270 1271<p>For example,</p> 1272 1273<p class="crtsnip"> 1274 -comment "%m:%f %wx%h" bird.miff 1275</p> 1276 1277<p>produces an image comment of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 1278that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 1279480.</p> 1280 1281<div style="margin: auto;"> 1282 <h4><a name="compose" id="compose"></a>-compose <em class="arg">operator</em></h4> 1283</div> 1284 1285<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the type of image composition.</td><td style='text-align:right;'></td></tr></table> 1286 1287<p>See <a href="/www/compose.html">Alpha Compositing</a> for 1288a detailed discussion of alpha compositing.</p> 1289 1290<p>This setting effects image processing operators that merge two (or more) 1291images together in some way. This includes the operators, 1292<a href="#composite">-composite</a>, 1293<a href="#layers">-layers</a> composite, 1294<a href="#flatten">-flatten</a>, 1295<a href="#mosaic">-mosaic</a>, 1296<a href="#layers">-layers</a> merge, 1297<a href="#border">-border</a>, 1298<a href="#frame">-frame</a>, 1299and <a href="#extent">-extent</a>. </p> 1300 1301<p>It is also one of the primary options for the "<kbd>composite</kbd>" 1302command. </p> 1303 1304 1305<div style="margin: auto;"> 1306 <h4><a name="composite" id="composite"></a>-composite</h4> 1307</div> 1308 1309<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Perform alpha composition on two images and an optional mask</td><td style='text-align:right;'></td></tr></table> 1310 1311<p>Take the first image 'destination' and overlay the second 'source' image 1312according to the current <a href="#compose">-compose</a> setting. The location 1313of the 'source' or 'overlay' image is controlled according to <a 1314href="#geometry" >-geometry</a>, and <a href="#geometry" >-geometry</a> 1315settings. </p> 1316 1317<p>If a third image is given this is treated as a gray-scale 'mask' image 1318relative to the first 'destination' image. This mask will limit what parts of 1319the destination can be modified by the image composition. However for the 1320'<kbd>displace</kbd>' compose method, the mask is used to provide a separate 1321Y-displacement image instead. </p> 1322 1323<p>If a <a href="#compose">-compose</a> method requires extra numerical 1324arguments or flags these can be provided by setting the <a 1325href="#set">-set</a> '<kbd class="arg">option:compose:args</kbd>' 1326appropriately for the compose method. </p> 1327 1328<p>Some <a href="#compose">-compose</a> methods can modify the 'destination' 1329image outside the overlay area. You can disable this by setting the special <a 1330href="#set">-set</a> '<kbd class="arg">option:compose:outside-overlay</kbd>' 1331to '<kbd>false</kbd>'. </p> 1332 1333 1334<div style="margin: auto;"> 1335 <h4><a name="compress" id="compress"></a>-compress <em class="arg">type</em></h4> 1336</div> 1337 1338<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use pixel compression specified by <em class="arg">type</em> when writing the image.</td><td style='text-align:right;'></td></tr></table> 1339 1340<p>Choices are: <kbd class="arg">None</kbd>, <kbd class="arg">BZip</kbd>, <kbd class="arg">Fax</kbd>, <kbd class="arg">Group4</kbd>, <kbd class="arg">JPEG</kbd>, <kbd class="arg">JPEG2000</kbd>, <kbd class="arg">Lossless</kbd>, <kbd class="arg">LZW</kbd>, <kbd class="arg">RLE</kbd> or <kbd class="arg">Zip</kbd>.</p> 1341 1342<p>To print a complete list of compression types, use <a href="#list">-list compress</a>.</p> 1343 1344<p>Specify <a href="#compress">+compress</a> to store the binary image in an uncompressed format. The default is the compression type of the specified image file.</p> 1345 1346<p>If <kbd>LZW</kbd> compression is specified but LZW compression has not been enabled, the image data is written in an uncompressed LZW format that can be read by LZW decoders. This may result in larger-than-expected GIF files.</p> 1347 1348<p><kbd>Lossless</kbd> refers to lossless JPEG, which is only available if the JPEG library has been patched to support it. Use of lossless JPEG is generally not recommended.</p> 1349 1350<p>Use the <a href="#quality">-quality</a> option to set the compression level to be used by JPEG, PNG, MIFF, and MPEG encoders. Use the <a href="#sampling-factor">-sampling-factor</a> option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling the chroma channels.</p> 1351 1352<div style="margin: auto;"> 1353 <h4><a name="contrast" id="contrast"></a>-contrast</h4> 1354</div> 1355 1356<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Enhance or reduce the image contrast.</td><td style='text-align:right;'></td></tr></table> 1357 1358<p>This option enhances the intensity differences between the lighter and darker elements of the image. Use <a href="#contrast">-contrast</a> to enhance the image or <a href="#contrast">+contrast</a> to reduce the image contrast.</p> 1359 1360<p>For a more pronounced effect you can repeat the option:</p> 1361 1362<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -contrast -contrast rose_c2.png</span></p> 1363<div style="margin: auto;"> 1364 <h4><a name="contrast-stretch" id="contrast-stretch"></a>-contrast-stretch <em class="arg">black-point</em><br />-contrast-stretch <em class="arg">black-point</em>{x<em class="arg">white-point</em>}{<em class="arg">%</em>}}</h4> 1365</div> 1366 1367<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Increase the contrast in an image by <em>stretching</em> the range of intensity values.</td><td style='text-align:right;'></td></tr></table> 1368 1369<p>While performing the stretch, black-out at most <em 1370class="arg" >black-point</em> pixels and white-out at most <em 1371class="arg" >white-point</em> pixels. Or, if percent is used, black-out at most 1372<em class="arg" >black-point %</em> pixels and white-out at most <em 1373class="arg" >white-point %</em> pixels.</p> 1374 1375<p>Prior to ImageMagick 6.4.7-0, <a href="#contrast-stretch" 1376>-contrast-stretch</a> will black-out at most <em class="arg" 1377>black-point</em> pixels and white-out at most <em class="arg" >total pixels 1378minus white-point</em> pixels. Or, if percent is used, black-out at most <em 1379class="arg">black-point %</em> pixels and white-out at most <em class="arg" 1380>100% minus white-point %</em> pixels.</p> 1381 1382<p>Note that <kbd>-contrast-stretch 0</kbd> will modify the image such that 1383the image's min and max values are stretched to 0 and <em class="QR" 1384>QuantumRange</em>, respectively, without any loss of data due to burn-out or 1385clipping at either end. This is not the same as <a href="#normalize" 1386>-normalize</a>, which is equivalent to <kbd>-contrast-stretch 0.15x0.05%</kbd> (or 1387prior to ImageMagick 6.4.7-0, <kbd>-contrast-stretch 2%x99%</kbd>).</p> 1388 1389<p>Internally operator works by creating a histogram bin, and then uses that 1390bin to modify the image. As such some colors may be merged together when they 1391originally fell into the same 'bin'. </p> 1392 1393<p>All the channels are normalized in concert by the came amount so as to 1394preserve color integrity, when the default <a href="#channel" >+channel</a> 1395setting is in use. Specifying any other <a href="#channel" >-channel</a> 1396setting will normalize the RGB channels independently.</p> 1397 1398<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 1399normalization of mathematical images. </p> 1400 1401<p>This operator is under review for re-development. </p> 1402 1403 1404<div style="margin: auto;"> 1405 <h4><a name="convolve" id="convolve"></a>-convolve <em class="arg">kernel</em></h4> 1406</div> 1407 1408<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Convolve an image with a user-supplied convolution kernel.</td><td style='text-align:right;'></td></tr></table> 1409 1410<p>The <em class="arg">kernel</em> is a matrix specified as 1411a comma-separated list of integers (with no spaces), ordered left-to right, 1412starting with the top row. Presently, only odd-dimensioned kernels are 1413supported, and therefore the number of entries in the specified <em 1414class="arg">kernel</em> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25, 14157<sup>2</sup>=49, etc. </p> 1416 1417<p>Note that the <a href="/www/command-line-options.html#convolve">‑convolve</a> operator supports the <a href="/www/command-line-options.html#bias">‑bias</a> setting. This option shifts the convolution so that 1418positive and negative results are relative to a user-specified bias value. 1419This is important for non-HDRI compilations of ImageMagick when dealing with 1420convolutions that contain negative as well as positive values. This is 1421especially the case with convolutions involving high pass filters or edge 1422detection. Without an output bias, the negative values is clipped at zero. 1423</p> 1424 1425<p>When using an ImageMagick with the HDRI compile-time setting, <a href="/www/command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 1426negative results without clipping to the color value range (0..QuantumRange). 1427See the discussion on HDRI implementations of ImageMagick on the page <a 1428href="/www/high-dynamic-range.html">High 1429Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a 1430href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this 1431<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 1432entry. </p> 1433 1434 1435<div style="margin: auto;"> 1436 <h4><a name="crop" id="crop"></a>-crop <em class="arg">geometry</em></h4> 1437</div> 1438 1439<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Cut out one or more rectangular regions of the image.</td><td style='text-align:right;'></td></tr></table> 1440 1441<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 1442 1443<p>The <em class="arg">width</em> and <em class="arg">height</em> of the <em class="arg">geometry</em> argument give the size of the image that remains after cropping, and <em class="arg">x</em> and <em class="arg">y</em> in the <em class="arg">offset</em> (if present) gives the location of the top left corner of the cropped image with respect to the original image. To specify the amount to be removed, use <a href="#shave">-shave</a> instead.</p> 1444 1445<p>If the <em class="arg">x</em> and <em class="arg">y</em> offsets are present, a single image is generated, consisting of the pixels from the cropping region. The offsets specify the location of the upper left corner of the cropping region measured downward and rightward with respect to the upper left corner of the image. If the <a href="#gravity">-gravity</a> option is present with <kbd>NorthEast</kbd>, <kbd>East</kbd>, or <kbd>SouthEast</kbd> gravity, it gives the distance leftward from the right edge of the image to the right edge of the cropping region. Similarly, if the <a href="#gravity">-gravity</a> option is present with <kbd>SouthWest</kbd>, <kbd>South</kbd>, or <kbd>SouthEast</kbd> gravity, the distance is measured upward between the bottom edges.</p> 1446 1447<p>If the <em class="arg">x</em> and <em class="arg">y</em> offsets are omitted, a set of tiles of the specified geometry, covering the entire input image, is generated. The rightmost tiles and the bottom tiles are smaller if the specified geometry extends beyond the dimensions of the input image.</p> 1448 1449<p>By adding a exclamation character flag to the geometry argument, the 1450cropped images virtual canvas page size and offset is set as if the 1451geometry argument was a viewport or window. This means the canvas page size 1452is set to exactly the same size you specified, the image offset set 1453relative top left corner of the region cropped. </p> 1454 1455<p>If the cropped image 'missed' the actual image on its virtual canvas, a 1456special single pixel transparent 'missed' image is returned, and a 'crop 1457missed' warning given. </p> 1458 1459<p>It might be necessary to <a href="#repage" >+repage</a> the image prior to cropping the image to ensure the crop coordinate frame is relocated to the upper-left corner of the visible image.</p> 1460 1461<div style="margin: auto;"> 1462 <h4><a name="cycle" id="cycle"></a>-cycle <em class="arg">amount</em></h4> 1463</div> 1464 1465<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>displace image colormap by amount.</td><td style='text-align:right;'></td></tr></table> 1466 1467<p><em class="arg">Amount</em> defines the number of positions each 1468colormap entry is shifted.</p> 1469 1470 1471<div style="margin: auto;"> 1472 <h4><a name="debug" id="debug"></a>-debug <em class="arg">events</em></h4> 1473</div> 1474 1475<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>enable debug printout.</td><td style='text-align:right;'></td></tr></table> 1476 1477<p>The <kbd>events</kbd> parameter specifies which events are to be logged. It can be either <kbd>None</kbd>, <kbd>All</kbd>, <kbd>Trace</kbd>, or a comma-separated list consisting of one or more of the following domains: <kbd>Annotate</kbd>, <kbd>Blob</kbd>, <kbd>Cache</kbd>, <kbd>Coder</kbd>, <kbd>Configure</kbd>, <kbd>Deprecate</kbd>, <kbd>Exception</kbd>, <kbd>Locale</kbd>, <kbd>Render</kbd>, <kbd>Resource</kbd>, <kbd>Security</kbd>, <kbd>TemporaryFile</kbd>, <kbd>Transform</kbd>, <kbd>X11</kbd>, or <kbd>User</kbd>. </p> 1478 1479 1480<p>For example, to log cache and blob events, use.</p> 1481 1482<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug "Cache,Blob" rose: rose.png</span></p> 1483<p>The <kbd>User</kbd> domain is normally empty, but developers can log user events in their private copy of ImageMagick.</p> 1484 1485<p>To print the complete list of debug methods, use <a href="#list">-list debug</a>.</p> 1486 1487<p>Use the <a href="#log">-log</a> option to specify the format for debugging output.</p> 1488 1489<p>Use <a href="#debug">+debug</a> to turn off all logging.</p> 1490 1491<p>Debugging may also be set using the <kbd>MAGICK_DEBUG</kbd> <a href="/www/resources.html#environment">environment variable</a>. The allowed values for the <kbd>MAGICK_DEBUG</kbd> environment variable are the same as for the <a href="#debug">-debug</a> option.</p> 1492 1493 1494<div style="margin: auto;"> 1495 <h4><a name="decipher" id="decipher"></a>-decipher <em class="arg">filename</em></h4> 1496</div> 1497 1498<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Decipher and restore pixels that were previously transformed by <a href="#encipher">-encipher</a>.</td><td style='text-align:right;'></td></tr></table> 1499 1500<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 1501 1502<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 1503 1504 1505<div style="margin: auto;"> 1506 <h4><a name="deconstruct" id="deconstruct"></a>-deconstruct</h4> 1507</div> 1508 1509<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>find areas that has changed between images </td><td style='text-align:right;'></td></tr></table> 1510 1511<p>Given a sequence of images all the same size, such as produced by <a href="#coalesce">-coalesce</a>, replace the second and later images, with a smaller image of just the area that changed relative to the previous image. </p> 1512 1513<p>The resulting sequence of images can be used to optimize an animation sequence, though will not work correctly for GIF animations when parts of the animation can go from opaque to transparent. </p> 1514 1515<p>This option is actually equivalent to the <a href="#layers">-layers</a> method '<kbd>compare-any</kbd>'. </p> 1516 1517 1518<div style="margin: auto;"> 1519 <h4><a name="define" id="define"></a>-define <em class="arg">key</em>{<em class="arg">=value</em>}<em class="arg">...</em></h4> 1520</div> 1521 1522<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>add specific global settings generally used to control 1523coders and image processing operations.</td><td style='text-align:right;'></td></tr></table> 1524 1525<p>This option creates one or more definitions for coders and decoders to use 1526while reading and writing image data. Definitions are generally used to 1527control image file format coder modules, and image processing operations, 1528beyond what is provided by normal means. Defined settings are listed in <a 1529href="#verbose" >-verbose</a> information ("<kbd>info:</kbd>" output format) 1530as "Artifacts". </p> 1531 1532<p>If <em class="arg">value</em> is missing for a definition, an empty-valued 1533definition of a flag is created with that name. This used to control on/off 1534options. Use <a href="#define">+define key</a> to remove definitions 1535previously created. Use <a href="#define">+define "*"</a> to remove all 1536existing definitions.</p> 1537 1538<p>The same 'artifact' settings can also be defined using the <a 1539href="#set" >-set "option:<em class="arg">key</em>" "<em class="arg" 1540>value</em>"</a> option, which also allows the use of <a href="/www/escape.html" >Format and Print Image 1541Properties</a> in the defined value. </p> 1542 1543<p>Such settings are global in scope, and effect all images and operations. </p> 1544 1545<p>The following definitions are just some of the artifacts that are 1546available:</p> 1547 1548<ul> 1549 1550<dt>dcm:display-range=reset</dt> 1551<dd>Set the display range to the minimum and maximum pixel values for the 1552 DCM image format.</dd><br /> 1553 1554<dt>dot:layout-engine=<em class="arg">value</em></dt> 1555<dd>Set the specify the layout engine for the DOT image format (e.g. 1556 <kbd>neato</kbd>).</dd><br /> 1557 1558<dt>jpeg:extent=<em class="arg">value</em></dt> 1559<dd>Restrict the maximum JPEG file size, for example <kbd>-define 1560 jpeg:extent=400kb</kbd>.</dd><br /> 1561 1562<dt>jpeg:size=<em class="arg">geometry</em></dt> 1563<dd>Set the size hint of a JPEG image, for example, -define jpeg:size=128x128. 1564 It is most useful for increasing performance and reducing the memory 1565 requirements when reducing the size of a large JPEG image.</dd><br /> 1566 1567<dt>jp2:rate=<em class="arg">value</em></dt> 1568<dd>Specify the compression factor to use while writing JPEG-2000 files. The 1569 compression factor is the reciprocal of the compression ratio. The valid 1570 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined, 1571 this value overrides the -quality setting. A quality setting of 75 1572 results in a rate value of 0.06641.</dd><br /> 1573 1574<dt>mng:need-cacheoff</dt> 1575 <dd>turn playback caching off for streaming MNG.</dd><br /> 1576 1577<dt>png:bit-depth=<em class="arg">value</em></dt> 1578<dt>png:color-type=<em class="arg">value</em></dt> 1579<dd>desired bit-depth and color-type for PNG output. You can force the PNG 1580 encoder to use a different bit-depth and color-type than it would have 1581 normally selected, but only if this does not cause any loss of image 1582 quality. Any attempt to reduce image quality is treated as an error and no 1583 PNG file is written. E.g., if you have a 1-bit black-and-white image, you 1584 can use these "defines" to cause it to be written as an 8-bit grayscale, 1585 indexed, or even a 64-bit RGBA. But if you have a 16-million color image, 1586 you cannot force it to be written as a grayscale or indexed PNG. If you 1587 wish to do this, you must use the appropriate <a href="#depth">-depth</a>, 1588 <a href="#colors">-colors</a>, or <a href="#type">-type</a> directives to 1589 reduce the image quality prior to using the PNG encoder. Note that in 1590 indexed PNG files, "bit-depth" refers to the number of bits per index, 1591 which can range from 1 to 8. In such files, the color samples always have 1592 8-bit depth.</dd><br /> 1593 1594<dt>ps:imagemask</dt> 1595<dd>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create 1596 Postscript files that render bilevel images with the Postscript imagemask 1597 operator instead of the image operator.</dd><br /> 1598 1599<dt>quantum:format=<em class="arg">type</em></dt> 1600<dd>Set the type to <kbd>floating-point</kbd> to specify a floating-point 1601 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode 1602 to preserve negative values. If <a href="#depth">-depth</a> 16 is 1603 included, the result is a single precision floating point format. 1604 If <a href="#depth">-depth</a> 32 is included, the result is 1605 double precision floating point format.</dd> 1606 1607</ul> 1608 1609<p>For example, to create a postscript file that will render only the black 1610pixels of a bilevel image, use:</p> 1611 1612<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p> 1613<p>Set attributes of the image registry by prefixing the value with 1614<kbd>registry:</kbd>. For example, to set a temporary path to put work files, 1615use:</p> 1616 1617<p class="crtsnip"> 1618-define registry:temporary-path=/data/tmp 1619</p> 1620 1621 1622 1623<div style="margin: auto;"> 1624 <h4><a name="delay" id="delay"></a>-delay <em class="arg">ticks</em> <br />-delay <em class="arg">ticks</em>x<em class="arg">ticks-per-second</em> {<em class="arg"><</em>} {<em class="arg">></em>}</h4> 1625</div> 1626 1627<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>display the next image after pausing.</td><td style='text-align:right;'></td></tr></table> 1628 1629<p>This option is useful for regulating the animation of image sequences <em>ticks/ticks-per-second</em> seconds must expire before the display of the next image. The default is no delay between each showing of the image sequence. The default ticks-per-second is 100.</p> 1630 1631<p>Use <kbd>></kbd> to change the image delay <em>only</em> if its current value exceeds the given delay. <kbd><</kbd> changes the image delay <em>only</em> if current value is less than the given delay. For example, if you specify <kbd>30></kbd> and the image delay is 20, the image delay does not change. However, if the image delay is 40 or 50, the delay it is changed to 30. Enclose the given delay in quotation marks to prevent the <kbd><</kbd> or <kbd>></kbd> from being interpreted by your shell as a file redirection.</p> 1632 1633 1634<div style="margin: auto;"> 1635 <h4><a name="delete" id="delete"></a>-delete <em class="arg">index</em></h4> 1636</div> 1637 1638<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>delete the image, specified by its index, from the image sequence.</td><td style='text-align:right;'></td></tr></table> 1639 1640<p>Specify the image by its index in the sequence. The first image is index 0. Negative indexes are relative to the end of the sequence, for example, -1 represents the last image of the sequence. Specify a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use <kbd>+delete</kbd> to delete the last image in the current image sequence.</p> 1641 1642 1643<div style="margin: auto;"> 1644 <h4><a name="density" id="density"></a>-density <em class="arg">width</em><br />-density <em class="arg">width</em>x<em class="arg">height</em></h4> 1645</div> 1646 1647<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the horizontal and vertical resolution of an image for rendering to devices.</td><td style='text-align:right;'></td></tr></table> 1648 1649<p>This option specifies the image resolution to store while encoding a raster image or the canvas resolution while rendering (reading) vector formats such as Postscript, PDF, WMF, and SVG into a raster image. Image resolution provides the unit of measure to apply when rendering to an output device or raster image. The default unit of measure is in dots per inch (DPI). The <a href="#units">-units</a> option may be used to select dots per centimeter instead.</p> 1650 1651<p>The default resolution is 72 dots per inch, which is equivalent to one point per pixel (Macintosh and Postscript standard). Computer screens are normally 72 or 96 dots per inch, while printers typically support 150, 300, 600, or 1200 dots per inch. To determine the resolution of your display, use a ruler to measure the width of your screen in inches, and divide by the number of horizontal pixels (1024 on a 1024x768 display).</p> 1652 1653<p>If the file format supports it, this option may be used to update the stored image resolution. Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile is not stripped from the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.</p> 1654 1655<p>The <a href="#density">-density</a> option sets an <em>attribute</em> and does not alter the underlying raster image. It may be used to adjust the rendered size for desktop publishing purposes by adjusting the scale applied to the pixels. To resize the image so that it is the same size at a different resolution, use the <a href="#resample">-resample</a> option.</p> 1656 1657<div style="margin: auto;"> 1658 <h4><a name="depth" id="depth"></a>-depth <em class="arg">value</em></h4> 1659</div> 1660 1661<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>depth of the image.</td><td style='text-align:right;'></td></tr></table> 1662 1663<p>This the number of bits in a color sample within a pixel. Use this option to specify the depth of raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any image after it has been read.</p> 1664 1665<div style="margin: auto;"> 1666 <h4><a name="descend" id="descend"></a>-descend</h4> 1667</div> 1668 1669<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>obtain image by descending window hierarchy.</td><td style='text-align:right;'></td></tr></table> 1670 1671<div style="margin: auto;"> 1672 <h4><a name="deskew" id="deskew"></a>-deskew <em class="arg">threshold</em></h4> 1673</div> 1674 1675<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>straighten an image. A threshold of 40% works for most images.</td><td style='text-align:right;'></td></tr></table> 1676 1677<p>Use <a href="#set">-set</a> <kbd>option:deskew:auto-crop <em>width</em></kbd> to auto crop the image. The set argument is the pixel width of the image background (e.g 40).</p> 1678 1679<div style="margin: auto;"> 1680 <h4><a name="despeckle" id="despeckle"></a>-despeckle</h4> 1681</div> 1682 1683<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce the speckles within an image.</td><td style='text-align:right;'></td></tr></table> 1684 1685<div style="margin: auto;"> 1686 <h4><a name="direction" id="direction"></a>-direction <em class="arg">type</em></h4> 1687</div> 1688 1689<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>render text right-to-left or left-to-right.</td><td style='text-align:right;'></td></tr></table> 1690 1691<div style="margin: auto;"> 1692 <h4><a name="displace" id="displace"></a>-displace <em class="arg">horizontal-scale</em><br />-displace <em class="arg">horizontal-scale</em>x<em class="arg">vertical-scale</em></h4> 1693</div> 1694 1695<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>shift image pixels as defined by a displacement map.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 1696 1697<p>With this option, the 'overlay' image, and optionally the 'mask' image, 1698is used as a displacement map, which is used to displace the lookup of 1699what part of the 'background' image is seen at each point of the overlaid 1700area. Much like the displacement map is a 'lens' that redirects light shining 1701through it so as to present a distorted view the original 'background' image 1702behind it. </p> 1703 1704<p>Any perfect grey areas of the displacement map produce a zero 1705displacement of the image. Black areas produce the given maximum negative 1706displacement of the lookup point, while white produce a maximum positive 1707displacement of the lookup. </p> 1708 1709<p>Note that it is the lookup of the 'background' that is displaced, not a 1710displacement of the image itself. As such an area of the displacement map 1711containing 'white' will have the lookup point 'shifted' by a positive amount, 1712and thus generating a copy of the destination image to the right/downward from 1713the correct position. That is the image will look like it may have been 1714'shifted' in a negative left/upward direction. Understanding this is a very 1715important in understanding how displacement maps work. </p> 1716 1717<p>The given arguments define the maximum amount of displacement in pixels 1718that a particular map can produce. If the displacement scale is large enough 1719it is also possible to lookup parts of the 'background' image that lie well 1720outside the bounds of the displacement map itself. That is you could very 1721easily copy a section of the original image from outside the overlay area 1722into the overlay area. </p> 1723 1724<p>The '%' flag makes the displacement scale relative to the size of the 1725overlay image (100% = half width/height of image). Using '!' switches 1726percentage arguments to refer to the destination image size instead. 1727these flags were added as of IM v6.5.3-5.</p> 1728 1729<p>Normally a single grayscale displacement map is provided, which with the 1730given scaling values will determine a single direction (vector) in which 1731displacements can occur (positively or negatively). However, if you also 1732specify a third image which is normally used as a <em class="arg">mask</em>, 1733the <em class="arg">composite image</em> is used for horizontal X 1734displacement, while the <em class="arg">mask image</em> is used for vertical Y 1735displacement. This allows you to define completely different displacement 1736values for the X and Y directions, and allowing you to lookup any point within 1737the <em class="arg">scale</em> bounds. In other words each pixel can lookup 1738any other nearby pixel, producing complex 2 dimensional displacements, rather 1739than a simple 1 dimensional vector displacements. </p> 1740 1741<p>Alteratively rather than suppling two separate images, as of IM v6.4.4-0, 1742you can use the 'red' channel of the overlay image to specify the horizontal 1743or X displacement, and the 'green' channel for the vertical or Y displacement. 1744</p> 1745 1746<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a 1747mask the transparency of the destination image. However areas outside the 1748overlaid areas will not be effected. </p> 1749 1750 1751<div style="margin: auto;"> 1752 <h4><a name="display" id="display"></a>-display <em class="arg">host:display[.screen]</em></h4> 1753</div> 1754 1755<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specifies the X server to contact.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 1756 1757<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p> 1758 1759<div style="margin: auto;"> 1760 <h4><a name="dispose" id="dispose"></a>-dispose <em class="arg">method</em></h4> 1761</div> 1762 1763<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>define the GIF disposal image setting for images that are being created or read in. </td><td style='text-align:right;'></td></tr></table> 1764 1765<p>The layer disposal method defines the way each the displayed image is to be 1766modified after the current 'frame' of an animation has finished being 1767displayed (after its 'delay' period), but before the next frame on an 1768animation is to be overlaid onto the display. </p> 1769 1770<p>Here are the valid methods:</p> 1771 1772<pre class="text"> 1773Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>'). 1774None 1 Do not dispose, just overlay next frame image. 1775Background 2 Clear the frame area with the background color. 1776Previous 3 Clear to the image prior to this frames overlay. 1777</pre> 1778 1779<p>You can also use the numbers given above, which is what the GIF format 1780uses internally to represent the above settings. </p> 1781 1782<p>To print a complete list of dispose methods, use <a href="#list">-list dispose</a>.</p> 1783 1784<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent 1785resetting the layer disposal methods of images being read in. </p> 1786 1787<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image 1788disposal method for images already in memory.</p> 1789 1790<div style="margin: auto;"> 1791 <h4><a name="dissimilarity-threshold" id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4> 1792</div> 1793 1794<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>maximum RMSE for subimage match (default 0.2).</td><td style='text-align:right;'>[<a href="/www/compare.html">compare</a>]</td></tr></table> 1795 1796 1797<div style="margin: auto;"> 1798 <h4><a name="dissolve" id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4> 1799</div> 1800 1801<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>dissolve an image into another by the given percent.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 1802 1803<p>The opacity of the composite image is multiplied by the given percent, then 1804it is composited 'over' the main image. If <em class="arg">src_percent</em> 1805is greater than 100, start dissolving the main image so it becomes 1806transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages 1807are given, each image are dissolved to the percentages given. </p> 1808 1809<p>Note that dissolve percentages do not add, two opaque images dissolved 1810'50,50', produce a 75% transparency. For a 50% + 50% blending of the two 1811images, you would need to use dissolve values of '50,100'. </p> 1812 1813<div style="margin: auto;"> 1814 <h4><a name="distort" id="distort"></a>-distort <em class="arg">method arguments</em></h4> 1815</div> 1816 1817<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>distort an image, using the given <em class="arg">method</em> and its required <em class="arg">arguments</em>.</td><td style='text-align:right;'></td></tr></table> 1818 1819<p>The <em class="arg">arguments</em> is a single string containing a list 1820of floating point numbers separated by commas or spaces. The number of 1821and meaning of the floating point values depends on the distortion <em 1822class="arg">method</em> being used. </p> 1823 1824<p>Choose from these distortion types:</p> 1825 1826<table class="doc"> 1827 <tr valign="top"> 1828 <th align="left" style="width: 8%">Method</th> 1829 <th align="left">Description</th> 1830 </tr> 1831 1832 <tr valign="top"> 1833 <td valign="top"><kbd>ScaleRotateTranslate</kbd> 1834 <br/>or <kbd>SRT</kbd></td> 1835 <td valign="top"> 1836 Distort image by first scaling and rotating about a given 'center', 1837 before translating that 'center' to the new location, in that order. It 1838 is an alternative method of specifying a '<kbd>Affine</kbd>' type of 1839 distortion, but without shearing effects. It also provides a good way 1840 of rotating and displacing a smaller image for tiling onto a larger 1841 background (IE 2-dimensional animations). <br/> 1842 1843 The number of arguments determine the specific meaning of each 1844 argument for the scales, rotation, and translation operations. <br/> 1845 1846 <table style="margin-left:auto; margin-right:auto;"> 1847 <tr><td># </td><td>arguments meaning</td></tr> 1848 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr> 1849 <tr><td>2:</td><td><em>Scale Angle</em></td></tr> 1850 <tr><td>3:</td><td><em>ScaleX,ScaleY Angle</em></td></tr> 1851 <tr><td>4:</td><td><em>X,Y Scale Angle</em></td></tr> 1852 <tr><td>5:</td> 1853 <td><em>X,Y ScaleX,ScaleY Angle</em></td></tr> 1854 <tr><td>6:</td> 1855 <td><em>X,Y Scale Angle NewX,NewY</em></td></tr> 1856 <tr><td>7:</td> 1857 <td><em>X,Y ScaleX,ScaleY Angle 1858 NewX,NewY</em></td></tr> 1859 </table> 1860 1861 This is actually an alternative way of specifying a 2 dimensional linear 1862 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr> 1863 1864 <tr valign="top"> 1865 <td valign="top"><kbd>Affine</kbd></td> 1866 <td valign="top"> 1867 Distort the image linearly by moving a list of at least 3 or more sets 1868 of control points (as defined below). Ideally 3 sets or 12 floating 1869 point values are given allowing the image to be linearly scaled, 1870 rotated, sheared, and translated, according to those three points. See 1871 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>' 1872 distortions. <br/> 1873 1874 More than 3 sets given control point pairs (12 numbers) is least 1875 squares fitted to best match a lineary affine distortion. If only 2 1876 control point pairs (8 numbers) are given a two point image translation 1877 rotation and scaling is performed, without any possible shearing, 1878 flipping or changes in aspect ratio to the resulting image. If only one 1879 control point pair is provides the image is only translated, (which may 1880 be a floating point non-integer translation). <br/> 1881 1882 This distortion does not include any form of perspective distortion. 1883 </td> 1884 1885 </tr> 1886 1887 <tr valign="top"> 1888 <td valign="top"><kbd>AffineProjection</kbd></td> 1889 <td valign="top"> 1890 Linearly distort an image using the given Affine Matrix of 6 1891 pre-calculated coefficients forming a set of Affine Equations to map 1892 the source image to the destination image. 1893 1894 <div style="text-align: center"><em> 1895 s<sub>x</sub>, r<sub>x</sub>, 1896 r<sub>y</sub>, s<sub>y</sub>, 1897 t<sub>x</sub>, t<sub>y</sub> 1898 </em></div> 1899 1900 See <a href="#affine" >-affine</a> setting for more detail, and 1901 meanings of these coefficients. <br/> 1902 1903 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide 1904 alternative methods of defining this distortion, with ImageMagick doing 1905 the calculations needed to generate the required coefficients. You can 1906 see the internally generated coefficients, by using a <a 1907 href="#verbose" >-verbose</a> setting with those other varients. </td> 1908 1909 </tr> 1910 1911 <tr valign="top"> 1912 <td valign="top"><kbd>BilinearForward</kbd><br/> 1913 <kbd>BilinearReverse</kbd></td> 1914 <td valign="top"> 1915 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or 1916 16 values (see below). Not that lines may not appear straight after 1917 distortion, though the distance between coordinates will remain 1918 consistent. <br/> 1919 1920 The '<kbd>BilinearForward</kbd>' is used to map rectangles to any 1921 quadrilateral, while the '<kbd>BilinearReverse</kbd>' form maps any 1922 quadrilateral to a rectangle, while preserving the straigth line edges 1923 in each case. <br/> 1924 1925 Note that '<kbd>BilinearForward</kbd>' can generate invalid pixels 1926 which will be colored using the <a href="#mattecolor" >-mattecolor</a> 1927 color setting. Also if the quadraterial becomes 'flipped' the image 1928 may dissappear. <br/> 1929 1930 There are future plans to produce a true Bilinear distortion that will 1931 attempt to map any quadrilateral to any other quadrilateral, while 1932 preserving edges (and edge distance ratios). 1933 1934 </td> 1935 </tr> 1936 1937 <tr valign="top"> 1938 <td valign="top"><kbd>Perspective</kbd></td> 1939 <td valign="top"> 1940 Perspective distort the images, using a list of 4 or more sets of 1941 control points (as defined below). More that 4 sets (16 numbers) of 1942 control points provide least squares fitting for more accurate 1943 distortions (for the purposes of image registration and panarama 1944 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>' 1945 linear distortion. <br/> 1946 1947 Perspective Distorted images ensures that straight lines remain 1948 straight, but the scale of the distorted image will vary. The horizon 1949 is anti-aliased, and the 'sky' color may be set using the 1950 <a href="#mattecolor" >-mattecolor</a> setting. </td> 1951 </tr> 1952 1953 <tr valign="top"> 1954 <td valign="top"><kbd>PerspectiveProjection</kbd> </td> 1955 <td valign="top"> 1956 Do a '<kbd>Perspective</kbd>' distortion biased on a set of 8 1957 pre-calculated coefficients. You can get these coefficients by looking 1958 at the <a href="#verbose" >-verbose</a> output of a 1959 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself. 1960 If the last two perspective scaling coefficients are zero, the 1961 remaining 6 represents a transposed 'Affine Matrix'. </td> 1962 1963 </tr> 1964 1965 <tr valign="top"> 1966 <td valign="top"><kbd>Arc</kbd></td> 1967 <td valign="top"> 1968 Arc the image (variation of polar mapping) over the angle given around 1969 a circle. <br/> 1970 <table width="90%" style = "margin-left: auto; margin-right: auto;"> 1971 <tr valign="top"><td>Argument</td> 1972 <td>Meaning</td></tr> 1973 <tr valign="top"><td><em>arc_angle</em></td> 1974 <td>The angle over which to arc the image side-to-side</td></tr> 1975 <tr valign="top"><td><em>rotate_angle</em></td> 1976 <td>Angle to rotate resulting image from vertical center</td></tr> 1977 <tr valign="top"><td><em>top_radius</em></td> 1978 <td>Set top edge of source image at this radius</td></tr> 1979 <tr valign="top"><td><em>bottom_radius</em> </td> 1980 <td>Set bottom edge to this radius (radial scaling)</td></tr> 1981 </table> 1982 1983 The resulting image is always resized to best fit the resulting image, 1984 (as if using <a href="#distort" >+distort</a>) while attempting to 1985 preserve scale and aspect ratio of the original image as much as 1986 possible with the arguments given by the user. All four arguments will 1987 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/> 1988 1989 This a variation of a polar distortion designed to try to preserve the 1990 aspect ratio of the image rather than direct Cartesian to Polar 1991 conversion. </td> 1992 </tr> 1993 1994 <tr valign="top"> 1995 <td valign="top"><kbd>Polar</kbd></td> 1996 <td valign="top"> 1997 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of 1998 the image. that is the height of the input image is mapped to the 1999 radius limits, while the width is wrapped around between the 2000 angle limits. <br/> 2001 2002 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/> 2003 2004 All arguments are optional. With <em>Rmin</em> defaulting to zero, the 2005 center to the center of the image, and the angles going from -180 (top) 2006 to +180 (top). If <em>Rmax</em> is given the special value of 2007 '<code>0</code>', the the distance from the center to the nearest edge 2008 is used for the radius of the output image, which will ensure the whole 2009 image is visible (though scaled smaller). However a special value of 2010 '<code>-1</code>' will use the distance from the center to the furthest 2011 corner, This may 'clip' the corners from the input rectangular image, 2012 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with 2013 the same arguments. <br/> 2014 2015 If the plus form of distort (<a href="#distort" >+distort</a>) is used 2016 output image center will default to <code>0,0</code> of the virtual 2017 canvas, and the image size adjusted to ensure the whole input image is 2018 made visible in the output image on the virtual canvas. </td> 2019 2020 </tr> 2021 2022 <tr valign="top"> 2023 <td valign="top"><kbd>DePolar</kbd></td> 2024 <td valign="top"> 2025 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion 2026 but generates the reverse Polar to Cartesian distortion. <br/> 2027 2028 The special <em>Rmax</em> setting of '<code>0</code>' may however clip 2029 the corners of the input image. However using the special 2030 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner 2031 distance) will ensure the whole distorted image is preserved in the 2032 generated result, so that the same argument to '<kbd>Polar</kbd>' will 2033 reverse the distortion re-producing the original. 2034 2035 Note that as this distortion requires the area resampling of a circular 2036 arc, which can not be handled by the builtin EWA resampling function. 2037 As such the normal EWA filters are turned off. It is recommended some 2038 form of 'super-sampling' image processing technique be used to produce 2039 a high quality result. </td> 2040 2041 </tr> 2042 2043 <tr valign="top"> 2044 <td valign="top"><kbd>Barrel</kbd></td> 2045 <td valign="top"> 2046 Given the four coefficients (A,B,C,D) as defined by <a 2047 href="http://www.all-in-one.ee/~dersch/barrel/barrel.html" >Helmut 2048 Dersch</a>, perform a barrell or pin-cushion distortion appropriate to 2049 correct radial lens distortions. That is in photographs, make straight 2050 lines straight again. <br/> 2051 2052 Arguments: <em>A B C</em> [ <em>D</em> [ 2053 <em>X</em> , <em>Y</em> ] ] <br/> 2054 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 2055 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> 2056 [ <em>X</em> , <em>Y</em> ] <br/> 2057 So that it forms the function <br/> 2058 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2059 <em>C</em>*r + <em>D</em> )<br/> 2060 2061 Where <em>X</em>,<em>Y</em> is the optional center of the distortion 2062 (defaulting to the center of the image). <br/> 2063 The second form is typically used to distort images, rather than 2064 correct lens distortions. <br/> 2065 </td> 2066 2067 </tr> 2068 2069 <tr valign="top"> 2070 <td valign="top"><kbd>BarrelInverse</kbd></td> 2071 <td valign="top"> 2072 This is very simular to '<kbd>Barrel</kbd>' with the same set of 2073 arguments, and argument handling. However it uses the inverse 2074 of the radial polynomial, 2075 so that it forms the function <br/> 2076 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2077 <em>C</em>*r + <em>D</em> )<br/> 2078 Note that this is not the reverse of the '<kbd>Barrel</kbd>' 2079 distortion, just a different barrel-like radial distortion method. 2080 2081 </td> 2082 </tr> 2083 2084 <tr valign="top"> 2085 <td valign="top"><kbd>Shepards</kbd></td> 2086 <td valign="top"> 2087 Distort the given list control points (any number) using an Inverse 2088 Squared Distance Interpolation Method (<a 2089 href="http://en.wikipedia.org/wiki/Shepard%27s_method" >Shepards 2090 Method</a>). The control points in effect do 'localized' displacement 2091 of the image around the given control point (preserving the look and 2092 the rotation of the area near the control points. For best results 2093 extra control points should be added to 'lock' the positions of the 2094 corners, edges and other unchanging parts of the image, to prevent 2095 their movement. <br/> 2096 2097 The distortion has been likened to 'taffy pulling' using nails, or 2098 pins' stuck in a block of 'jelly' which is then moved to the new 2099 position, distorting te surface of the jelly. <br/> 2100 2101 Internally it is equivelent to generating a displacement map (see <a 2102 href="#displace" >-displace</a>) for source image color look-up using 2103 the <a href="#sparse-color" >-sparse-color</a> method of the same name. 2104 2105 </td> 2106 </tr> 2107 2108</table> 2109 2110<p>To print a complete list of distortion methods, use <a href="#list">-list 2111distort</a>.</p> 2112 2113<p>Many of the above distortion methods such as '<kbd>Affine</kbd>', 2114'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points 2115defining how these points in the given image should be distorted in the 2116destination image. Each set of four floating point values represent a source 2117image coordinate, followed immediately by the destination image coordinate. 2118This produces a list of values such as...</p> 2119<div style="text-align: center"><em> 2120 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 2121 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 2122 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 2123 ... 2124 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 2125</em></div> 2126<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the 2127destination image. </p> 2128 2129<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion, 2130needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 2131perspective distortion of the built-in "rose:" image. Note how spaces were 2132used to group the 4 sets of coordinate pairs, to make it easier to read and 2133understand.</p> 2134 2135<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2136convert rose: -virtual-pixel black \<br/> 2137 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \<br/> 2138 rose_3d_rotated.gif</span></p> 2139<p>If more that the required number of coordinate pairs are given for 2140a distortion, the distortion method is 'least squares' fitted to produce the 2141best result for all the coordinate pairs given. If less than the ideal number 2142of points are given, the distort will generally fall back to a simpler form of 2143distortion that can handles the smaller number of coordinates (usally a linear 2144'<kbd>Affine</kbd>' distortion). </p> 2145 2146<p>By using more coordinates you can make use of image registration tool to 2147find matching coordinate pairs in overlapping images, so as to improve the 2148'fit' of the distortion. Of course a bad coordinate pair can also make the 2149'fit' worse. Caution is always advised. </p> 2150 2151<p>Colors are acquired from the source image according to the <a 2152href="#interpolate" >-interpolate</a> color lookup setting, when the image is 2153magnified. However if the viewed image is minified (image becomes smaller), 2154a special area resampling function (added ImageMagick v6.3.5-9), is used to 2155produce a higher quality image. For example you can use 2156a '<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all 2157the way to the horizon. </p> 2158 2159<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2160convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \<br/> 2161 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \<br/> 2162 checks_tiled.jpg</span></p> 2163<p>Note that a infinitely tiled perspective images involving the horizon can 2164be very slow to generate due to the use of the high quality 'area resampling' 2165function (added ImageMagick v6.3.5-9). You can turn off 'area resampling' 2166using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>' 2167(recommended if you plan to use super-sampling instead). </p> 2168 2169<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 2170'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a> 2171will use the current <a href="#mattecolor" >-mattecolor</a> setting for these 2172pixels. If you do not what these pixels to be visible, set the color to match 2173the rest of the ground. </p> 2174 2175<p>The output image size will by default be the same as the input image. This 2176means that if the part of the distorted image falls outside the viewed area of 2177the 'distorted space', those parts is clipped and lost. However if you use 2178the plus form of the operator (<a href="#distort" >+distort</a>) the operator 2179will attempt (if possible) to show the whole of the distorted image, while 2180retaining a correct 'virtual canvas' offset, for image layering. This offset 2181may need to be removed using <a href="#repage" >+repage</a>, to remove if it 2182is unwanted. </p> 2183 2184<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a> 2185option:distort:viewport {geometry_string}</kbd>" setting which will specify 2186the size and the offset of the generated 'viewport' image of the distorted 2187image space.</p> 2188 2189<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale 2190{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by 2191that factor without changing the viewed contents of the distorted image. This 2192can be used either for 'super-sampling' the image for a higher quality result, 2193or for panning and zooming around the image (with appropriate viewport 2194changes, or post-distort cropping and resizing). </p> 2195 2196<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a 2197href="#distort" >-distort</a> to attempt to output the internal coefficients, 2198and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study, 2199and debugging purposes. This many not be available for all distorts. </p> 2200 2201<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to 2202produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a> 2203and/or <a href="#shear" >-shear</a> operation, with more control of due to the 2204above settings. It is algorithmically slower however, though that may not be 2205the case in ImageMagick's implementation. </p> 2206 2207 2208<div style="margin: auto;"> 2209 <h4><a name="dither" id="dither"></a>-dither <em class="arg">method</em></h4> 2210</div> 2211 2212<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a Riemersma or Floyd-Steinberg error diffusion dither to images when general color reduction is applied via an option, or automagically when saving to specific formats. This enabled by default. </td><td style='text-align:right;'></td></tr></table> 2213 2214<p>Dithering places two or more colors in neighboring pixels so that to the eye a closer approximation of the images original color is reproduced. This reduces the number of colors needed to reproduce the image but at the cost of a lower level pattern of colors. Error diffusion dithers can use any set of colors (generated or user defined) to an image. </p> 2215 2216<p>Dithering is turned on by default, to turn it off use the plus form of the 2217setting, <a href="#dither">+dither</a>. This will also also render PostScript 2218without text or graphic aliasing. Disabling dithering often (but not always) 2219leads to faster process, a smaller number of colors, but more cartoon like 2220image coloring. Generally resulting in 'color banding' effects in areas with 2221color gradients. </p> 2222 2223<p>The color reduction operators <a href="#colors">-colors</a>, <a 2224href="#monochrome">-monochrome</a>, <a href="#remap ">-remap</a>, and <a href="#posterize">-posterize</a>, apply dithering to images using the reduced color set they created. These operators are also used as part of automatic color reduction when saving images to formats with limited color support, such as <kbd>GIF:</kbd>, <kbd>XBM:</kbd>, and others, so dithering may also be used in these cases. </p> 2225 2226<p>Alternatively you can use <a href="#random-threshold">-random-threshold</a> to generate purely random dither. Or use <a href="#ordered-dither">-ordered-dither</a> to apply threshold mapped dither patterns, using uniform color maps, rather than specific color maps. </p> 2227 2228 2229<div style="margin: auto;"> 2230 <h4><a name="draw" id="draw"></a>-draw <em class="arg">string</em></h4> 2231</div> 2232 2233<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Annotate an image with one or more graphic primitives.</td><td style='text-align:right;'></td></tr></table> 2234 2235<p>Use this option to annotate or decorate an image with one or more graphic primitives. The primitives include shapes, text, transformations, and pixel operations.</p> 2236 2237<p>The shape primitives:</p> 2238 2239<pre class="text"> 2240 point x,y 2241 line x0,y0 x1,y1 2242 rectangle x0,y0 x1,y1 2243 roundRectangle x0,y0 x1,y1 wc,hc 2244 arc x0,y0 x1,y1 a0,a1 2245 ellipse x0,y0 rx,ry a0,a1 2246 circle x0,y0 x1,y1 2247 polyline x0,y0 ... xn,yn 2248 polygon x0,y0 ... xn,yn 2249 bezier x0,y0 ... xn,yn 2250 path path specification 2251 image operator x0,y0 w,h filename 2252</pre> 2253 2254<p>The text primitive:</p> 2255 2256<pre class="text"> 2257 text x0,y0 string 2258</pre> 2259<p>The text gravity primitive:</p> 2260 2261<pre class="text"> 2262 gravity NorthWest, North, NorthEast, West, Center, 2263 East, SouthWest, South, or SouthEast 2264</pre> 2265 2266<p>The text gravity primitive only affects the placement of text and does not interact with the other primitives. It is equivalent to using the <a href="#gravity">-gravity</a> command-line option, except that it is limited in scope to the <a href="#draw">-draw</a> option in which it appears.</p> 2267 2268<p>The transformation primitives:</p> 2269 2270<pre class="text"> 2271 rotate degrees 2272 translate dx,dy 2273 scale sx,sy 2274 skewX degrees 2275 skewY degrees 2276</pre> 2277 2278<p>The pixel operation primitives:</p> 2279 2280<pre class="text"> 2281 color x0,y0 method 2282 matte x0,y0 method 2283</pre> 2284 2285<p>The shape primitives are drawn in the color specified by the preceding <a href="#fill">-fill</a> setting. For unfilled shapes, use <a href="#fill">-fill none</a>. You can optionally control the stroke (the "outline" of a shape) with the <a href="#stroke">-stroke</a> and <a href="#strokewidth">-strokewidth</a> settings.</p> 2286 2287<p>A <kbd>point</kbd> primitive is specified by a single <em>point</em> in the pixel plane, that is, by an ordered pair of integer coordinates, <em>x</em>,<em>y</em>. (As it involves only a single pixel, a <kbd>point</kbd> primitive is not affected by <a href="#stroke">-stroke</a> or <a href="#strokewidth">-strokewidth</a>.)</p> 2288 2289<p>A <kbd>line</kbd> primitive requires a start point and end point.</p> 2290 2291<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p> 2292 2293<p>A <kbd>roundRectangle</kbd> primitive takes the same corner points as a <kbd>rectangle</kbd> followed by the width and height of the rounded corners to be removed.</p> 2294 2295<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p> 2296 2297<p>The <kbd>arc</kbd> primitive is used to inscribe an elliptical segment in to a given rectangle. An <kbd>arc</kbd> requires the two corners used for <kbd>rectangle</kbd> (see above) followed by the start and end angles of the arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end points produced are then joined with a line segment and the resulting segment of an ellipse is filled.</p> 2298 2299<p>Use <kbd>ellipse</kbd> to draw a partial (or whole) ellipse. Give the center point, the horizontal and vertical "radii" (the <em>semi-axes</em> of the ellipse) and start and end angles in degrees (e.g. 100,100 100,150 0,360).</p> 2300 2301<p>The <kbd>polyline</kbd> and <kbd>polygon</kbd> primitives require three or more points to define their perimeters. A <kbd>polyline</kbd> is simply a <kbd>polygon</kbd> in which the final point is not stroked to the start point. When unfilled, this is a <em>polygonal line</em>. If the <a href="#stroke">-stroke</a> setting is <kbd>none</kbd> (the default), then a <kbd>polyline</kbd> is identical to a <kbd>polygon</kbd>. 2302</p> 2303 2304<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p> 2305 2306<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p> 2307 2308<p class="crtsnip"> 2309 -draw 'circle 100,100 150,150' 2310</p> 2311 2312<p>The <kbd>Bezier</kbd> primitive creates a spline curve and requires three or points to define its shape. The first and last points are the <em>knots</em> and these points are attained by the curve, while any intermediate coordinates are <em>control points</em>. If two control points are specified, the line between each end knot and its sequentially respective control point determines the tangent direction of the curve at that end. If one control point is specified, the lines from the end knots to the one control point determines the tangent directions of the curve at each end. If more than two control points are specified, then the additional control points act in combination to determine the intermediate shape of the curve. In order to 2313draw complex curves, it is highly recommended either to use the <kbd>path</kbd> primitive or to draw multiple four-point bezier segments with the start and end knots of each successive segment repeated. For example:</p> 2314 2315<p class="crtsnip"> 2316 -draw 'bezier 20,50 45,100 45,0 70,50' 2317</p> 2318<p class="crtsnip"> 2319 -draw 'bezier 70,50 95,100 95,0 120,50' 2320</p> 2321 2322 2323<p>A <kbd>path</kbd> represents an outline of an object, defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a Bezier curve), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with subpaths, each consisting of a single moveto followed by one or more line or curve operations) are possible to allow effects such as <em>donut holes</em> in objects. (See <a href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p> 2324 2325<p>Use <kbd>image</kbd> to composite an image with another image. Follow the image keyword with the composite operator, image location, image size, and filename:</p> 2326 2327<p class="crtsnip"> 2328 -draw 'image SrcOver 100,100 225,225 image.jpg' 2329</p> 2330 2331<p>You can use 0,0 for the image size, which means to use the actual 2332dimensions found in the image header. Otherwise, it is scaled to the given 2333dimensions. See <a href="/www/compose.html">Alpha Compositing</a> for 2334a detailed discussion of alpha composition methods that are available. </p> 2335 2336<p>Use <kbd>text</kbd> to annotate an image with text. Follow the text coordinates with a string. If the string has embedded spaces, enclose it in single or double quotes.</p> 2337 2338<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p> 2339 2340<p class="crtsnip"> 2341 -draw 'text 100,100 "Works like magick!"' 2342</p> 2343 2344<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p> 2345 2346<p>The <kbd>rotate</kbd> primitive rotates subsequent shape primitives and text primitives about the origin of the main image. If the <a href="#region">-region</a> option precedes the <a href="#draw">-draw</a> option, the origin for transformations is the upper left corner of the region.</p> 2347 2348<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p> 2349 2350<p>The <kbd>scale</kbd> primitive scales them.</p> 2351 2352<p>The <kbd>skewX</kbd> and <kbd>skewY</kbd> primitives skew them with respect to the origin of the main image or the region.</p> 2353 2354<p>The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the <a href="#affine">-affine</a> option. Transformations are cumulative within the <a href="#draw">-draw</a> option. The initial affine matrix is not affected; that matrix is only changed by the appearance of another <a href="#affine">-affine</a> option. If another <a href="#draw">-draw</a> option appears, the current affine matrix is reinitialized from the initial affine 2355matrix.</p> 2356 2357<p>Use the <kbd>color</kbd> primitive to change the color of a pixel to the fill color (see <a href="#fill">-fill</a>). Follow the pixel coordinate with a method:</p> 2358 2359<pre class="text"> 2360 point 2361 replace 2362 floodfill 2363 filltoborder 2364 reset 2365</pre> 2366 2367<p>Consider the target pixel as that specified by your coordinate. The <kbd>point</kbd> method recolors the target pixel. The <kbd>replace</kbd> method recolors any pixel that matches the color of the target pixel. <kbd>Floodfill</kbd> recolors any pixel that matches the color of the target pixel and is a neighbor, whereas <kbd>filltoborder</kbd> recolors any neighbor pixel that is not the border color. Finally, <kbd>reset</kbd> recolors all pixels.</p> 2368 2369<p>Use <kbd>matte</kbd> to the change the pixel matte value to transparent. Follow the pixel coordinate with a method (see the <kbd>color</kbd> primitive for a description of methods). The <kbd>point</kbd> method changes the matte value of the target pixel. The <kbd>replace</kbd> method changes the matte value of any pixel that matches the color of the target pixel. <kbd>Floodfill</kbd> changes the matte value of any pixel that matches the color of the target pixel and is a neighbor, whereas <kbd>filltoborder</kbd> changes the matte value of any neighbor pixel that is not the border color (<a href="#bordercolor">-bordercolor</a>). Finally <kbd>reset</kbd> changes the matte value of all pixels.</p> 2370 2371<p>You can set the primitive color, font, and font bounding box color with <a href="#fill">-fill</a>, <a href="#font">-font</a>, and <a href="#box">-box</a> respectively. Options are processed in command line order so be sure to use these options <em>before</em> the <a href="#draw">-draw</a> option.</p> 2372 2373<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p> 2374 2375<p>Drawing primitives conform to the <a href="/www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p> 2376 2377 2378<div style="margin: auto;"> 2379 <h4><a name="edge" id="edge"></a>-edge <em class="arg">radius</em></h4> 2380</div> 2381 2382<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>detect edges within an image.</td><td style='text-align:right;'></td></tr></table> 2383 2384<div style="margin: auto;"> 2385 <h4><a name="emboss" id="emboss"></a>-emboss <em class="arg">radius</em></h4> 2386</div> 2387 2388<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>emboss an image.</td><td style='text-align:right;'></td></tr></table> 2389 2390<div style="margin: auto;"> 2391 <h4><a name="encipher" id="encipher"></a>-encipher <em class="arg">filename</em></h4> 2392</div> 2393 2394<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Encipher pixels for later deciphering by <a href="#decipher">-decipher</a>.</td><td style='text-align:right;'></td></tr></table> 2395 2396<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 2397 2398<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 2399 2400 2401 2402<div style="margin: auto;"> 2403 <h4><a name="encoding" id="encoding"></a>-encoding <em class="arg">type</em></h4> 2404</div> 2405 2406<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the text encoding.</td><td style='text-align:right;'></td></tr></table> 2407 2408<p>Choose from <kbd>AdobeCustom</kbd>, <kbd>AdobeExpert</kbd>, <kbd>AdobeStandard</kbd>, <kbd>AppleRoman</kbd>, <kbd>BIG5</kbd>, <kbd>GB2312</kbd>, <kbd>Latin 2</kbd>, <kbd>None</kbd>, <kbd>SJIScode</kbd>, <kbd>Symbol</kbd>, <kbd>Unicode</kbd>, <kbd>Wansung</kbd>.</p> 2409 2410<div style="margin: auto;"> 2411 <h4><a name="endian" id="endian"></a>-endian <em class="arg">type</em></h4> 2412</div> 2413 2414<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify endianness (<kbd>MSB</kbd> or <kbd>LSB</kbd>) of the image.</td><td style='text-align:right;'></td></tr></table> 2415 2416<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p> 2417 2418<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p> 2419 2420 2421<div style="margin: auto;"> 2422 <h4><a name="enhance" id="enhance"></a>-enhance</h4> 2423</div> 2424 2425<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a digital filter to enhance a noisy image.</td><td style='text-align:right;'></td></tr></table> 2426 2427 2428<div style="margin: auto;"> 2429 <h4><a name="equalize" id="equalize"></a>-equalize</h4> 2430</div> 2431 2432<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform histogram equalization on the image channel-by-channel.</td><td style='text-align:right;'></td></tr></table> 2433 2434<p>To perform histogram equalization on all channels in concert, transform the image into some other color space, such as HSL, OHTA, YIQ or YUV, then equalize the appropriate intensity-like channel, then convert back to RGB.</p> 2435 2436<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p> 2437 2438<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal components transformation that puts most of the information in the first channel. Here we have ... <kbd>-colorspace OHTA -channel red -equalize -colorspace RGB</kbd> ...</p> 2439 2440<div style="margin: auto;"> 2441 <h4><a name="evaluate" id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4> 2442</div> 2443 2444<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</td><td style='text-align:right;'></td></tr></table> 2445 2446<p>(See the <a href="#function" >-function</a> operator for some multi-parameter functions. See the <a href="#fx" >-fx</a> operator if more elaborate calculations are needed.)</p> 2447 2448<p>The behaviors of each <em class="arg">operator</em> are summarized in the following list. For brevity, the numerical value of a "pixel" referred to below is the value of the corresponding channel of that pixel, while a "normalized pixel" is that number divided by the maximum (installation-dependent) value <em class="QR">QuantumRange</em>. (If normalized pixels are used, they are restored, following the other calculations, to the full range by multiplying by <em class="QR">QuantumRange</em>.)</p> 2449 2450<table class="doc"> 2451 <col width="25%" /> 2452 <col width="75%" /> 2453 <thead> 2454 <tr> 2455 <th><em class="arg">operator</em></th> 2456 <th>Summary (see further below for details)</th> 2457 </tr> 2458 </thead> 2459 <tbody> 2460 2461 <tr><td>Abs </td> <td>Add <em class="arg">value</em> to pixels and return absolute value. </td></tr> 2462 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr> 2463 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr> 2464 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr> 2465 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2466 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr> 2467 <tr><td>LeftShift </td> <td>Shift the pixel values left by <em class="arg">value</em> bits (i.e., multiply pixels by 2<sup><em class="arg">value</em></sup>).</td></tr> 2468 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr> 2469 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr> 2470 <tr><td>Mean </td> <td>Add the <em class="arg">value</em> and divide by 2.</td></tr> 2471 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr> 2472 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr> 2473 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr> 2474 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr> 2475 <tr><td>RightShift </td> <td>Shift the pixel values right by <em class="arg">value</em> bits (i.e., divide pixels by 2<sup><em class="arg">value</em></sup>).</td></tr> 2476 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr> 2477 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2478 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr> 2479 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr> 2480 2481 <tr><td> </td></tr> 2482 2483 <tr><td>Gaussian-noise</td></tr> 2484 <tr><td>Impulse-noise</td></tr> 2485 <tr><td>Laplacian-noise</td></tr> 2486 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr> 2487 <tr><td>PoissonNoise</td></tr> 2488 <tr><td>Uniform-noise</td></tr> 2489 2490 <tr><td> </td></tr> 2491 2492 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr> 2493 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr> 2494 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr> 2495 </tbody> 2496 </table> 2497 2498<p>The specified functions are applied only to each previously set <a 2499href="#channel" >-channel</a> in the image. If necessary, the results of the 2500calculations are truncated (clipped) to fit in the interval [0, <em 2501class="QR">QuantumRange</em>]. The transparency channel of the image is 2502represented as a 'alpha' values (0 = fully transparent), so, for example, a 2503<kbd>Divide</kbd> by 2 of the alpha channel will make the image 2504semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value 2505as a percentage of the <em class="QR">QuantumRange</em>.</p> 2506 2507<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use 2508<a href="#list">-list evaluate</a>.</p> 2509 2510<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and 2511<kbd>Multiply</kbd> methods can also be achieved using either the <a 2512href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with 2513appropriate argument, to linearly modify the overall range of color values. 2514Please note, however, that <a href="#level" >-level</a> treats transparency as 2515'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with 2516'alpha' values.</p> 2517 2518<p><kbd>AddModulus</kbd> has been added as of ImageMagick 6.4.8-4 and provides addition modulo the <em class="QR">QuantumRange</em>. It is therefore equivalent to <kbd>Add</kbd> unless the resulting pixel value is outside the interval [0, <em class="QR">QuantumRange</em>]. </p> 2519 2520<p><kbd>Log</kbd> has been added as of ImageMagick 6.4.2-1 and works on normalized pixel values. This a <em>scaled</em> log function. The <em class="arg">value</em> used with <kbd>Log</kbd> provides a <em>scaling factor</em> that adjusts the curvature in the graph of the log function. The formula applied to a normalized value <b><em>u</em></b> is below. </p> 2521 2522 <div style="text-align:center;"> 2523 log(<em class="arg">value</em> × <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1) 2524 </div> 2525 2526<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on 2527normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a 2528href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent 2529to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used 2530with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used 2531with <kbd>Pow</kbd>.</p> 2532 2533<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and 2534converts the image values into a value according to a (co)sine wave function. 2535The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output 2536is biased 50% and normalized by 50% so as to fit in the respective color value 2537range. The <em class="arg">value</em> scaling of the <em>period</em> of the 2538function (its frequency), and thus determines the number of 'waves' that will 2539be generated over the input color range. For example, if the <em 2540class="arg">value</em> is 1, the effective period is simply the <em 2541class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is 2, 2542then the effective period is the <em>half</em> the <em 2543class="QR">QuantumRange</em>. 2544 2545 <div style="text-align:center;"> 2546 0.5 + 0.5 × cos(2 π <b><em>u</em></b> × <em class="arg">value</em>). 2547 </div> 2548 2549See also the <a href="#function" >-function</a> operator, which is a 2550multi-value version of evaluate. </P> 2551 2552<div style="margin: auto;"> 2553 <h4><a name="evaluate-sequence" id="evaluate-sequence"></a>-evaluate-sequence <em class="arg">operator</em></h4> 2554</div> 2555 2556<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Alter channel pixels by evaluating an arithmetic, relational, or logical expression over a sequence of images.</td><td style='text-align:right;'></td></tr></table> 2557 2558<div style="margin: auto;"> 2559 <h4><a name="extent" id="extent"></a>-extent <em class="arg">geometry</em></h4> 2560</div> 2561 2562<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the image size and offset.</td><td style='text-align:right;'></td></tr></table> 2563 2564<p>If the image is enlarged, unfilled areas are set to the background color. To position the image, use offsets in the <em class="arg">geometry</em> specification or precede with a <a href="#gravity">-gravity</a> setting. To specify how to compose the image with the background, use <a href="#compose" >-compose</a>.</p> 2565 2566<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 2567 2568<div style="margin: auto;"> 2569 <h4><a name="extract" id="extract"></a>-extract <em class="arg">geometry</em></h4> 2570</div> 2571 2572<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Extract the specified area from image.</td><td style='text-align:right;'></td></tr></table> 2573 2574<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p> 2575 2576<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \ <br/> image.rgb image.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \ <br/> image.rgb image.png</span></p><p>If you omit the offsets, as in</p> 2577 2578<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480 \ <br/> image.rgb image.png</span></p> 2579<p>the image is <em>resized</em> to the specified dimensions instead, 2580equivalent to:</p> 2581 2582<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png</span></p> 2583<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 2584 2585<div style="margin: auto;"> 2586 <h4><a name="family" id="family"></a>-family <em class="arg">fontFamily</em></h4> 2587</div> 2588 2589<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font family for text.</td><td style='text-align:right;'></td></tr></table> 2590 2591<p>This setting suggests a font family that ImageMagick should try to use for rendering text. If the family can be found it is used; if not, a default font (e.g., "Arial") or a family known to be similar is substituted (e.g., "Courier" might be used if "System" is requested but not found). 2592</p> 2593 2594<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#stretch">-stretch</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. 2595</p> 2596 2597<div style="margin: auto;"> 2598 <h4><a name="features" id="features"></a>-features <em class="arg">distance</em></h4> 2599</div> 2600 2601<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>display features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</td><td style='text-align:right;'></td></tr></table> 2602 2603<div style="margin: auto;"> 2604 <h4><a name="fft" id="fft"></a>-fft</h4> 2605</div> 2606 2607<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implements the forward discrete Fourier transform (DFT).</td><td style='text-align:right;'></td></tr></table> 2608 2609<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows users in ImageMagick 6.6.0-9). It transforms an image from the normal (spatial) domain to the frequency domain. In the frequency domain, an image is represented as a superposition of complex sinusoidal waves of varying amplitudes. The image x and y coordinates are the possible frequencies along the x and y directions, respectively, and the pixel intensity values are complex numbers that correspond to the sinusoidal wave amplitudes. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform" target="_blank">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT" target="_blank">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT" target="_blank">Fast Fourier Transform</a>.</p> 2610 2611<p>A single image name is provided as output for this option. However, the output result will have two components. It is either a two-frame image or two separate images, depending upon whether the image format specified supports multi-frame images. The reason that we get a dual output result is because the frequency domain represents an image using complex numbers, which cannot be visualized directly. Therefore, the complex values are automagically separated into a two-component image representation. The first component is the magnitude of the complex number and the second is the phase of the complex number. See for example, <a href="http://en.wikipedia.org/wiki/Complex_numbers" target="_blank">Complex Numbers</a>.<p> 2612 2613<p>The magnitude and phase component images must be specified using image formats that do not limit the color or compress the image. Thus, MIFF, TIF, PFM, EXR and PNG are the recommended image formats to use. All of these formats, except PNG support multi-frame images. So for example,</p> 2614 2615<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p> 2616<p>generates a magnitude image as <kbd>fft_image.miff[0]</kbd> and a phase image as <kbd>fft_image.miff[1]</kbd>. Similarly,</p> 2617 2618<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.png</span></p> 2619<p>generates a magnitude image as <kbd>fft_image-0.png</kbd> and a phase image as <kbd>fft_image-1.png</kbd>. If you prefer this representation, then you can force any of the other formats to produce two output images by including <a href="#adjoin">+adjoin</a> following -fft in the command line.</p> 2620 2621<p>The input image can be any size, but if not square and even-dimensioned, it is padded automagically to the larger of the width or height of the input image and to an even number of pixels. The padding will occur at the bottom and/or right sides of the input image. The resulting output magnitude and phase images is square at this size. The kind of padding relies on the <a href="#virtual-pixel">-virtual-pixel</a> setting.</p> 2622 2623<p>Both output components will have dynamic ranges that fit within [0, <em class="QR">QuantumRange</em>], so that HDRI need not be enabled. Phase values nominally range from 0 to 2*π, but for non-HDRI compilations of ImageMagick, the phase image is scaled to span the full dynamic range. The magnitude image is not scaled and thus generally will contain very small values. As such, the image normally will appear totally black. In order to view any detail, the magnitude image typically is enhanced with a log function into what is usually called the spectrum. A log function is used to enhance the darker values more in comparison to the lighter values. This can be done, for example, as follows:</p> 2624 2625<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br /> 2626 -evaluate log 1000 fft_image_spectrum.png</span></p> 2627<p>where the <a href="#contrast-stretch">-contrast-stretch</a> 0 is used to scale the image to full dynamic range, first. The argument to the <a href="#evaluate">-evaluate</a> log typically is specified between 100 and 10,000, depending upon the amount of detail that one wants to bring out in the spectrum. Larger values produce more visible detail. Too much detail, however, may hide the important features.</p> 2628 2629<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>. 2630 2631<p>Use <a href="#fft">+fft</a> to produce two output images that are the real and imaginary components of the complex valued Fourier transform.</p> 2632 2633<p>However, as the real and imaginary components can contain negative values, this requires that IM be configured with HDRI enabled. In this case, you must use either MIFF, TIF or PFM formats for the real and imaginary component results, since they are formats that preserve both negative and fractional values without clipping them or truncating the fractional part.</p> 2634 2635<p>The real and imaginary component images resulting from <a href="#fft">+fft</a> is also square, even dimensioned images due to the same padding that was discussed above for the magnitude and phase component images.</a> 2636 2637<p>See the discussion on HDRI implementations of ImageMagick on the page 2638<a href="/www/high-dynamic-range.html">High Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> entry. 2639</p> 2640 2641 2642<div style="margin: auto;"> 2643 <h4><a name="fill" id="fill"></a>-fill <em class="arg">color</em></h4> 2644</div> 2645 2646<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color to use when filling a graphic primitive.</td><td style='text-align:right;'></td></tr></table> 2647 2648<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA, HSL, HSLA, CMYK, or CMYKA specification. See <a href="/www/color.html">Color Names</a> for a description of how to properly specify the color argument.</p> 2649 2650<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p> 2651 2652<p>For example,</p> 2653 2654<p class="crtsnip"> 2655 -fill blue 2656</p> 2657<p class="crtsnip"> 2658 -fill "#ddddff" 2659</p> 2660<p class="crtsnip"> 2661 -fill "rgb(255,255,255)" 2662</p> 2663 2664<p>See <a href="#draw">-draw</a> for further details.</p> 2665 2666<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p> 2667 2668<div style="margin: auto;"> 2669 <h4><a name="filter" id="filter"></a>-filter <em class="arg">type</em></h4> 2670</div> 2671 2672<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use this <em class="arg">type</em> of filter when resizing or 2673distorting an image.</td><td style='text-align:right;'></td></tr></table> 2674 2675<p>Use this option to affect the resizing operation of an image during 2676operations such as <a href="#resize">-resize</a> and <a href="#distort" 2677>-distort</a>. For example you can use a simple resize filter such as:</p> 2678 2679<pre class="text"> 2680 Point Hermite Cubic 2681 Box Gaussian Catrom 2682 Triangle Quadratic Mitchell 2683</pre> 2684 2685<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided (as well 2686as a faster <kbd>SincFast</kbd> equivalent form). However these filters are 2687generally useless on their own as they are infinite filters that are being 2688clipped to the filters support size. Their direct use is not recommended 2689except via expert settings (see below). </p> 2690 2691Instead these special filter functions are typically windowed by a windowing 2692function that the <a href="#filter" >-filter</a> setting defines. That is 2693using these functions will define a 'Windowed' filter, appropriate to the 2694operator involved. Windowed filters include: </p> 2695 2696<pre class="text"> 2697 Lanczos Hamming Parzen 2698 Blackman Kaiser Welsh 2699 Hanning Bartlett Bohman 2700</pre> 2701 2702<p>Also one special self-windowing filter is also provided 2703<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending 2704on the current 'support' or 'lobes' expert settings (see below).</p> 2705 2706<p>If you do not select a filter with this option, the filter defaults to 2707<kbd>Mitchell</kbd> for a colormapped image, a image with a matte channel, or 2708if the image is enlarged. Otherwise the filter default to 2709<kbd>Lanczos</kbd>.</p> 2710 2711<p>To print a complete list of resize filters, use the <a href="#list">-list 2712filter</a> option.</p> 2713 2714<p>You can modify how the filter behaves as it scales your image through the 2715use of these expert settings (see also <a href="#define" >-define</a> and <a 2716href="#set" >-set</a>):-</p> 2717 2718<dl class="doc"> 2719<dt>-define filter:blur=<em>factor</em></dt> 2720<dd>Scale the X axis of the filter (and its window). Use > 1.0 for 2721 blurry or < 1.0 for sharp. This should only be used with Gaussian and 2722 Gaussian-like filters simple filters, or you may not get the expected 2723 results. </dd> 2724 2725<dt>-define filter:support=<em>radius</em></dt> 2726<dd>Set the filter support radius. Defines how large the filter should be and 2727 thus directly defines how slow the filtered resampling process is. All 2728 filters have a default 'prefered' support size. Some filters like 2729 <kbd>Lagrange</kbd> and windowed filters adjust themselves depending on 2730 this value. With simple filters this value either does nothing (but slow 2731 the resampling), or will clip the filter function in a detrimental way. 2732 </dd> 2733 2734<dt>-define filter:lobes=<em>count</em></dt> 2735<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an 2736 alternative way of specifying the 'support' range of the filter, that is 2737 designed to be more suited to windowed filters, especially when used for 2738 image distorts.</dd> 2739 2740<dt>-define filter:b=<em>b-spline_factor</em></dt> 2741<dt>-define filter:c=<em>keys_alpha_factor</em></dt> 2742<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>, 2743 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as 2744 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values 2745 are defined, the other is set so as to generate a 'Keys' type cubic 2746 filter. Values meaning was defined by a research paper by 2747 Mitchell-Netravali. 2748 2749<dt>-define filter:filter=<em>filter_function</em></dt> 2750<dd>Use this function directly as the scaling filter. This will allow 2751 you to directly use a windowing filter such as <kbd>Blackman</kbd>, 2752 rather than as its normal usage as a windowing function for 'Sinc' or 2753 'Bessel' functions. If defined, no windowing function is used, unless the 2754 following expert setting is also defined.</dd> 2755 2756<dt>-define filter:window=<em>filter_function</em></dt> 2757<dd>The IIR (infinite impulse response) filters <kbd>Bessel</kbd> and 2758 <kbd>Sinc</kbd> are windowed (brought down to zero over the defined 2759 support range) with the given filter. This allows you to specify a filter 2760 function that is not normally used as a windowing function, such as 2761 <kbd>Box</kbd>, (which effectively turns off the windowing function), 2762 to window a <kbd>Sinc</kbd>, or the function the previous setting defined. 2763 </dd> 2764 2765<dt>-define filter:verbose=<em>1</em></dt> 2766<dd>This causes IM to print information on the final internal filter 2767 selection to standard output. This includes a commented header on the 2768 filter settings being used, and data allowing the filter weights to be 2769 easily graphed. </dd> 2770 2771<dd>Note however that some filters are internally defined in terms of other 2772 filters. The <kbd>Lanczos</kbd> filter for example is defined in terms of 2773 a <kbd>SincFast</kbd> windowed <kbd>SincFast</kbd> filter, while 2774 <kbd>Mitchell</kbd> is defined as a <kbd>Cubic</kbd> filter with specific 2775 'B' and 'C' settings. </dd> 2776 2777</dl> 2778 2779<p>For example, to get a 8 lobe Bessel windowed Bessel filter:</p> 2780 2781<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -filter bessel \ <br/> 2782 -set filter:window=bessel -set filter:lobes=8 \ <br/> 2783 -resize 150% image.jpg</span></p> 2784<p>Or a raw un-windowed Sinc filter with 4 lobes:</p> 2785 2786<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/> 2787 -resize 150% image.jpg</span></p> 2788<p>Note that the use of expert options (except for 'blur' with simple resize 2789filters, and 'verbose' for viewing the internal filter selection), are 2790provided for image processing experts who have studied and understood how 2791resize filters work. Without this knowledge, and an understanding of the 2792definition of the actual filters involved, using expert settings are more 2793likely to be detrimental to your image resizing.</p> 2794 2795 2796<div style="margin: auto;"> 2797 <h4><a name="flatten" id="flatten"></a>-flatten</h4> 2798</div> 2799 2800<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>This is a simple alias for the <a href="#layers" >-layers</a> method "flatten".</td><td style='text-align:right;'></td></tr></table> 2801 2802 2803<div style="margin: auto;"> 2804 <h4><a name="flip" id="flip"></a>-flip</h4> 2805</div> 2806 2807<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>create a <em>mirror image</em>.</td><td style='text-align:right;'></td></tr></table> 2808 2809<p>reflect the scanlines in the vertical direction.</p> 2810 2811<div style="margin: auto;"> 2812 <h4><a name="floodfill" id="floodfill"></a>-floodfill {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em> <em class="arg">color</em></h4> 2813</div> 2814 2815<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>floodfill the image with color at the specified offset. Using <a href="#fuzz" >-fuzz</a> to floodfill pixels which only change by a small amount.</td><td style='text-align:right;'></td></tr></table> 2816 2817<div style="margin: auto;"> 2818 <h4><a name="flop" id="flop"></a>-flop</h4> 2819</div> 2820 2821<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>create a <em>mirror image</em>.</td><td style='text-align:right;'></td></tr></table> 2822 2823<p>reflect the scanlines in the horizontal direction.</p> 2824 2825 2826<div style="margin: auto;"> 2827 <h4><a name="font" id="font"></a>-font <em class="arg">name</em></h4> 2828</div> 2829 2830<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the font to use when annotating images with text, or creating labels.</td><td style='text-align:right;'></td></tr></table> 2831 2832<p>To print a complete list of fonts, use the <a href="#list">-list font</a> option (for versions prior to 6.3.6, use 'type' instead of 'font').</p> 2833 2834<p>In addition to the fonts specified by the above pre-defined list, you can 2835also specify a font from a specific source. For example <kbd>Arial.ttf</kbd> 2836is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and 2837<kbd>x:fixed</kbd> is X11 font.</p> 2838 2839<p>For other settings that affect fonts, see the options <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. </p> 2840 2841 2842<div style="margin: auto;"> 2843 <h4><a name="foreground" id="foreground"></a>-foreground <em class="arg">color</em></h4> 2844</div> 2845 2846<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Define the foreground color.</td><td style='text-align:right;'></td></tr></table> 2847 2848<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 2849 2850<p>The default foreground color is black.</p> 2851 2852<div style="margin: auto;"> 2853 <h4><a name="format" id="format"></a>-format <em class="arg">type</em></h4> 2854</div> 2855 2856<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the image format type.</td><td style='text-align:right;'></td></tr></table> 2857 2858<p>When used with the <kbd>mogrify</kbd> utility, this option converts any image to the image <a href="/www/formats.html">format</a> you specify. For a list of image format types supported by ImageMagick, use <a href="#list">-list format</a>.</p> 2859 2860<p>By default the file is written to its original name. However, if the filename extension matches a supported format, the extension is replaced with the image format type specified with <a href="#format">-format</a>. For example, if you specify <em class="arg">tiff</em> as the format type and the input image filename is <em class="arg">image.gif</em>, the output image filename becomes <em class="arg">image.tiff</em>.</p> 2861 2862<div style="margin: auto;"> 2863 <h4><a name="format_identify_" id="format_identify_"></a>-format <em class="arg">string</em></h4> 2864</div> 2865 2866<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>output formatted image characteristics.</td><td style='text-align:right;'>[<a href="/www/identify.html">identify</a>]</td></tr></table> 2867 2868<p>See <a href="/www/escape.html">Format and Print Image Properties</a> for an explanation on how to specify the argument to this option.</p> 2869 2870<div style="margin: auto;"> 2871 <h4><a name="frame" id="frame"></a>-frame <em class="arg">geometry</em></h4> 2872</div> 2873 2874<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Surround the image with a border or beveled frame.</td><td style='text-align:right;'></td></tr></table> 2875 2876<p>The color of the border is specified with the <a href="#mattecolor" 2877>-mattecolor</a> command line option. </p> 2878 2879<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <em class="arg">size</em> portion of the <em 2880class="arg">geometry</em> argument indicates the amount of extra width and 2881height that is added to the dimensions of the image. If no offsets are given 2882in the <em class="arg">geometry</em> argument, then the border added is 2883a solid color. Offsets <em>x</em> and <em>y</em>, if present, specify that 2884the width and height of the border is partitioned to form an outer bevel of 2885thickness <em>x</em> pixels and an inner bevel of thickness 2886<em>y</em> pixels. Negative offsets make no sense as frame arguments. 2887</p> 2888 2889<p>The <a href="#frame">-frame</a> option is affected by the current <a 2890href="#compose">-compose</a> setting and assumes that this is using the default 2891'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 2892size with the current <a href="#bordercolor">-bordercolor</a> setting, and then 2893draws the frame of four distinct colors close to the current <a 2894href="#mattecolor">-mattecolor</a>. The original image is then overlaid onto 2895center of this image. This means that with the default compose method of 2896'<kbd>Over</kbd>' any transparent parts may be replaced by the current <a 2897href="#bordercolor">-bordercolor</a> setting.</p> 2898 2899<p>The image composition is not 2900affected by the <a href="#gravity">-gravity</a> option.</p> 2901 2902 2903<div style="margin: auto;"> 2904 <h4><a name="frame_import_" id="frame_import_"></a>-frame</h4> 2905</div> 2906 2907<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>include the X window frame in the imported image.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 2908 2909<div style="margin: auto;"> 2910 <h4><a name="function" id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</em></h4> 2911</div> 2912 2913<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a function to channel values.</td><td style='text-align:right;'></td></tr></table> 2914 2915<p>This operator performs calculations based on the given arguments to modify each of the color values for each previously set <a href="#channel">-channel</a> in the image. See <a href="#evaluate">-evaluate</a> for details concerning how the results of the calculations are handled.</p> 2916 2917<p>This is can be considered a multi-argument version of the <a href="#evaluate">-evaluate</a> operator. (Added in ImageMagick 6.4.8−8.)</p> 2918 2919<p>Here, <em class="arg">parameters</em> is a comma-separated list of numerical values. The number of values varies depending on which <em class="arg">function</em> is selected. Choose the <em class="arg">function</em> from:</p> 2920 2921<pre class="text"> 2922 Polynomial 2923 Sinusoid 2924 Arcsin 2925 Arctan 2926</pre> 2927 2928<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p> 2929 2930<dl class="doc"> 2931<dt><kbd>Polynomial</kbd></dt> 2932<dd> 2933<p>The <kbd>Polynomial</kbd> function takes an arbitrary number of parameters, these being the coefficients of a polynomial, in decreasing order of degree. That is, entering</p> 2934 2935<div style="text-align: center"> 2936 -function Polynomial <em>a</em><sub><em>n</em></sub>,<em>a</em><sub><em>n</em>-1</sub>,...<em>a</em><sub>1</sub>,<em>a</em><sub>0</sub> 2937</div> 2938 2939<p>will invoke a polynomial function given by</p> 2940 2941<div style="text-align: center"> 2942 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> + 2943 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> + 2944 ··· <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>, 2945</div> 2946 2947<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p> 2948 2949<p>The <kbd>Polynomial</kbd> function can be used in place of <kbd>Set</kbd> (the <em>constant</em> polynomial) and <kbd>Add</kbd>, <kbd>Divide</kbd>, <kbd>Multiply</kbd>, and <kbd>Subtract</kbd> (some <em>linear</em> polynomials) of the <a href="#evaluate">-evaluate</a> operator. The <a href="#level">-level</a> operator also affects channels linearly. Some correspondences follow.</p> 2950 2951<table class="doc"> 2952 <col width="35%" /> 2953 <col width="35%" /> 2954 <col width="30%" /> 2955 <tr> 2956 <td>-evaluate Set <em class="arg">value</em> </td> 2957 <td>-function Polynomial <em class="arg">value</em></td> 2958 <td>(Constant functions; set <em class="arg">value</em>×100% gray when channels are RGB.)</td> 2959 </tr> 2960 <tr> 2961 <td>-evaluate Add <em class="arg">value</em> </td> 2962 <td>-function Polynomial 1,<em class="arg">value</em></td> 2963 </tr> 2964 <tr> 2965 <td>-evaluate Subtract <em class="arg">value</em> </td> 2966 <td>-function Polynomial 1,−<em class="arg">value</em></td> 2967 </tr> 2968 <tr> 2969 <td>-evaluate Multiply <em class="arg">value</em> </td> 2970 <td>-function Polynomial <em class="arg">value</em>,0</td> 2971 </tr> 2972 <tr> 2973 <td>+level black% x white%</td> 2974 <td>-function Polynomial A,B</td> 2975 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td> 2976 </tr> 2977</table> 2978 2979<p>The <kbd>Polynomial</kbd> function gives great versatility, since polynomials can be used to fit any continuous curve to any degree of accuracy desired.</p> 2980</dd> 2981 2982<dt><kbd>Sinusoid</kbd></dt> 2983<dd> 2984<p>The <kbd>Sinusoid</kbd> function can be used to vary the channel values sinusoidally by setting frequency, phase shift, amplitude, and a bias. These values are given as one to four parameters, as follows,</p> 2985 2986<div style="text-align: center"> 2987 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]] 2988</div> 2989 2990<p>where <em>phase</em> is in degrees. (The domain [0,1] of the function corresponds to 0 through <em class="arg">freq</em>×360 degrees.) The result is that if a pixel's normalized channel value is originally <b><em>u</em></b>, its resulting normalized value is given by </p> 2991 2992<div style="text-align: center"> 2993<em class="arg">amp</em> * sin(2*π* (<em class="arg">freq</em> * <b><em>u</em></b> + <em class="arg">phase</em> / 360)) + <em class="arg">bias</em> 2994</div> 2995 2996<p> For example, the following generates a curve that starts and ends at 0.9 (when <b><em>u</em></b>=0 and 1, resp.), oscillating three times between .7−.2=.5 and .7+.2=.9. </p> 2997 2998<p class="crtsnip"> 2999 -function Sinusoid 3,-90,.2,.7 3000</p> 3001 3002<p>The default values of <em class="arg">amp</em> and <em class="arg">bias</em> are both .5. The default for <em class="arg">phase</em> is 0.</p> 3003 3004<p>The <kbd>Sinusoid</kbd> function generalizes <kbd>Sin</kbd> and <kbd>Cos</kbd> of the <a href="#evaluate">-evaluate</a> operator by allowing varying amplitude, phase and bias. The correspondence is as follows.</p> 3005 3006<table class="doc"> 3007 <tr> 3008 <td>-evaluate Sin <em class="arg">freq</em> </td> 3009 <td>-function Sinusoid <em class="arg">freq</em>,0 </td> 3010 </tr> 3011 <tr> 3012 <td>-evaluate Cos <em class="arg">freq</em> </td> 3013 <td>-function Sinusoid <em class="arg">freq</em>,90 </td> 3014 </tr> 3015</table> 3016</dd> 3017 3018<dt><kbd>ArcSin</kbd></dt> 3019<dd> 3020<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid, 3021and can be used to generate cylindrical distortion and displacement maps. 3022The curve can be adjusted relative to both the input values and output range 3023of values. 3024 3025<div style="text-align: center"> 3026 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3027</div> 3028 3029<p>with all values given in terms of noramlize color values (0.0 for black, 30301.0 for white). Defaulting to values covering the full range from 0.0 to 1.0 3031for bout input (<em class="arg">width</em>), and output (<em 3032class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p> 3033 3034<div style="text-align: center"> 3035<em class="arg">range</em>/π * asin( 2/<em class="arg">width</em> * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em> 3036</div> 3037 3038</dd> 3039 3040<dt><kbd>ArcTan</kbd></dt> 3041<dd> 3042<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from 3043limit values at infinities, though a center using the given slope value. 3044All these values can be adjusted via the arguments. 3045 3046<div style="text-align: center"> 3047 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3048</div> 3049 3050<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'. 3051</p> 3052 3053<div style="text-align: center"> 3054<em class="arg">range</em>/π * atan( <em class="arg">slope</em>*π * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em> 3055</div> 3056 3057</dd> 3058 3059</dl> 3060 3061 3062<div style="margin: auto;"> 3063 <h4><a name="fuzz" id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4> 3064</div> 3065 3066<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Colors within this <em class="arg">distance</em> are considered equal.</td><td style='text-align:right;'></td></tr></table> 3067 3068<p>A number of algorithms search for a target color. By default the color must be exact. Use this option to match colors that are close to the target color in RGB space. For example, if you want to automagically trim the edges of an image with <a href="#trim">-trim</a> but the image was scanned and the target background color may differ by a small amount. This option can account for these differences.</p> 3069 3070<p>The <em class="arg">distance</em> can be in absolute intensity units or, by appending <kbd>%</kbd> as a percentage of the maximum possible intensity (255, 65535, or 4294967295).</p> 3071 3072 3073<div style="margin: auto;"> 3074 <h4><a name="fx" id="fx"></a>-fx <em class="arg">expression</em></h4> 3075</div> 3076 3077<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a mathematical expression to an image or image channels.</td><td style='text-align:right;'></td></tr></table> 3078 3079<p>If the first character of <em class="arg">expression</em> is <kbd>@</kbd>, the expression is read from a file titled by the remaining characters in the string.</p> 3080 3081<p>See <a href="/www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p> 3082 3083 3084<div style="margin: auto;"> 3085 <h4><a name="gamma" id="gamma"></a>-gamma <em class="arg">value</em></h4> 3086</div> 3087 3088<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>level of gamma correction.</td><td style='text-align:right;'></td></tr></table> 3089 3090<p>The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from <kbd>0.8</kbd> to <kbd>2.3</kbd>. Gamma less than 1.0 darkens the image and gamma greater than 1.0 lightens it. Large adjustments to image gamma may result in the loss of some image information if the pixel quantum size is only eight bits (quantum range 0 to 255).</p> 3091 3092<p>Gamma adjusts the image's channel values pixel-by-pixel according to a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the normalized or 0 to 1 color value. For example, using a value of gamma=2 is the same as taking the square root of the image.</p> 3093 3094<p>You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delimited with commas (e.g., <kbd>1.7,2.3,1.2</kbd>).</p> 3095 3096<p>Use <a href="#gamma">+gamma <em class="arg">value</em></a> to set the image gamma level without actually adjusting the image pixels. This option is useful if the image is of a known gamma but not set as an image attribute (e.g. PNG images).</p> 3097 3098<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p> 3099 3100<div style="margin: auto;"> 3101 <h4><a name="gaussian-blur" id="gaussian-blur"></a>-gaussian-blur <em class="arg">radius</em><br />-gaussian-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 3102</div> 3103 3104<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Blur the image with a Gaussian operator.</td><td style='text-align:right;'></td></tr></table> 3105 3106<p>Convolve the image with a Gaussian or normal distribution using the given 3107<em class="arg" >Sigma</em> value. The formula is:</p> 3108 3109<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 3110</div> 3111 3112<p>The <em class="arg" >Sigma</em> value is the important argument, and 3113determines the actual amount of bluring that will take place. </p> 3114 3115<p>The <em class="arg" >Radius</em> is only used to determine the size of the 3116array which will hold the calculated gaussian distribution. It should be an 3117integer. If not given, or set to zero, IM will calculate the largest possible 3118radius that will provide meaningful results for the Gaussian distribution. 3119</p> 3120 3121<p>The larger the <em class="arg" >Radius</em> the radius the slower the 3122operation is. However too small a <em class="arg" >Radius</em>, and sever 3123aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 3124should be at least twice the <em class="arg" >Sigma</em> value, though three 3125times will produce a more accurite result. </p> 3126 3127<p>This differs from the faster <a href="#blur">-blur</a> operator in that a 3128full 2-dimensional convolution is used to generate the weighted average of the 3129neighboring pixels. </p> 3130 3131<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 3132pixels which are outside the image proper are blurred into the final result. 3133</p> 3134 3135 3136<div style="margin: auto;"> 3137 <h4><a name="geometry" id="geometry"></a>-geometry <em class="arg">geometry</em></h4> 3138</div> 3139 3140<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the preferred size and location of the image.</td><td style='text-align:right;'></td></tr></table> 3141 3142<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 3143 3144<div style="margin: auto;"> 3145 <h4><a name="gravity" id="gravity"></a>-gravity <em class="arg">type</em></h4> 3146</div> 3147 3148<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Sets the current gravity suggestion for various other settings and options.</td><td style='text-align:right;'></td></tr></table> 3149 3150<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>, 3151<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>, 3152<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete 3153list of <a href="#gravity">-gravity</a> settings available in your ImageMagick 3154installation.</p> 3155 3156<p>The direction you choose specifies where to position text or subimages. For example, a gravity of <kbd>Center</kbd> forces the text to be centered within the image. By default, the image gravity is <kbd>NorthWest</kbd>. See <a href="#draw">-draw</a> for more details about graphic primitives. Only the text primitive of <a href="#draw">-draw</a> affected by the <a href="#gravity">-gravity</a> option.</p> 3157 3158<p>The <a href="#gravity">-gravity</a> option is also used in concert with the <a href="#geometry">-geometry</a> setting and other settings or options that take <em class="arg">geometry</em> as an argument, such as the <a href="#crop">-crop</a> option. </p> 3159 3160<p>If a <a href="#gravity">-gravity</a> setting occurs before another option or setting having a <em class="arg">geometry</em> argument that specifies an offset, the offset is usually applied to the point within the image suggested by the <a href="#gravity">-gravity</a> argument. Thus, in the following command, for example, suppose the file <kbd>image.png</kbd> has dimensions 200x100. The offset specified by the argument to <a href="#region">-region</a> is (−40,+20). The argument to <a href="#gravity">-gravity</a> is <kbd>Center</kbd>, which suggests the midpoint of the image, at the point (100,50). The offset (−40,20) is applied to that point, giving (100−40,50+20)=(60,70), so the specified 10x10 region is located at that point. (In addition, the <a href="#gravity">-gravity</a> affects the region itself, which is <em>centered</em> at the pixel coordinate (60,70). (See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.)</p> 3161 3162<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -gravity Center -region 10x10-40+20 \ <br/> -negate output.png</span></p> 3163<p>When used as an option to <a href="/www/composite.html">composite</a>, <a href="#gravity">-gravity</a> gives the direction that the image gravitates within the composite.</p> 3164 3165<p>When used as an option to <a href="/www/montage.html">montage</a>, <a href="#gravity">-gravity</a> gives the direction that an image gravitates within a tile. The default gravity is <kbd>Center</kbd> for this purpose.</p> 3166 3167 3168<div style="margin: auto;"> 3169 <h4><a name="green-primary" id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4> 3170</div> 3171 3172<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>green chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 3173 3174 3175<div style="margin: auto;"> 3176 <h4><a name="hald-clut" id="hald-clut"></a>-hald-clut</h4> 3177</div> 3178 3179<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a Hald color lookup table to the image.</td><td style='text-align:right;'></td></tr></table> 3180 3181<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2 3182dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You 3183can apply any color transformation to the Hald image and then use this option 3184to apply the transform to the image. </p> 3185 3186<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p> 3187<p>This option provides a convenient method for you to use Gimp or Photoshop 3188to make color corrections to the Hald CLUT image and subsequently apply them 3189to multiple images using an ImageMagick script. </p> 3190 3191<p>Note that the representation is only of the normal RGB color space and that 3192the whole color value triplet is used for the interpolated lookup of the 3193represented Hald color cube image. Because of this the operation is not <a 3194href="#channel" >-channel</a> setting effected, nor can it adjust or modify an 3195images transparency or alpha/matte channel.</p> 3196 3197<p>See also <a href="#clut" >-clut</a> which provides color value replacement 3198of the individual color channels, usally involving a simplier gray-scale 3199image. E.g: gray-scale to color replacement, or modification by a histogram 3200mapping. </p> 3201 3202 3203<div style="margin: auto;"> 3204 <h4><a name="help" id="help"></a>-help</h4> 3205</div> 3206 3207<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print usage instructions.</td><td style='text-align:right;'></td></tr></table> 3208 3209<div style="margin: auto;"> 3210 <h4><a name="highlight-color" id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4> 3211</div> 3212 3213<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>when comparing images, emphasize pixel differences with this color.</td><td style='text-align:right;'></td></tr></table> 3214 3215<div style="margin: auto;"> 3216 <h4><a name="iconGeometry" id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4> 3217</div> 3218 3219<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the icon geometry.</td><td style='text-align:right;'></td></tr></table> 3220 3221<p>Offsets, if present in the geometry specification, are handled in the same manner as the <a href="#geometry">-geometry</a> option, using X11 style to handle negative offsets.</p> 3222 3223<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 3224 3225<div style="margin: auto;"> 3226 <h4><a name="iconic" id="iconic"></a>-iconic</h4> 3227</div> 3228 3229<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>iconic animation.</td><td style='text-align:right;'></td></tr></table> 3230 3231<div style="margin: auto;"> 3232 <h4><a name="identify" id="identify"></a>-identify</h4> 3233</div> 3234 3235<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>identify the format and characteristics of the image.</td><td style='text-align:right;'></td></tr></table> 3236 3237<p>This information is printed: image scene number; image name; image size; the image class (<em class="arg">DirectClass</em> or <em class="arg">PseudoClass</em>); the total number of unique colors; and the number of seconds to read and transform the image. Refer to <a href="/www/miff.html">MIFF</a> for a description of the image class.</p> 3238 3239<p>If <a href="#colors">-colors</a> is also specified, the total unique colors in the image and color reduction error values are printed. Refer to <a href="/www/quantize.html">color reduction algorithm</a> for a description of these values.</p> 3240 3241<p>If <a href="#verbose">-verbose</a> precedes this option, copious 3242amounts of image properties are displayed including image statistics, profiles, 3243image histogram, and others.</p> 3244 3245<div style="margin: auto;"> 3246 <h4><a name="ift" id="ift"></a>-ift</h4> 3247</div> 3248 3249<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implements the inverse discrete Fourier transform (DFT).</td><td style='text-align:right;'></td></tr></table> 3250 3251<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase images from the frequency domain to a single image in the normal or spatial domain. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform" target="_blank">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT" target="_blank">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT" target="_blank">Fast Fourier Transform</a>.</p> 3252 3253<p>For example, depending upon the image format used to store the result of the <a href="#fft">-fft</a>, one would use either</p> 3254 3255<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p> 3256<p>or</p> 3257 3258<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png</span></p> 3259 3260<p>The resulting image may need to be cropped due to padding introduced when the original image, prior to the <a href="#fft">-fft</a> or <a href="#fft">+fft</a>, was not square or even dimensioned. Any padding is at the right and/or bottom sides of the image. 3261 3262<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>. 3263 3264<p>Use <a href="#ift">+ift</a> (with HDRI enabled) to transform a pair of real and imaginary images from the frequency domain to a single image in the normal (spatial) domain. 3265 3266<div style="margin: auto;"> 3267 <h4><a name="immutable" id="immutable"></a>-immutable</h4> 3268</div> 3269 3270<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>make image immutable.</td><td style='text-align:right;'></td></tr></table> 3271 3272<div style="margin: auto;"> 3273 <h4><a name="implode" id="implode"></a>-implode <em class="arg">factor</em></h4> 3274</div> 3275 3276<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implode image pixels about the center.</td><td style='text-align:right;'></td></tr></table> 3277 3278<div style="margin: auto;"> 3279 <h4><a name="insert" id="insert"></a>-insert <em class="arg">index</em></h4> 3280</div> 3281 3282<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>insert the last image into the image sequence.</td><td style='text-align:right;'></td></tr></table> 3283 3284<p>This option takes last image in the current image sequence and inserts it at the given index. If a negative index is used, the insert position is calculated before the last image is removed from the sequence. As such <kbd>-insert -1</kbd> will result in no change to the image sequence.</p> 3285 3286<p>The <kbd>+insert</kbd> option is equivalent to <kbd>-insert -1</kbd>. In other words, insert the last image, at the end of the current image sequence. Consequently this has no effect on the image sequence order.</p> 3287 3288<div style="margin: auto;"> 3289 <h4><a name="intent" id="intent"></a>-intent <em class="arg">type</em></h4> 3290</div> 3291 3292<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>use this type of rendering intent when managing the image color.</td><td style='text-align:right;'></td></tr></table> 3293 3294<p>Use this option to affect the color management operation of an image (see <a href="#profile">-profile</a>). Choose from these intents: <kbd>Absolute, Perceptual, Relative, Saturation</kbd>.</p> 3295 3296<p>The default intent is undefined.</p> 3297 3298<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p> 3299 3300<div style="margin: auto;"> 3301 <h4><a name="interlace" id="interlace"></a>-interlace <em class="arg">type</em></h4> 3302</div> 3303 3304<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the type of interlacing scheme.</td><td style='text-align:right;'></td></tr></table> 3305 3306<p>Choose from:</p> 3307 3308<pre class="text"> 3309 none 3310 line 3311 plane 3312 partition 3313 JPEG 3314 GIF 3315 PNG 3316</pre> 3317 3318<p>This option is used to specify the type of interlacing scheme for raw image formats such as <kbd>RGB</kbd> or <kbd>YUV</kbd>.</p> 3319 3320<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p> 3321 3322<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p> 3323 3324<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p> 3325 3326<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R, 3327image.G, and image.B).</p> 3328 3329<p>Use <kbd>Line</kbd> or <kbd>Plane</kbd> to create an <kbd>interlaced PNG</kbd> or <kbd>GIF</kbd> or <kbd>progressive JPEG</kbd> 3330image.</p> 3331 3332<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p> 3333 3334<div style="margin: auto;"> 3335 <h4><a name="interpolate" id="interpolate"></a>-interpolate <em class="arg">type</em></h4> 3336</div> 3337 3338<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.</td><td style='text-align:right;'></td></tr></table> 3339 3340<p>When looking up the color of a pixel using a non-integer floating point 3341value, you typically fall in between the pixel colors defined by the source 3342image. This setting determines how the color is determined from the colors of 3343the pixels surrounding that point. That is how to determine the color of a 3344point that falls between two, or even four different colored pixels. </p> 3345 3346<pre class="text"> 3347 integer: The color of the top-left pixel (floor function) 3348 nearest-neighbor: The nearest pixel to the lookup point (rounded function) 3349 average: The average color of the surrounding four pixels 3350 bilinear A double linear interpolation of pixels (the default) 3351 mesh Divide area into two flat triangular interpolations 3352 bicubic Fitted bicubic-spines of surrounding 16 pixels 3353 spline Direct spline curves (colors are blurred) 3354 filter Use resize <a href="#filter">-filter</a> settings 3355</pre> 3356 3357<p>This most important for distortion operators such as <a href="#distort" 3358>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform" 3359>-transform</a> and <a href="#fx" >-fx</a>. </p> 3360 3361<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p> 3362 3363<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the 3364lookup for positions outside the boundaries of the image. </p> 3365 3366 3367<div style="margin: auto;"> 3368 <h4><a name="interline-spacing" id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4> 3369</div> 3370 3371<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two text lines.</td><td style='text-align:right;'></td></tr></table> 3372 3373<div style="margin: auto;"> 3374 <h4><a name="interword-spacing" id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4> 3375</div> 3376 3377<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two words.</td><td style='text-align:right;'></td></tr></table> 3378 3379<div style="margin: auto;"> 3380 <h4><a name="kerning" id="kerning"></a>-kerning <em class="arg">value</em></h4> 3381</div> 3382 3383<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two letters.</td><td style='text-align:right;'></td></tr></table> 3384 3385<div style="margin: auto;"> 3386 <h4><a name="label" id="label"></a>-label <em class="arg">name</em></h4> 3387</div> 3388 3389<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>assign a label to an image.</td><td style='text-align:right;'></td></tr></table> 3390 3391<p>Use this option to assign a specific label to the image, as it is read in 3392or created. You can use the <a href="#set" >-set</a> operation to re-assign 3393a the labels of images already read in. Image formats such as TIFF, PNG, 3394MIFF, supports saving the label information with the image.</p> 3395 3396<p>When saving an image to a <em class="arg">PostScript</em> file, any label 3397assigned to an image is used as a header string to print above the postscript 3398image. </p> 3399 3400<p>You can include the image filename, type, width, height, or other image 3401attribute by embedding special format character. See <a href="/www/escape.html">Format and Print Image 3402Properties</a> for details of the percent escape codes.</p> 3403 3404<p>For example,</p> 3405 3406<p class="crtsnip"> 3407 -label "%m:%f %wx%h" bird.miff 3408</p> 3409 3410<p>assigns an image label of <kbd>MIFF:bird.miff 512x480</kbd> to the 3411"<kbd>bird.miff</kbd>" image and whose width is 512 and height is 480, as it 3412is read in. If a <a href="#label">+label</a> option was used instead, any 3413existing label present in the image would be used. You can remove all labels 3414from an image by assigning the empty string. </p> 3415 3416<p>A label is not drawn on the image, but is embedded in the image datastream 3417via <em>Label</em> tag or similar mechanism. If you want the label to be 3418visible on the image itself, use the <a href="#draw">-draw</a> option, or 3419during the final processing in the creation of a image montage.</p> 3420 3421<p>If the first character of <em class="arg">string</em> is <em 3422class="arg">@</em>, the image label is read from a file titled by the 3423remaining characters in the string. Labels in a file are literal, no embedded 3424formatting characters are recognized.</p> 3425 3426 3427<div style="margin: auto;"> 3428 <h4><a name="lat" id="lat"></a>-lat <em class="arg">width</em><br />-lat <em class="arg">width</em>x<em class="arg">height</em>{<em class="arg">+-</em>}<em class="arg">offset</em>{<em class="arg">%</em>}</h4> 3429</div> 3430 3431<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform local adaptive threshold.</td><td style='text-align:right;'></td></tr></table> 3432 3433<p>Adaptively threshold each pixel based on the value of pixels in a 3434surrounding window. If the current pixel is lighter than this average plus 3435the optional <kbd>offset</kbd>, then it is made white, otherwise it is made 3436black. Small variations in pixel values such as found in scanned documents 3437can be ignored if offset is positive. A negative offset will make it more 3438sensitive to those small variations. </p> 3439 3440<p>This is commonly used to threshold images with an uneven background. It is 3441based on the assumption that average color of the small window is the 3442the local background color, from which to separate the forground color. </p> 3443 3444 3445<div style="margin: auto;"> 3446 <h4><a name="layers" id="layers"></a>-layers <em class="arg">method</em></h4> 3447</div> 3448 3449<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>handle multiple images forming a set of image layers or animation frames.</td><td style='text-align:right;'></td></tr></table> 3450 3451<p>Perform various image operation methods to a ordered sequence of images 3452which may represent either a set of overlaid 'image layers', a GIF disposal 3453animation, or a fully-'coalesced' animation sequence. </p> 3454 3455<table class="doc"> 3456 <tbody> 3457 <tr valign="top"> 3458 <th align="left" style="width: 8%">Method</th> 3459 <th align="left">Description</th> 3460 </tr> 3461 3462 <tr valign="top"> 3463 <td valign="top">compare-any</td> 3464 <td valign="top">Crop the second and later frames to the smallest rectangle 3465 that contains all the differences between the two images. No GIF <a 3466 href="#dispose" >-dispose</a> methods are taken into account. </td> 3467 </tr> 3468 3469 <tr><td></td><td>This exactly the same as the <a href="#deconstruct" 3470 >-deconstruct</a> operator, and does not preserve animations normal 3471 working, especially when animation used layer disposal methods such as 3472 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td> 3473 </tr> 3474 3475 <tr valign="top"> 3476 <td valign="top">compare-clear</td> 3477 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any 3478 opaque pixels which become transparent in the second frame. That is the 3479 smallest image needed to mask or erase pixels for the next frame. </td> 3480 </tr> 3481 3482 <tr valign="top"> 3483 <td valign="top">compare-overlay</td> 3484 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add 3485 extra color to the next image, as a result of overlaying color pixels. 3486 That is the smallest single overlaid image to add or change colors. </td> 3487 </tr> 3488 3489 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha 3490 composition method '<kbd>change-mask</kbd>', to reduce the image to 3491 just the pixels that need to be overlaid. </td> 3492 </tr> 3493 3494 <tr valign="top"> 3495 <td valign="top">coalesce</td> 3496 <td valign="top">Equivalent to a call to the <a href="#coalesce" 3497 >-coalesce</a> operator. Apply the layer disposal methods set in the 3498 current image sequence to form a fully defined animation sequence, as 3499 it should be displayed. Effectively converting a GIF animation into a 3500 'film strip'-like animation. </td> 3501 </tr> 3502 3503 <tr valign="top"> 3504 <td valign="top">composite</td> 3505 <td valign="top">Alpha Composition of two image lists, separated by a 3506 "<kbd>null:</kbd>" image, with the destination image list first, and 3507 the source images last. An image from each list are composited 3508 together until one list is finished. The separator image and source 3509 image lists are removed. </td> 3510 </tr> 3511 3512 3513 <tr><td></td> 3514 <td>The <a href="#geometry" >-geometry</a> offset is adjusted according 3515 to <a href="#gravity" >-gravity</a> in accordance of the virtual 3516 canvas size of the first image in each list. Unlike a normal <a 3517 href="#composite" >-composite</a> operation, the canvas offset is also 3518 added to the final composite positioning of each image. </td> </tr> 3519 3520 <tr><td></td> 3521 <td>If one of the image lists only contains one image, that image is 3522 applied to all the images in the other image list, regardless of which 3523 list it is. In this case it is the image meta-data of the list which 3524 preserved. </td> 3525 </tr> 3526 3527 3528 <tr valign="top"> 3529 <td valign="top">dispose</td> 3530 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of 3531 the animation after the layer disposal method has been applied, before 3532 the next sub-frame image is overlaid. That is the 'dispose' image that 3533 results from the application of the GIF <a href="#dispose" 3534 >-dispose</a> method. This allows you to check what 3535 is going wrong with a particular animation you may be developing. 3536 </td> 3537 </tr> 3538 3539 <tr valign="top"> 3540 <td valign="top">flatten</td> 3541 <td valign="top">Create a canvas the size of the first images virtual 3542 canvas using the current <a href="#background" >-background</a> color, 3543 and <a href="#compose" >-compose</a> each image in turn onto that 3544 canvas. Images falling outside that canvas is clipped. Final 3545 image will have a zero virtual canvas offset. </td> 3546 </tr> 3547 3548 <tr><td></td> 3549 <td>This usally used as one of the final 'image layering' operations 3550 overlaying all the prepared image layers into a final image. </td> 3551 </tr> 3552 3553 <tr><td></td> 3554 <td>For a single image this method can also be used to fillout a virtual 3555 canvas with real pixels, or to underlay a opaque color to remove 3556 transparency from an image.</td> 3557 </tr> 3558 3559 3560 <tr valign="top"> 3561 <td valign="top">merge</td> 3562 <td valign="top">As 'flatten' method but merging all the given image 3563 layers into a new layer image just large enough to hold all the image 3564 without clipping or extra space. The new images virtual offset will 3565 prevere the position of the new layer, even if this offset is 3566 negative. the virtual canvas size of the first image is preserved. 3567 </td> 3568 </tr> 3569 3570 <tr><td></td><td>Caution is advised when handling image layers with negative offsets 3571 as few image file formats handle them correctly. </td> 3572 </tr> 3573 3574 <tr valign="top"> 3575 <td valign="top">mosaic</td> 3576 <td valign="top">As 'flatten' method but expanding the initial canvas size 3577 of the first image so as to hold all the image layers. However as a 3578 virtual canvas is 'locked' to the origin, by definition, image layers 3579 with a negative offsets will still be clipped by the top and left 3580 edges.</td> 3581 </tr> 3582 3583 <tr><td></td><td>This method is commonly used to layout individual image using various 3584 offset but without knowing the final canvas size. The resulting image 3585 will, like 'flatten' not have any virtual offset, so can be saved to 3586 any image file format. </td> 3587 </tr> 3588 3589 3590 <tr valign="top"> 3591 <td valign="top">optimize</td> 3592 <td valign="top">Optimize a coalesced animation, into GIF animation using 3593 a number of general techniques. This currently a short cut to 3594 apply both the '<kbd>optimize-frame</kbd>', and 3595 '<kbd>optimize-transparency</kbd>' methods but may be expanded to 3596 include other optimization methods as they are developed. </td> 3597 </tr> 3598 3599 <tr valign="top"> 3600 <td valign="top">optimize-frame</td> 3601 <td valign="top">Optimize a coalesced animation, into GIF animation by 3602 reducing the number of pixels per frame as much as possible by 3603 attempting to pick the best layer disposal method to use, while ensuring 3604 the result will continue to animate properly. </td> 3605 </tr> 3606 3607 <tr><td></td><td> There is no guarantee that the best optimization is found. But 3608 then no reasonably fast GIF optimization algorithm can do this. 3609 However this does seem to do better than most other GIF frame 3610 optimizers seen. </td> 3611 </tr> 3612 3613 <tr valign="top"> 3614 <td valign="top">optimize-plus</td> 3615 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the 3616 overall optimization by adding extra frames to the animation, without 3617 changing the final look or timing of the animation. The frames are 3618 added to attempt to separate the clearing of pixels from the 3619 overlaying of new additional pixels from one animation frame to the 3620 next. If this does not improve the optimization (for the next frame 3621 only), it will fall back to the results of the previous normal 3622 '<kbd>optimize-frame</kbd>' technique. </td> 3623 </tr> 3624 3625 <tr><td></td><td>There is the possibility that the change in the disposal style will 3626 result in a worsening in the optimization of later frames, though this 3627 is unlikely. In other words there no guarantee that it is better than 3628 the normal '<kbd>optimize-frame</kbd>' technique. For some animations 3629 however you can get a vast improvement in the final animation size. </td> 3630 </tr> 3631 3632 <tr valign="top"> 3633 <td valign="top">optimize-transparency</td> 3634 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame 3635 overlay images with transparency, if it does not change the resulting 3636 animation by more than the current <a href="#fuzz" >-fuzz</a> factor. 3637 </td> 3638 </tr> 3639 3640 <tr><td></td><td>This should allow a existing frame optimized GIF animation to compress 3641 into a smaller file size due to larger areas of one (transparent) 3642 color rather than a pattern of multiple colors repeating the current 3643 disposed image of the last frame. </td> 3644 </tr> 3645 3646 <tr valign="top"> 3647 <td valign="top">remove-dups</td> 3648 <td valign="top">Remove (and merge time delays) of duplicate consecutive 3649 images, so as to simplify layer overlays of coalesced animations. 3650 </td> 3651 </tr> 3652 3653 <tr><td></td><td>Usually this a result of using a constant time delay across the 3654 whole animation, or after a larger animation was split into smaller 3655 sub-animations. The duplicate frames could also have been used as 3656 part of some frame optimization methods. </td> 3657 </tr> 3658 3659 <tr valign="top"> 3660 <td valign="top">remove-zero</td> 3661 <td valign="top">Remove any image with a zero time delay, unless ALL the 3662 images have a zero time delay (and is not a proper timed animation, a 3663 warning is then issued). </td> 3664 </tr> 3665 3666 <tr><td></td><td>In a GIF animation, such images are usually frames which provide 3667 partial intermediary updates between the frames that are actually 3668 displayed to users. These frames are usally added for improved frame 3669 optimization in GIF animations. </td> 3670 </tr> 3671 3672 <tr valign="top"> 3673 <td valign="top">trim-bounds</td> 3674 <td valign="top">Find the bounds of all the images in the current 3675 image sequence, then adjust the offsets so all images are contained on 3676 a minimal positive canvas. None of the image data is modified, only 3677 there virtual canvas size and offset. The all the image is given 3678 the same canvas size, and and will have a positive offset, but will 3679 remain in the same position relative to each other. As a result of the 3680 minimal canvas size at least one image will touch every edge of that 3681 canvas. The image data however may be transparent. 3682 </td> 3683 </tr> 3684 3685 </tbody> 3686</table> 3687 3688<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p> 3689 3690<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct" 3691>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic" 3692>-mosaic</a> are only aliases for the above methods. Also see <a 3693href="#page" >-page</a>, <a href="#repage" >-repage</a> operators, the <a 3694href="#compose" >-compose</a> setting, and the GIF <a href="#dispose" 3695>-dispose</a> and <a href="#delay" >-delay</a> settings. </p> 3696 3697 3698<div style="margin: auto;"> 3699 <h4><a name="level" id="level"></a>-level <em class="arg">black_point</em>{,<em class="arg">white_point</em>}{<em class="arg">%</em>}{,<em class="arg">gamma</em>}</h4> 3700</div> 3701 3702<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>adjust the level of image channels.</td><td style='text-align:right;'></td></tr></table> 3703 3704<p>Given one, two or three values delimited with commas: black-point, 3705white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and 3706white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white 3707point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center 3708contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string, 3709both black and white points are percentages of the full color range. Gamma 3710will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is 3711omitted, the default of 1.0 (no gamma correction) is assumed.</p> 3712 3713<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that 3714the given '<kbd>black_point</kbd>' value in the original image is set to 3715zero (or black), while the given '<kbd>white_point</kbd>' value is set to 3716<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments 3717to the image. The '<kbd>gamma</kbd>' of the resulting image will then be 3718adjusted. </p> 3719 3720<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or 3721adding the special '!' flag anywhere in the argument list, will cause the 3722operator to do the reverse of the level adjustment. That is a zero, or 3723<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is 3724adjusted to the given level values, allowing you to de-contrast, or compress 3725the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p> 3726 3727<p>Only the channels defined by the current <a href="#channel">-channel</a> 3728setting are adjusted (defaults to RGB color channels only), allowing you to 3729limit the effect of this operator. </p> 3730 3731<p>Please note that the transparency channel is treated as 'matte' 3732values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 3733 3734 3735<div style="margin: auto;"> 3736 <h4><a name="level-colors" id="level-colors"></a>-level-colors {<em 3737 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4> 3738</div> 3739 3740<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>adjust the level of an image using the provided dash separated colors.</td><td style='text-align:right;'></td></tr></table> 3741 3742<p>This function is exactly like <a href="#level">-level</a>, except that the 3743value value for each color channel is determined by the 3744'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as 3745described under the <a href="#fill">-fill</a> option). </p> 3746 3747<p>This effectually means the colors provided to <kbd>-level-colors</kbd> 3748is mapped to become 'black' and 'white' respectively, with all the other 3749colors linearly adjusted (or clipped) to match that change. Each channel is 3750adjusted separately using the channel values of the colors specified. </p> 3751 3752<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>) 3753will map the image color 'black' and 'white' to the given colors 3754respectively, resulting in a gradient (de-contrasting) tint of the image to 3755those colors. This can also be used to convert a plain gray-scale image into a 3756one using the gradient of colors specified. </p> 3757 3758<p>By supplying a single color with a comma separator either before or after 3759that color, will just replace the respective 'black' or 'white' point 3760respectively. But if no comma separator is provided, the given color is 3761used for both the black and white color points, making the operator either 3762threshold the images around that color (- form) or set all colors to that 3763color (+ form). </p> 3764 3765 3766<div style="margin: auto;"> 3767 <h4><a name="limit" id="limit"></a>-limit <em class="arg">type value</em></h4> 3768</div> 3769 3770<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the pixel cache resource limit.</td><td style='text-align:right;'></td></tr></table> 3771 3772<p>Choose from: <kbd>area</kbd>, <kbd>disk</kbd>, <kbd>file</kbd>, <kbd>map</kbd>, <kbd>memory</kbd>, <kbd>threads</kbd>, or <kbd>time</kbd>.</p> 3773 3774<p>The value for <kbd>file</kbd> is in number of files. The other limits are in bytes. By default the limits are 768 files, 2GB of image area, 1.5GiB memory, 8GiB memory map, and 18.45EB of disk. These limits are adjusted relative to the available resources on your computer if this information is available. When any limit is reached, ImageMagick fails in some fashion but attempts to take compensating actions, if possible. For example, the following limits memory:</p> 3775 3776<p class="crtsnip"> 3777 -limit memory 32MiB -limit map 64MiB 3778</p> 3779 3780<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p> 3781 3782<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list resource</span><span class='crtout'><pre>File Area Memory Map Disk Thread Time 3783------------------------------------------------------------------------------ 3784 768 12.404GB 8.6642GiB 23.104GiB 18.446744EB 8 unlimited</pre> 3785</span></p> 3786<p>Requests for pixel storage to keep intermediate images are satisfied by one of three resource categories: in-memory pool, memory-mapped files pool, and disk pool (in that order) depending on the <a href="/www/command-line-options.html#limit">‑limit</a> settings and whether the system honors a resource request. If the total size of allocated pixel storage in the given pool reaches the corresponding limit, the request is passed to the next pool. Additionally, requests that exceed the <kbd>area</kbd> limit automagically are allocated on disk.</p> 3787 3788<p>To illustrate how ImageMagick utilizes resource limits, consider a typical image resource request. First, ImageMagick tries to allocate the pixels in memory. The request might be denied if the resource request exceeds the <kbd>memory</kbd> limit or if the system does not honor the request. If a memory request is not honored, the pixels are allocated to disk and the file is memory-mapped. However, if the allocation request exceeds the <kbd>map</kbd> limit, the resource allocation goes to disk. In all cases, if the resource request exceeds the <kbd>area</kbd> limit, the pixels are automagically cached to disk. If the disk has a hard limit, the program fails.</p> 3789 3790<p>In most cases you simply do not need to concern yourself with resource limits. ImageMagick chooses reasonable defaults and most images do not tax your computer resources. Where limits do come in handy is when you process images that are large or on shared systems where ImageMagick can consume all or most of the available memory. In this case, the ImageMagick workflow slows other processes or, in extreme cases, brings the system to a halt. Under these circumstances, setting limits give some assurances that the ImageMagick workflow will not interfere with other concurrent uses of the computer. For example, assume you have a web interface that processes images uploaded from the Internet. To assure ImageMagick does not exceed 10mb of memory you can simply set the area limit to 10mb:</p> 3791 3792<p class="crtsnip"> 3793-limit area 10mb 3794</p> 3795 3796<p>Now whenever a large image is processed, the pixels are automagically cached to disk instead of memory. This of course implies that large images typically process very slowly, simply because pixel processing in memory can be an order of magnitude faster than on disk. Because your web site users might inadvertently upload a huge image to process, you should set a disk limit as well:</p> 3797 3798<p class="crtsnip"> 3799-limit area 10mb -limit disk 500mb 3800</p> 3801 3802<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p> 3803 3804<p>In addition to command-line resource limit option, resources can be set with <a href="/www/resources.html#environment">environment variables</a>. Set the environment variables <kbd>MAGICK_AREA_LIMIT</kbd>, <kbd>MAGICK_DISK_LIMIT</kbd>, <kbd>MAGICK_FILE_LIMIT</kbd>, <kbd>MAGICK_MEMORY_LIMIT</kbd>, <kbd>MAGICK_MAP_LIMIT</kbd>, <kbd>MAGICK_THREAD_LIMIT</kbd>, <kbd>MAGICK_TIME_LIMIT</kbd> for limits of image area, disk space, open files, heap memory, memory map, number of threads of execution, and maximum elapsed time in seconds respectively.</p> 3805 3806<p> Inquisitive users can try adding <a href="#debug">-debug cache</a> to their commands and then scouring the generated output for references to the pixel cache, in order to determine how the pixel cache was allocated and how resources were consumed. Advanced Unix/Linux users can pipe that output through <kbd>grep memory|open|destroy|disk</kbd> for more readable sifting. 3807</p> 3808 3809<p>For more about ImageMagick's use of resources, see the section <b>Cache Storage and Resource Requirements</b> on the <a href="/www/architecture.html#cache">Architecture</a> page. 3810</p> 3811 3812<div style="margin: auto;"> 3813 <h4><a name="linear-stretch" id="linear-stretch"></a>-linear-stretch <em class="arg">black-point</em><br />-linear-stretch <em class="arg">black-point</em>{x<em class="arg">white-point</em>}{<em class="arg">%</em>}}</h4> 3814</div> 3815 3816<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Linear with saturation stretch.</td><td style='text-align:right;'></td></tr></table> 3817 3818<p>This is very similar to <a href="#contrast-stretch" >-contrast-stretch</a>, 3819and uses a 'histogram bin' to determine the range of color values that needs to 3820be stretched. However it then stretchs those colors using the <a 3821href="#level" >-level</a> operator.</p> 3822 3823<p>As such while the initial determination may have 'binning' round off 3824effects, the image colors are stretched mathematically, rather than using the 3825histogram bins. This makes the operator more accurate. </p> 3826 3827<p>note however that a <a href="#linear-stretch" >-linear-stretch</a> of 3828'<kbd>0</kbd>' does nothing, while a value of '<kbd>1</kbd>' does a near 3829perfect stretch of the color range. </p> 3830 3831<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 3832normalization of mathematical images. </p> 3833 3834<p>This operator is under review for re-development. </p> 3835 3836 3837<div style="margin: auto;"> 3838 <h4><a name="linewidth" id="linewidth"></a>-linewidth</h4> 3839</div> 3840 3841<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the line width for subsequent draw operations.</td><td style='text-align:right;'></td></tr></table> 3842 3843<div style="margin: auto;"> 3844 <h4><a name="liquid-rescale" id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4> 3845</div> 3846 3847<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>rescale image with seam-carving.</td><td style='text-align:right;'></td></tr></table> 3848 3849<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 3850 3851<div style="margin: auto;"> 3852 <h4><a name="list" id="list"></a>-list <em class="arg">type</em></h4> 3853</div> 3854 3855<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Print a list of supported arguments for various options or settings. Choose from these list types:</td><td style='text-align:right;'></td></tr></table> 3856 3857<pre class="text"> 3858 Align 3859 Alpha 3860 Boolean 3861 Channel 3862 Class 3863 ClipPath 3864 Coder 3865 Color 3866 Colorspace 3867 Command 3868 Compose 3869 Compress 3870 Configure 3871 DataType 3872 Debug 3873 Decoration 3874 Delegate 3875 Direction 3876 Dispose 3877 Distort 3878 Dither 3879 Endian 3880 Evaluate 3881 FillRule 3882 Filter 3883 Font 3884 Format 3885 Function 3886 Gravity 3887 ImageList 3888 Intent 3889 Interlace 3890 Interpolate 3891 Kernel 3892 Layers 3893 LineCap 3894 LineJoin 3895 List 3896 Locale 3897 LogEvent 3898 Log 3899 Magic 3900 Method 3901 Metric 3902 Mime 3903 Mode 3904 Morphology 3905 Module 3906 Noise 3907 Orientation 3908 Policy 3909 PolicyDomain 3910 PolicyRights 3911 Preview 3912 Primitive 3913 QuantumFormat 3914 Resource 3915 SparseColor 3916 Storage 3917 Stretch 3918 Style 3919 Threshold 3920 Type 3921 Units 3922 Validate 3923 VirtualPixel 3924</pre> 3925 3926<p>These lists vary depending on your version of ImageMagick. Use "<kbd>-list 3927list</kbd>" to get a complete listing of all the "<kbd>-list</kbd>" arguments 3928available:</p> 3929 3930<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list list</span></p> 3931<div style="margin: auto;"> 3932 <h4><a name="log" id="log"></a>-log <em class="arg">string</em></h4> 3933</div> 3934 3935<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify format for debug log.</td><td style='text-align:right;'></td></tr></table> 3936 3937<p>This option specifies the format for the log printed when the <a 3938href="#debug">-debug</a> option is active.</p> 3939 3940<p>You can display the following components by embedding special format 3941characters:</p> 3942 3943<pre class="text"> 3944 %d domain 3945 %e event 3946 %f function 3947 %l line 3948 %m module 3949 %p process ID 3950 %r real CPU time 3951 %t wall clock time 3952 %u user CPU time 3953 %% percent sign 3954 \n newline 3955 \r carriage return 3956</pre> 3957 3958<p>For example:</p> 3959 3960<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug coders -log "%u %m:%l %e" in.gif out.png</span></p> 3961<p>The default behavior is to print all of the components.</p> 3962 3963<div style="margin: auto;"> 3964 <h4><a name="loop" id="loop"></a>-loop <em class="arg">iterations</em></h4> 3965</div> 3966 3967<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>add Netscape loop extension to your GIF animation.</td><td style='text-align:right;'></td></tr></table> 3968 3969<p>Set iterations to zero to repeat the animation an infinite number of times, 3970otherwise the animation repeats itself up to <em class="arg">iterations</em> 3971times.</p> 3972 3973<div style="margin: auto;"> 3974 <h4><a name="lowlight-color" id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4> 3975</div> 3976 3977<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>when comparing images, de-emphasize pixel differences with this color.</td><td style='text-align:right;'></td></tr></table> 3978 3979<div style="margin: auto;"> 3980 <h4><a name="magnify" id="magnify"></a>-magnify <em class="arg">factor</em></h4> 3981</div> 3982 3983<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>magnify the image.</td><td style='text-align:right;'></td></tr></table> 3984 3985 3986<div style="margin: auto;"> 3987 <h4><a name="map" id="map"></a>-map <em class="arg">type</em></h4> 3988</div> 3989 3990<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Display image using this <em class="arg">type</em>.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 3991 3992<p>Choose from these <em class="arg">Standard Colormap</em> types:</p> 3993 3994<pre class="text"> 3995 best 3996 default 3997 gray 3998 red 3999 green 4000 blue 4001</pre> 4002 4003<p>The <em class="arg">X server</em> must support the <em class="arg">Standard 4004Colormap</em> you choose, otherwise an error occurs. Use <kbd>list</kbd> as 4005the type and <kbd>display</kbd> searches the list of colormap types in 4006<kbd>top-to-bottom</kbd> order until one is located. See <em 4007class="arg">xstdcmap(1)</em> for one way of creating Standard Colormaps.</p> 4008 4009 4010<div style="margin: auto;"> 4011 <h4><a name="map_stream_" id="map_stream_"></a>-map <em class="arg">components</em></h4> 4012</div> 4013 4014<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pixel map.</td><td style='text-align:right;'>[<a href="/www/stream.html">stream</a>]</td></tr></table> 4015 4016<p>Here are the valid components of a map:</p> 4017 4018<pre class="text"> 4019 r red pixel component 4020 g green pixel component 4021 b blue pixel component 4022 a alpha pixel component (0 is transparent) 4023 o opacity pixel component (0 is opaque) 4024 i grayscale intensity pixel component 4025 c cyan pixel component 4026 m magenta pixel component 4027 y yellow pixel component 4028 k black pixel component 4029 p pad component (always 0) 4030</pre> 4031 4032<p>You can specify as many of these components as needed in any order (e.g. 4033bgr). The components can repeat as well (e.g. rgbr).</p> 4034 4035 4036<div style="margin: auto;"> 4037 <h4><a name="mask" id="mask"></a>-mask 4038<em class="arg">filename</em></h4> 4039</div> 4040 4041<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Composite the image pixels as defined by the mask.</td><td style='text-align:right;'></td></tr></table> 4042 4043<p>Use <a href="#mask">+mask</a> to remove the image mask.</p> 4044 4045<div style="margin: auto;"> 4046 <h4><a name="mattecolor" id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4> 4047</div> 4048 4049<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the color to be used with the <a href="#frame">-frame</a> option.</td><td style='text-align:right;'></td></tr></table> 4050 4051<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 4052 4053<p>The default matte color is <kbd>#BDBDBD</kbd>, <span 4054style="background-color: #bdbdbd;">this shade of gray</span>.</p> 4055 4056<div style="margin: auto;"> 4057 <h4><a name="maximum" id="maximum"></a>-maximum</h4> 4058</div> 4059 4060<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the maximum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table> 4061 4062<div style="margin: auto;"> 4063 <h4><a name="median" id="median"></a>-median <em class="arg">radius</em></h4> 4064</div> 4065 4066<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a median filter to the image.</td><td style='text-align:right;'></td></tr></table> 4067 4068<div style="margin: auto;"> 4069 <h4><a name="metric" id="metric"></a>-metric <em class="arg">type</em></h4> 4070</div> 4071 4072<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Output to STDERR a measure of the differences between images according to the <em class="arg">type</em> given metric.</td><td style='text-align:right;'></td></tr></table> 4073 4074<p>Choose from:</p> 4075 4076<pre class="text"> 4077 AE absolute error count, number of different pixels (-fuzz effected) 4078 MAE mean absolute error (normalized), average channel error distance 4079 MEPP mean error per pixel (normalized mean error, normalized peak error) 4080 MSE mean error squared, average of the channel error squared 4081 PAE peak absolute (normalize peak absolute) 4082 PSNR peak signal to noise ratio 4083 RMSE root mean squared (normalized root mean squared) 4084</pre> 4085 4086<p>The '<kbd>AE</kbd>' or absolute count of pixels that are different, can be 4087controlled using a <a href="#fuzz" >-fuzz</a> factor to ignore pixels which 4088only changed by a small amount. The '<kbd>PAE</kbd>' can be used to find the 4089size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels 4090'similar', while '<kbd>MAE</kbd>' can be used to find out the factor needed 4091for about half the pixels to be similar. </p> 4092 4093<p>The '<kbd>MEPP</kbd>' metric returns three different metrics 4094('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>' 4095normalized) from a single comparison run. </p> 4096 4097<p>To print a complete list of metrics, use the <a href="#list">-list 4098metrics</a> option.</p> 4099 4100 4101<div style="margin: auto;"> 4102 <h4><a name="minimum" id="minimum"></a>-minimum</h4> 4103</div> 4104 4105<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the minimum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table> 4106 4107 4108<div style="margin: auto;"> 4109 <h4><a name="mode" id="mode"></a>-mode <em class="arg">value</em></h4> 4110</div> 4111 4112<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mode of operation.</td><td style='text-align:right;'>[<a href="/www/montage.html">montage</a>]</td></tr></table> 4113 4114<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, 4115Unframe, or Concatenate</kbd></p> 4116 4117<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>' argument 4118for a list of <a href="#mode" >-mode</a> arguments available in your 4119ImageMagick installation.</p> 4120 4121 4122<div style="margin: auto;"> 4123 <h4><a name="modulate" id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4> 4124</div> 4125 4126<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Vary the <em class="arg">brightness</em>, <em 4127class="arg">saturation</em>, and <em class="arg">hue</em> of an image.</td><td style='text-align:right;'></td></tr></table> 4128 4129<p>The arguments are given as a percentages of variation. A value of 100 means 4130no change, and any missing values are taken to mean 100.</p> 4131 4132<p>The <em class="arg">brightness</em> is a multiplier of the overall 4133brightness of the image, so 0 means pure black, 50 is half as bright, 200 is 4134twice as bright. To invert its meaning <a href="#negate">-negate</a> the image 4135before and after. </p> 4136 4137<p>The <em class="arg">saturation</em> controls the amount of color in an 4138image. For example, 0 produce a grayscale image, while a large value such as 4139200 produce a very colorful, 'cartoonish' color.</p> 4140 4141<p>The <em class="arg">hue</em> argument causes a "rotation" of the colors 4142within the image by the amount specified. For example, 50 results in 4143a counter-clockwise rotation of 90, mapping red shades to purple, and so on. 4144A value of either 0 or 200 results in a complete 180 degree rotation of the 4145image. Using a value of 300 is a 360 degree rotation resulting in no change to 4146the original image. </p> 4147 4148<p>For example, to increase the color brightness by 20% and decrease the color 4149saturation by 10% and leave the hue unchanged, use <a 4150href="#modulate">-modulate 120,90</a>.</p> 4151 4152<p>Use <a href="#set">-set</a> attribute of '<kbd 4153class="arg">option:modulate:colorspace</kbd>' to specify which colorspace to 4154modulate. Choose from <kbd>HSB</kbd>, <kbd>HSL</kbd> (the default), or 4155<kbd>HWB</kbd>. For example,</p> 4156 4157<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png</span></p> 4158 4159<div style="margin: auto;"> 4160 <h4><a name="monitor" id="monitor"></a>-monitor</h4> 4161</div> 4162 4163<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>monitor progress.</td><td style='text-align:right;'></td></tr></table> 4164 4165 4166<div style="margin: auto;"> 4167 <h4><a name="monochrome" id="monochrome"></a>-monochrome</h4> 4168</div> 4169 4170<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>transform the image to black and white.</td><td style='text-align:right;'></td></tr></table> 4171 4172 4173<div style="margin: auto;"> 4174 <h4><a name="morph" id="morph"></a>-morph <em class="arg">frames</em></h4> 4175</div> 4176 4177<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>morphs an image sequence.</td><td style='text-align:right;'></td></tr></table> 4178 4179<p>Both the image pixels and size are linearly interpolated to give the 4180appearance of a meta-morphosis from one image to the next, over all the images 4181in the current image list. The added images are the equivalent of a <a 4182href="#blend">-blend</a> composition. The <em class="arg">frames</em> 4183argument determine how many images to interpolate between each image. </p> 4184 4185 4186<div style="margin: auto;"> 4187 <h4><a name="morphology" id="morphology"></a>-morphology</h4> 4188 <h4><a name="morphology" id="morphology"></a>-morphology <em class="arg">method</em> <em class="arg">kernel</em></h4> 4189</div> 4190 4191<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a morphology method to the image.</td><td style='text-align:right;'></td></tr></table> 4192 4193Until I get around to writing a option summary for this, see <A 4194HREF="http://www.imagemagick.org/Usage/morphology/" >IM Usage Examples, 4195Morphology</A>. </P> 4196 4197 4198<div style="margin: auto;"> 4199 <h4><a name="mosaic" id="mosaic"></a>-mosaic</h4> 4200</div> 4201 4202<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>an simple alias for the <a href="#layers" >-layers</a> method "mosaic"</td><td style='text-align:right;'></td></tr></table> 4203 4204 4205<div style="margin: auto;"> 4206 <h4><a name="motion-blur" id="motion-blur"></a>-motion-blur <em class="arg">radius</em><br />-motion-blur <em class="arg">radius</em>x<em class="arg">sigma</em>+<em class="arg">angle</em></h4> 4207</div> 4208 4209<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate motion blur.</td><td style='text-align:right;'></td></tr></table> 4210 4211<p>Blur with the given radius, standard deviation (sigma), and angle. The 4212angle given is the angle toward which the image is blurred. That is the 4213direction people would consider the object is coming from. </p> 4214 4215<p>Note that the blur is not uniform distribution, giving the motion a 4216definite sense of direction of movement. </p> 4217 4218<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4219pixels which are outside the image proper are blurred into the final result. 4220</p> 4221 4222<div style="margin: auto;"> 4223 <h4><a name="name" id="name"></a>-name</h4> 4224</div> 4225 4226<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>name an image.</td><td style='text-align:right;'></td></tr></table> 4227<div style="margin: auto;"> 4228 <h4><a name="negate" id="negate"></a>-negate</h4> 4229</div> 4230 4231<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>replace each pixel with its complementary color.</td><td style='text-align:right;'></td></tr></table> 4232 4233<p>The red, green, and blue intensities of an image are negated. White becomes black, yellow becomes blue, etc. Use <a href="#negate">+negate</a> to only negate the grayscale pixels of the image.</p> 4234 4235<div style="margin: auto;"> 4236 <h4><a name="noise" id="noise"></a>-noise <em class="arg">radius</em><br/> 4237 +noise <em class="arg">type</em></h4> 4238</div> 4239 4240<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Add or reduce noise in an image.</td><td style='text-align:right;'></td></tr></table> 4241 4242<p>The principal function of noise peak elimination filter is to smooth the objects within an image without losing edge information and without creating undesired structures. The central idea of the algorithm is to replace a pixel with its next neighbor in value within a pixel window, if this pixel has been found to be noise. A pixel is defined as noise if and only if this pixel is a maximum or minimum within the pixel window.</p> 4243 4244<p>Use <kbd><a href="#noise">-noise</a> <em class="arg">radius</em></kbd> to specify the width of the neighborhood when reducing noise.</p> 4245 4246<p>Use <a href="#noise">+noise</a> followed by a noise <em class="arg">type</em> to add noise to an image. Choose from these noise types:</p> 4247 4248<pre class="text"> 4249Gaussian 4250Impulse 4251Laplacian 4252Multiplicative 4253Poisson 4254Random 4255Uniform 4256</pre> 4257 4258<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p> 4259 4260<p>Also see the <a href="#evaluate">-evaluate</a> noise functions that allos 4261the use of a controlling value to specify teh amount of noise that should be 4262added to an image. </p> 4263 4264 4265<div style="margin: auto;"> 4266 <h4><a name="normalize" id="normalize"></a>-normalize</h4> 4267</div> 4268 4269<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Increase the contrast in an image by <em>stretching</em> the range of intensity values.</td><td style='text-align:right;'></td></tr></table> 4270 4271<p>The intensity values are stretched to cover the entire range of possible 4272values. While doing so, black-out at most <em>2%</em> of the pixels and 4273white-out at most <em>1%</em> of the pixels.</p> 4274 4275<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a> 4276is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>. 4277(Before this version, it was equivalent to <a href="#contrast-stretch" 4278>-contrast-stretch 2%x99%</a>).</p> 4279 4280<p>All the channels are normalized in concert by the came amount so as to 4281preserve color integrity, when the default <a href="#channel" >+channel</a> 4282setting is in use. Specifying any other <a href="#channel" >-channel</a> 4283setting will normalize the RGB channels independently.</p> 4284 4285<p>See <a href="#contrast-stretch" >-contrast-stretch</A> for more details. 4286Also see <a href="#auto-level" >-auto-level</a> for a 'perfect' normalization 4287that is better suited to mathematically generated images. </p> 4288 4289<p>This operator is under review for re-development. </p> 4290 4291 4292<div style="margin: auto;"> 4293 <h4><a name="ordered-dither" id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4> 4294</div> 4295 4296<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>dither the image using a pre-defined ordered dither <em 4297class="arg">threshold map</em> specified, and a uniform color map with the 4298given number of <em class="arg">levels</em> per color channel . </td><td style='text-align:right;'></td></tr></table> 4299 4300<p>You can choose from these standard threshold maps:</p> 4301 4302<pre class="text"> 4303 threshold 4304 checks 4305 o2x2 4306 o3x3 4307 o4x4 4308 o8x8 4309 h4x4a 4310 h6x6a 4311 h8x8a 4312 h4x4o 4313 h6x6o 4314 h8x8o 4315 h16x16o 4316</pre> 4317 4318<p>The '<kbd>o</kbd>' maps are ordered diffused pixel threshold maps, while the 4319'<kbd>h</kbd>' maps are halftone threshold maps which are either 'a' angled, or 4320'o' orthogonal. The '<kbd>checks</kbd>' produce a 3 level checkerbord dither 4321pattern. Or you can define your own <em class="arg" >threshold map</em> in a 4322personal or system "<kbd>thresholds.xml</kbd>" XML file. </p> 4323 4324<p>To print a complete list of threshold, use the <a href="#list" >-list 4325threshold</a> option.</p> 4326 4327<p>It is recommended that the <a href="#map" >+map</a> operator be used after 4328applying <a href="#ordered-dither" >-ordered-dither</a> to reduce the number of 4329colors an animated image sequence, to less that 256 colors. This ensures that 4330a common or global color table is used when saving the result to a color 4331limited file format such as GIF. </p> 4332 4333<p>Note that at this time the exact same threshold dithering map is used for 4334all color channels, no attempt is made to offset or rotate the map for 4335different channels is made, to create an offset printing effect. (possible 4336future expansion) </p> 4337 4338 4339<div style="margin: auto;"> 4340 <h4><a name="opaque" id="opaque"></a>-opaque <em class="arg">color</em></h4> 4341</div> 4342 4343<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>change this color to the fill color within the image.</td><td style='text-align:right;'></td></tr></table> 4344 4345<p>The <em class="arg">color</em> argument is defined using the format 4346described under the <a href="#fill" >-fill</a> option. The <a href="#fuzz" 4347>-fuzz</a> setting can be used to match and replace colors similar to the one 4348given.</p> 4349 4350<p>Use <a href="#opaque">+opaque</a> to paint any pixel that does not match 4351the target color. </p> 4352 4353<p>The <a href="#transparent">-transparent</a> operator is exactly the same 4354as <a href="#opaque" >-opaque</a> but replaces the matching color with 4355transparency rather than the current <a href="#fill">-fill</a> color setting. 4356To ensure that it can do this it also ensures that the image has an alpha 4357channel enabled, as per "<kbd><a href="#alpha" >-alpha</a> set</kbd>", for 4358the new transparent colors, and does not require you to modify the <a 4359href="#channel">-channel</a> to enable alpha channel handling. </p> 4360 4361 4362<div style="margin: auto;"> 4363 <h4><a name="orient" id="orient"></a>-orient <em class="arg">image orientation</em></h4> 4364</div> 4365 4366<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify orientation of a digital camera image.</td><td style='text-align:right;'></td></tr></table> 4367 4368<p>Choose from these orientations:</p> 4369 4370<pre class="text"> 4371 bottom-left 4372 bottom-right 4373 left-bottom 4374 left-top 4375 right-bottom 4376 right-top 4377 top-left 4378 top-right 4379 undefined 4380</pre> 4381 4382<p>To print a complete list of orientations, use the <a href="#list" >-list 4383orientation</a> option.</p> 4384 4385 4386<div style="margin: auto;"> 4387 <h4><a name="page" id="page"></a>-page <em class="arg">geometry</em><br/> 4388 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!<></em>}]<br/> 4389 +page 4390 </h4> 4391</div> 4392 4393<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the size and location of an image on the larger virtual canvas.</td><td style='text-align:right;'></td></tr></table> 4394 4395<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4396 4397<p>For convenience you can specify the page size using <em class="arg">media</em> (see below). Offsets can then be added as with other <em class="arg">geometry</em> arguments (e.g. <a href="#page">-page</a> <kbd>Letter+43+43</kbd>).</p> 4398 4399<p>Use <em class="arg">media</em> as shorthand to specify the dimensions (<em class="arg">width</em>x<em class="arg">height</em>) of the <em class="arg">PostScript</em> page in dots per inch or a TEXT page in pixels. The choices for a PostScript page are:</p> 4400<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;"> 4401<thead> 4402 <tr valign="top"> 4403 <th align="center"><em class="arg">media</em></th> 4404 <th align="center"><em class="arg">width</em></th> 4405 <th align="center"><em class="arg">height</em></th> 4406 </tr> 4407</thead> 4408<tbody> 4409<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr> 4410<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr> 4411<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr> 4412<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4413<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4414<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr> 4415<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr> 4416<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr> 4417<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr> 4418<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr> 4419<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr> 4420<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr> 4421<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr> 4422<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr> 4423<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4424<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4425<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr> 4426<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr> 4427<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr> 4428<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr> 4429<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr> 4430<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr> 4431<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr> 4432<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr> 4433<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr> 4434<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr> 4435<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr> 4436<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr> 4437<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr> 4438<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr> 4439<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr> 4440<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr> 4441<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr> 4442<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr> 4443<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr> 4444<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4445<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4446<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr> 4447</tbody> 4448</table> 4449 4450 4451 4452 4453<p>This option is also used to place subimages when writing to a multi-image format that supports offsets, such as GIF89 and MNG. When used for this purpose the offsets are always measured from the top left corner of the canvas and are not affected by the <a href="#gravity">-gravity</a> option. To position a GIF or MNG image, use <a href="#page">-page</a><em class="arg">{+-}x{+-}y</em> (e.g. -page +100+200). When writing to a MNG file, a <a href="#page">-page</a> option appearing ahead of the first image in the sequence with nonzero width and height defines the width and height values that are written in the <kbd>MHDR</kbd> chunk. Otherwise, the MNG width and height are computed from the bounding box that contains all images in the sequence. When writing a GIF89 file, only the bounding box method is used to determine its dimensions.</p> 4454 4455<p>For a PostScript page, the image is sized as in <a href="#geometry">-geometry</a> but positioned relative to the <em>lower left-hand corner</em> of the page by {+-}<kbd>x</kbd><em class="arg">offset</em>{+-}<kbd>y</kbd> <em class="arg">offset</em>. Use <a href="#page">-page 612x792</a>, for example, to center the image within the page. If the image size exceeds the PostScript page, it is reduced to fit the page. The default gravity for the <a href="#page">-page</a> option is <em class="arg">NorthWest</em>, i.e., positive <kbd>x</kbd> and <kbd>y</kbd> <em class="arg">offset</em> are measured rightward and downward from the top left corner of the page, unless the <a href="#gravity">-gravity</a> option is present with a value other than <em class="arg">NorthWest</em>.</p> 4456 4457<p>The default page dimensions for a TEXT image is 612x792.</p> 4458 4459<p>This option is used in concert with <a href="#density">-density</a>.</p> 4460 4461<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p> 4462 4463<div style="margin: auto;"> 4464 <h4><a name="paint" id="paint"></a>-paint <em class="arg">radius</em></h4> 4465</div> 4466 4467<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate an oil painting.</td><td style='text-align:right;'></td></tr></table> 4468 4469<p>Each pixel is replaced by the most frequent color in a circular neighborhood whose width is specified with <em class="arg">radius</em>.</p> 4470 4471<div style="margin: auto;"> 4472 <h4><a name="path" id="path"></a>-path <em class="arg">path</em></h4></div> 4473 4474<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>write images to this path on disk.</td><td style='text-align:right;'></td></tr></table> 4475 4476<div style="margin: auto;"> 4477 <h4><a name="pause_animate_" id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4> 4478</div> 4479 4480<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pause between animation loops.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>]</td></tr></table> 4481 4482<p>Pause for the specified number of seconds before repeating the animation.</p> 4483 4484<div style="margin: auto;"> 4485 <h4><a name="pause_import_" id="pause_import_"></a>-pause <em class="arg">seconds</em></h4> 4486</div> 4487 4488<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pause between snapshots.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 4489 4490<p>Pause for the specified number of seconds before taking the next snapshot.</p> 4491 4492<div style="margin: auto;"> 4493 <h4><a name="ping" id="ping"></a>-ping</h4> 4494</div> 4495 4496<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>efficiently determine image characteristics.</td><td style='text-align:right;'></td></tr></table> 4497 4498<div style="margin: auto;"> 4499 <h4><a name="pointsize" id="pointsize"></a>-pointsize <em class="arg">value</em></h4> 4500</div> 4501 4502<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pointsize of the PostScript, OPTION1, or TrueType font.</td><td style='text-align:right;'></td></tr></table> 4503 4504<div style="margin: auto;"> 4505 <h4><a name="polaroid" id="polaroid"></a>-polaroid <em class="arg">angle</em></h4> 4506</div> 4507 4508<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a Polaroid picture.</td><td style='text-align:right;'></td></tr></table> 4509 4510<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p> 4511 4512<div style="margin: auto;"> 4513 <h4><a name="posterize" id="posterize"></a>-posterize <em class="arg">levels</em></h4> 4514</div> 4515 4516<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce the image to a limited number of color levels.</td><td style='text-align:right;'></td></tr></table> 4517 4518<div style="margin: auto;"> 4519 <h4><a name="precision" id="precision"></a>-precision <em class="arg">value</em></h4> 4520</div> 4521 4522<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the maximum number of significant digits to be printed.</td><td style='text-align:right;'></td></tr></table> 4523 4524<div style="margin: auto;"> 4525 <h4><a name="preview" id="preview"></a>-preview <em class="arg">type</em></h4> 4526</div> 4527 4528<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>image preview type.</td><td style='text-align:right;'></td></tr></table> 4529 4530<p>Use this option to affect the preview operation of an image (e.g. <kbd>convert file.png -preview Gamma Preview:gamma.png</kbd>). Choose from these previews:</p> 4531 4532<pre class="text"> 4533 Rotate 4534 Shear 4535 Roll 4536 Hue 4537 Saturation 4538 Brightness 4539 Gamma 4540 Spiff 4541 Dull 4542 Grayscale 4543 Quantize 4544 Despeckle 4545 ReduceNoise 4546 Add Noise 4547 Sharpen 4548 Blur 4549 Threshold 4550 EdgeDetect 4551 Spread 4552 Shade 4553 Raise 4554 Segment 4555 Solarize 4556 Swirl 4557 Implode 4558 Wave 4559 OilPaint 4560 CharcoalDrawing 4561 JPEG 4562</pre> 4563 4564<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p> 4565 4566<p>The default preview is <kbd>JPEG</kbd>.</p> 4567 4568<div style="margin: auto;"> 4569 <h4><a name="print" id="print"></a>-print <em class="arg">string</em></h4> 4570</div> 4571 4572<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>interpret string and print to console.</td><td style='text-align:right;'></td></tr></table> 4573 4574<div style="margin: auto;"> 4575 <h4><a name="process" id="process"></a>-process <em class="arg">command</em></h4> 4576</div> 4577 4578<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>process the image with a custom image filter.</td><td style='text-align:right;'></td></tr></table> 4579 4580<p>The command arguments has the form <kbd>"module arg1 arg2 arg3 ... argN"</kbd> where <kbd>module</kbd> is the name of the module to invoke (e.g. "Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to pass to the process module.</p> 4581 4582<div style="margin: auto;"> 4583 <h4><a name="profile" id="profile"></a>-profile <em class="arg">filename</em><br/> 4584 +profile <em class="arg">profile_name</em></h4> 4585</div> 4586 4587<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Manage ICM, IPTC, or generic profiles in an image.</td><td style='text-align:right;'></td></tr></table> 4588 4589<p>Using <a href="#profile">-profile</a> <em class="arg">filename</em> adds an ICM (ICC color management), IPTC (newswire information), or a generic profile to the image.</p> 4590 4591<p>Use <a href="#profile">+profile <em class="arg">profile_name</em></a> to remove the indicated profile. ImageMagick uses standard filename globbing, so wildcard expressions may be used to remove more than one profile. Here we remove all profiles from the image except for the XMP profile: <kbd>+profile "!xmp,*"</kbd>. </p> 4592 4593<p>Use <kbd>identify -verbose</kbd> to find out which profiles are in the image file. Use <a href="#strip">-strip</a> to remove all profiles (and comments).</p> 4594 4595<p>To extract a profile, the <a href="#profile">-profile</a> option is not used. Instead, simply write the file to an image format such as <em class="arg">APP1, 8BImageMagick, ICM,</em> or <em class="arg">IPTC</em>.</p> 4596 4597<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p> 4598 4599<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p> 4600<p>It is important to note that results may depend on whether or not the original image already has an included profile. Also, keep in mind that <a href="#profile">-profile</a> is an "operator" (as opposed to a "setting") and therefore a conversion is made each time it is encountered, in order, in the command-line. For instance, in the following example, if the original image is CMYK with profile, a CMYK-CMYK-RGB conversion results.</p> 4601 4602<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff</span></p> 4603<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results. 4604CMYK profiles are often very asymmetric since they involve 3−>4 and 4−>3 channel mapping. 4605</p> 4606 4607<div style="margin: auto;"> 4608 <h4><a name="quality" id="quality"></a>-quality <em class="arg">value</em></h4> 4609</div> 4610 4611<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>JPEG/MIFF/PNG compression level.</td><td style='text-align:right;'></td></tr></table> 4612 4613<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and highest compression) to 100 (best quality but least effective compression). The default is to use the estimate quality of your input image otherwise 92. Use the <a href="#sampling-factor">-sampling-factor</a> option to specify the factors for chroma downsampling.</p> 4614 4615<p>For the MIFF image format, quality/10 is the zlib compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.</p> 4616 4617<p>For the JPEG-2000 image format, quality is mapped using a non-linear equation to the compression ratio required by the Jasper library. This non-linear equation is intended to loosely approximate the quality provided by the JPEG v1 format. The default quality value 100, a request for non-lossy compression. A quality of 75 results in a request for 16:1 compression.</p> 4618 4619<p>For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression. The default PNG compression is 75.</p> 4620 4621<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p> 4622 4623<pre class="text"> 4624 0: none 4625 1: sub 4626 2: up 4627 3: average 4628 4: Paeth 4629</pre> 4630 4631<p>If filter-type is 5, adaptive filtering is used when quality is greater than 50 and the image does not have a color map, otherwise no filtering is used.</p> 4632 4633<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p> 4634 4635<p>Only if the output is MNG, if filter-type is 7, the LOCO color transformation and adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> are used.</p> 4636 4637<p>The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.</p> 4638 4639<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p> 4640 4641<div style="margin: auto;"> 4642 <h4><a name="quantize" id="quantize"></a>-quantize <em class="arg">colorspace</em></h4> 4643</div> 4644 4645<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce colors using this colorspace.</td><td style='text-align:right;'></td></tr></table> 4646 4647<p>This setting defines the colorspace used to sort out and reduce the number 4648of colors needed by an image (for later dithering) by operators such as <a 4649href="#colors" >-colors</a>, Note that color reducion also happens 4650automatically when saving images to color-limited image file formats, such as 4651GIF, and PNG8.</p> 4652 4653 4654<div style="margin: auto;"> 4655 <h4><a name="quiet" id="quiet"></a>-quiet</h4> 4656</div> 4657 4658<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>suppress all warning messages. Error messages are still reported.</td><td style='text-align:right;'></td></tr></table> 4659 4660<div style="margin: auto;"> 4661 <h4><a name="radial-blur" id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4> 4662</div> 4663 4664<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Blur around the center of the image.</td><td style='text-align:right;'></td></tr></table> 4665 4666<p>Note that this is actually a rotational blur rather than a radial and as 4667such actually mis-named. </p> 4668 4669<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4670pixels which are outside the image proper are blurred into the final result. 4671</p> 4672 4673 4674<div style="margin: auto;"> 4675 <h4><a name="raise" id="raise"></a>-raise <em class="arg">thickness</em></h4> 4676</div> 4677 4678<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Lighten or darken image edges.</td><td style='text-align:right;'></td></tr></table> 4679 4680<p>This will create a 3-D effect. Use <a href="#raise">-raise</a> to create a raised effect, otherwise use <a href="#raise">+raise</a>. 4681</p> 4682 4683<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p> 4684 4685<div style="margin: auto;"> 4686 <h4><a name="random-threshold" id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4> 4687</div> 4688 4689<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a random threshold to the image.</td><td style='text-align:right;'></td></tr></table> 4690 4691<div style="margin: auto;"> 4692 <h4><a name="red-primary" id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4> 4693</div> 4694 4695<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the red chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 4696 4697<div style="margin: auto;"> 4698 <h4><a name="regard-warnings" id="regard-warnings"></a>-regard-warnings</h4> 4699</div> 4700 4701<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pay attention to warning messages.</td><td style='text-align:right;'></td></tr></table> 4702 4703<div style="margin: auto;"> 4704 <h4><a name="remap" id="remap"></a>-remap <em class="arg">filename</em></h4> 4705</div> 4706 4707<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reduce the number of colors in an image to the colors used by this image.</td><td style='text-align:right;'></td></tr></table> 4708 4709<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then 4710the given colors are dithered over the image as necessary, otherwise the closest 4711color (in RGB colorspace) is selected to replace that pixel in the image. </p> 4712 4713<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all 4714images in the current image sequence, all the images will have the same color 4715table. That means that when saved to a file format such as GIF, it will use 4716that color table as a single common or global color table, for all the images, 4717without requiring extra local color tables. </p> 4718 4719<p>Use <a href="#remap">+remap</a> to reduce all images in the current image 4720sequence to use a common color map over all the images. This equivalent to 4721appending all the images together (without extra background colors) and color 4722reducing those images using <a href="#colors">-colors</a> with a 256 color 4723limit, then <a href="#remap">-remap</a> those colors over the original list of 4724images. This ensures all the images follow a single color map. </p> 4725 4726<p>If the number of colors over all the images is less than 256, then <a 4727href="#remap">+remap</a> should not perform any color reduction or dithering, as 4728no color changes are needed. In that case, its only effect is to force the use 4729of a global color table. This recommended after using either <a 4730href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to 4731reduce the number of colors in an animated image sequence. </p> 4732 4733<div style="margin: auto;"> 4734 <h4><a name="region" id="region"></a>-region <em class="arg">geometry</em></h4> 4735</div> 4736 4737<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a region in which subsequent operations apply.</td><td style='text-align:right;'></td></tr></table> 4738 4739<p>The <em class="arg">x</em> and <em class="arg">y</em> offsets are treated in the same manner as in <a href="#crop">-crop</a>.</p> 4740 4741<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4742 4743<div style="margin: auto;"> 4744 <h4><a name="remote" id="remote"></a>-remote</h4> 4745</div> 4746 4747<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform a remote operation.</td><td style='text-align:right;'></td></tr></table> 4748 4749<p>The only command recognized is the name of an image file to load.</p> 4750 4751<p>If you have more than one <a href="/www/display.html">display</a> application running simultaneously, use the <a href="#window"> window</a> option to specify which application to control.</p> 4752 4753<div style="margin: auto;"> 4754 <h4><a name="render" id="render"></a>-render</h4> 4755</div> 4756 4757<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>render vector operations.</td><td style='text-align:right;'></td></tr></table> 4758 4759<p>Use <a href="#render">+render</a> to turn off rendering vector operations. This useful when saving the result to vector formats such as MVG or SVG.</p> 4760 4761<div style="margin: auto;"> 4762<h4><a name="repage" id="repage"></a>-repage <em class="arg">geometry</em></h4> 4763</div> 4764 4765<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adjust the canvas and offset information of the image.</td><td style='text-align:right;'></td></tr></table> 4766 4767<p>This option is like <a href="#page">-page</a> but acts as an image operator 4768rather than a setting. You can separately set the canvas size or the offset 4769of the image on that canvas by only providing those components. </p> 4770 4771<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4772 4773<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing 4774offset to move the image relative to its previous position. This useful for 4775animation sequences. </p> 4776 4777<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to 4778recalculate the canvas size so the image (at its current offset) will appear 4779completely on that canvas (unless it has a negative offset).</p> 4780 4781<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual 4782canvas meta-data from the images. </p> 4783 4784<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to 4785directly assign virtual canvas meta-data. </p> 4786 4787 4788<div style="margin: auto;"> 4789 <h4><a name="resample" id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4> 4790</div> 4791 4792<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resample image to specified horizontal and vertical resolution.</td><td style='text-align:right;'></td></tr></table> 4793 4794<p>Resize the image so that its rendered size remains the same as the original at the specified target resolution. For example, if a 300 DPI image renders at 3 inches by 2 inches on a 300 DPI device, when the image has been resampled to 72 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of storing the image resolution. For formats which do not support an image resolution, the original resolution of the image must be specified via <a href="#density">-density</a> on the command line prior to specifying the resample resolution.</p> 4795 4796<p>Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile exists in the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.</p> 4797 4798<div style="margin: auto;"> 4799 <h4><a name="resize" id="resize"></a>-resize <em class="arg">geometry</em></h4> 4800</div> 4801 4802<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resize an image.</td><td style='text-align:right;'></td></tr></table> 4803 4804<p>See <a href="/www/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 ignored, and the <a href="#gravity">-gravity</a> option has no effect.</p> 4805 4806<p>If the <a href="#filter">-filter</a> option precedes the <a href="#resize">-resize</a> option, the image is resized with the specified filter.</p> 4807 4808<p>Many image processing algorithms assume your image is in a linear-light coding. If your image is gamma-corrected, you can remove the nonlinear gamma correction, apply the transform, then restore it like this:</p> 4809 4810<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \ <br/> -quality 92 passport.jpg</span></p> 4811<div style="margin: auto;"> 4812 <h4><a name="respect-parentheses" id="respect-parentheses"></a>-respect-parentheses</h4> 4813</div> 4814 4815<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>settings remain in effect until parenthesis boundary.</td><td style='text-align:right;'></td></tr></table> 4816 4817<div style="margin: auto;"> 4818 <h4><a name="reverse" id="reverse"></a>-reverse</h4> 4819</div> 4820 4821<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reverse the order of images in the current image list.</td><td style='text-align:right;'></td></tr></table> 4822 4823 4824<div style="margin: auto;"> 4825 <h4><a name="roll" id="roll"></a>-roll {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 4826</div> 4827 4828<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>roll an image vertically or horizontally by the amount given.</td><td style='text-align:right;'></td></tr></table> 4829 4830<p>A negative <em class="arg">x</em> offset rolls the image left-to-right. A negative <em class="arg">y</em> offset rolls the image top-to-bottom.</p> 4831 4832 4833<div style="margin: auto;"> 4834 <h4><a name="rotate" id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg"><</em>}{<em class="arg">></em>}</h4> 4835</div> 4836 4837<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply Paeth image rotation (using shear operations) to the image.</td><td style='text-align:right;'></td></tr></table> 4838 4839<p>Use <kbd>></kbd> to rotate the image only if its width exceeds the height. <kbd><</kbd> rotates the image <em>only</em> if its width is less than the height. For example, if you specify <kbd>-rotate "-90>"</kbd> and the image size is 480x640, the image is not rotated. However, if the image is 640x480, it is rotated by -90 degrees. If you use <kbd>></kbd> or <kbd><</kbd>, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.</p> 4840 4841<p>Empty triangles in the corners, left over from rotating the image, are 4842filled with the <kbd>background</kbd> color. </p> 4843 4844<p>See also the <a href="#distort">-distort</a> operator and specifically the 4845'<kbd>ScaleRotateTranslate</kbd>' distort method. </p> 4846 4847 4848<div style="margin: auto;"> 4849 <h4><a name="sample" id="sample"></a>-sample <em class="arg">geometry</em></h4> 4850</div> 4851 4852<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>minify/magnify the image using pixel subsampling and pixel replication, respectively.</td><td style='text-align:right;'></td></tr></table> 4853 4854<p>Change the image size simply by directly sampling the pixels original 4855image. When magnifying, pixels are replicated in blocks. When minifying, 4856pixels are sub-sampled (i.e., some rows and columns are skipped over). </p> 4857 4858<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 4859a <a href="#filter">-filter</a> setting of <kbd>point</kbd> (nearest 4860neighbour), though <a href="#sample">-sample</a> is a lot faster, as it 4861avoids all the filter processing of the image. As such it completely ignores 4862the current <a href="#filter">-filter</a> setting. </p> 4863 4864<p>The key feature of the <a href="#sample">-sample</a> is that no new colors 4865will be added to the resulting image, though some colors may disappear. </p> 4866 4867<p>See <a href="/www/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 4868ignored, unlike <a href="#resize">-resize</a>. </p> 4869 4870 4871<div style="margin: auto;"> 4872 <h4><a name="sampling-factor" id="sampling-factor"></a>-sampling-factor <em class="arg">horizontal-factor</em>x<em class="arg">vertical-factor</em></h4> 4873</div> 4874 4875<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</td><td style='text-align:right;'></td></tr></table> 4876 4877<p>This option specifies the sampling factors to be used by the JPEG encoder for chroma downsampling. If this option is omitted, the JPEG library will use its own default values. When reading or writing the YUV format and when writing the M2V (MPEG-2) format, use <a href="#sampling-factor">-sampling-factor 2x1</a> or <a href="#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2 downsampling method.</p> 4878 4879<div style="margin: auto;"> 4880 <h4><a name="scale" id="scale"></a>-scale <em class="arg">geometry</em></h4> 4881</div> 4882 4883<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>minify/magnify the image using pixel block averaging and pixel replication, respectively.</td><td style='text-align:right;'></td></tr></table> 4884 4885<p>Change the image size simply by replacing pixels by averaging pixels 4886together when minifying, or replacing pixels when magnifing. </p> 4887 4888<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 4889a <a href="#filter">-filter</a> setting of <kbd>box</kbd>. Though it is a lot 4890faster, as it avoids all the filter processing of the image. As such it 4891completely ignores the current <a href="#filter">-filter</a> setting. </p> 4892 4893<p>If when shrinking (minifying) images the original image is some integer 4894multiple of the new image size, the number of pixels avergaed together to 4895produce the new pixel color is the same across the whole image. This is 4896a special case known as 'binning' and is often used as a method of reducing 4897noise in image such as those generated by digital cameras, especially in low 4898light conditions. </p> 4899 4900 4901<div style="margin: auto;"> 4902 <h4><a name="scene" id="scene"></a>-scene <em class="arg">value</em></h4> 4903</div> 4904 4905<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set scene number.</td><td style='text-align:right;'></td></tr></table> 4906 4907<p>This option sets the scene number of an image or the first image in an image sequence.</p> 4908 4909<div style="margin: auto;"> 4910 <h4><a name="screen" id="screen"></a>-screen</h4> 4911</div> 4912 4913<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the screen to capture.</td><td style='text-align:right;'></td></tr></table> 4914 4915<p>This option indicates that the GetImage request used to obtain the image should be done on the root window, rather than directly on the specified window. In this way, you can obtain pieces of other windows that overlap the specified window, and more importantly, you can capture menus or other popups that are independent windows but appear over the specified window.</p> 4916 4917<div style="margin: auto;"> 4918 <h4><a name="seed" id="seed"></a>-seed</h4> 4919</div> 4920 4921<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>seed a new sequence of pseudo-random numbers</td><td style='text-align:right;'></td></tr></table> 4922 4923<div style="margin: auto;"> 4924 <h4><a name="segment" id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4> 4925</div> 4926 4927<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>segment the colors of an image.</td><td style='text-align:right;'></td></tr></table> 4928 4929<p>Segment an image by analyzing the histograms of the color components and identifying units that are homogeneous with the fuzzy c-means technique. This is part of the ImageMagick color quantization routines. </p> 4930 4931<p>Specify <em class="arg">cluster threshold</em> as the number of pixels in each cluster that must exceed the cluster threshold to be considered valid. <em class="arg">Smoothing threshold</em> eliminates noise in the second derivative of the histogram. As the value is increased, you can expect a smoother second derivative. The default is 1.5.</p> 4932 4933<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report 4934of the color clusters is returned.</p> 4935 4936 4937<div style="margin: auto;"> 4938 <h4><a name="selective-blur" id="selective-blur"></a>-selective-blur <em class="arg">geometry</em></h4> 4939</div> 4940 4941<div style="margin: auto;"> 4942 <h4><a name="selective-blur" id="selective-blur"></a>-selective-blur <em class="arg">radius</em><br />-unsharp <em class="arg">radius</em>x<em class="arg">sigma</em>{<em class="arg">+threshold</em>}</h4> 4943</div> 4944 4945<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Selectively blur pixels within a contrast threshold.</td><td style='text-align:right;'></td></tr></table> 4946 4947<p>Blurs those pixels that are less than or equal to the threshold in contrast. The threshold may be expressed as a fraction of <em class="QR">QuantumRange</em> or as a percentage.</p> 4948 4949<div style="margin: auto;"> 4950 <h4><a name="separate" id="separate"></a>-separate</h4> 4951</div> 4952 4953<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>separate an image channel into a grayscale image. Specify the channel with <a href="#channel">-channel</a>.</td><td style='text-align:right;'></td></tr></table> 4954 4955<div style="margin: auto;"> 4956 <h4><a name="sepia-tone" id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</em></h4> 4957</div> 4958 4959<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a sepia-toned photo.</td><td style='text-align:right;'></td></tr></table> 4960 4961<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p> 4962 4963<p>This option applies a special effect to the image, similar to the effect achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to <em class="QR">QuantumRange</em> and is a measure of the extent of the sepia toning. A threshold of 80% is a good starting point for a reasonable tone.</p> 4964 4965 4966 4967<div style="margin: auto;"> 4968 <h4><a name="set" id="set"></a>-set <em class="arg">key value</em></h4> 4969 <h4><a name="set" id="set"></a>+set <em class="arg">key</em></h4> 4970</div> 4971 4972<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sets image attributes and properties for images in the current 4973image sequence.</td><td style='text-align:right;'></td></tr></table> 4974 4975<p>This will assign (or modify) specific settings attached to all the images 4976in the current image sequence. Using the <a href="#set">+set</a> form of the 4977option will either remove, or reset that setting to a default state, as 4978appropriate. </p> 4979 4980<p>For example, it will modify specific well known image meta-data 4981'attributes' such as those normally overridden by: the options <a 4982href="#delay" >-delay</a>, <a href="#dispose" >-dispose</a>, and <a 4983href="#page" >-page</a>, <a href="#colorspace" >-colorspace</a>; generally 4984assigned before the image is read in, by using a <em class="arg">key</em> of 4985the same name. </p> 4986 4987<p>If the given <em class="arg">key</em> does not match a specific known 4988'attribute ', such as shown above, the setting is stored as a a free form 4989'properity' string. Such settings are listed in <a href="#verbose" 4990>-verbose</a> information ("<kbd>info:</kbd>" output format) as "Properties". 4991</p> 4992 4993<p>This includes string 'properities' that are set by and assigned to images 4994using the options <a href="#comment" >-comment</a>, <a href="#label" 4995>-label</a>, <a href="#caption" >-caption</a>. These options actually assign 4996a global 'artifact' which are automatically assigned (and any <a href="/www/escape.html" >Format Percent 4997Escapes</a> expanded) to images as they are read in. For example:</p> 4998 4999<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png</span><span class='crtout'>identify -format %c rose.png</span><span class="crtprompt"> $magick> </span><span class='crtin'>Rose is a rose is a rose is a rose</span></p> 5000<p>The set value can also make use of <a href="/www/escape.html" >Format and Print Image 5001Properties</a> in the defined value. For example:</p> 5002 5003<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set origsize '%wx%h' -resize 50% \</span><span class='crtout'> -format 'Old size = %[origsize] New size = %wx%h' info:</span><span class="crtprompt"> $magick> </span><span class='crtin'>Old size = 70x46 New size = 35x23</span></p> 5004<p>Other well known 'properities' that can be include: 5005'<kbd>date:create</kbd>' and '<kbd>date:modify</kbd>' and 5006'<kbd>signature</kbd>'. </p> 5007 5008<p>The <a href="#repage">-repage</a> operator will also allow you to modify 5009the '<kbd>page</kbd>' attribute of an image for images already in memory (also 5010see <a href="#repage">-page</a>). However it is designed to provide a finer 5011control of the sub-parts of this 'attribute'. The <a href="#set">-set page</a> 5012option will only provide a direct, unmodified assignment of '<kbd>page</kbd>' 5013attribute. </p> 5014 5015<p>This option can also associate a colorspace or profile with your image. 5016For example,</p> 5017 5018<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd</span></p> 5019<p>Some 'properties' must be defined in a specific way to be used. For 5020example only 'properties' prefixed with "<kbd>filename:</kbd>" can be used to 5021modify the output filename of an image. For example</p> 5022 5023<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'</span></p> 5024<p>If the setting value is prefixed with "<kbd>option:</kbd>" the setting will 5025be saved as a global "Artifact" exactly as if it was set using the <a 5026href="#define" >-define</a> option. As such settings are globel in scope, they 5027can be used to pass 'attributes' and 'properities' of one specific image, 5028in a way that allows you to use them in a completely different image, even if 5029the original image has long since been modified or destroyed. For example: </p> 5030 5031<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set option:rosesize '%wx%h' -delete 0 \</span><span class='crtout'> label:'%[rosesize]' label_size_of_rose.gif</span></p> 5032<p>Note that <a href="/www/escape.html" >Format Percent Escapes</a> will only match 5033a 'artifact' if the given <em class="arg">key</em> does not match an existing 5034'attribute' or 'properity'. </p> 5035 5036<p>You can set the attributes of the image registry by prefixing the value 5037with <kbd>registry:</kbd>.</p> 5038 5039 5040 5041<div style="margin: auto;"> 5042 <h4><a name="shade" id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4> 5043</div> 5044 5045<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>shade the image using a distant light source.</td><td style='text-align:right;'></td></tr></table> 5046 5047<p>Specify <em class="arg">azimuth</em> and <em class="arg">elevation</em> as the position of the light source. Use <a href="#shade">+shade</a> to return the shading results as a grayscale image.</p> 5048 5049<div style="margin: auto;"> 5050 <h4><a name="shadow" id="shadow"></a>-shadow <em class="arg">percent-opacity</em>{x<em class="arg">sigma</em>}{<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em>{<em class="arg">%</em>}</h4> 5051</div> 5052 5053<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate an image shadow.</td><td style='text-align:right;'></td></tr></table> 5054 5055<div style="margin: auto;"> 5056 <h4><a name="shared-memory" 5057id="shared-memory"></a>-shared-memory</h4> 5058</div> 5059 5060<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>use shared memory.</td><td style='text-align:right;'></td></tr></table> 5061 5062<p>This option specifies whether the utility should attempt to use shared memory for pixmaps. ImageMagick must be compiled with shared memory support, and the display must support the <em class="arg">MIT-SHM</em> extension. Otherwise, this option is ignored. The default is <kbd>True</kbd>.</p> 5063 5064<div style="margin: auto;"> 5065 <h4><a name="sharpen" id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4> 5066</div> 5067 5068<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sharpen the image.</td><td style='text-align:right;'></td></tr></table> 5069 5070<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p> 5071 5072<div style="margin: auto;"> 5073 <h4><a name="shave" id="shave"></a>-shave <em class="arg">geometry</em></h4> 5074</div> 5075 5076<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shave pixels from the image edges.</td><td style='text-align:right;'></td></tr></table> 5077 5078<p>The <em class="arg">size</em> portion of the <em class="arg">geometry</em> argument specifies the width of the region to be removed from both sides of the image and the height of the regions to be removed from top and bottom. Offsets are ignored.</p> 5079 5080<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5081 5082<div style="margin: auto;"> 5083 <h4><a name="shear" id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4> 5084</div> 5085 5086<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shear the image along the x-axis and/or y-axis.</td><td style='text-align:right;'></td></tr></table> 5087 5088<p>The shear angles may be positive, negative, or zero. When <em class="arg">Ydegrees</em> is omitted it defaults to 0. When both angles are given, the horizontal component of the shear is performed before the vertical component.</p> 5089 5090<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e., horizontally or vertically, respectively),creating a parallelogram. The amount of each is controlled by the respective shear angle. For horizontal shears, <em class="arg">Xdegrees</em> is measured clockwise relative to "up" (the negative y-axis), sliding the top edge to the right when 0°<<em class="arg">Xdegrees</em><90° and to the left when 90°<<em class="arg">Xdegrees</em><180°. For vertical shears <em class="arg">Ydegrees</em> is measured clockwise relative to "right" (the positive x-axis), sliding the right edge down when 0°<<em class="arg">Ydegrees</em><90° and up when 90°<<em class="arg">Ydegrees</em><180°.</p> 5091 5092<p>Empty triangles left over from shearing the image are filled with the color defined by the <a href="#fill">-background</a> option. The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5093 5094<p>The horizontal shear is performed before the vertical part. This is important to note, since horizontal and vertical shears do not <em>commute</em>, i.e., the order matters in a sequence of shears. For example, the following two commands are not equivalent.</p> 5095 5096<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x0 -shear 0x60 logo-sheared.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 0x60 -shear 20x0 logo-sheared.png</span></p> 5097<p>The first of the two commands above is equivalent to the following, except for the amount of empty space created; the command that follows generates a smaller image, and so is a better choice in terms of time and space.</p> 5098 5099<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p> 5100<div style="margin: auto;"> 5101 <h4><a name="sigmoidal" id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4> 5102</div> 5103 5104<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>increase the contrast without saturating highlights or shadows.</td><td style='text-align:right;'></td></tr></table> 5105 5106<p>Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. <em class="arg">Contrast</em> indicates how much to increase the contrast (0 is none; 3 is typical; 20 is a lot); <em class="arg">mid-point</em> indicates where midtones fall in the resultant image (0 is white; 50% is middle-gray; 100% is black). By default the image contrast is increased, use <em class="arg">+sigmoidal-contrast</em> to decrease the contrast.</p> 5107 5108<div style="margin: auto;"> 5109 <h4><a name="silent" id="silent"></a>-silent</h4> 5110</div> 5111 5112<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>operate silently.</td><td style='text-align:right;'></td></tr></table> 5113 5114<div style="margin: auto;"> 5115 <h4><a name="size" id="size"></a>-size <em class="arg">width</em>[x<em class="arg">height</em>][<em class="arg">+offset</em>]</h4> 5116</div> 5117 5118<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the width and height of the image.</td><td style='text-align:right;'></td></tr></table> 5119 5120<p>Use this option to specify the width and height of raw images whose dimensions are unknown such as <kbd>GRAY</kbd>, <kbd>RGB</kbd>, or <kbd>CMYK</kbd>. In addition to width and height, use <a href="#size">-size</a> with an offset to skip any header information in the image or tell the number of colors in a <kbd>MAP</kbd> image file, (e.g. -size 640x512+256).</p> 5121 5122<p>For Photo CD images, choose from these sizes:</p> 5123 5124<pre class="text"> 5125 192x128 5126 384x256 5127 768x512 5128 1536x1024 5129 3072x2048 5130</pre> 5131 5132<div style="margin: auto;"> 5133 <h4><a name="sketch" id="sketch"></a>-sketch <em class="arg">radius</em><br />-sketch <em class="arg">radius</em>x<em class="arg">sigma</em>+<em class="arg">angle</em></h4> 5134</div> 5135 5136<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a pencil sketch.</td><td style='text-align:right;'></td></tr></table> 5137 5138<p>Sketch with the given radius, standard deviation (sigma), and angle. The angle given is the angle toward which the image is sketched. That is the direction people would consider the object is coming from. </p> 5139 5140<div style="margin: auto;"> 5141 <h4><a name="snaps" id="snaps"></a>-snaps <em class="arg">value</em></h4> 5142</div> 5143 5144<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the number of screen snapshots.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 5145 5146<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p> 5147 5148<div style="margin: auto;"> 5149 <h4><a name="solarize" id="solarize"></a>-solarize <em class="arg">threshold</em></h4> 5150</div> 5151 5152<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>negate all pixels above the threshold level.</td><td style='text-align:right;'></td></tr></table> 5153 5154<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p> 5155 5156<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p> 5157 5158<div style="margin: auto;"> 5159 <h4><a name="sparse-color" id="sparse-color"></a>-sparse-color <em 5160 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4> 5161</div> 5162 5163<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'> color the given image using the specified points of color, and filling the other intervening colors using the given methods. </td><td style='text-align:right;'></td></tr></table> 5164 5165 5166<table class="doc"> 5167 <tbody> 5168 <tr valign="top"> 5169 <th align="left" style="width: 8%">Method</th> 5170 <th align="left">Description</th> 5171 </tr> 5172 5173 <tr valign="top"> 5174 <td valign="top">voronoi</td> 5175 <td valign="top">Simply map each pixel to the to nearest color point 5176 given. The result are polygonal 'cells' of solid color. </td> 5177 </tr> 5178 5179 <tr valign="top"> 5180 <td valign="top">shepards</td> 5181 <td valign="top">Colors points biased on the ratio of inverse distance 5182 squared. Generating spots of color in a sea of the average of 5183 colors. </td> 5184 </tr> 5185 5186 <tr valign="top"> 5187 <td valign="top">barycentric</td> 5188 <td valign="top">three point triangle of color given 3 points. 5189 Giving only 2 points will form a linear gradient between those points. 5190 Gradient is however not restricted to just the triangle or line. </td> 5191 </tr> 5192 5193 <tr valign="top"> 5194 <td valign="top">bilinear</td> 5195 <td valign="top">Like barycentric but for 4 points. Less than 4 points 5196 fall back to barycentric. </td> 5197 </tr> 5198 5199 </tbody> 5200</table> 5201 5202<p>The points are placed according to the images location on the virtual 5203canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a> 5204offset), and do not actually have to exist on the given image, but may be 5205some point beyond the edge of the image. All points are floating point values. 5206</p> 5207 5208<p>Only the color channels defined by the <a href="#channel" >-channel</a> are 5209modified, whcih means the matte/alpha transparency channel is not effected by 5210default. If enabled, the image also needs a the matte/alpha channel to be 5211enabled for this operator to effect an images transparency. This is typical 5212transparency handling for images. </p> 5213 5214<p>All the above methods when given a single point of color will replace all 5215the colors in the image with the color given, regardless of the point. This is 5216logical, and provides an alternative technique to recolor a image to some 5217default value. </p> 5218 5219 5220<div style="margin: auto;"> 5221 <h4><a name="splice" id="splice"></a>-splice <em class="arg">geometry</em></h4> 5222</div> 5223 5224<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Splice the current background color into the image.</td><td style='text-align:right;'></td></tr></table> 5225 5226<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. See <a href="#background">-background</a> to reset the background color.</p> 5227 5228<div style="margin: auto;"> 5229 <h4><a name="spread" id="spread"></a>-spread <em class="arg">amount</em></h4> 5230</div> 5231 5232<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>displace image pixels by a random amount.</td><td style='text-align:right;'></td></tr></table> 5233 5234<p>The argument <em class="arg">amount</em> defines the size of the neighborhood around each pixel from which to choose a candidate pixel to swap.</p> 5235 5236<div style="margin: auto;"> 5237 <h4><a name="stegano" id="stegano"></a>-stegano <em class="arg">offset</em></h4> 5238</div> 5239 5240<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>hide watermark within an image.</td><td style='text-align:right;'></td></tr></table> 5241 5242<p>Use an offset to start the image hiding some number of pixels from the beginning of the image. Note this offset and the image size. You will need this information to recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).</p> 5243 5244<div style="margin: auto;"> 5245 <h4><a name="stereo" id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4> 5246</div> 5247 5248<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>composite two images to create a stereo anaglyph.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5249 5250<p>The left side of the stereo pair is saved as the red channel of the output image. The right side is saved as the green channel. Red-green stereo glasses are required to properly view the stereo image.</p> 5251 5252<div style="margin: auto;"> 5253 <h4><a name="storage-type" id="storage-type"></a>-storage-type <em class="arg">type</em></h4> 5254</div> 5255 5256<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pixel storage type. Here are the valid types:</td><td style='text-align:right;'></td></tr></table> 5257 5258<pre class="text"> 5259 char store pixels as unsigned characters 5260 double store pixels as doubles 5261 float store pixels as floats 5262 integer store pixels as integers 5263 long store pixels as longs 5264 quantum store pixels in the native depth of your ImageMagick distribution 5265 short store pixels as unsigned shorts 5266</pre> 5267 5268<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels 5269values range from 0 to the maximum value the storage type can support.</p> 5270 5271<div style="margin: auto;"> 5272 <h4><a name="stretch" id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4> 5273</div> 5274 5275<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a type of stretch style for fonts.</td><td style='text-align:right;'></td></tr></table> 5276 5277<p>This setting suggests a type of stretch that ImageMagick should try to apply to the currently selected font family. Select <em class="arg">fontStretch</em> from the following.</p> 5278 5279<pre class="text"> 5280 Any 5281 Condensed 5282 Expanded 5283 ExtraCondensed 5284 ExtraExpanded 5285 Normal 5286 SemiCondensed 5287 SemiExpanded 5288 UltraCondensed 5289 UltraExpanded 5290</pre> 5291 5292<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p> 5293 5294<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. </p> 5295 5296<div style="margin: auto;"> 5297 <h4><a name="strip" id="strip"></a>-strip</h4> 5298</div> 5299 5300<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>strip the image of any profiles or comments.</td><td style='text-align:right;'></td></tr></table> 5301 5302<div style="margin: auto;"> 5303 <h4><a name="stroke" id="stroke"></a>-stroke <em class="arg">color</em></h4> 5304</div> 5305 5306<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color to use when stroking a graphic primitive.</td><td style='text-align:right;'></td></tr></table> 5307 5308<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5309 5310<p>See <a href="#draw">-draw</a> for further details.</p> 5311 5312<div style="margin: auto;"> 5313 <h4><a name="strokewidth" id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4> 5314</div> 5315 5316<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the stroke width.</td><td style='text-align:right;'></td></tr></table> 5317 5318<p>See <a href="#draw">-draw</a> for further details.</p> 5319 5320<div style="margin: auto;"> 5321 <h4><a name="style" id="style"></a>-style <em class="arg">fontStyle</em></h4> 5322</div> 5323 5324<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font style for text.</td><td style='text-align:right;'></td></tr></table> 5325 5326<p>This setting suggests a font style that ImageMagick should try to apply to 5327the currently selected font family. Select <em class="arg">fontStyle</em> from 5328the following.</p> 5329 5330<pre class="text"> 5331 Any 5332 Italic 5333 Normal 5334 Oblique 5335</pre> 5336 5337<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, and <a href="#weight">-weight</a>. </p> 5338 5339<div style="margin: auto;"> 5340 <h4><a name="subimage-search" id="subimage-search"></a>-subimage-search</h4> 5341</div> 5342 5343<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>search for subimage.</td><td style='text-align:right;'>[<a href="/www/compare.html">compare</a>]</td></tr></table> 5344 5345<p>This option is required to have compare search for the best match location 5346of a small image within a larger image. This search will produce two images 5347(or two frames). The first is the "difference" image and the second will 5348be the "match score" image.</p> 5349 5350<p>The "match-score" image is smaller containing a pixel for ever possible 5351position of the top-left corner of the given sub-image. that is its size will 5352be the size of the larger_image - sub_image + 1. The brightest location in 5353this image is the location s the locate on the best match that is also 5354reported. Note that this may or may nor be a perfect match, and the actual 5355brightness will reflect this. Other bright 'peaks' can be used to locate other 5356possible matching loctions. </p> 5357 5358<p>Note that the search will try to compare teh sub-image at every possible 5359location in the larger image, as such it can be very slow. The smaller the 5360sub-image the faster this search is. </p> 5361 5362 5363<div style="margin: auto;"> 5364 <h4><a name="swap" id="swap"></a>-swap <em class="arg">index,index</em></h4> 5365</div> 5366 5367<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Swap the positions of two images in the image sequence.</td><td style='text-align:right;'></td></tr></table> 5368 5369<p>For example, <a href="#swap">-swap 0,2</a> swaps the first and the third 5370images in the current image sequence. Use <a href="#swap">+swap</a> to switch 5371the last two images in the sequence.</p> 5372 5373<div style="margin: auto;"> 5374 <h4><a name="swirl" id="swirl"></a>-swirl <em class="arg">degrees</em></h4> 5375</div> 5376 5377<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>swirl image pixels about the center.</td><td style='text-align:right;'></td></tr></table> 5378 5379<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p> 5380 5381<div style="margin: auto;"> 5382 <h4><a name="taint" id="taint"></a>-taint</h4> 5383</div> 5384 5385<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mark the image as modified even if it isn't.</td><td style='text-align:right;'></td></tr></table> 5386 5387<div style="margin: auto;"> 5388 <h4><a name="text-font" id="text-font"></a>-text-font <em class="arg">name</em></h4> 5389</div> 5390 5391<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>font for writing fixed-width text.</td><td style='text-align:right;'></td></tr></table> 5392 5393<p>Specifies the name of the preferred font to use in fixed (typewriter style) formatted text. The default is 14 point <em class="arg">Courier</em>.</p> 5394 5395<p>You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example, <kbd>Courier.ttf</kbd> is a TrueType font and <kbd>x:fixed</kbd> is OPTION1.</p> 5396 5397<div style="margin: auto;"> 5398 <h4><a name="texture" id="texture"></a>-texture <em class="arg">filename</em></h4> 5399</div> 5400 5401<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>name of texture to tile onto the image background.</td><td style='text-align:right;'></td></tr></table> 5402 5403<div style="margin: auto;"> 5404 <h4><a name="threshold" id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5405</div> 5406 5407<!-- {<em class="arg">green,blue,opacity</em>} 5408<p>If the green or blue value is omitted, these channels use the same value as the first one provided. If all three color values are the same, the result is a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used and any partially transparent pixel becomes fully transparent.</p> 5409--> 5410 5411<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply simultaneous black/white threshold to the image.</td><td style='text-align:right;'></td></tr></table> 5412 5413<p>Any pixel values (more specifically, those channels set using <a href="/www/command-line-options.html#channel">‑channel</a>) that exceed the specified threshold are reassigned the maximum channel value, while all other values are assigned the minimum.</p> 5414 5415<p> The threshold value can be given as a percentage or as an absolute integer value corresponding to the desired channel value. When given as an integer, the minimum attainable value is 0 (corresponding to black when all channels are affected), but the maximum value (corresponding to white) is that of the <kbd>quantum depth</kbd> of the particular build of ImageMagick, and is therefore dependent on the installation. For that reason, a reasonable recommendation for most applications is to specify the threshold values as a percentage. 5416</p> 5417 5418<p> The following would force pixels with red values above 50% to have 100% red values, while those at or below 50% red would be set to 0 in the red channel. The green, blue, and alpha channels (if present) would be unchanged. </p> 5419 5420<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p> 5421<p>As (possibly) impractical but instructive examples, the following would generate an all-black and an all-white image with the same dimensions as the input image.</p> 5422 5423 5424<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -threshold 100% black.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -threshold -1 white.png</span></p> 5425<p>Note that the values of the transparency channel is treated as 'matte' 5426values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 5427 5428<p> See also <a href="/www/command-line-options.html#black-threshold">‑black‑threshold</a> and <a href="/www/command-line-options.html#white-threshold">‑white‑threshold</a>. 5429</p> 5430 5431<div style="margin: auto;"> 5432 <h4><a name="thumbnail" id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4> 5433</div> 5434 5435<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Create a thumbnail of the image.</td><td style='text-align:right;'></td></tr></table> 5436 5437<p>This is similar to <a href="#resize">-resize</a>, except it is optimized for speed and any image profile, other than a color profile, is removed to reduce the thumbnail size. To strip the color profiles as well, add <a href="#strip">-strip</a> just before of after this option.</p> 5438 5439<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5440 5441<div style="margin: auto;"> 5442 <h4><a name="tile" id="tile"></a>-tile <em class="arg">filename</em></h4> 5443</div> 5444 5445<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the tile image used for filling a subsequent graphic primitive.</td><td style='text-align:right;'></td></tr></table> 5446 5447<div style="margin: auto;"> 5448 <h4>-tile <em class="arg">geometry</em></h4> 5449</div> 5450 5451<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the layout of images .</td><td style='text-align:right;'>[<a href="/www/montage.html">montage</a>]</td></tr></table> 5452 5453<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5454 5455<div style="margin: auto;"> 5456 <h4>-tile</h4> 5457</div> 5458 5459<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specifies that a subsequent composite operation is repeated across and down image.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5460 5461<div style="margin: auto;"> 5462 <h4><a name="tile-offset" id="tile-offset"></a>-tile-offset {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 5463</div> 5464 5465<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the offset for tile images, relative to the background image it is tiled on.</td><td style='text-align:right;'></td></tr></table> 5466 5467<p>This should be set before the tiling image is set by <a href="#tile" >-tile</a> or <a href="#texture" >-texture</a>, or directly applied for creating a tiled canvas using <kbd>TILE:</kbd> or <kbd>PATTERN:</kbd> input formats. </p> 5468 5469<p>Internally ImageMagick does a <a href="#roll" >-roll</a> of the tile image by the arguments given when the tile image is set. </p> 5470 5471<div style="margin: auto;"> 5472 <h4><a name="tint" id="tint"></a>-tint <em class="arg">value</em></h4> 5473</div> 5474 5475<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Tint the image with the fill color.</td><td style='text-align:right;'></td></tr></table> 5476 5477<p>Tint the image with the fill color.</p> 5478 5479<p>Specify the amount of tinting as a percentage. Pure colors like black, white red, yellow, will not be affected by -tint. Only mid-range colors such as the various shades of grey.</p> 5480 5481<div style="margin: auto;"> 5482 <h4><a name="title" id="title"></a>-title <em class="arg">string</em></h4> 5483</div> 5484 5485<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Assign a title to displayed image.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>, <a href="/www/montage.html">montage</a>]</td></tr></table> 5486 5487<p>Use this option to assign a specific title to the image. This assigned to the image window and is typically displayed in the window title bar. Optionally you can include the image filename, type, width, height, Exif data, or other image attribute by embedding special format characters described under the <a href="#format">-format</a> option.</p> 5488 5489<p>For example,</p> 5490 5491<p class="crtsnip"> 5492 -title "%m:%f %wx%h" 5493</p> 5494 5495<p>produces an image title of <kbd>MIFF:bird.miff 512x480</kbd> for an image titled <kbd>bird.miff</kbd> and whose width is 512 and height is 480.</p> 5496 5497 5498<div style="margin: auto;"> 5499 <h4><a name="transform" id="transform"></a>-transform</h4> 5500</div> 5501 5502<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>transform the image.</td><td style='text-align:right;'></td></tr></table> 5503 5504<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p> 5505 5506<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg</span></p> 5507 5508<p>This operator has been now been superseded by the <a 5509href="#distort">-distort</a> '<kbd>AffineProjection</kbd>' method. </p> 5510 5511 5512<div style="margin: auto;"> 5513 <h4><a name="transparent" id="transparent"></a>-transparent <em class="arg">color</em></h4> 5514</div> 5515 5516<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make this color transparent within the image.</td><td style='text-align:right;'></td></tr></table> 5517 5518<p>The <em class="arg">color</em> argument is defined using the format 5519described under the <a href="#fill">-fill</a> option. The <a href="#fuzz" 5520>-fuzz</a> setting can be used to match and replace colors similar to the one 5521given. </p> 5522 5523<p>Use <a href="#transparent" >+transparent</a> to invert the pixels matched. 5524that is make all non-matching colors transparent. </p> 5525 5526<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a 5527href="#transparent" >-transparent</a> but replaces the matching color with the 5528current <a href="#fill">-fill</a> color setting, rather than transparent. 5529However the <a href="#transparent" >-transparent</a> operator also ensures 5530that the image has an alpha channel enabled, as per "<kbd><a href="#alpha" 5531>-alpha</a> set</kbd>", and does not require you to modify the <a 5532href="#channel">-channel</a> to enable alpha channel handling. </p> 5533 5534<p>Note that this does not define the color as being the 'transparency color' 5535used for color-mapped image formats, such as GIF. For that use <a 5536href="#transparent-color" >-transparent-color</a> </p> 5537 5538 5539<div style="margin: auto;"> 5540 <h4><a name="transparent-color" id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4> 5541</div> 5542 5543<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the transparent color.</td><td style='text-align:right;'></td></tr></table> 5544 5545<p>Sometimes this is used for saving to image formats such as 5546GIF and PNG8 which uses this color to represent boolean transparency. This 5547does not make a color transparent, it only defines what color the transparent 5548color is in the color palette of the saved image. Use <a 5549href="#transparent">-transparent</a> to make an opaque color transparent.</p> 5550 5551<p>This option allows you to have both an opaque visible color, as well as a 5552transparent color of the same color value without conflict. That is, you can 5553use the same color for both the transparent and opaque color areas within an 5554image. This, in turn, frees to you to select a transparent color that is 5555appropriate when an image is displayed by an application that does not handle a 5556transparent color index, while allowing ImageMagick to correctly handle images of this 5557type. </p> 5558 5559<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p> 5560 5561<div style="margin: auto;"> 5562 <h4><a name="transpose" id="transpose"></a>-transpose</h4> 5563</div> 5564 5565<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mirror the image along the top-left to bottom-right diagonal.</td><td style='text-align:right;'></td></tr></table> 5566 5567<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>. 5568</p> 5569 5570<div style="margin: auto;"> 5571 <h4><a name="transverse" id="transverse"></a>-transverse</h4> 5572</div> 5573 5574<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mirror the image along the images bottom-left top-right diagonal. Equivalent to the operations <kbd>-flop -rotate 90</kbd>.</td><td style='text-align:right;'></td></tr></table> 5575 5576 5577<div style="margin: auto;"> 5578 <h4><a name="treedepth" id="treedepth"></a>-treedepth <em class="arg">value</em></h4> 5579</div> 5580 5581<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>tree depth for the color reduction algorithm.</td><td style='text-align:right;'></td></tr></table> 5582 5583<p>Normally, this integer value is zero or one. A value of zero or one causes the use of an optimal tree depth for the color reduction algorithm.</p> 5584 5585<p>An optimal depth generally allows the best representation of the source image with the fastest computational speed and the least amount of memory. However, the default depth is inappropriate for some images. To assure the best representation, try values between 2 and 8 for this parameter. Refer to the <a href="/www/quantize.html">color reduction algorithm</a> for more details.</p> 5586 5587<p>The <a href="#colors">-colors</a> or <a href="#monochrome">-monochrome</a> option, or writing to an image format which requires color reduction, is required for this option to take effect.</p> 5588 5589<div style="margin: auto;"> 5590 <h4><a name="trim" id="trim"></a>-trim</h4> 5591</div> 5592 5593<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>trim an image.</td><td style='text-align:right;'></td></tr></table> 5594 5595<p>This option removes any edges that are exactly the same color as the corner pixels. Use <a href="#fuzz">-fuzz</a> to make <a href="#trim">-trim</a> remove edges that are nearly the same color as the corner pixels.</p> 5596 5597<p>The page or virtual canvas information of the image is preserved allowing 5598you to extract the result of the <a href="#trim">-trim</a> operation from the 5599image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page 5600information if it is unwanted.</p> 5601 5602<p>If the trimmed image 'disappears' an warning is produced, and a special 5603single pixel transparent 'missed' image is returned, in the same way as when a 5604<a href="#crop">-crop</a> operation 'misses' the image proper. </p> 5605 5606 5607<div style="margin: auto;"> 5608 <h4><a name="type" id="type"></a>-type <em class="arg">type</em></h4> 5609</div> 5610 5611<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the image type.</td><td style='text-align:right;'></td></tr></table> 5612 <p>Choose from: <kbd>Bilevel</kbd>, <kbd>Grayscale</kbd>, <kbd>GrayscaleMatte</kbd>, <kbd>Palette</kbd>, <kbd>PaletteMatte</kbd>, <kbd>TrueColor</kbd>, <kbd>TrueColorMatte</kbd>, <kbd>ColorSeparation</kbd>, <kbd>ColorSeparationMatte</kbd>, or <kbd>Optimize</kbd>.</p> 5613 5614<p>Normally, when a format supports different subformats such as grayscale and truecolor, the encoder will try to choose an efficient subformat. The <a href="#type">-type</a> option can be used to overrride this behavior. For example, to prevent a JPEG from being written in grayscale format even though only gray pixels are present, use.</p> 5615 5616<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p> 5617<p>Similarly, use <a href="#type">-type TrueColorMatte</a> to force the encoder to write an alpha channel even though the image is opaque, if the output format supports transparency.</p> 5618 5619<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p> 5620 5621<div style="margin: auto;"> 5622 <h4><a name="undercolor" id="undercolor"></a>-undercolor <em class="arg">color</em></h4> 5623</div> 5624 5625<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the color of the annotation bounding box.</td><td style='text-align:right;'></td></tr></table> 5626 5627<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5628 5629<p>See <a href="#draw">-draw</a> for further details.</p> 5630 5631 5632<div style="margin: auto;"> 5633 <h4><a name="update" id="update"></a>-update <em class="arg">seconds</em></h4> 5634</div> 5635 5636<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>detect when image file is modified and redisplay.</td><td style='text-align:right;'></td></tr></table> 5637 5638<p>Suppose that while you are displaying an image the file that is currently displayed is over-written. <kbd>display</kbd> will automagically detect that the input file has been changed and update the displayed image accordingly.</p> 5639 5640 5641<div style="margin: auto;"> 5642 <h4><a name="unique-colors" id="unique-colors"></a>-unique-colors</h4> 5643</div> 5644 5645<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>discard all but one of any pixel color.</td><td style='text-align:right;'></td></tr></table> 5646 5647 5648<div style="margin: auto;"> 5649 <h4><a name="units" id="units"></a>-units <em class="arg">type</em></h4> 5650</div> 5651 5652<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the units of image resolution.</td><td style='text-align:right;'></td></tr></table> 5653 5654<p>Choose from: <kbd>Undefined</kbd>, <kbd>PixelsPerInch</kbd>, or <kbd>PixelsPerCentimeter</kbd>. This option is normally used in conjunction with the <a href="#density">-density</a> option.</p> 5655 5656 5657<div style="margin: auto;"> 5658 <h4><a name="unsharp" id="unsharp"></a>-unsharp <em class="arg">radius</em><br />-unsharp <em class="arg">radius</em>x<em class="arg">sigma</em>{<em class="arg">+amount</em>}{<em class="arg">+threshold</em>}</h4> 5659</div> 5660 5661<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sharpen the image with an unsharp mask operator.</td><td style='text-align:right;'></td></tr></table> 5662 5663<p>The <a href="#unsharp">-unsharp</a> option sharpens an image. The image is convolved with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.</p> 5664 5665<p>The parameters are:</p> 5666 5667<pre class="text"> 5668 radius: The radius of the Gaussian, in pixels, not counting the center 5669 pixel (default 0). 5670 sigma: The standard deviation of the Gaussian, in pixels (default 1.0). 5671 amount: The fraction of the difference between the original and the blur 5672 image that is added back into the original (default 1.0). 5673 threshold: The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the 5674 difference amount (default 0.05). 5675</pre> 5676 5677 5678<div style="margin: auto;"> 5679 <h4><a name="verbose" id="verbose"></a>-verbose</h4> 5680</div> 5681 5682<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print detailed information about the image when this option precedes the <a href="#identify">-identify</a> option or <kbd>info:</kbd>.</td><td style='text-align:right;'></td></tr></table> 5683 5684 5685<div style="margin: auto;"> 5686 <h4><a name="version" id="version"></a>-version</h4> 5687</div> 5688 5689<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print ImageMagick version string and exit.</td><td style='text-align:right;'></td></tr></table> 5690 5691 5692<div style="margin: auto;"> 5693 <h4><a name="view" id="view"></a>-view <em class="arg">string</em></h4> 5694</div> 5695 5696<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>FlashPix viewing parameters.</td><td style='text-align:right;'></td></tr></table> 5697 5698 5699<div style="margin: auto;"> 5700 <h4><a name="vignette" id="vignette"></a>-vignette <em class="arg">radius</em>{x<em class="arg">sigma</em>}{<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em>{<em class="arg">%</em>}</h4> 5701</div> 5702 5703<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>soften the edges of the image in vignette style.</td><td style='text-align:right;'></td></tr></table> 5704 5705 5706<div style="margin: auto;"> 5707 <h4><a name="virtual-pixel" id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4> 5708</div> 5709 5710<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify contents of <em>virtual pixels</em>.</td><td style='text-align:right;'></td></tr></table> 5711 5712<p>This option defines what color source should be used if and when a color 5713lookup completely 'misses' the source image. The color(s) that appear to 5714surround the source image. Generally this color is derived from the source 5715image, but could also be set to a specify background color. </p> 5716 5717<p>Choose from these methods:</p> 5718 5719<pre class="text"> 5720 background: the area surrounding the image is the background color 5721 black: the area surrounding the image is black 5722 checker-tile: alternate squares with image and background color 5723 dither: non-random 32x32 dithered pattern 5724 edge: extend the edge pixel toward infinity 5725 gray: the area surrounding the image is gray 5726 horizontal-tile: horizontally tile the image, background color above/below 5727 horizontal-tile-edge: horizontally tile the image and replicate the side edge pixels 5728 mirror: mirror tile the image 5729 random: choose a random pixel from the image 5730 tile: tile the image (default) 5731 transparent: the area surrounding the image is transparent blackness 5732 vertical-tile: vertically tile the image, sides are background color 5733 vertical-tile-edge: vertically tile the image and replicate the side edge pixels 5734 white: the area surrounding the image is white 5735</pre> 5736 5737<p>The default value is "edge".</p> 5738 5739<p>This most important for distortion operators such as <a href="#distort" 5740>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>. 5741However it also effects operations that may access pixels just outside the 5742image proper, such as <a href="#convolve">-convolve</a>, <a 5743href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p> 5744 5745<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p> 5746 5747 5748<div style="margin: auto;"> 5749 <h4><a name="visual" id="visual"></a>-visual <em class="arg">type</em></h4> 5750</div> 5751 5752<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Animate images using this X visual type.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 5753 5754<p>Choose from these visual classes:</p> 5755 5756<pre class="text"> 5757 StaticGray 5758 GrayScale 5759 StaticColor 5760 PseudoColor 5761 TrueColor 5762 DirectColor 5763 default 5764 visual id 5765</pre> 5766 5767<p>The X server must support the visual you choose, otherwise an error occurs. If a visual is not specified, the visual class that can display the most simultaneous colors on the default screen is chosen.</p> 5768 5769 5770<div style="margin: auto;"> 5771 <h4><a name="watermark" id="watermark"></a>-watermark <em 5772 class="arg">brightness</em>x<em class="arg">saturation</em></h4> 5773</div> 5774 5775<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Watermark an image using the given percentages of brightness and 5776saturation.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5777 5778<p>Take a grayscale image (with alpha mask) and modify the destination image's 5779brightness according to watermark image's grayscale value and the <em 5780class="arg">brightness</em> percentage. The destinations color saturation 5781attribute is just direct modified by the <em class="arg">saturation</em> 5782percentage, which defaults to 100 percent (no color change). </p> 5783 5784 5785<div style="margin: auto;"> 5786 <h4><a name="wave" id="wave"></a>-wave <em class="arg">amplitude</em><br />-wave <em class="arg">amplitude</em>x<em class="arg">wavelength</em></h4> 5787</div> 5788 5789<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shear the columns of an image into a sine wave.</td><td style='text-align:right;'></td></tr></table> 5790 5791<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p> 5792 5793<div style="margin: auto;"> 5794 <h4><a name="weight" id="weight"></a>-weight <em class="arg">fontWeight</em></h4> 5795</div> 5796 5797<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font weight for text.</td><td style='text-align:right;'></td></tr></table> 5798 5799<p>This setting suggests a font weight that ImageMagick should try to apply to the currently selected font family. Use a positive integer for <em class="arg">fontWeight</em> or select from the following.</p> 5800 5801<table class="doc"> 5802 <col width="25%" /> 5803 <col width="75%" /> 5804 <thead> 5805 <tr> 5806 <th><em class="arg">fontWeight</em></th> 5807 <th>Description</th> 5808 </tr> 5809 </thead> 5810 <tbody> 5811 <tr><td>All </td> <td>No effect. </td></tr> 5812 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr> 5813 <tr><td>Bolder </td> <td>Add 100 to font weight if currently ≤ 800.</td></tr> 5814 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently ≤ 100.</td></tr> 5815 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr> 5816 </tbody> 5817 </table> 5818 5819<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p> 5820 5821<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, and <a href="#style">-style</a>. </p> 5822 5823<div style="margin: auto;"> 5824 <h4><a name="white-point" id="white-point"></a>-white-point <em class="arg">x,y</em></h4> 5825</div> 5826 5827<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>chromaticity white point.</td><td style='text-align:right;'></td></tr></table> 5828 5829<div style="margin: auto;"> 5830 <h4><a name="white-threshold" id="white-threshold"></a>-white-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5831</div> 5832 5833<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</td><td style='text-align:right;'></td></tr></table> 5834 5835<p> The threshold value can be given as a percentage or as an absolute integer value within [0, <em class="QR">QuantumRange</em>] corresponding to the desired <a href="/www/command-line-options.html#channel">‑channel</a> value. See <a href="/www/command-line-options.html#threshold">‑threshold</a> for more details on thresholds and resulting values. 5836</p> 5837 5838<div style="margin: auto;"> 5839 <h4><a name="window" id="window"></a>-window <em class="arg">id</em></h4> 5840</div> 5841 5842<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make the image the background of a window.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 5843 5844<p><em class="arg">id</em> can be a window id or name. Specify <kbd>root</kbd> to select X's root window as the target window.</p> 5845 5846<p>By default the image is tiled onto the background of the target window. If <kbd>backdrop</kbd> or <a href="#geometry">-resize</a> are specified, the image is surrounded by the background color. Refer to <kbd>X RESOURCES</kbd> for details.</p> 5847 5848<p>The image will not display on the root window if the image has more unique colors than the target window colormap allows. Use <a href="#colors">-colors</a> to reduce the number of colors.</p> 5849 5850<div style="margin: auto;"> 5851 <h4><a name="window-group" id="window-group"></a>-window-group</h4> 5852</div> 5853 5854<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the window group.</td><td style='text-align:right;'></td></tr></table> 5855 5856<div style="margin: auto;"> 5857 <h4><a name="write" id="write"></a>-write <em class="arg">filename</em></h4> 5858</div> 5859 5860<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>write an image sequence.</td><td style='text-align:right;'></td></tr></table> 5861 <p>The image sequence preceding the <a href="#write">-write</a> <em class="arg">filename</em> 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="#write">+write</a> <em class="arg">filename</em> option.</p> 5862 5863<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p> 5864 5865 5866</div> 5867 5868<div id="linkbar"> 5869 <span id="linkbar-west"> </span> 5870 <span id="linkbar-center"> 5871 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> • 5872 <a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi">Studio</a> 5873 </span> 5874 <span id="linkbar-east"> </span> 5875 </div> 5876 <div class="footer"> 5877 <span id="footer-west">© 1999-2010 ImageMagick Studio LLC</span> 5878 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span> 5879 </div> 5880 <div style="clear: both; margin: 0; width: 100%; "></div> 5881 <script type="text/javascript"> 5882 var _gaq = _gaq || []; 5883 _gaq.push(['_setAccount', 'UA-17690367-1']); 5884 _gaq.push(['_trackPageview']); 5885 5886 (function() { 5887 var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; 5888 ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; 5889 var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); 5890 })(); 5891 </script> 5892</body> 5893</html> 5894
