command-line-options.html revision bf126f7596e112266716c6ca94a8ff638a7c4400
1 2 3 4 5<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" 6 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> 7<html version="-//W3C//DTD XHTML 1.1//EN" 8 xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" 9 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 10 xsi:schemaLocation="http://www.w3.org/1999/xhtml 11 http://www.w3.org/MarkUp/SCHEMA/xhtml11.xsd"> 12<head> 13 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> 14 <meta name="verify-v1" content="g222frIIxcQTrvDR3NBRUSKP3AnMNoqxOkIniCEkV7U="/> 15 <title>ImageMagick: Command-line Options</title> 16 <meta http-equiv="Content-Language" content="en-US"/> 17 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> 18 <meta http-equiv="Reply-to" content="magick-users@imagemagick.org"/> 19 <meta name="Application-name" content="ImageMagick"/> 20 <meta name="Description" content="Use ImageMagick to convert, edit, or compose bitmap images in a variety of formats. In addition resize, rotate, shear, distort and transform images."/> 21 <meta name="Application-url" content="http://www.imagemagick.org"/> 22 <meta name="Generator" content="PHP"/> 23 <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"/> 24 <meta name="Rating" content="GENERAL"/> 25 <meta name="Robots" content="INDEX, FOLLOW"/> 26 <meta name="Generator" content="ImageMagick Studio LLC"/> 27 <meta name="Author" content="ImageMagick Studio LLC"/> 28 <meta name="Revisit-after" content="2 DAYS"/> 29 <meta name="Resource-type" content="document"/> 30 <meta name="Copyright" content="Copyright (c) 1999-2011 ImageMagick Studio LLC"/> 31 <meta name="Distribution" content="Global"/> 32 <link rel="icon" href="/images/wand.png"/> 33 <link rel="shortcut icon" href="/images/wand.ico" type="images/x-icon"/> 34 <link rel="meta" type="application/rdf+xml" title="ICI" href="http://imagemagick.org/ici.rdf"/> 35 <link rel="stylesheet" href="http://www.google.com/cse/style/look/default.css" type="text/css" /> 36 <style type="text/css" media="all"> 37 @import url("/www/magick.css"); 38 </style> 39 <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script> 40 <script type="text/javascript" src="/fancybox/jquery.fancybox-1.3.4.pack.js"></script> 41 <link rel="stylesheet" type="text/css" href="/fancybox/jquery.fancybox-1.3.4.css" media="screen" /> 42 <script type="text/javascript"> 43 $(document).ready(function() { 44 $("a[href$=.jpg],a[href$=.png],a[href$=.gif]").fancybox({ 45 'transitionIn' : 'elastic', 46 'transitionOut' : 'elastic', 47 'overlayShow' : false, 48 'opacity' : true 49 }); 50 }); 51 </script> 52</head> 53 54<body id="www-imagemagick-org"> 55<div class="titlebar"> 56<div style="margin: 17px auto; float: left;"> 57 <script type="text/javascript"> 58 <!-- 59 google_ad_client = "pub-3129977114552745"; 60 google_ad_slot = "5439289906"; 61 google_ad_width = 728; 62 google_ad_height = 90; 63 //--> 64 </script> 65 <script type="text/javascript" 66 src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> 67 </script> 68</div> 69<a href="http://www.imagemagick.org/discourse-server/"> 70 <img src="/images/logo.jpg" 71 alt="ImageMagick Logo" 72 style="width: 123px; height: 118px; border: 0px; float: right;" /></a> 73<a href="/index.html"> 74 <img src="/images/sprite.jpg" 75 alt="ImageMagick Sprite" 76 style="width: 114px; height: 118px; border: 0px; float: right;" /></a> 77</div> 78 79<div class="westbar"> 80 81<div class="menu"> 82 <a title="About ImageMagick" href="/index.html">About ImageMagick</a> 83</div> 84<div class="sep"></div> 85<div class="menu"> 86 <a title="Binary Releases" href="/www/binary-releases.html">Binary Releases</a> 87</div> 88<div class="sub"> 89 <a title="Binary Release: Unix" href="/www/binary-releases.html#unix">Unix</a> 90</div> 91<div class="sub"> 92 <a title="Binary Release: MacOS X" href="/www/binary-releases.html#macosx">Mac OS X</a> 93</div> 94<div class="sub"> 95 <a title="Binary Release: iPhone" href="/www/binary-releases.html#iPhone">iPhone</a> 96</div> 97<div class="sub"> 98 <a title="Binary Release: Windows" href="/www/binary-releases.html#windows">Windows</a> 99</div> 100<div class="sep"></div> 101<div class="menu"> 102 <a title="Command-line Tools" href="/www/command-line-tools.html">Command-line Tools</a> 103</div> 104<div class="sub"> 105 <a title="Command-line Tools: Processing" href="/www/command-line-processing.html">Processing</a> 106</div> 107<div class="sub"> 108 <a title="Command-line Tools: Options" href="/www/command-line-options.html">Options</a> 109</div> 110<div class="sub"> 111 <a title="Command-line Tools: Usage" href="http://www.imagemagick.org/Usage/">Usage</a> 112</div> 113<div class="menu"> 114 <a title="Program Interfaces" href="/www/api.html">Program Interfaces</a> 115</div> 116<div class="sub"> 117 <a title="Program Interface: MagickWand" href="/www/magick-wand.html">MagickWand</a> 118</div> 119<div class="sub"> 120 <a title="Program Interface: MagickCore" href="/www/magick-core.html">MagickCore</a> 121</div> 122<div class="sub"> 123 <a title="Program Interface: PerlMagick" href="/www/perl-magick.html">PerlMagick</a> 124</div> 125<div class="sub"> 126 <a title="Program Interface: Magick++" href="/www/magick++.html">Magick++</a> 127</div> 128<div class="sep"></div> 129<div class="menu"> 130 <a title="Install from Source" href="/www/install-source.html">Install from Source</a> 131</div> 132<div class="sub"> 133 <a title="Install from Source: Unix" href="/www/install-source.html#unix">Unix</a> 134</div> 135<div class="sub"> 136 <a title="Install from Source: Windows" href="/www/install-source.html#windows">Windows</a> 137 </div> 138<div class="menu"> 139 <a title="Resources" href="/www/resources.html">Resources</a> 140</div> 141<div class="menu"> 142 <a title="Architecture" href="/www/architecture.html">Architecture</a> 143</div> 144<div class="menu"> 145 <a title="Download" href="/www/download.html">Download</a> 146</div> 147<div class="sep"></div> 148<div class="menu"> 149 <a title="Search" href="/www/search.html">Search</a> 150</div> 151<div class="sep"></div> 152<div class="menu"> 153 <a title="Site Map" href="/www/sitemap.html">Site Map</a> 154</div> 155<div class="sub"> 156 <a title="Site Map: Links" href="/www/links.html">Links</a> 157</div> 158<div class="sep"></div> 159<div class="menu"> 160 <a rel="follow" title="Sponsors" href="/www/sponsors.html">Sponsors:</a> 161 162<a href="http://www.networkredux.com"> 163 <img src="/images/networkredux.png" alt="[sponsor]" 164 style="margin-top: 4px; margin-left: 4px; border: 0px; float: left;" /></a> 165<div class="sponsbox"> 166<div class="sponsor"> 167 <a rel="follow" title="Sponsor: Web Hosting Break" href="http://www.webhostingbreak.com">Web Hosting Break</a><!-- 201109010090 ian@ian-m... --> 168</div> 169<div class="sponsor"> 170 <a rel="follow" title="Sponsor: Druckerei" href="http://www.allesdruck.de">Druckerei</a><!-- 201303011500 r.leo --> 171</div> 172<div class="sponsor"> 173 <a rel="follow" title="Sponsor: Website Hosting" href="http://www.hostreviewgeeks.com">Website Hosting</a><!-- 201110010090 alexanian media --> 174</div> 175<div class="sponsor"> 176 <a rel="follow" title="Sponsor: Hotel München" href="http://www.messehotel-erb-muenchen.de">Hotel München</a><!-- 201111010450 cerb --> 177</div> 178<div class="sponsor"> 179 <a rel="follow" title="Sponsor: Best Web Hosting" href="http://webhostinggeeks.com">Best Web Hosting</a><!-- 201110010720 --> 180</div> 181<div class="sponsor"> 182 <a rel="follow" title="Sponsor: Flyer drucken" href="http://www.online-druck.biz">Flyer drucken</a><!-- 201109010900 Floeter--> 183</div> 184<div class="sponsor"> 185 <a rel="follow" title="Sponsor: Web Hosting Reviews" href="http://www.webhostingmasters.com">Web Hosting Reviews</a><!-- 201107011500 affliatelabel --> 186</div> 187<div class="sponsor"> 188 <a rel="follow" title="Sponsor: Druckerei" href="http://print24.com/de/">Druckerei</a><!-- 201110010720 --> 189</div> 190<div class="sponsor"> 191 <a rel="follow" title="Sponsor: Web Hosting Ratings" href="http://webhostingrating.com">Web Hosting Ratings</a><!-- 201110010720 --> 192</div> 193<div class="sponsor"> 194 <a rel="follow" title="Sponsor: alaTest.com" href="http://alatest.com">alaTest.com</a><!-- 20110801000300 --> 195</div> 196</div> 197</div> 198</div> 199 200<div class="eastbar"> 201 202</div> 203 204<div class="main"> 205 206<h1>Create, Edit, or Compose Bitmap Images With These Command-line Options</h1> 207<p class="navigation-index"> 208[ <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#black-point-compensation">‑black‑point‑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#duplicate">‑duplicate</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#smush">‑smush</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#statistic">‑statistic</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#synchronize">‑synchronize</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> 209 210<div class="doc-section"> 211 212<p>Below is list of command-line options recognized by the ImageMagick <a 213href="/www/command-line-tools.html">command-line 214tools</a>. If you want a description of a particular option, click on the 215option name in the navigation bar above and you will go right to it. Unless 216otherwise noted, each option is recognized by the commands <a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>.</p> 217 218<div style="margin: auto;"> 219 <h4><a id="adaptive-blur"></a>-adaptive-blur <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 220</div> 221 222<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> 223<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> 224 225<div style="margin: auto;"> 226 <h4><a id="adaptive-resize"></a>-adaptive-resize <em class="arg">geometry</em></h4> 227</div> 228 229<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> 230 231<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> 232 233<div style="margin: auto;"> 234 <h4><a id="adaptive-sharpen"></a>-adaptive-sharpen <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 235</div> 236 237<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> 238 239<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> 240 241<div style="margin: auto;"> 242 <h4><a id="adjoin"></a>-adjoin</h4> 243</div> 244 245<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> 246 247<p>This option is enabled by default. An attempt is made to save all images of 248an image sequence into the given output file. However, some formats, such as 249JPEG and PNG, do not support more than one image per file, and in that case 250ImageMagick is forced to write each image as a separate file. As such, if 251more than one image needs to be written, the filename given is modified by 252adding a <a href="#scene">-scene</a> number before the suffix, in order to 253make distinct names for each image. </p> 254 255<p>Use <a href="#adjoin">+adjoin</a> to force each image to be written to 256separate files, whether or not the file format allows multiple images per file 257(for example, GIF, MIFF, and TIFF). </p> 258 259<p>Including a C-style integer format string in the output filename will 260automagically enable <a href="#adjoin">+adjoin</a> and are used to specify 261where the <a href="#scene">-scene</a> number is placed in the filenames. These 262strings, such as '<kbd>%d</kbd>' or '<kbd>%03d</kbd>', are familiar to those 263who have used the standard <kbd>printf()</kbd>' C-library function. As an 264example, the command</p> 265 266<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: rose: -morph 15 my%02dmorph.jpg</span></p> 267<p>will create a sequence of 17 images (the two given plus 15 more created by 268<a href="#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg, 269my02morph.jpg, ..., my16morph.jpg. </p> 270 271<p>In summary, ImageMagick tries to write all images to one file, but will 272save to multiple files, if any of the following conditions exist... 273<ol> 274<li>the output image's file format does not allow multi-image files, 275<li>the <a href="#adjoin">+adjoin</a> option is given, or 276<li>a printf() integer format string (eg: "%d") is present in the output 277 filename. 278</ol></p> 279 280 281<div style="margin: auto;"> 282 <h4><a id="affine"></a>-affine 283 <em class="arg">s<sub>x</sub></em>,<em class="arg">r<sub>x</sub></em>,<em 284 class="arg">r<sub>y</sub></em>,<em class="arg">s<sub>y</sub></em>[,<em 285 class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em>]</h4> 286</div> 287 288<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> 289 290<p>This option sets a transformation matrix, for use by subsequent <a 291href="#draw">-draw</a> or <a href="#transform">-transform</a> options. </p> 292 293<p>The matrix entries are entered as comma-separated numeric values either in 294quotes or without spaces. </p> 295 296<p>Internally, the transformation matrix has 3x3 elements, but three of them 297are omitted from the input because they are constant. The new (transformed) 298coordinates (<em class="arg">x'</em>, <em class="arg">y'</em>) of a pixel at 299position (<em class="arg">x</em>, <em class="arg">y</em>) in the original 300image are calculated using the following matrix equation.</p> 301 302<div class="eqn"> 303<img alt="affine transformation" src="/images/affine.png"/> 304</div> 305 306<p> The size of the resulting image is that of the smallest rectangle that 307contains the transformed source image. The parameters <em 308class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> 309subsequently shift the image pixels so that those that are moved out of the 310image area are cut off.</p> 311 312<p>The transformation matrix complies with the left-handed pixel coordinate 313system: positive <em class="arg">x</em> and <em class="arg">y</em> directions 314are rightward and downward, resp.; positive rotation is clockwise.</p> 315 316<p> If the translation coefficients <em class="arg">t<sub>x</sub></em> and <em 317class="arg">t<sub>y</sub></em> are omotted they default to 0,0. Therefore, 318four parameters suffice for rotation and scaling without translation.</p> 319 320<p>Scaling by the factors <em class="arg">s<sub>x</sub></em> and <em 321class="arg">s<sub>y</sub></em> in the <em>x</em> and <em>y</em> directions, 322respectively, is accomplished with the following.</p> 323 324<p>See <a href="#transform">-transform</a>, and the <a 325href="#distort">-distort</a> method '<kbd>Affineprojection</kbd> for more 326information </p> 327 328 329<p class="crtsnip"> 330 -affine <em class="arg">s<sub>x</sub></em>,0,0,<em class="arg">s<sub>y</sub></em> 331</p> 332 333<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> 334 335<p class="crtsnip"> 336 -affine 1,0,0,1,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em> 337</p> 338 339<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle <em>a</em> by letting 340<em>c</em> = cos(<em>a</em>), <em>s</em> = sin(<em>a</em>), and using the following.</p> 341 342<p class="crtsnip"> 343 -affine <em>c</em>,<em>s</em>,-<em>s</em>,<em>c</em> 344</p> 345 346<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> 347 348<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> 349 350<div style="margin: auto;"> 351 <h4><a id="alpha"></a>-alpha <em class="arg">type</em></h4> 352</div> 353 354<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> 355 356<p>Used to set a flag on an image indicating whether or not to use existing alpha 357channel 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> 358 359 360<table class="doc"> 361 <tbody> 362 <tr valign="top"> 363 <th align="left" style="width: 8%">type</th> 364 <th align="left">Description</th> 365 </tr> 366 367 <tr valign="top"> 368 <td valign="top"><kbd>Activate</kbd> or <kbd>On</kbd></td> 369 <td valign="top"> 370 Enable the image's transparency channel. Note normally <kbd>Set</kbd> 371 should be used instead of this, unless you specifically need to 372 preserve existing (but specifically turned <kbd>Off</kbd>) transparency 373 channel. </td></tr> 374 375 <tr valign="top"> 376 <td valign="top"><kbd>Deactivate</kbd> or <kbd>Off</kbd></td> 377 <td valign="top"> 378 Disables the image's transparency channel. Does not delete or change the 379 existing data, just turns off the use of that data.</td></tr> 380 381 <tr valign="top"> 382 <td valign="top"><kbd>Set</kbd></td> 383 <td valign="top"> 384 Activates the alpha/matte channel. If it was previously turned off 385 then it also resets the channel to opaque. If the image already had 386 the alpha channel turned on, it will have no effect.</td></tr> 387 388 <tr valign="top"> 389 <td valign="top"><kbd>Opaque</kbd></td> 390 <td valign="top"> 391 Enables the alpha/matte channel and forces it to be fully opaque. 392 </td></tr> 393 394 <tr valign="top"> 395 <td valign="top"><kbd>Transparent</kbd></td> 396 <td valign="top"> 397 Activates the alpha/matte channel and forces it to be fully 398 transparent. This effectively creates a fully transparent image the 399 same size as the original and with all its original RGB data still 400 intact, but fully transparent. </td></tr> 401 402 <tr valign="top"> 403 <td valign="top"><kbd>Extract</kbd></td> 404 <td valign="top"> 405 Copies the alpha channel values into all the color channels and turns 406 '<kbd>Off</kbd>' the the image's transparency, so as to generate 407 a gray-scale mask of the image's shape. The alpha channel data is left 408 intact just deactivated. This is the inverse of '<kbd>Copy</kbd>'. 409 </td></tr> 410 411 <tr valign="top"> 412 <td valign="top"><kbd>Copy</kbd></td> 413 <td valign="top"> 414 Turns '<kbd>On</kbd>' the alpha/matte channel, then copies the 415 gray-scale intensity of the image, into the alpha channel, converting 416 a gray-scale mask into a transparent shaped mask ready to be colored 417 appropriately. The color channels are not modified. </td></tr> 418 419 <tr valign="top"> 420 <td valign="top"><kbd>Shape</kbd></td> 421 <td valign="top"> 422 As per '<kbd>Copy</kbd>' but also colors the resulting shape mask with 423 the current background color. That is the RGB color channels is 424 replaced, with appropriate alpha shape. 425 </td></tr> 426 427 <tr valign="top"> 428 <td valign="top"><kbd>Background</kbd></td> 429 <td valign="top"> 430 Set any fully-transparent pixel to the background color, while leaving 431 it fully-transparent. This can make some image file formats, such as 432 PNG, smaller as the RGB values of transparent pixels are more uniform, 433 and thus can compress better. 434 </td></tr> 435 </tbody> 436</table> 437 438<p>Note that while the <a href="#matte" >+matte</a> operation is the same as 439"<kbd><a href="#alpha" >-alpha</a> Off</kbd>", the <a href="#matte" 440>-matte</a> operation is the same as "<kbd><a href="#alpha" >-alpha</a> 441Set</kbd>" and not "<kbd><a href="#alpha" >-alpha</a> On</kbd>". </p> 442 443 444<div style="margin: auto;"> 445 <h4><a id="annotate"></a> 446 -annotate <em class="arg">degrees</em> <em class="arg">text</em><br /> 447 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> <em class="arg">text</em><br /> 448 -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> 449</div> 450 451<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> 452 453<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> 454 455 456<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> 457 458<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> 459 460<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> 461<div class="eqn"><img alt="annotate transformation" src="/images/annotate.png"/></div> 462 463<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> 464 465<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> 466 467<div style="margin: auto;"> 468 <h4><a id="antialias"></a>-antialias</h4> 469</div> 470 471<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 472drawing fonts and lines.</td><td style='text-align:right;'></td></tr></table> 473 474<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when 475drawn. Use <a href="#antialias">+antialias</a> to disable the addition of 476antialiasing edge pixels. This will then reduce the number of colors added to 477an image to just the colors being directly drawn. That is, no mixed colors 478are added when drawing such objects. </p> 479 480<div style="margin: auto;"> 481 <h4><a id="append"></a>-append</h4> 482</div> 483 484<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> 485 486<p>This option creates a single longer image image, by joining all the current 487images in sequence top-to-bottom. Use <a href="#append">+append</a> to 488stack images left-to-right. </p> 489 490<p>If they are not of the same width, narrower images are padded with the 491current <a href="#background">-background</a> color setting, and their 492position relative to each other can be controlled by the current <a 493href="#gravity">-gravity</a> setting. </p> 494 495 496<div style="margin: auto;"> 497 <h4><a id="attenuate"></a>-attenuate <em class="arg">value</em></h4> 498</div> 499 500<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> 501 502 503<div style="margin: auto;"> 504 <h4><a id="authenticate"></a>-authenticate <em class="arg">password</em></h4> 505</div> 506 507<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> 508 509<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> 510 511<p>For a different encryption method, see <a href="#encipher">-encipher</a> and <a href="#decipher">-decipher</a>. </p> 512 513 514 515<div style="margin: auto;"> 516 <h4><a id="auto-gamma"></a>-auto-gamma</h4> 517</div> 518 519<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> 520 521<p>This calculates the mean values of an image, then applies a calculated <a 522href="#gamma" >-gamma</a> adjustment so that is the mean color exists in the 523image it will get a have a value of 50%. </p> 524 525<p>This means that any solid 'gray' image becomes 50% gray. </p> 526 527<p>This works well for real-life images with little or no extreme dark and 528light areas, but tend to fail for images with large amounts of bright sky or 529dark shadows. It also does not work well for diagrams or cartoon like images. 530</p> 531 532<p>It uses the <a href="#channel" >-channel</a> setting, (including the 533'<em>sync</em>' flag for channel syncronization), to determine which color 534values is used and modified. As the default <a href="#channel" 535>-channel</a> setting is '<em>RGB,sync</em>', channels are modified 536together by the same gamma value, preserving colors. </p> 537 538 539 540<div style="margin: auto;"> 541 <h4><a id="auto-level"></a>-auto-level</h4> 542</div> 543 544<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> 545 546<p>This is a 'perfect' image normalization operator. It finds the exact 547minimum and maximum color values in the image and then applies a <a 548href="#level" >-level</a> operator to stretch the values to the full range of 549values. </p> 550 551<p>The operator is not typically used for real-life images, image scans, or 552JPEG format images, as a single 'out-rider' pixel can set a bad min/max values 553for the <a href="#level" >-level</a> operation. On the other hand it is the 554right operator to use for color stretching gradient images being used to 555generate Color lookup tables, distortion maps, or other 'mathematically' 556defined images. </p> 557 558<p>The operator is very similar to the <a href="#normalize">-normalize</a>, <a 559href="#contrast-stretch" >-contrast-stretch</a>, and <a href="#linear-stretch" 560>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping' 561problems that these operators may have. That is <a href="#auto-level" 562>-auto-level</a> is the perfect or ideal version these operators. </p> 563 564<p>It uses the <a href="#channel" >-channel</a> setting, (including the 565special '<em>sync</em>' flag for channel syncronization), to determine 566which color values are used and modified. As the default <a 567href="#channel" >+channel</a> setting is '<em>RGB,sync</em>', the 568'<em>sync</em>' ensures that the color channels will are modified 569together by the same gamma value, preserving colors, and ignoring 570transparency. </p> 571 572 573<div style="margin: auto;"> 574 <h4><a id="auto-orient"></a>-auto-orient</h4> 575</div> 576 577<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> 578 579<p>This operator reads and resets the EXIF image profile setting 'Orientation' 580and then performs the appropriate 90 degree rotation on the image to orient 581the image, for correct viewing. </p> 582 583<p>This EXIF profile setting is usually set using a gravity sensor in digital 584camara, however photos taken directly downward or upward may not have an 585appropriate value. Also images that have been orientation 'corrected' without 586reseting this setting, may be 'corrected' again resulting in a incorrect 587result. If the he EXIF profile was previously stripped, the <a 588href="#auto-orient" >-auto-orient</a> operator will do nothing. </p> 589 590 591<div style="margin: auto;"> 592 <h4><a id="average"></a>-average</h4> 593</div> 594 595<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> 596 597<p>An error results if the images are not identically sized.</p> 598 599 600<div style="margin: auto;"> 601 <h4><a id="backdrop"></a>-backdrop</h4> 602</div> 603 604<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> 605 606<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> 607 608<div style="margin: auto;"> 609 <h4><a id="background"></a>-background <em class="arg">color</em></h4> 610</div> 611 612<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> 613 614<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> 615 616<div style="margin: auto;"> 617 <h4><a id="bench"></a>-bench <em class="arg">iterations</em></h4> 618</div> 619 620<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> 621 622<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> 623 624<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> 625<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> 626 627<div style="margin: auto;"> 628 <h4><a id="bias"></a>-bias <em class="arg">value</em>{<em class="arg">%</em>}</h4> 629</div> 630 631<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> 632 633<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> 634 635<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> 636 637<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 638negative results without clipping to the color value range 639(0..QuantumRange).</p> 640 641<p>See the discussion on HDRI implementations of ImageMagick on the page 642<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. 643</p> 644 645<div style="margin: auto;"> 646 <h4><a id="black-point-compensation"></a>-black-point-compensation</h4> 647</div> 648 649<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> 650 651<div style="margin: auto;"> 652 <h4><a id="black-threshold"></a>-black-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 653</div> 654 655<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> 656 657<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. 658</p> 659 660 661<div style="margin: auto;"> 662 <h4><a id="blend"></a>-blend <em class="arg">geometry</em></h4> 663</div> 664 665<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> 666 667<p>Blend will average the images together ('plus') according to the 668percentages given and each pixels transparency. If only a single percentage 669value is given it sets the weight of the composite or 'source' image, while 670the background image is weighted by the exact opposite amount. That is a 671<kbd>-blend 30%</kbd> merges 30% of the 'source' image with 70% of the 672'destination' image. Thus it is equivalent to <kbd>-blend 30x70%</kbd>.</p> 673 674 675<div style="margin: auto;"> 676 <h4><a id="blue-primary"></a>-blue-primary <em class="arg">x</em>,<em class="arg">y</em></h4> 677</div> 678 679<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> 680 681<div style="margin: auto;"> 682 <h4><a id="blue-shift"></a>-blue-shift <em class="arg">factor</em></h4> 683</div> 684 685<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> 686 687<div style="margin: auto;"> 688 689<div style="margin: auto;"> 690 <h4><a id="blur"></a>-blur <em class="arg">radius</em><br />-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 691</div> 692 693<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> 694 695<p>Convolve the image with a Gaussian or normal distribution using the given 696<em class="arg" >Sigma</em> value. The formula is:</p> 697 698<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 699</div> 700 701<p>The <em class="arg" >Sigma</em> value is the important argument, and 702determines the actual amount of blurring that will take place. </p> 703 704<p>The <em class="arg" >Radius</em> is only used to determine the size of the 705array which will hold the calculated Gaussian distribution. It should be an 706integer. If not given, or set to zero, IM will calculate the largest possible 707radius that will provide meaningful results for the Gaussian distribution. 708</p> 709 710<p>The larger the <em class="arg" >Radius</em> the radius the slower the 711operation is. However too small a <em class="arg" >Radius</em>, and sever 712aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 713should be at least twice the <em class="arg" >Sigma</em> value, though three 714times will produce a more accurite result. </p> 715 716<p>This option differs from <a href="#gaussian-blur">-gaussian-blur</a> simply 717by taking advantage of the separability properties of the distribution. Here 718we apply a single-dimensional Gaussian matrix in the horizontal direction, 719then repeat the process in the vertical direction.</p> 720 721<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 722pixels which are outside the image proper are blurred into the final result. 723</p> 724 725 726<div style="margin: auto;"> 727 <h4>-blur <em class="arg">Width</em>[x<em class="arg">Height</em>[+<em class="arg">Angle</em>]]</h4> 728</div> 729 730<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> 731 732<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted 733Average (EWA) of the source image, scaled according to the grayscale 734mapping. </p> 735 736<p>The ellipse is weighted with sigma set to the given <em class="arg" 737>Width</em> and <em class="arg" >Height</em>. The <em class="arg" >Height</em> 738defaults to the <em class="arg" >Width</em> for a normal circular Guassian 739weighting. The <em class="arg" >Angle</em> will rotate the ellipse from 740horizontal clock-wise. </p> 741 742<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 743pixels which are outside the image proper are blurred into the final result. 744</p> 745 746 747<div style="margin: auto;"> 748 <h4><a id="border"></a>-border <em class="arg">geometry</em></h4> 749</div> 750 751<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> 752 753<p>Set the width and height using the <em class="arg">size</em> portion of the 754<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 755ignored. </p> 756 757<p>Set the border color by preceding with the <a 758href="#bordercolor">-bordercolor</a> setting.</p> 759 760<p>The <a href="#border">-border</a> operation is affected by the current <a 761href="#compose">-compose</a> setting and assumes that this is using the default 762'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 763size colors by the current <a href="#bordercolor">-bordercolor</a> before 764overlaying the original image in the center of this net image. This means that 765with the default compose method of '<kbd>Over</kbd>' any transparent parts may 766be replaced by the current <a href="#bordercolor">-bordercolor</a> setting.</p> 767<p>See also the <a href="#frame">-frame</a> option, which has more 768functionality.</p> 769 770<div style="margin: auto;"> 771 <h4><a id="bordercolor"></a>-bordercolor <em class="arg">color</em></h4> 772</div> 773 774<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> 775 776<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 777 778<p>The default border color is <kbd>#DFDFDF</kbd>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p> 779 780<div style="margin: auto;"> 781 <h4><a id="borderwidth"></a>-borderwidth <em class="arg">geometry</em> </h4> 782</div> 783 784<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> 785 786<div style="margin: auto;"> 787 <h4><a 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> 788</div> 789 790<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> 791 792<p>Brightness and Contrast values apply changes to the input image. They are 793not absolute settings. A brightness or contrast value of zero means no change. 794The range of values is -100 to +100 on each. Positive values increase the 795brightness or contrast and negative values decrease the brightness or contrast. 796To control only contrast, set the brightness=0. To control only brightness, 797set contrast=0 or just leave it off.</p> 798 799<p>You may also use <a href="#fill">-channel</a> to control which channels to 800apply the brightness and/or contrast change. The default is to apply the same 801transformation to all channels.</p> 802 803<p>Brightness and Contrast arguments are converted to offset and slope of a 804linear transform and applied 805using <a href="#fill">-function polynomial "slope,offset"</a>.</p> 806 807<p>The slope varies from 0 at contrast=-100 to almost vertical at 808contrast=+100. For brightness=0 and contrast=-100, the result are totally 809midgray. For brightness=0 and contrast=+100, the result will approach but 810not quite reach a threshold at midgray; that is the linear transformation 811is a very steep vertical line at mid gray.</p> 812 813<p>Negative slopes, i.e. negating the image, are not possible with this 814function. All achievable slopes are zero or positive.</p> 815 816<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5 817at brightness=+100. Thus, when contrast=0 and brightness=100, the result is 818totally white. Similarly, when contrast=0 and brightness=-100, the result is 819totally black.</p> 820 821<p>As the range of values for the arguments are -100 to +100, adding the '%' 822symbol is no different than leaving it off.</p> 823 824<div style="margin: auto;"> 825 <h4><a id="cache"></a>-cache <em class="arg">threshold</em></h4> 826</div> 827 828<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> 829 830<div style="margin: auto;"> 831 <h4><a id="caption"></a>-caption <em class="arg">string</em></h4> 832</div> 833 834<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> 835 836<p>This option sets the caption meta-data of an image read in after this 837option has been given. To modify a caption of images already in memory use 838"<kbd><a href="#set">-set</a> caption</kbd>". </p> 839 840<p>The caption can contain special format characters listed in the <a 841href="/www/escape.html">Format and 842Print Image Properties</a>. These attributes are expanded when the caption 843is finally assigned to the individual images. </p> 844 845<p>If the first character of <em class="arg">string</em> is <em 846class="arg">@</em>, the image caption is read from a file titled by the 847remaining characters in the string. Comments read in from a file are literal; 848no embedded formatting characters are recognized.</p> 849 850<p>Caption meta-data ais not visible on the image itself. To do that use the 851<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 852instead.</p> 853 854<p>For example,</p> 855 856<p class="crtsnip"> 857 -caption "%m:%f %wx%h" bird.miff 858</p> 859 860<p>produces an image caption of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 861that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 862480.</p> 863 864 865<div style="margin: auto;"> 866 <h4><a id="cdl"></a>-cdl <em class="arg">filename</em></h4> 867</div> 868 869<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> 870 871<p>Here is an example color correction collection:</p> 872 873<pre class="text"> 874<?xml version="1.0" encoding="UTF-8"?> 875<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 876 <ColorCorrection id="cc06668"> 877 <SOPNode> 878 <Slope> 0.9 1.2 0.5 </Slope> 879 <Offset> 0.4 -0.5 0.6 </Offset> 880 <Power> 1.0 0.8 1.5 </Power> 881 </SOPNode> 882 <SATNode> 883 <Saturation> 0.85 </Saturation> 884 </SATNode> 885 </ColorCorrection> 886</ColorCorrectionCollection> 887</pre> 888 889<div style="margin: auto;"> 890 <h4><a id="channel"></a>-channel <em class="arg">type</em></h4> 891</div> 892 893<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> 894 895<p>Choose from: <kbd>Red</kbd>, <kbd>Green</kbd>, <kbd>Blue</kbd>, 896<kbd>Alpha</kbd>, <kbd>Cyan</kbd>, <kbd>Magenta</kbd>, <kbd>Yellow</kbd>, 897<kbd>Black</kbd>, <kbd>Opacity</kbd>, <kbd>Index</kbd>, <kbd>RGB</kbd>, 898<kbd>RGBA</kbd>, <kbd>CMYK</kbd>, or <kbd>CMYKA</kbd>.</p> 899 900<p>The channels above can also be specified as a comma-separated list or can be 901abbreviated as a concatenation of the letters '<kbd>R</kbd>', '<kbd>G</kbd>', 902'<kbd>B</kbd>', '<kbd>A</kbd>', '<kbd>O</kbd>', '<kbd>C</kbd>', 903'<kbd>M</kbd>', '<kbd>Y</kbd>', '<kbd>K</kbd>'. 904 905For example, to only select the <kbd>Red</kbd> and <kbd>Blue</kbd> channels 906you can either use </p> 907<p class="crtsnip"> 908 -channel Red,Blue 909</p> 910<p>or you can use the short hand form</p> 911<p class="crtsnip"> 912 -channel RB 913</p> 914 915<p>All the channels that is present in an image can be specified using the 916special channel type <kbd>All</kbd>. Not all operators are 'channel capable', 917but generally any operators that are generally 'grey-scale' image operators, 918will understand this setting. See individual operator documentation. </p> 919 920<br /> 921 922<p>On top of the normal channel selection a extra flag can be specified, 923'<kbd>Sync</kbd>'. This is turned on by default and if set means that 924operators that understand this flag should perform: cross-channel 925syncronization of the channels. If not specified, then most grey-scale 926operators will apply their image processing operations to each individual 927channel (as specified by the rest of the <a href="#channel">-channel</a> 928setting) completely independently from each other. </p> 929 930<p>For example for operators such as <a href="#auto-level">-auto-level</a> and 931<a href="#auto-gamma">-auto-gamma</a> the color channels are modified 932together in exactly the same way so that colors will remain in-sync. Without 933it being set, then each channel is modified separately and 934independently, which may produce color distortion. </p> 935 936<p>The <a href="#morphology">-morphology</a> '<kbd>Convolve</kbd>' method 937and the <a href="#compose">-compose</a> mathematical methods, also understands 938the '<kbd>Sync</kbd>' flag to modify the behaviour of pixel colors according 939to the alpha channel (if present). That is to say it will modify the image 940processing with the understanding that fully-transparent colors should not 941contribute to the final result. </p> 942 943<p>Basically, by default, operators work with color channels in syncronous, and 944treats transparency as special, unless the <a href="#channel">-channel</a> 945setting is modified so as to remove the effect of the '<kbd>Sync</kbd>' flag. 946How each operator does this depends on that operators current implementation. 947Not all operators understands this flag at this time, but that is changing. 948</p> 949 950<p>To print a complete list of channel types, use <a href="#list">-list 951channel</a>.</p> 952 953<br /> 954 955<p>By default, ImageMagick sets <a href="#channel">-channel</a> to the value 956'<kbd>RGBK,sync</kbd>', which specifies that operators act on all color 957channels except the transparency channel, and that all the color channels are 958to be modified in exactly the same way, with a understanding of transprancy 959(depending on the operation being applied). The 'plus' form <a 960href="#channel" >+channel</a> will reset the value back to this default. </p> 961 962<p>Options that are affected by the <a href="#channel" >-channel</a> setting 963include the following. 964 965<a href="#auto-gamma">-auto-gamma</a>, 966<a href="#auto-level">-auto-level</a>, 967<a href="#black-threshold">-black-threshold</a>, 968<a href="#blur">-blur</a>, 969<a href="#clamp">-clamp</a>, 970<a href="#clut">-clut</a>, 971<a href="#combine">-combine</a>, 972<a href="#composite">-composite</a> (Mathematical compose methods only), 973<a href="#convolve">-convolve</a>, 974<a href="#contrast-stretch">-contrast-stretch</a>, 975<a href="#evaluate">-evaluate</a>, 976<a href="#function">-function</a>, 977<a href="#fx">-fx</a>, 978<a href="#gaussian-blur">-gaussian-blur</a>, 979<a href="#hald-clut">-hald-clut</a>, 980<a href="#motion-blur">-motion-blur</a>, 981<a href="#morphology">-morphology</a>, 982<a href="#negate">-negate</a>, 983<a href="#normalize">-normalize</a>, 984<a href="#ordered-dither">-ordered-dither</a>, 985<a href="#radial-blur">-radial-blur</a>, 986<a href="#random-threshold">-random-threshold</a>, 987<a href="#separate">-separate</a>, 988<a href="#threshold">-threshold</a>, and 989<a href="#white-threshold">-white-threshold</a>. 990</p> 991 992<p>Warning, some operators behave differently when the <a href="#channel" 993>+channel</a> default setting is in effect, verses ANY user defined <a 994href="#channel" >-channel</a> setting (including the equivalent of the 995default). These operators have yet to be made to understand the newer 'Sync' 996flag. </p> 997 998<p>For example <a href="#threshold">-threshold</a> will by default gray-scale 999the image before thresholding, if no <a href="#channel" >-channel</a> setting 1000has been defined. This is not 'Sync flag controlled, yet. </p> 1001 1002<p>Also some operators such as <a href="#blur">-blur</a>, <a 1003href="#gaussian-blur">-gaussian-blur</a>, will modify their handling of the 1004color channels if the '<kbd>alpha</kbd>' channel is also enabled by <a 1005href="#channel" >-channel</a>. Generally this done to ensure that 1006fully-transparent colors are treated as being fully-transparent, and thus any 1007underlying 'hidden' color has no effect on the final results. Typically 1008resulting in 'halo' effects. The newer <a href="#morphology">-morphology</a> 1009convolution equivalents however does have a understanding of the 'Sync' flag 1010and will thus handle transparency correctly by default. </p> 1011 1012<p>As a alpha channel is optional within images, some operators will read the 1013color channels of an image as a greyscale alpha mask, when the image has no 1014alpha channel present, and the <a href="#channel" >-channel</a> setting tells 1015the operator to apply the operation using alpha channels. The <a 1016href="#clut">-clut</a> operator is a good example of this. </p> 1017 1018 1019<div style="margin: auto;"> 1020 <h4><a id="clamp"></a>-clamp</h4> 1021</div> 1022 1023<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> 1024 1025<div style="margin: auto;"> 1026 <h4><a id="charcoal"></a>-charcoal <em class="arg">factor</em></h4> 1027</div> 1028 1029<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> 1030 1031<div style="margin: auto;"> 1032 <h4><a id="chop"></a>-chop <em class="arg">geometry</em></h4> 1033</div> 1034 1035<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> 1036 1037<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> 1038and <em class="arg">height</em> given in the of the <em class="arg">size</em> 1039portion of the <em class="arg">geometry</em> argument give the number of 1040columns and rows to remove. The <em class="arg">offset</em> portion of 1041the <em class="arg">geometry</em> argument is influenced by 1042a <a href="#gravity">-gravity</a> setting, if present.</p> 1043 1044<p>The <a href="#chop">-chop</a> option removes entire rows and columns, 1045and moves the remaining corner blocks leftward and upward to close the gaps.</p> 1046 1047<p>While it can remove internal rows and columns of pixels, it is more 1048typically used with as <a href="#gravity">-gravity</a> setting and zero 1049offsets so as to remove a single edge from an image. Compare this to <a 1050href="#shave" >-shave</a> which removes equal numbers of pixels from oppisite 1051sides of the image. </p> 1052 1053<p>Using <a href="#chop">-chop</a> will effectivally undo the results of a <a 1054href="#splice">-splice</a> that was given the same <em 1055class="arg">geometry</em> and <a href="#gravity">-gravity</a> settings. </p> 1056 1057 1058<div style="margin: auto;"> 1059 <h4><a id="clip"></a>-clip</h4> 1060</div> 1061 1062<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> 1063 1064<p>If a clipping path is present, it is applied to subsequent operations.</p> 1065 1066<p>For example, in the command</p> 1067 1068<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -clip -negate cockatoo.tif negated.tif</span></p> 1069<p>only the pixels within the clipping path are negated.</p> 1070 1071<p>The <a href="#clip">-clip</a> feature requires the XML library. If the XML library is not present, the option is ignored.</p> 1072 1073<div style="margin: auto;"> 1074 <h4><a id="clip-mask"></a>-clip-mask</h4> 1075</div> 1076 1077<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> 1078 1079<p>Use the given image as a 'do-not-modify' mask of the current images in the 1080current image sequence. Assuming the clipmask is a greyscale image the same 1081size at the one already in memory, any areas that is white will not be 1082modified by any of the 'image processing operators' that follow, until the 1083mask is removed. Pixels in the black areas of the clip mask will be modified 1084as normal. </p> 1085 1086<p>In some ways this is similar to (though not the same) as defining 1087a rectangular <a href="#region" >-region</a>, or using the negative of the 1088mask (thrid) image in a three image <a href="#composite" >-composite</a>, 1089operation. </p> 1090 1091 1092<div style="margin: auto;"> 1093 <h4><a id="clip-path"></a>-clip-path <em class="arg">id</em></h4> 1094</div> 1095 1096<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> 1097 1098<p>This is almost identical to <a href="#clip">-clip</a>. </p> 1099 1100 1101<div style="margin: auto;"> 1102 <h4><a id="clone"></a>-clone <em class="arg">index(s)</em></h4> 1103</div> 1104 1105<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>make a clone of an image (or images).</td><td style='text-align:right;'></td></tr></table> 1106 1107<p>Inside parenthesis (where the operator is normally used) it will make a 1108clone of the images from the last 'pushed' image sequence, and adds them to 1109the end of the current image sequence. Outside parenthesis 1110(not recommended) it clones the images from the current image sequence. </p> 1111 1112<p>Specify the image by its index in the sequence. The first image is index 11130. Negative indexes are relative to the end of the sequence; for 1114example, <kbd>−1</kbd> 1115represents the last image of the sequence. Specify a range of images with a 1116dash (e.g. <kbd>0−4</kbd>). Separate multiple indexes with commas but no 1117spaces (e.g. <kbd>0,2,5</kbd>). A value of '<kbd>0−−1</kbd> will 1118effectively clone all the images. </p> 1119 1120<p>The <a href="#clone">+clone</a> will simply make a copy of the last image 1121in the image sequence, and is thus equivalent to using a argument of 1122'<kbd>−1</kbd>'. </p> 1123 1124<div style="margin: auto;"> 1125 <h4><a id="clut"></a>-clut</h4> 1126</div> 1127 1128<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 1129corresponding channel in the second image as a <b>c</b>olor 1130<b>l</b>ook<b>u</b>p <b>t</b>able.</td><td style='text-align:right;'></td></tr></table> 1131 1132<p>The second (LUT) image is ordinarily a gradient image containing the 1133histogram mapping of how each channel should be modified. Typically it is a 1134either a single row or column image of replacement color values. If larger 1135than a single row or column, values are taken from a diagonal line from 1136top-left to bottom-right corners.</p> 1137 1138<p>The lookup is further controlled by the <a 1139href="#interpolate">-interpolate</a> setting, which is especially handy for an 1140LUT which is not the full length needed by the ImageMagick installed Quality 1141(Q) level. Good settings for this are the '<kbd>bilinear</kbd>' and 1142'<kbd>bicubic</kbd>' interpolation settings, which give smooth color 1143gradients, and the '<kbd>integer</kbd>' setting for a direct, unsmoothed 1144lookup of color values. </p> 1145 1146<p>This operator is especially suited to replacing a grayscale image with a 1147specific color gradient from the CLUT image. </p> 1148 1149<p>Only the channel values defined by the <a href="#channel">-channel</a> 1150setting will have their values replaced. In particular, since the default <a 1151href="#channel">-channel</a> setting is <kbd>RGB</kbd>, this means that 1152transparency (alpha/matte channel) is not affected, unless the <a 1153href="#channel">-channel</a> setting is modified. When the alpha channel is 1154set, it is treated by the <a href="#clut" >-clut</a> operator in the same way 1155as the other channels, implying that alpha/matte values are replaced using the 1156alpha/matte values of the original image. </p> 1157 1158<p>If either the image being modified, or the lookup image, contains no 1159transparency (i.e. <a href="#alpha" >-alpha</a> is turned 'off') but the <a 1160href="#channel">-channel</a> setting includes alpha replacement, then it is 1161assumed that image represents a gray-scale gradient which is used for the 1162replacement alpha values. That is you can use a gray-scale CLUT image to 1163adjust a existing images alpha channel, or you can color a gray-scale image 1164using colors form CLUT containing the desired colors, including transparency. 1165</p> 1166 1167<p>See also <a href="#hald-clut" >-hald-clut</a> which replaces colors 1168according to the lookup of the full color RGB value from a 2D representation 1169of a 3D color cube. </p> 1170 1171 1172<div style="margin: auto;"> 1173 <h4><a id="coalesce"></a>-coalesce</h4> 1174</div> 1175 1176<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> 1177 1178<p>Overlay each image in an image sequence according to 1179its <a href="#dispose">-dispose</a> meta-data, to reproduce the look of 1180an animation at each point in the animation sequence. All images should be 1181the same size, and are assigned appropriate GIF disposal settings for the 1182animation to continue working as expected as a GIF animation. Such frames 1183are more easily viewed and processed than the highly optimized GIF overlay 1184images. </p> 1185 1186<p>The animation can be re-optimized after processing using 1187the <a href="#layers">-layers</a> method '<kbd>optimize</kbd>', although 1188there is no guarantee that the restored GIF animation optimization is 1189better than the original. </p> 1190 1191 1192<div style="margin: auto;"> 1193 <h4><a id="colorize"></a>-colorize <em class="arg">value</em></h4> 1194</div> 1195 1196<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> 1197 1198<p>Specify the amount of colorization as a percentage. Separate colorization 1199values can be applied to the red, green, and blue channels of the image with 1200a comma-delimited list of colorization 1201values (e.g., <kbd>-colorize 0,0,50</kbd>).</p> 1202 1203<div style="margin: auto;"> 1204 <h4><a id="colormap"></a>-colormap <em class="arg">type</em></h4> 1205</div> 1206 1207<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> 1208 1209<p>The <em class="arg">type</em> can be <kbd>shared</kbd> or <kbd>private</kbd>.</p> 1210 1211<p>This option only applies when the default X server visual 1212is <kbd>PseudoColor</kbd> or <kbd>GrayScale</kbd>. Refer 1213to <a href="#visual">-visual</a> for more details. By default, 1214a shared colormap is allocated. The image shares colors with 1215other X clients. Some image colors could be approximated, 1216therefore your image may look very different than intended. 1217If <kbd>private</kbd> is chosen, the image colors appear exactly 1218as they are defined. However, other clients may go <em>technicolor</em> 1219when the image colormap is installed.</p> 1220 1221<div style="margin: auto;"> 1222 <h4><a id="colors"></a>-colors <em class="arg">value</em></h4> 1223</div> 1224 1225<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> 1226 1227<p>The actual number of colors in the image may be less than your request, 1228but never more. Note that this a color reduction option. Images with fewer 1229unique colors than specified by <em class="arg">value</em> will have any 1230duplicate or unused colors removed. The ordering of an existing color 1231palette may be altered. When converting an image from color to grayscale, 1232it is more efficient to convert the image to the gray colorspace before 1233reducing the number of colors. Refer to 1234the <a href="/www/quantize.html"> 1235color reduction algorithm</a> for more details.</p> 1236 1237<div style="margin: auto;"> 1238 <h4><a id="color-matrix"></a>-color-matrix <em class="arg">matrix</em></h4> 1239</div> 1240 1241<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> 1242 1243<p>This option permits saturation changes, hue rotation, luminance to alpha, 1244and various other effects. Although variable-sized transformation matrices 1245can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 1246for CMYKA (or RGBA with offsets). The matrix is similar to those used by 1247Adobe Flash except offsets are in column 6 rather than 5 (in support of 1248CMYKA images) and offsets are normalized (divide Flash offset by 255).</p> 1249 1250<p>As an example, to add contrast to an image with offsets, try this command:</p> 1251 1252<pre class="text"> 1253 convert kittens.jpg -color-matrix \ 1254 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \ 1255 0.0 1.5 0.0 0.0, 0.0, -0.157 \ 1256 0.0 0.0 1.5 0.0, 0.0, -0.157 \ 1257 0.0 0.0 0.0 1.0, 0.0, 0.0 \ 1258 0.0 0.0 0.0 0.0, 1.0, 0.0 \ 1259 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png 1260</pre> 1261<div style="margin: auto;"> 1262 <h4><a id="colorspace"></a>-colorspace <em class="arg">value</em></h4> 1263</div> 1264 1265<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> 1266 1267<p>Choices are:</p> 1268 1269<pre class="text"> 1270 CMY CMYK Gray HSB 1271 HSL HWB Lab Log 1272 OHTA Rec601Luma Rec601YCbCr Rec709Luma 1273 Rec709YCbCr RGB sRGB Transparent 1274 XYZ YCbCr YCC YIQ 1275 YPbPr YUV 1276</pre> 1277 1278<p>To print a complete list of colorspaces, use <a href="#list">-list colorspace</a>.</p> 1279 1280<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> 1281 1282<table class="doc"> 1283 <caption>Conversion Of RGB To Other Color Spaces</caption> 1284 <tr><th align="left" valign="middle">CMY</th></tr> 1285 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>−R</td></tr> 1286 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>−G</td></tr> 1287 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>−B</td></tr> 1288 <tr><th align="left" valign="middle">CMYK — starts with CMY from above</th></tr> 1289 <tr><td align="left" valign="middle">K=min(C,Y,M)</td></tr> 1290 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>*(C−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1291 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>*(M−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1292 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>*(Y−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1293 1294 <tr><th align="left" valign="middle">Gray</th></tr> 1295 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1296 1297 <tr><th align="left" valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr> 1298 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1299 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1300 <tr><td align="left" valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <em>intensity-like</em></td></tr> 1301 1302 <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> 1303 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1304 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1305 <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> 1306 1307 <tr><th align="left" valign="middle">HWB — Hue, Whiteness, Blackness</th></tr> 1308 <tr><td align="left" valign="middle">Hue (complicated equation)</td></tr> 1309 <tr><td align="left" valign="middle">Whiteness (complicated equation)</td></tr> 1310 <tr><td align="left" valign="middle">Blackness (complicated equation)</td></tr> 1311 1312 <tr><th align="left" valign="middle">LAB</th></tr> 1313 <tr><td align="left" valign="middle">L (complicated equation relating X,Y,Z)</td></tr> 1314 <tr><td align="left" valign="middle">A (complicated equation relating X,Y,Z)</td></tr> 1315 <tr><td align="left" valign="middle">B (complicated equation relating X,Y,Z)</td></tr> 1316 1317 <tr><th align="left" valign="middle">LOG</th></tr> 1318 <tr><td align="left" valign="middle">I1 (complicated equation involving logarithm of R)</td></tr> 1319 <tr><td align="left" valign="middle">I2 (complicated equation involving logarithm of G)</td></tr> 1320 <tr><td align="left" valign="middle">I3 (complicated equation involving logarithm of B)</td></tr> 1321 1322 <tr><th align="left" valign="middle">OHTA — approximates principal components transformation</th></tr> 1323 <tr><td align="left" valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <em>intensity-like</em></td></tr> 1324 <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> 1325 <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> 1326 1327 <tr><th align="left" valign="middle">Rec601Luma</th></tr> 1328 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1329 1330 <tr><th align="left" valign="middle">Rec601YCbCr</th></tr> 1331 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1332 <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> 1333 <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> 1334 1335 <tr><th align="left" valign="middle">Rec709Luma</th></tr> 1336 <tr><td align="left" valign="middle">Gray=0.21260*R+0.71520*G+0.07220*B</td></tr> 1337 1338 <tr><th align="left" valign="middle">Rec709YCbCr</th></tr> 1339 <tr><td align="left" valign="middle">Y=0.212600*R+0.715200*G+0.072200*B; <em>intensity-like</em></td></tr> 1340 <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> 1341 <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> 1342 1343 <tr><th align="left" valign="middle">sRGB</th></tr> 1344 <tr><td align="left" valign="middle">if Rs ≤ .04045 then Rs=R/12.92 else Rs=((R+.055)/1.055)^2.4</td></tr> 1345 <tr><td align="left" valign="middle">if Gs ≤ .04045 then Gs=B/12.92 else Gs=((G+.055)/1.055)^2.4</td></tr> 1346 <tr><td align="left" valign="middle">if Bs ≤ .04045 then Bs=B/12.92 else Bs=((B+.055)/1.055)^2.4</td></tr> 1347 1348 <tr><th align="left" valign="middle">XYZ</th></tr> 1349 <tr><td align="left" valign="middle">X=0.4124240*R+0.3575790*G+0.1804640*B</td></tr> 1350 <tr><td align="left" valign="middle">Y=0.2126560*R+0.7151580*G+0.0721856*B</td></tr> 1351 <tr><td align="left" valign="middle">Z=0.0193324*R+0.1191930*G+0.9504440*B</td></tr> 1352 1353 <tr><th align="left" valign="middle">YCC</th></tr> 1354 <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> 1355 <tr><td align="left" valign="middle">C1=(−0.29900*R−0.58700*G+0.88600*B) (with complicated scaling)</td></tr> 1356 <tr><td align="left" valign="middle">C2=(0.70100*R−0.58700*G−0.11400*B) (with complicated scaling)</td></tr> 1357 1358 <tr><th align="left" valign="middle">YCbCr</th></tr> 1359 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1360 <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> 1361 <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> 1362 1363 <tr><th align="left" valign="middle">YIQ</th></tr> 1364 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1365 <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> 1366 <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> 1367 1368 <tr><th align="left" valign="middle">YPbPr</th></tr> 1369 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1370 <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> 1371 <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> 1372 1373 <tr><th align="left" valign="middle">YUV</th></tr> 1374 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1375 <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> 1376 <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> 1377</table> 1378 1379<div style="margin: auto;"> 1380 <h4><a id="combine"></a>-combine</h4> 1381</div> 1382 1383<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> 1384 1385<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> 1386 1387<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. 1388</p> 1389 1390<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> 1391<div style="margin: auto;"> 1392 <h4><a id="comment"></a>-comment <em class="arg">string</em></h4> 1393</div> 1394 1395<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> 1396 1397<p>This option sets the comment meta-data of an image read in after this 1398option has been given. To modify a comment of images already in memory use 1399"<kbd><a href="#set">-set</a> comment</kbd>". </p> 1400 1401<p>The comment can contain special format characters listed in the <a 1402href="/www/escape.html">Format and 1403Print Image Properties</a>. These attributes are expanded when the comment 1404is finally assigned to the individual images. </p> 1405 1406<p>If the first character of <em class="arg">string</em> is <em 1407class="arg">@</em>, the image comment is read from a file titled by the 1408remaining characters in the string. Comments read in from a file are literal; 1409no embedded formatting characters are recognized.</p> 1410 1411<p>Comment meta-data are not visible on the image itself. To do that use the 1412<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 1413instead.</p> 1414 1415<p>For example,</p> 1416 1417<p class="crtsnip"> 1418 -comment "%m:%f %wx%h" bird.miff 1419</p> 1420 1421<p>produces an image comment of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 1422that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 1423480.</p> 1424 1425<div style="margin: auto;"> 1426 <h4><a id="compose"></a>-compose <em class="arg">operator</em></h4> 1427</div> 1428 1429<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> 1430 1431<p>See <a href="/www/compose.html">Alpha Compositing</a> for 1432a detailed discussion of alpha compositing.</p> 1433 1434<p>This setting effects image processing operators that merge two (or more) 1435images together in some way. This includes the operators, 1436<a href="#composite">-composite</a>, 1437<a href="#layers">-layers</a> composite, 1438<a href="#flatten">-flatten</a>, 1439<a href="#mosaic">-mosaic</a>, 1440<a href="#layers">-layers</a> merge, 1441<a href="#border">-border</a>, 1442<a href="#frame">-frame</a>, 1443and <a href="#extent">-extent</a>. </p> 1444 1445<p>It is also one of the primary options for the "<kbd>composite</kbd>" 1446command. </p> 1447 1448 1449<div style="margin: auto;"> 1450 <h4><a id="composite"></a>-composite</h4> 1451</div> 1452 1453<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> 1454 1455<p>Take the first image 'destination' and overlay the second 'source' image 1456according to the current <a href="#compose">-compose</a> setting. The location 1457of the 'source' or 'overlay' image is controlled according to <a 1458href="#geometry" >-geometry</a>, and <a href="#geometry" >-geometry</a> 1459settings. </p> 1460 1461<p>If a third image is given this is treated as a gray-scale 'mask' image 1462relative to the first 'destination' image. This mask will limit what parts of 1463the destination can be modified by the image composition. However for the 1464'<kbd>displace</kbd>' compose method, the mask is used to provide a separate 1465Y-displacement image instead. </p> 1466 1467<p>If a <a href="#compose">-compose</a> method requires extra numerical 1468arguments or flags these can be provided by setting the <a 1469href="#set">-set</a> '<kbd class="arg">option:compose:args</kbd>' 1470appropriately for the compose method. </p> 1471 1472<p>Some <a href="#compose">-compose</a> methods can modify the 'destination' 1473image outside the overlay area. You can disable this by setting the special <a 1474href="#set">-set</a> '<kbd class="arg">option:compose:outside-overlay</kbd>' 1475to '<kbd>false</kbd>'. </p> 1476 1477 1478<div style="margin: auto;"> 1479 <h4><a id="compress"></a>-compress <em class="arg">type</em></h4> 1480</div> 1481 1482<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> 1483 1484<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> 1485 1486<p>To print a complete list of compression types, use <a href="#list">-list compress</a>.</p> 1487 1488<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> 1489 1490<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> 1491 1492<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> 1493 1494<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> 1495 1496<div style="margin: auto;"> 1497 <h4><a id="contrast"></a>-contrast</h4> 1498</div> 1499 1500<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> 1501 1502<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> 1503 1504<p>For a more pronounced effect you can repeat the option:</p> 1505 1506<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -contrast -contrast rose_c2.png</span></p> 1507<div style="margin: auto;"> 1508 <h4><a 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> 1509</div> 1510 1511<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> 1512 1513<p>While performing the stretch, black-out at most <em 1514class="arg" >black-point</em> pixels and white-out at most <em 1515class="arg" >white-point</em> pixels. Or, if percent is used, black-out at most 1516<em class="arg" >black-point %</em> pixels and white-out at most <em 1517class="arg" >white-point %</em> pixels.</p> 1518 1519<p>Prior to ImageMagick 6.4.7-0, <a href="#contrast-stretch" 1520>-contrast-stretch</a> will black-out at most <em class="arg" 1521>black-point</em> pixels and white-out at most <em class="arg" >total pixels 1522minus white-point</em> pixels. Or, if percent is used, black-out at most <em 1523class="arg">black-point %</em> pixels and white-out at most <em class="arg" 1524>100% minus white-point %</em> pixels.</p> 1525 1526<p>Note that <kbd>-contrast-stretch 0</kbd> will modify the image such that 1527the image's min and max values are stretched to 0 and <em class="QR" 1528>QuantumRange</em>, respectively, without any loss of data due to burn-out or 1529clipping at either end. This is not the same as <a href="#normalize" 1530>-normalize</a>, which is equivalent to <kbd>-contrast-stretch 0.15x0.05%</kbd> (or 1531prior to ImageMagick 6.4.7-0, <kbd>-contrast-stretch 2%x99%</kbd>).</p> 1532 1533<p>Internally operator works by creating a histogram bin, and then uses that 1534bin to modify the image. As such some colors may be merged together when they 1535originally fell into the same 'bin'. </p> 1536 1537<p>All the channels are normalized in concert by the came amount so as to 1538preserve color integrity, when the default <a href="#channel" >+channel</a> 1539setting is in use. Specifying any other <a href="#channel" >-channel</a> 1540setting will normalize the RGB channels independently.</p> 1541 1542<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 1543normalization of mathematical images. </p> 1544 1545<p>This operator is under review for re-development. </p> 1546 1547 1548<div style="margin: auto;"> 1549 <h4><a id="convolve"></a>-convolve <em class="arg">kernel</em></h4> 1550</div> 1551 1552<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> 1553 1554<p>The <em class="arg">kernel</em> is a matrix specified as 1555a comma-separated list of integers (with no spaces), ordered left-to right, 1556starting with the top row. Presently, only odd-dimensioned kernels are 1557supported, and therefore the number of entries in the specified <em 1558class="arg">kernel</em> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25, 15597<sup>2</sup>=49, etc. </p> 1560 1561<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 1562positive and negative results are relative to a user-specified bias value. 1563This is important for non-HDRI compilations of ImageMagick when dealing with 1564convolutions that contain negative as well as positive values. This is 1565especially the case with convolutions involving high pass filters or edge 1566detection. Without an output bias, the negative values is clipped at zero. 1567</p> 1568 1569<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 1570negative results without clipping to the color value range (0..QuantumRange). 1571See the discussion on HDRI implementations of ImageMagick on the page <a 1572href="/www/high-dynamic-range.html">High 1573Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a 1574href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this 1575<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 1576entry. </p> 1577 1578 1579<div style="margin: auto;"> 1580 <h4><a id="crop"></a>-crop <em class="arg">geometry</em></h4> 1581</div> 1582 1583<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> 1584 1585<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> 1586 1587<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> 1588 1589<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> 1590 1591<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> 1592 1593<p>By adding a exclamation character flag to the geometry argument, the 1594cropped images virtual canvas page size and offset is set as if the 1595geometry argument was a viewport or window. This means the canvas page size 1596is set to exactly the same size you specified, the image offset set 1597relative top left corner of the region cropped. </p> 1598 1599<p>If the cropped image 'missed' the actual image on its virtual canvas, a 1600special single pixel transparent 'missed' image is returned, and a 'crop 1601missed' warning given. </p> 1602 1603<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> 1604 1605<div style="margin: auto;"> 1606 <h4><a id="cycle"></a>-cycle <em class="arg">amount</em></h4> 1607</div> 1608 1609<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> 1610 1611<p><em class="arg">Amount</em> defines the number of positions each 1612colormap entry is shifted.</p> 1613 1614 1615<div style="margin: auto;"> 1616 <h4><a id="debug"></a>-debug <em class="arg">events</em></h4> 1617</div> 1618 1619<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> 1620 1621<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> 1622 1623 1624<p>For example, to log cache and blob events, use.</p> 1625 1626<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug "Cache,Blob" rose: rose.png</span></p> 1627<p>The <kbd>User</kbd> domain is normally empty, but developers can log user events in their private copy of ImageMagick.</p> 1628 1629<p>To print the complete list of debug methods, use <a href="#list">-list debug</a>.</p> 1630 1631<p>Use the <a href="#log">-log</a> option to specify the format for debugging output.</p> 1632 1633<p>Use <a href="#debug">+debug</a> to turn off all logging.</p> 1634 1635<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> 1636 1637 1638<div style="margin: auto;"> 1639 <h4><a id="decipher"></a>-decipher <em class="arg">filename</em></h4> 1640</div> 1641 1642<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> 1643 1644<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 1645 1646<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 1647 1648 1649<div style="margin: auto;"> 1650 <h4><a id="deconstruct"></a>-deconstruct</h4> 1651</div> 1652 1653<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> 1654 1655<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> 1656 1657<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> 1658 1659<p>This option is actually equivalent to the <a href="#layers">-layers</a> method '<kbd>compare-any</kbd>'. </p> 1660 1661 1662<div style="margin: auto;"> 1663 <h4><a id="define"></a>-define <em class="arg">key</em>{<em class="arg">=value</em>}<em class="arg">...</em></h4> 1664</div> 1665 1666<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 1667coders and image processing operations.</td><td style='text-align:right;'></td></tr></table> 1668 1669<p>This option creates one or more definitions for coders and decoders to use 1670while reading and writing image data. Definitions are generally used to 1671control image file format coder modules, and image processing operations, 1672beyond what is provided by normal means. Defined settings are listed in <a 1673href="#verbose" >-verbose</a> information ("<kbd>info:</kbd>" output format) 1674as "Artifacts". </p> 1675 1676<p>If <em class="arg">value</em> is missing for a definition, an empty-valued 1677definition of a flag is created with that name. This used to control on/off 1678options. Use <a href="#define">+define key</a> to remove definitions 1679previously created. Use <a href="#define">+define "*"</a> to remove all 1680existing definitions.</p> 1681 1682<p>The same 'artifact' settings can also be defined using the <a 1683href="#set" >-set "option:<em class="arg">key</em>" "<em class="arg" 1684>value</em>"</a> option, which also allows the use of <a href="/www/escape.html" >Format and Print Image 1685Properties</a> in the defined value. </p> 1686 1687<p>The <em>option</em> and <em>key</em> are case-independent (they are 1688converted to lowercase for use within the decoders) while the <em>value</em> 1689is case-dependent.</p> 1690 1691<p>Such settings are global in scope, and effect all images and operations. </p> 1692 1693<p>The following definitions are just some of the artifacts that are 1694available:</p> 1695 1696<dl> 1697<dt>dcm:display-range=reset</dt> 1698<dd>Set the display range to the minimum and maximum pixel values for the 1699 DCM image format.</dd> 1700 1701<dt>dot:layout-engine=<em class="arg">value</em></dt> 1702<dd>Set the specify the layout engine for the DOT image format (e.g. 1703 <kbd>neato</kbd>).</dd> 1704 1705<dt>jpeg:extent=<em class="arg">value</em></dt> 1706<dd>Restrict the maximum JPEG file size, for example <kbd>-define 1707 jpeg:extent=400kb</kbd>.</dd> 1708 1709<dt>jpeg:size=<em class="arg">geometry</em></dt> 1710<dd>Set the size hint of a JPEG image, for example, -define jpeg:size=128x128. 1711 It is most useful for increasing performance and reducing the memory 1712 requirements when reducing the size of a large JPEG image.</dd> 1713 1714<dt>jp2:rate=<em class="arg">value</em></dt> 1715<dd>Specify the compression factor to use while writing JPEG-2000 files. The 1716 compression factor is the reciprocal of the compression ratio. The valid 1717 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined, 1718 this value overrides the -quality setting. A quality setting of 75 1719 results in a rate value of 0.06641.</dd> 1720 1721<dt>mng:need-cacheoff</dt> 1722 <dd>turn playback caching off for streaming MNG.</dd> 1723 1724<dt>png:bit-depth=<em class="arg">value</em></dt> 1725<dt>png:color-type=<em class="arg">value</em></dt> 1726<dd>desired bit-depth and color-type for PNG output. You can force the PNG 1727 encoder to use a different bit-depth and color-type than it would have 1728 normally selected, but only if this does not cause any loss of image 1729 quality. Any attempt to reduce image quality is treated as an error and no 1730 PNG file is written. E.g., if you have a 1-bit black-and-white image, you 1731 can use these "defines" to cause it to be written as an 8-bit grayscale, 1732 indexed, or even a 64-bit RGBA. But if you have a 16-million color image, 1733 you cannot force it to be written as a grayscale or indexed PNG. If you 1734 wish to do this, you must use the appropriate <a href="#depth">-depth</a>, 1735 <a href="#colors">-colors</a>, or <a href="#type">-type</a> directives to 1736 reduce the image quality prior to using the PNG encoder. Note that in 1737 indexed PNG files, "bit-depth" refers to the number of bits per index, 1738 which can be 1, 2, 4, or 8. In such files, the color samples always have 1739 8-bit depth.</dd> 1740 1741<dt>png:exclude-chunk=<em class="arg">value</em></dt> 1742<dt>png:include-chunk=<em class="arg">value</em></dt> 1743<dd>ancillary chunks to be excluded from or included in PNG output. 1744 1745 <p>The<em class="arg">value</em> can be the name of a PNG chunk-type such 1746 as <em class="arg">bKGD</em>, a comma-separated list of chunk-types, 1747 or the word <em class="arg">all</em> or 1748 the word <em class="arg">none</em>. There must be no spaces in the 1749 list. Although PNG chunk-names are case-dependent, you can use 1750 all lowercase names if you prefer.</p> 1751 1752 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior 1753 of the PNG encoder and have no effect on the PNG decoder.</p> 1754 1755 <p>As a special case, if the <kbd>sRGB</kbd> chunk is excluded and 1756 the <kbd>gAMA</kbd> chunk is included, the <kbd>gAMA</kbd> chunk will 1757 only be written if gamma is not 1/2.2, since most decoders assume 1758 sRGB and gamma=1/2.2 when no colorspace information is included in 1759 the PNG file. Because the list is processed from left to right, you 1760 can achieve this with a single define:</p> 1761 1762<pre class="text"> 1763 -define png:include-chunk=none,gAMA 1764</pre> 1765 1766 <p>The critical PNG chunks <kbd>IHDR</kbd>, <kbd>PLTE</kbd>, 1767 <kbd>IDAT</kbd>, and <kbd>IEND</kbd> cannot be excluded. Any of 1768 these entries appearing in the list will be ignored.</p> 1769 1770 <p>If the ancillary PNG <kbd>tRNS</kbd> chunk is excluded and the 1771 image has transparency, the PNG colortype is forced to be 4 or 6 1772 (GRAY_ALPHA or RGBA). If the image is not transparent, then the 1773 <kbd>tRNS</kbd> chunk isn't written anyhow, and there is no effect 1774 on the PNG colortype of the output image.</p> 1775 1776 <p>The <a href="#strip">-strip</a> option does the equivalent of the 1777 following for PNG output:</p> 1778 1779<pre class="text"> 1780 -define png:include-chunk=none,gama 1781</pre> 1782 1783 <p>The default behavior is to include all known PNG ancillary chunks 1784 plus ImageMagick's private <kbd>vpAg</kbd> ("virtual page") chunk, 1785 and to exclude all PNG chunks that are unknown to ImageMagick, 1786 regardless of their PNG "copy-safe" status as described in the 1787 PNG specification.</p> 1788 1789 <p>Any chunk names that are not known to ImageMagick are ignored 1790 if they appear in either the "include-chunk" or "exclude-chunk" list. 1791 The ancillary chunks currently known to ImageMagick are 1792 <kbd>bKGD</kbd>, <kbd>cHRM</kbd>, <kbd>gAMA</kbd>, <kbd>iCCP</kbd>, 1793 <kbd>oFFs</kbd>, <kbd>pHYs</kbd>, <kbd>sRGB</kbd>, <kbd>tEXt</kbd>, 1794 <kbd>tRNS</kbd>, <kbd>vpAg</kbd>, and <kbd>zTXt</kbd>.</p> 1795 1796 <p>You can also put <kbd>date</kbd> in the list to include or exclude 1797 the "Date:create" and "Date:modify" text chunks that ImageMagick normally 1798 inserts in the output PNG.</p> 1799 1800</dd> 1801 1802<dt>png:preserve-colormap</dt> 1803 <dd>Use the existing image->colormap. Normally the PNG encoder will 1804 try to optimize the palette, eliminating unused entries and putting 1805 the transparent colors first. If this flag is set, that behavior 1806 is suppressed.</dd> 1807 1808<dt>ps:imagemask</dt> 1809<dd>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create 1810 Postscript files that render bilevel images with the Postscript imagemask 1811 operator instead of the image operator.</dd> 1812 1813<dt>quantum:format=<em class="arg">type</em></dt> 1814<dd>Set the type to <kbd>floating-point</kbd> to specify a floating-point 1815 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode 1816 to preserve negative values. If <a href="#depth">-depth</a> 16 is 1817 included, the result is a single precision floating point format. 1818 If <a href="#depth">-depth</a> 32 is included, the result is 1819 double precision floating point format.</dd> 1820 1821</dl> 1822 1823<p>For example, to create a postscript file that will render only the black 1824pixels of a bilevel image, use:</p> 1825 1826<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p> 1827<p>Set attributes of the image registry by prefixing the value with 1828<kbd>registry:</kbd>. For example, to set a temporary path to put work files, 1829use:</p> 1830 1831<p class="crtsnip"> 1832-define registry:temporary-path=/data/tmp 1833</p> 1834 1835 1836 1837<div style="margin: auto;"> 1838 <h4><a 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> 1839</div> 1840 1841<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> 1842 1843<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> 1844 1845<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> 1846 1847 1848<div style="margin: auto;"> 1849 <h4><a id="delete"></a>-delete <em class="arg">indexes</em></h4> 1850</div> 1851 1852<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> 1853 1854<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> 1855 1856 1857<div style="margin: auto;"> 1858 <h4><a id="density"></a>-density <em class="arg">width</em><br />-density <em class="arg">width</em>x<em class="arg">height</em></h4> 1859</div> 1860 1861<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> 1862 1863<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> 1864 1865<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> 1866 1867<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> 1868 1869<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> 1870 1871<div style="margin: auto;"> 1872 <h4><a id="depth"></a>-depth <em class="arg">value</em></h4> 1873</div> 1874 1875<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> 1876 1877<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> 1878 1879<div style="margin: auto;"> 1880 <h4><a id="descend"></a>-descend</h4> 1881</div> 1882 1883<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> 1884 1885<div style="margin: auto;"> 1886 <h4><a id="deskew"></a>-deskew <em class="arg">threshold</em></h4> 1887</div> 1888 1889<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> 1890 1891<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> 1892 1893<div style="margin: auto;"> 1894 <h4><a id="despeckle"></a>-despeckle</h4> 1895</div> 1896 1897<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> 1898 1899<div style="margin: auto;"> 1900 <h4><a id="direction"></a>-direction <em class="arg">type</em></h4> 1901</div> 1902 1903<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> 1904 1905<div style="margin: auto;"> 1906 <h4><a 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> 1907</div> 1908 1909<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> 1910 1911<p>With this option, the 'overlay' image, and optionally the 'mask' image, 1912is used as a displacement map, which is used to displace the lookup of 1913what part of the 'background' image is seen at each point of the overlaid 1914area. Much like the displacement map is a 'lens' that redirects light shining 1915through it so as to present a distorted view the original 'background' image 1916behind it. </p> 1917 1918<p>Any perfect grey areas of the displacement map produce a zero 1919displacement of the image. Black areas produce the given maximum negative 1920displacement of the lookup point, while white produce a maximum positive 1921displacement of the lookup. </p> 1922 1923<p>Note that it is the lookup of the 'background' that is displaced, not a 1924displacement of the image itself. As such an area of the displacement map 1925containing 'white' will have the lookup point 'shifted' by a positive amount, 1926and thus generating a copy of the destination image to the right/downward from 1927the correct position. That is the image will look like it may have been 1928'shifted' in a negative left/upward direction. Understanding this is a very 1929important in understanding how displacement maps work. </p> 1930 1931<p>The given arguments define the maximum amount of displacement in pixels 1932that a particular map can produce. If the displacement scale is large enough 1933it is also possible to lookup parts of the 'background' image that lie well 1934outside the bounds of the displacement map itself. That is you could very 1935easily copy a section of the original image from outside the overlay area 1936into the overlay area. </p> 1937 1938<p>The '%' flag makes the displacement scale relative to the size of the 1939overlay image (100% = half width/height of image). Using '!' switches 1940percentage arguments to refer to the destination image size instead. 1941these flags were added as of IM v6.5.3-5.</p> 1942 1943<p>Normally a single grayscale displacement map is provided, which with the 1944given scaling values will determine a single direction (vector) in which 1945displacements can occur (positively or negatively). However, if you also 1946specify a third image which is normally used as a <em class="arg">mask</em>, 1947the <em class="arg">composite image</em> is used for horizontal X 1948displacement, while the <em class="arg">mask image</em> is used for vertical Y 1949displacement. This allows you to define completely different displacement 1950values for the X and Y directions, and allowing you to lookup any point within 1951the <em class="arg">scale</em> bounds. In other words each pixel can lookup 1952any other nearby pixel, producing complex 2 dimensional displacements, rather 1953than a simple 1 dimensional vector displacements. </p> 1954 1955<p>Alteratively rather than suppling two separate images, as of IM v6.4.4-0, 1956you can use the 'red' channel of the overlay image to specify the horizontal 1957or X displacement, and the 'green' channel for the vertical or Y displacement. 1958</p> 1959 1960<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a 1961mask the transparency of the destination image. However areas outside the 1962overlaid areas will not be effected. </p> 1963 1964 1965<div style="margin: auto;"> 1966 <h4><a id="display"></a>-display <em class="arg">host:display[.screen]</em></h4> 1967</div> 1968 1969<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> 1970 1971<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p> 1972 1973<div style="margin: auto;"> 1974 <h4><a id="dispose"></a>-dispose <em class="arg">method</em></h4> 1975</div> 1976 1977<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> 1978 1979<p>The layer disposal method defines the way each the displayed image is to be 1980modified after the current 'frame' of an animation has finished being 1981displayed (after its 'delay' period), but before the next frame on an 1982animation is to be overlaid onto the display. </p> 1983 1984<p>Here are the valid methods:</p> 1985 1986<pre class="text"> 1987 Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>'). 1988 None 1 Do not dispose, just overlay next frame image. 1989 Background 2 Clear the frame area with the background color. 1990 Previous 3 Clear to the image prior to this frames overlay. 1991</pre> 1992 1993<p>You can also use the numbers given above, which is what the GIF format 1994uses internally to represent the above settings. </p> 1995 1996<p>To print a complete list of dispose methods, use <a href="#list">-list dispose</a>.</p> 1997 1998<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent 1999resetting the layer disposal methods of images being read in. </p> 2000 2001<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image 2002disposal method for images already in memory.</p> 2003 2004<div style="margin: auto;"> 2005 <h4><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4> 2006</div> 2007 2008<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> 2009 2010 2011<div style="margin: auto;"> 2012 <h4><a id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4> 2013</div> 2014 2015<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> 2016 2017<p>The opacity of the composite image is multiplied by the given percent, then 2018it is composited 'over' the main image. If <em class="arg">src_percent</em> 2019is greater than 100, start dissolving the main image so it becomes 2020transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages 2021are given, each image are dissolved to the percentages given. </p> 2022 2023<p>Note that dissolve percentages do not add, two opaque images dissolved 2024'50,50', produce a 75% transparency. For a 50% + 50% blending of the two 2025images, you would need to use dissolve values of '50,100'. </p> 2026 2027<div style="margin: auto;"> 2028 <h4><a id="distort"></a>-distort <em class="arg">method arguments</em></h4> 2029</div> 2030 2031<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> 2032 2033<p>The <em class="arg">arguments</em> is a single string containing a list 2034of floating point numbers separated by commas or spaces. The number of 2035and meaning of the floating point values depends on the distortion <em 2036class="arg">method</em> being used. </p> 2037 2038<p>Choose from these distortion types:</p> 2039 2040<table class="doc"> 2041 <tr valign="top"> 2042 <th align="left" style="width: 8%">Method</th> 2043 <th align="left">Description</th> 2044 </tr> 2045 2046 <tr valign="top"> 2047 <td valign="top"><kbd>ScaleRotateTranslate</kbd> 2048 <br/>or <kbd>SRT</kbd></td> 2049 <td valign="top"> 2050 Distort image by first scaling and rotating about a given 'center', 2051 before translating that 'center' to the new location, in that order. It 2052 is an alternative method of specifying a '<kbd>Affine</kbd>' type of 2053 distortion, but without shearing effects. It also provides a good way 2054 of rotating and displacing a smaller image for tiling onto a larger 2055 background (IE 2-dimensional animations). <br/> 2056 2057 The number of arguments determine the specific meaning of each 2058 argument for the scales, rotation, and translation operations. <br/> 2059 2060 <table style="margin-left:auto; margin-right:auto;"> 2061 <tr><td># </td><td>arguments meaning</td></tr> 2062 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr> 2063 <tr><td>2:</td><td><em>Scale Angle</em></td></tr> 2064 <tr><td>3:</td><td><em>X,Y Angle</em></td></tr> 2065 <tr><td>4:</td><td><em>X,Y Scale Angle</em></td></tr> 2066 <tr><td>5:</td> 2067 <td><em>X,Y ScaleX,ScaleY Angle</em></td></tr> 2068 <tr><td>6:</td> 2069 <td><em>X,Y Scale Angle NewX,NewY</em></td></tr> 2070 <tr><td>7:</td> 2071 <td><em>X,Y ScaleX,ScaleY Angle 2072 NewX,NewY</em></td></tr> 2073 </table> 2074 2075 This is actually an alternative way of specifying a 2 dimensional linear 2076 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr> 2077 2078 <tr valign="top"> 2079 <td valign="top"><kbd>Affine</kbd></td> 2080 <td valign="top"> 2081 Distort the image linearly by moving a list of at least 3 or more sets 2082 of control points (as defined below). Ideally 3 sets or 12 floating 2083 point values are given allowing the image to be linearly scaled, 2084 rotated, sheared, and translated, according to those three points. See 2085 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>' 2086 distortions. <br/> 2087 2088 More than 3 sets given control point pairs (12 numbers) is least 2089 squares fitted to best match a lineary affine distortion. If only 2 2090 control point pairs (8 numbers) are given a two point image translation 2091 rotation and scaling is performed, without any possible shearing, 2092 flipping or changes in aspect ratio to the resulting image. If only one 2093 control point pair is provides the image is only translated, (which may 2094 be a floating point non-integer translation). <br/> 2095 2096 This distortion does not include any form of perspective distortion. 2097 </td> 2098 2099 </tr> 2100 2101 <tr valign="top"> 2102 <td valign="top"><kbd>AffineProjection</kbd></td> 2103 <td valign="top"> 2104 Linearly distort an image using the given Affine Matrix of 6 2105 pre-calculated coefficients forming a set of Affine Equations to map 2106 the source image to the destination image. 2107 2108 <div style="text-align: center"><em> 2109 s<sub>x</sub>, r<sub>x</sub>, 2110 r<sub>y</sub>, s<sub>y</sub>, 2111 t<sub>x</sub>, t<sub>y</sub> 2112 </em></div> 2113 2114 See <a href="#affine" >-affine</a> setting for more detail, and 2115 meanings of these coefficients. <br/> 2116 2117 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide 2118 alternative methods of defining this distortion, with ImageMagick doing 2119 the calculations needed to generate the required coefficients. You can 2120 see the internally generated coefficients, by using a <a 2121 href="#verbose" >-verbose</a> setting with those other varients. </td> 2122 2123 </tr> 2124 2125 <tr valign="top"> 2126 <td valign="top"><kbd>BilinearForward</kbd><br/> 2127 <kbd>BilinearReverse</kbd></td> 2128 <td valign="top"> 2129 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or 2130 16 values (see below). Not that lines may not appear straight after 2131 distortion, though the distance between coordinates will remain 2132 consistent. <br/> 2133 2134 The '<kbd>BilinearForward</kbd>' is used to map rectangles to any 2135 quadrilateral, while the '<kbd>BilinearReverse</kbd>' form maps any 2136 quadrilateral to a rectangle, while preserving the straigth line edges 2137 in each case. <br/> 2138 2139 Note that '<kbd>BilinearForward</kbd>' can generate invalid pixels 2140 which will be colored using the <a href="#mattecolor" >-mattecolor</a> 2141 color setting. Also if the quadraterial becomes 'flipped' the image 2142 may dissappear. <br/> 2143 2144 There are future plans to produce a true Bilinear distortion that will 2145 attempt to map any quadrilateral to any other quadrilateral, while 2146 preserving edges (and edge distance ratios). 2147 2148 </td> 2149 </tr> 2150 2151 <tr valign="top"> 2152 <td valign="top"><kbd>Perspective</kbd></td> 2153 <td valign="top"> 2154 Perspective distort the images, using a list of 4 or more sets of 2155 control points (as defined below). More that 4 sets (16 numbers) of 2156 control points provide least squares fitting for more accurate 2157 distortions (for the purposes of image registration and panarama 2158 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>' 2159 linear distortion. <br/> 2160 2161 Perspective Distorted images ensures that straight lines remain 2162 straight, but the scale of the distorted image will vary. The horizon 2163 is anti-aliased, and the 'sky' color may be set using the 2164 <a href="#mattecolor" >-mattecolor</a> setting. </td> 2165 </tr> 2166 2167 <tr valign="top"> 2168 <td valign="top"><kbd>PerspectiveProjection</kbd> </td> 2169 <td valign="top"> 2170 Do a '<kbd>Perspective</kbd>' distortion biased on a set of 8 2171 pre-calculated coefficients. You can get these coefficients by looking 2172 at the <a href="#verbose" >-verbose</a> output of a 2173 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself. 2174 If the last two perspective scaling coefficients are zero, the 2175 remaining 6 represents a transposed 'Affine Matrix'. </td> 2176 2177 </tr> 2178 2179 <tr valign="top"> 2180 <td valign="top"><kbd>Arc</kbd></td> 2181 <td valign="top"> 2182 Arc the image (variation of polar mapping) over the angle given around 2183 a circle. <br/> 2184 <table width="90%" style = "margin-left: auto; margin-right: auto;"> 2185 <tr valign="top"><td>Argument</td> 2186 <td>Meaning</td></tr> 2187 <tr valign="top"><td><em>arc_angle</em></td> 2188 <td>The angle over which to arc the image side-to-side</td></tr> 2189 <tr valign="top"><td><em>rotate_angle</em></td> 2190 <td>Angle to rotate resulting image from vertical center</td></tr> 2191 <tr valign="top"><td><em>top_radius</em></td> 2192 <td>Set top edge of source image at this radius</td></tr> 2193 <tr valign="top"><td><em>bottom_radius</em> </td> 2194 <td>Set bottom edge to this radius (radial scaling)</td></tr> 2195 </table> 2196 2197 The resulting image is always resized to best fit the resulting image, 2198 (as if using <a href="#distort" >+distort</a>) while attempting to 2199 preserve scale and aspect ratio of the original image as much as 2200 possible with the arguments given by the user. All four arguments will 2201 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/> 2202 2203 This a variation of a polar distortion designed to try to preserve the 2204 aspect ratio of the image rather than direct Cartesian to Polar 2205 conversion. </td> 2206 </tr> 2207 2208 <tr valign="top"> 2209 <td valign="top"><kbd>Polar</kbd></td> 2210 <td valign="top"> 2211 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of 2212 the image. that is the height of the input image is mapped to the 2213 radius limits, while the width is wrapped around between the 2214 angle limits. <br/> 2215 2216 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/> 2217 2218 All arguments are optional. With <em>Rmin</em> defaulting to zero, the 2219 center to the center of the image, and the angles going from -180 (top) 2220 to +180 (top). If <em>Rmax</em> is given the special value of 2221 '<code>0</code>', the the distance from the center to the nearest edge 2222 is used for the radius of the output image, which will ensure the whole 2223 image is visible (though scaled smaller). However a special value of 2224 '<code>-1</code>' will use the distance from the center to the furthest 2225 corner, This may 'clip' the corners from the input rectangular image, 2226 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with 2227 the same arguments. <br/> 2228 2229 If the plus form of distort (<a href="#distort" >+distort</a>) is used 2230 output image center will default to <code>0,0</code> of the virtual 2231 canvas, and the image size adjusted to ensure the whole input image is 2232 made visible in the output image on the virtual canvas. </td> 2233 2234 </tr> 2235 2236 <tr valign="top"> 2237 <td valign="top"><kbd>DePolar</kbd></td> 2238 <td valign="top"> 2239 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion 2240 but generates the reverse Polar to Cartesian distortion. <br/> 2241 2242 The special <em>Rmax</em> setting of '<code>0</code>' may however clip 2243 the corners of the input image. However using the special 2244 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner 2245 distance) will ensure the whole distorted image is preserved in the 2246 generated result, so that the same argument to '<kbd>Polar</kbd>' will 2247 reverse the distortion re-producing the original. 2248 2249 Note that as this distortion requires the area resampling of a circular 2250 arc, which can not be handled by the builtin EWA resampling function. 2251 As such the normal EWA filters are turned off. It is recommended some 2252 form of 'super-sampling' image processing technique be used to produce 2253 a high quality result. </td> 2254 2255 </tr> 2256 2257 <tr valign="top"> 2258 <td valign="top"><kbd>Barrel</kbd></td> 2259 <td valign="top"> 2260 Given the four coefficients (A,B,C,D) as defined by <a 2261 href="http://wiki.panotools.org/Lens_correction_model" >Helmut 2262 Dersch</a>, perform a barrell or pin-cushion distortion appropriate to 2263 correct radial lens distortions. That is in photographs, make straight 2264 lines straight again. <br/> 2265 2266 Arguments: <em>A B C</em> [ <em>D</em> [ 2267 <em>X</em> , <em>Y</em> ] ] <br/> 2268 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 2269 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> 2270 [ <em>X</em> , <em>Y</em> ] <br/> 2271 So that it forms the function <br/> 2272 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2273 <em>C</em>*r + <em>D</em> )<br/> 2274 2275 Where <em>X</em>,<em>Y</em> is the optional center of the distortion 2276 (defaulting to the center of the image). <br/> 2277 The second form is typically used to distort images, rather than 2278 correct lens distortions. <br/> 2279 </td> 2280 2281 </tr> 2282 2283 <tr valign="top"> 2284 <td valign="top"><kbd>BarrelInverse</kbd></td> 2285 <td valign="top"> 2286 This is very simular to '<kbd>Barrel</kbd>' with the same set of 2287 arguments, and argument handling. However it uses the inverse 2288 of the radial polynomial, 2289 so that it forms the function <br/> 2290 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2291 <em>C</em>*r + <em>D</em> )<br/> 2292 Note that this is not the reverse of the '<kbd>Barrel</kbd>' 2293 distortion, just a different barrel-like radial distortion method. 2294 2295 </td> 2296 </tr> 2297 2298 <tr valign="top"> 2299 <td valign="top"><kbd>Shepards</kbd></td> 2300 <td valign="top"> 2301 Distort the given list control points (any number) using an Inverse 2302 Squared Distance Interpolation Method (<a 2303 href="http://en.wikipedia.org/wiki/Shepard%27s_method" >Shepards 2304 Method</a>). The control points in effect do 'localized' displacement 2305 of the image around the given control point (preserving the look and 2306 the rotation of the area near the control points. For best results 2307 extra control points should be added to 'lock' the positions of the 2308 corners, edges and other unchanging parts of the image, to prevent 2309 their movement. <br/> 2310 2311 The distortion has been likened to 'taffy pulling' using nails, or 2312 pins' stuck in a block of 'jelly' which is then moved to the new 2313 position, distorting te surface of the jelly. <br/> 2314 2315 Internally it is equivalent to generating a displacement map (see <a 2316 href="#displace" >-displace</a>) for source image color look-up using 2317 the <a href="#sparse-color" >-sparse-color</a> method of the same name. 2318 2319 </td> 2320 </tr> 2321 2322</table> 2323 2324<p>To print a complete list of distortion methods, use <a href="#list">-list 2325distort</a>.</p> 2326 2327<p>Many of the above distortion methods such as '<kbd>Affine</kbd>', 2328'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points 2329defining how these points in the given image should be distorted in the 2330destination image. Each set of four floating point values represent a source 2331image coordinate, followed immediately by the destination image coordinate. 2332This produces a list of values such as...</p> 2333<div style="text-align: center"><em> 2334 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 2335 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 2336 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 2337 ... 2338 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 2339</em></div> 2340<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the 2341destination image. </p> 2342 2343<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion, 2344needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 2345perspective distortion of the built-in "rose:" image. Note how spaces were 2346used to group the 4 sets of coordinate pairs, to make it easier to read and 2347understand.</p> 2348 2349<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2350convert rose: -virtual-pixel black \<br/> 2351 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \<br/> 2352 rose_3d_rotated.gif</span></p> 2353<p>If more that the required number of coordinate pairs are given for 2354a distortion, the distortion method is 'least squares' fitted to produce the 2355best result for all the coordinate pairs given. If less than the ideal number 2356of points are given, the distort will generally fall back to a simpler form of 2357distortion that can handles the smaller number of coordinates (usally a linear 2358'<kbd>Affine</kbd>' distortion). </p> 2359 2360<p>By using more coordinates you can make use of image registration tool to 2361find matching coordinate pairs in overlapping images, so as to improve the 2362'fit' of the distortion. Of course a bad coordinate pair can also make the 2363'fit' worse. Caution is always advised. </p> 2364 2365<p>Colors are acquired from the source image according to the <a 2366href="#interpolate" >-interpolate</a> color lookup setting, when the image is 2367magnified. However if the viewed image is minified (image becomes smaller), 2368a special area resampling function (added ImageMagick v6.3.5-9), is used to 2369produce a higher quality image. For example you can use 2370a '<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all 2371the way to the horizon. </p> 2372 2373<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2374convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \<br/> 2375 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \<br/> 2376 checks_tiled.jpg</span></p> 2377<p>Note that a infinitely tiled perspective images involving the horizon can 2378be very slow to generate due to the use of the high quality 'area resampling' 2379function (added ImageMagick v6.3.5-9). You can turn off 'area resampling' 2380using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>' 2381(recommended if you plan to use super-sampling instead). </p> 2382 2383<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 2384'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a> 2385will use the current <a href="#mattecolor" >-mattecolor</a> setting for these 2386pixels. If you do not what these pixels to be visible, set the color to match 2387the rest of the ground. </p> 2388 2389<p>The output image size will by default be the same as the input image. This 2390means that if the part of the distorted image falls outside the viewed area of 2391the 'distorted space', those parts is clipped and lost. However if you use 2392the plus form of the operator (<a href="#distort" >+distort</a>) the operator 2393will attempt (if possible) to show the whole of the distorted image, while 2394retaining a correct 'virtual canvas' offset, for image layering. This offset 2395may need to be removed using <a href="#repage" >+repage</a>, to remove if it 2396is unwanted. </p> 2397 2398<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a> 2399option:distort:viewport {geometry_string}</kbd>" setting which will specify 2400the size and the offset of the generated 'viewport' image of the distorted 2401image space.</p> 2402 2403<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale 2404{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by 2405that factor without changing the viewed contents of the distorted image. This 2406can be used either for 'super-sampling' the image for a higher quality result, 2407or for panning and zooming around the image (with appropriate viewport 2408changes, or post-distort cropping and resizing). </p> 2409 2410<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a 2411href="#distort" >-distort</a> to attempt to output the internal coefficients, 2412and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study, 2413and debugging purposes. This many not be available for all distorts. </p> 2414 2415<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to 2416produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a> 2417and/or <a href="#shear" >-shear</a> operation, with more control of due to the 2418above settings. It is algorithmically slower however, though that may not be 2419the case in ImageMagick's implementation. </p> 2420 2421 2422<div style="margin: auto;"> 2423 <h4><a id="dither"></a>-dither <em class="arg">method</em></h4> 2424</div> 2425 2426<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> 2427 2428<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> 2429 2430<p>Dithering is turned on by default, to turn it off use the plus form of the 2431setting, <a href="#dither">+dither</a>. This will also also render PostScript 2432without text or graphic aliasing. Disabling dithering often (but not always) 2433leads to faster process, a smaller number of colors, but more cartoon like 2434image coloring. Generally resulting in 'color banding' effects in areas with 2435color gradients. </p> 2436 2437<p>The color reduction operators <a href="#colors">-colors</a>, <a 2438href="#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> 2439 2440<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> 2441 2442 2443<div style="margin: auto;"> 2444 <h4><a id="draw"></a>-draw <em class="arg">string</em></h4> 2445</div> 2446 2447<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> 2448 2449<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> 2450 2451<p>The shape primitives:</p> 2452 2453<pre class="text"> 2454 point x,y 2455 line x0,y0 x1,y1 2456 rectangle x0,y0 x1,y1 2457 roundRectangle x0,y0 x1,y1 wc,hc 2458 arc x0,y0 x1,y1 a0,a1 2459 ellipse x0,y0 rx,ry a0,a1 2460 circle x0,y0 x1,y1 2461 polyline x0,y0 ... xn,yn 2462 polygon x0,y0 ... xn,yn 2463 bezier x0,y0 ... xn,yn 2464 path path specification 2465 image operator x0,y0 w,h filename 2466</pre> 2467 2468<p>The text primitive:</p> 2469 2470<pre class="text"> 2471 text x0,y0 string 2472</pre> 2473<p>The text gravity primitive:</p> 2474 2475<pre class="text"> 2476 gravity NorthWest, North, NorthEast, West, Center, 2477 East, SouthWest, South, or SouthEast 2478</pre> 2479 2480<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> 2481 2482<p>The transformation primitives:</p> 2483 2484<pre class="text"> 2485 rotate degrees 2486 translate dx,dy 2487 scale sx,sy 2488 skewX degrees 2489 skewY degrees 2490</pre> 2491 2492<p>The pixel operation primitives:</p> 2493 2494<pre class="text"> 2495 color x0,y0 method 2496 matte x0,y0 method 2497</pre> 2498 2499<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> 2500 2501<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> 2502 2503<p>A <kbd>line</kbd> primitive requires a start point and end point.</p> 2504 2505<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p> 2506 2507<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> 2508 2509<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p> 2510 2511<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> 2512 2513<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> 2514 2515<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>. 2516</p> 2517 2518<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p> 2519 2520<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p> 2521 2522<p class="crtsnip"> 2523 -draw 'circle 100,100 150,150' 2524</p> 2525 2526<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 2527draw 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> 2528 2529<p class="crtsnip"> 2530 -draw 'bezier 20,50 45,100 45,0 70,50' 2531</p> 2532<p class="crtsnip"> 2533 -draw 'bezier 70,50 95,100 95,0 120,50' 2534</p> 2535 2536 2537<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> 2538 2539<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> 2540 2541<p class="crtsnip"> 2542 -draw 'image SrcOver 100,100 225,225 image.jpg' 2543</p> 2544 2545<p>You can use 0,0 for the image size, which means to use the actual 2546dimensions found in the image header. Otherwise, it is scaled to the given 2547dimensions. See <a href="/www/compose.html">Alpha Compositing</a> for 2548a detailed discussion of alpha composition methods that are available. </p> 2549 2550<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> 2551 2552<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p> 2553 2554<p class="crtsnip"> 2555 -draw "text 100,100 'Works like magick!' " 2556</p> 2557 2558<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p> 2559 2560<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> 2561 2562<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p> 2563 2564<p>The <kbd>scale</kbd> primitive scales them.</p> 2565 2566<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> 2567 2568<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 2569matrix.</p> 2570 2571<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> 2572 2573<pre class="text"> 2574 point 2575 replace 2576 floodfill 2577 filltoborder 2578 reset 2579</pre> 2580 2581<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> 2582 2583<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> 2584 2585<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> 2586 2587<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p> 2588 2589<p>Drawing primitives conform to the <a href="/www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p> 2590 2591<div style="margin: auto;"> 2592 <h4><a id="duplicate"></a>-duplicate <em class="arg">count,indexes</em></h4> 2593</div> 2594 2595<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>duplicate an image one or more times.</td><td style='text-align:right;'></td></tr></table> 2596 2597<p>Specify the count and the image to duplicate 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>+duplicate</kbd> to duplicate the last image in the current image sequence.</p> 2598 2599<div style="margin: auto;"> 2600 <h4><a id="edge"></a>-edge <em class="arg">radius</em></h4> 2601</div> 2602 2603<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> 2604 2605<div style="margin: auto;"> 2606 <h4><a id="emboss"></a>-emboss <em class="arg">radius</em></h4> 2607</div> 2608 2609<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> 2610 2611<div style="margin: auto;"> 2612 <h4><a id="encipher"></a>-encipher <em class="arg">filename</em></h4> 2613</div> 2614 2615<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> 2616 2617<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 2618 2619<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 2620 2621 2622 2623<div style="margin: auto;"> 2624 <h4><a id="encoding"></a>-encoding <em class="arg">type</em></h4> 2625</div> 2626 2627<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> 2628 2629<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> 2630 2631<div style="margin: auto;"> 2632 <h4><a id="endian"></a>-endian <em class="arg">type</em></h4> 2633</div> 2634 2635<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> 2636 2637<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p> 2638 2639<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p> 2640 2641 2642<div style="margin: auto;"> 2643 <h4><a id="enhance"></a>-enhance</h4> 2644</div> 2645 2646<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> 2647 2648 2649<div style="margin: auto;"> 2650 <h4><a id="equalize"></a>-equalize</h4> 2651</div> 2652 2653<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> 2654 2655<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> 2656 2657<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p> 2658 2659<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> 2660 2661<div style="margin: auto;"> 2662 <h4><a id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4> 2663</div> 2664 2665<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> 2666 2667<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> 2668 2669<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> 2670 2671<table class="doc"> 2672 <col width="25%" /> 2673 <col width="75%" /> 2674 <thead> 2675 <tr> 2676 <th><em class="arg">operator</em></th> 2677 <th>Summary (see further below for details)</th> 2678 </tr> 2679 </thead> 2680 <tbody> 2681 2682 <tr><td>Abs </td> <td>Add <em class="arg">value</em> to pixels and return absolute value. </td></tr> 2683 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr> 2684 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr> 2685 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr> 2686 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2687 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr> 2688 <tr><td>Exp </td> <td>base-e exponential function</td></tr> 2689 <tr><td>Exponential </td> <td>base-e exponential function</td></tr> 2690 <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> 2691 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr> 2692 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr> 2693 <tr><td>Mean </td> <td>Add the <em class="arg">value</em> and divide by 2.</td></tr> 2694 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr> 2695 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr> 2696 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr> 2697 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr> 2698 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr> 2699 <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> 2700 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr> 2701 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2702 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr> 2703 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr> 2704 2705 <tr><td> </td></tr> 2706 2707 <tr><td>Gaussian-noise</td></tr> 2708 <tr><td>Impulse-noise</td></tr> 2709 <tr><td>Laplacian-noise</td></tr> 2710 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr> 2711 <tr><td>PoissonNoise</td></tr> 2712 <tr><td>Uniform-noise</td></tr> 2713 2714 <tr><td> </td></tr> 2715 2716 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr> 2717 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr> 2718 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr> 2719 </tbody> 2720 </table> 2721 2722<p>The specified functions are applied only to each previously set <a 2723href="#channel" >-channel</a> in the image. If necessary, the results of the 2724calculations are truncated (clipped) to fit in the interval [0, <em 2725class="QR">QuantumRange</em>]. The transparency channel of the image is 2726represented as a 'alpha' values (0 = fully transparent), so, for example, a 2727<kbd>Divide</kbd> by 2 of the alpha channel will make the image 2728semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value 2729as a percentage of the <em class="QR">QuantumRange</em>.</p> 2730 2731<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use 2732<a href="#list">-list evaluate</a>.</p> 2733 2734<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and 2735<kbd>Multiply</kbd> methods can also be achieved using either the <a 2736href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with 2737appropriate argument, to linearly modify the overall range of color values. 2738Please note, however, that <a href="#level" >-level</a> treats transparency as 2739'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with 2740'alpha' values.</p> 2741 2742<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> 2743 2744<p><kbd>Exp or Exponential</kbd> has been added as of ImageMagick 6.6.5-1 and works on normalized pixel values. The <em class="arg">value</em> used with <kbd>Exp</kbd> should be negative so as to produce a decaying exponential function. Non-negative values will always produce results larger unity and thus outside the interval [0, <em class="QR">QuantumRange</em>]. The formula is expressed below. </p> 2745 2746 <div style="text-align:center;"> 2747 exp(<em class="arg">value</em> × <b><em>u</em></b>) 2748 </div> 2749 2750<p> If the input image is squared, for example, using <a 2751href="#-function" >-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be the result.</p> 2752 2753<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> 2754 2755 <div style="text-align:center;"> 2756 log(<em class="arg">value</em> × <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1) 2757 </div> 2758 2759<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on 2760normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a 2761href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent 2762to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used 2763with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used 2764with <kbd>Pow</kbd>.</p> 2765 2766<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and 2767converts the image values into a value according to a (co)sine wave function. 2768The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output 2769is biased 50% and normalized by 50% so as to fit in the respective color value 2770range. The <em class="arg">value</em> scaling of the <em>period</em> of the 2771function (its frequency), and thus determines the number of 'waves' that will 2772be generated over the input color range. For example, if the <em 2773class="arg">value</em> is 1, the effective period is simply the <em 2774class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is 2, 2775then the effective period is the <em>half</em> the <em 2776class="QR">QuantumRange</em>.</p> 2777 2778 <div style="text-align:center;"> 2779 0.5 + 0.5 × cos(2 π <b><em>u</em></b> × <em class="arg">value</em>). 2780 </div> 2781 2782<p>See also the <a href="#function" >-function</a> operator, which is a 2783multi-value version of evaluate. </p> 2784 2785<div style="margin: auto;"> 2786 <h4><a id="evaluate-sequence"></a>-evaluate-sequence <em class="arg">operator</em></h4> 2787</div> 2788 2789<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> 2790 2791<div style="margin: auto;"> 2792 <h4><a id="extent"></a>-extent <em class="arg">geometry</em></h4> 2793</div> 2794 2795<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> 2796 2797<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> 2798<p>This command reduces or expands a JPEG image to fit on an 800x600 2799display. If the aspect ratio of the input image isn't exactly 4:3, then the 2800image is centered on an 800x600 black canvas: </p> 2801 2802<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert input.jpg -resize 800x600 -background black -compose Copy \ <br /> -gravity center -extent 800x600 -quality 92 output.jpg</span></p> 2803 2804 2805<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> 2806 2807<div style="margin: auto;"> 2808 <h4><a id="extract"></a>-extract <em class="arg">geometry</em></h4> 2809</div> 2810 2811<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> 2812 2813<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p> 2814 2815<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> 2816 2817<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> 2818<p>the image is <em>resized</em> to the specified dimensions instead, 2819equivalent to:</p> 2820 2821<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png</span></p> 2822<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> 2823 2824<div style="margin: auto;"> 2825 <h4><a id="family"></a>-family <em class="arg">fontFamily</em></h4> 2826</div> 2827 2828<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> 2829 2830<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). 2831</p> 2832 2833<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>. 2834</p> 2835 2836<div style="margin: auto;"> 2837 <h4><a id="features"></a>-features <em class="arg">distance</em></h4> 2838</div> 2839 2840<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> 2841 2842<div style="margin: auto;"> 2843 <h4><a id="fft"></a>-fft</h4> 2844</div> 2845 2846<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> 2847 2848<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">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p> 2849 2850<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">Complex Numbers</a>.</p> 2851 2852<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> 2853 2854<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p> 2855<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> 2856 2857<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.png</span></p> 2858<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> 2859 2860<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> 2861 2862<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> 2863 2864<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br /> 2865 -evaluate log 1000 fft_image_spectrum.png</span></p> 2866<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> 2867 2868<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>.</p> 2869 2870<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> 2871 2872<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> 2873 2874<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.</p> 2875 2876<p>See the discussion on HDRI implementations of ImageMagick on the page 2877<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. 2878</p> 2879 2880 2881<div style="margin: auto;"> 2882 <h4><a id="fill"></a>-fill <em class="arg">color</em></h4> 2883</div> 2884 2885<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> 2886 2887<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> 2888 2889<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p> 2890 2891<p>For example,</p> 2892 2893<p class="crtsnip"> 2894 -fill blue 2895</p> 2896<p class="crtsnip"> 2897 -fill "#ddddff" 2898</p> 2899<p class="crtsnip"> 2900 -fill "rgb(255,255,255)" 2901</p> 2902 2903<p>See <a href="#draw">-draw</a> for further details.</p> 2904 2905<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p> 2906 2907<div style="margin: auto;"> 2908 <h4><a id="filter"></a>-filter <em class="arg">type</em></h4> 2909</div> 2910 2911<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 2912distorting an image.</td><td style='text-align:right;'></td></tr></table> 2913 2914<p>Use this option to affect the resizing operation of an image during 2915operations such as <a href="#resize">-resize</a> and <a href="#distort" 2916>-distort</a>. For example you can use a simple resize filter such as:</p> 2917 2918<pre class="text"> 2919 Point Hermite Cubic 2920 Box Gaussian Catrom 2921 Triangle Quadratic Mitchell 2922</pre> 2923 2924<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided (as well 2925as a faster <kbd>SincFast</kbd> equivalent form). However these filters are 2926generally useless on their own as they are infinite filters that are being 2927clipped to the filters support size. Their direct use is not recommended 2928except via expert settings (see below). </p> 2929 2930<p>Instead these special filter functions are typically windowed by a windowing 2931function that the <a href="#filter" >-filter</a> setting defines. That is 2932using these functions will define a 'Windowed' filter, appropriate to the 2933operator involved. Windowed filters include: </p> 2934 2935<pre class="text"> 2936 Lanczos Hamming Parzen 2937 Blackman Kaiser Welsh 2938 Hanning Bartlett Bohman 2939</pre> 2940 2941<p>Also one special self-windowing filter is also provided 2942<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending 2943on the current 'support' or 'lobes' expert settings (see below).</p> 2944 2945<p>If you do not select a filter with this option, the filter defaults to 2946<kbd>Mitchell</kbd> for a colormapped image, a image with a matte channel, or 2947if the image is enlarged. Otherwise the filter default to 2948<kbd>Lanczos</kbd>.</p> 2949 2950<p>To print a complete list of resize filters, use the <a href="#list">-list 2951filter</a> option.</p> 2952 2953<p>You can modify how the filter behaves as it scales your image through the 2954use of these expert settings (see also <a href="#define" >-define</a> and <a 2955href="#set" >-set</a>):-</p> 2956 2957<dl class="doc"> 2958<dt>-define filter:blur=<em>factor</em></dt> 2959<dd>Scale the X axis of the filter (and its window). Use > 1.0 for 2960 blurry or < 1.0 for sharp. This should only be used with Gaussian and 2961 Gaussian-like filters simple filters, or you may not get the expected 2962 results. </dd> 2963 2964<dt>-define filter:support=<em>radius</em></dt> 2965<dd>Set the filter support radius. Defines how large the filter should be and 2966 thus directly defines how slow the filtered resampling process is. All 2967 filters have a default 'prefered' support size. Some filters like 2968 <kbd>Lagrange</kbd> and windowed filters adjust themselves depending on 2969 this value. With simple filters this value either does nothing (but slow 2970 the resampling), or will clip the filter function in a detrimental way. 2971 </dd> 2972 2973<dt>-define filter:lobes=<em>count</em></dt> 2974<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an 2975 alternative way of specifying the 'support' range of the filter, that is 2976 designed to be more suited to windowed filters, especially when used for 2977 image distorts.</dd> 2978 2979<dt>-define filter:b=<em>b-spline_factor</em></dt> 2980<dt>-define filter:c=<em>keys_alpha_factor</em></dt> 2981<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>, 2982 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as 2983 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values 2984 are defined, the other is set so as to generate a 'Keys' type cubic 2985 filter. Values meaning was defined by a research paper by 2986 Mitchell-Netravali.</dd> 2987 2988<dt>-define filter:filter=<em>filter_function</em></dt> 2989<dd>Use this function directly as the scaling filter. This will allow 2990 you to directly use a windowing filter such as <kbd>Blackman</kbd>, 2991 rather than as its normal usage as a windowing function for 'Sinc' or 2992 'Bessel' functions. If defined, no windowing function is used, unless the 2993 following expert setting is also defined.</dd> 2994 2995<dt>-define filter:window=<em>filter_function</em></dt> 2996<dd>The IIR (infinite impulse response) filters <kbd>Bessel</kbd> and 2997 <kbd>Sinc</kbd> are windowed (brought down to zero over the defined 2998 support range) with the given filter. This allows you to specify a filter 2999 function that is not normally used as a windowing function, such as 3000 <kbd>Box</kbd>, (which effectively turns off the windowing function), 3001 to window a <kbd>Sinc</kbd>, or the function the previous setting defined. 3002 </dd> 3003 3004<dt>-define filter:verbose=<em>1</em></dt> 3005<dd>This causes IM to print information on the final internal filter 3006 selection to standard output. This includes a commented header on the 3007 filter settings being used, and data allowing the filter weights to be 3008 easily graphed. </dd> 3009 3010<dd>Note however that some filters are internally defined in terms of other 3011 filters. The <kbd>Lanczos</kbd> filter for example is defined in terms of 3012 a <kbd>SincFast</kbd> windowed <kbd>SincFast</kbd> filter, while 3013 <kbd>Mitchell</kbd> is defined as a <kbd>Cubic</kbd> filter with specific 3014 'B' and 'C' settings. </dd> 3015 3016</dl> 3017 3018<p>For example, to get a 8 lobe Bessel windowed Bessel filter:</p> 3019 3020<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -filter bessel \ <br/> 3021 -set filter:window=bessel -set filter:lobes=8 \ <br/> 3022 -resize 150% image.jpg</span></p> 3023<p>Or a raw un-windowed Sinc filter with 4 lobes:</p> 3024 3025<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/> 3026 -resize 150% image.jpg</span></p> 3027<p>Note that the use of expert options (except for 'blur' with simple resize 3028filters, and 'verbose' for viewing the internal filter selection), are 3029provided for image processing experts who have studied and understood how 3030resize filters work. Without this knowledge, and an understanding of the 3031definition of the actual filters involved, using expert settings are more 3032likely to be detrimental to your image resizing.</p> 3033 3034 3035<div style="margin: auto;"> 3036 <h4><a id="flatten"></a>-flatten</h4> 3037</div> 3038 3039<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> 3040 3041 3042<div style="margin: auto;"> 3043 <h4><a id="flip"></a>-flip</h4> 3044</div> 3045 3046<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> 3047 3048<p>reflect the scanlines in the vertical direction.</p> 3049 3050<div style="margin: auto;"> 3051 <h4><a 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> 3052</div> 3053 3054<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> 3055 3056<div style="margin: auto;"> 3057 <h4><a id="flop"></a>-flop</h4> 3058</div> 3059 3060<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> 3061 3062<p>reflect the scanlines in the horizontal direction.</p> 3063 3064 3065<div style="margin: auto;"> 3066 <h4><a id="font"></a>-font <em class="arg">name</em></h4> 3067</div> 3068 3069<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> 3070 3071<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> 3072 3073<p>In addition to the fonts specified by the above pre-defined list, you can 3074also specify a font from a specific source. For example <kbd>Arial.ttf</kbd> 3075is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and 3076<kbd>x:fixed</kbd> is X11 font.</p> 3077 3078<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> 3079 3080 3081<div style="margin: auto;"> 3082 <h4><a id="foreground"></a>-foreground <em class="arg">color</em></h4> 3083</div> 3084 3085<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> 3086 3087<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 3088 3089<p>The default foreground color is black.</p> 3090 3091<div style="margin: auto;"> 3092 <h4><a id="format"></a>-format <em class="arg">type</em></h4> 3093</div> 3094 3095<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> 3096 3097<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> 3098 3099<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> 3100 3101<div style="margin: auto;"> 3102 <h4><a id="format_identify_"></a>-format <em class="arg">string</em></h4> 3103</div> 3104 3105<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> 3106 3107<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> 3108 3109<div style="margin: auto;"> 3110 <h4><a id="frame"></a>-frame <em class="arg">geometry</em></h4> 3111</div> 3112 3113<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> 3114 3115<p>The color of the border is specified with the <a href="#mattecolor" 3116>-mattecolor</a> command line option. </p> 3117 3118<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 3119class="arg">geometry</em> argument indicates the amount of extra width and 3120height that is added to the dimensions of the image. If no offsets are given 3121in the <em class="arg">geometry</em> argument, then the border added is 3122a solid color. Offsets <em>x</em> and <em>y</em>, if present, specify that 3123the width and height of the border is partitioned to form an outer bevel of 3124thickness <em>x</em> pixels and an inner bevel of thickness 3125<em>y</em> pixels. Negative offsets make no sense as frame arguments. 3126</p> 3127 3128<p>The <a href="#frame">-frame</a> option is affected by the current <a 3129href="#compose">-compose</a> setting and assumes that this is using the default 3130'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 3131size with the current <a href="#bordercolor">-bordercolor</a> setting, and then 3132draws the frame of four distinct colors close to the current <a 3133href="#mattecolor">-mattecolor</a>. The original image is then overlaid onto 3134center of this image. This means that with the default compose method of 3135'<kbd>Over</kbd>' any transparent parts may be replaced by the current <a 3136href="#bordercolor">-bordercolor</a> setting.</p> 3137 3138<p>The image composition is not 3139affected by the <a href="#gravity">-gravity</a> option.</p> 3140 3141 3142<div style="margin: auto;"> 3143 <h4><a id="frame_import_"></a>-frame</h4> 3144</div> 3145 3146<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> 3147 3148<div style="margin: auto;"> 3149 <h4><a id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</em></h4> 3150</div> 3151 3152<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> 3153 3154<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> 3155 3156<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> 3157 3158<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> 3159 3160<pre class="text"> 3161 Polynomial 3162 Sinusoid 3163 Arcsin 3164 Arctan 3165</pre> 3166 3167<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p> 3168 3169<dl class="doc"> 3170<dt><kbd>Polynomial</kbd></dt> 3171<dd> 3172<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> 3173 3174<div style="text-align: center"> 3175 -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> 3176</div> 3177 3178<p>will invoke a polynomial function given by</p> 3179 3180<div style="text-align: center"> 3181 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> + 3182 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> + 3183 ··· <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>, 3184</div> 3185 3186<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p> 3187 3188<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> 3189 3190<table class="doc"> 3191 <col width="35%" /> 3192 <col width="35%" /> 3193 <col width="30%" /> 3194 <tr> 3195 <td>-evaluate Set <em class="arg">value</em> </td> 3196 <td>-function Polynomial <em class="arg">value</em></td> 3197 <td>(Constant functions; set <em class="arg">value</em>×100% gray when channels are RGB.)</td> 3198 </tr> 3199 <tr> 3200 <td>-evaluate Add <em class="arg">value</em> </td> 3201 <td>-function Polynomial 1,<em class="arg">value</em></td> 3202 </tr> 3203 <tr> 3204 <td>-evaluate Subtract <em class="arg">value</em> </td> 3205 <td>-function Polynomial 1,−<em class="arg">value</em></td> 3206 </tr> 3207 <tr> 3208 <td>-evaluate Multiply <em class="arg">value</em> </td> 3209 <td>-function Polynomial <em class="arg">value</em>,0</td> 3210 </tr> 3211 <tr> 3212 <td>+level black% x white%</td> 3213 <td>-function Polynomial A,B</td> 3214 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td> 3215 </tr> 3216</table> 3217 3218<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> 3219</dd> 3220 3221<dt><kbd>Sinusoid</kbd></dt> 3222<dd> 3223<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> 3224 3225<div style="text-align: center"> 3226 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]] 3227</div> 3228 3229<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> 3230 3231<div style="text-align: center"> 3232<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> 3233</div> 3234 3235<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> 3236 3237<p class="crtsnip"> 3238 -function Sinusoid 3,-90,.2,.7 3239</p> 3240 3241<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> 3242 3243<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> 3244 3245<table class="doc"> 3246 <tr> 3247 <td>-evaluate Sin <em class="arg">freq</em> </td> 3248 <td>-function Sinusoid <em class="arg">freq</em>,0 </td> 3249 </tr> 3250 <tr> 3251 <td>-evaluate Cos <em class="arg">freq</em> </td> 3252 <td>-function Sinusoid <em class="arg">freq</em>,90 </td> 3253 </tr> 3254</table> 3255</dd> 3256 3257<dt><kbd>ArcSin</kbd></dt> 3258<dd> 3259<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid, 3260and can be used to generate cylindrical distortion and displacement maps. 3261The curve can be adjusted relative to both the input values and output range 3262of values.</p> 3263 3264<p style="text-align: center"> 3265 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3266</p> 3267 3268<p>with all values given in terms of noramlize color values (0.0 for black, 32691.0 for white). Defaulting to values covering the full range from 0.0 to 1.0 3270for bout input (<em class="arg">width</em>), and output (<em 3271class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p> 3272 3273<p style="text-align: center"> 3274<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> 3275</p> 3276 3277</dd> 3278 3279<dt><kbd>ArcTan</kbd></dt> 3280<dd> 3281<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from 3282limit values at infinities, though a center using the given slope value. 3283All these values can be adjusted via the arguments.</p> 3284 3285<p style="text-align: center"> 3286 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3287</p> 3288 3289<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'. 3290</p> 3291 3292<p style="text-align: center"> 3293<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> 3294</p> 3295 3296</dd> 3297 3298</dl> 3299 3300 3301<div style="margin: auto;"> 3302 <h4><a id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4> 3303</div> 3304 3305<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> 3306 3307<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> 3308 3309<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> 3310 3311 3312<div style="margin: auto;"> 3313 <h4><a id="fx"></a>-fx <em class="arg">expression</em></h4> 3314</div> 3315 3316<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> 3317 3318<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> 3319 3320<p>See <a href="/www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p> 3321 3322 3323<div style="margin: auto;"> 3324 <h4><a id="gamma"></a>-gamma <em class="arg">value</em></h4> 3325</div> 3326 3327<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> 3328 3329<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> 3330 3331<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> 3332 3333<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> 3334 3335<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> 3336 3337<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p> 3338 3339<div style="margin: auto;"> 3340 <h4><a 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> 3341</div> 3342 3343<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> 3344 3345<p>Convolve the image with a Gaussian or normal distribution using the given 3346<em class="arg" >Sigma</em> value. The formula is:</p> 3347 3348<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 3349</div> 3350 3351<p>The <em class="arg" >Sigma</em> value is the important argument, and 3352determines the actual amount of blurring that will take place. </p> 3353 3354<p>The <em class="arg" >Radius</em> is only used to determine the size of the 3355array which will hold the calculated Gaussian distribution. It should be an 3356integer. If not given, or set to zero, IM will calculate the largest possible 3357radius that will provide meaningful results for the Gaussian distribution. 3358</p> 3359 3360<p>The larger the <em class="arg" >Radius</em> the radius the slower the 3361operation is. However too small a <em class="arg" >Radius</em>, and sever 3362aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 3363should be at least twice the <em class="arg" >Sigma</em> value, though three 3364times will produce a more accurite result. </p> 3365 3366<p>This differs from the faster <a href="#blur">-blur</a> operator in that a 3367full 2-dimensional convolution is used to generate the weighted average of the 3368neighboring pixels. </p> 3369 3370<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 3371pixels which are outside the image proper are blurred into the final result. 3372</p> 3373 3374 3375<div style="margin: auto;"> 3376 <h4><a id="geometry"></a>-geometry <em class="arg">geometry</em></h4> 3377</div> 3378 3379<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> 3380 3381<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> 3382 3383<div style="margin: auto;"> 3384 <h4><a id="gravity"></a>-gravity <em class="arg">type</em></h4> 3385</div> 3386 3387<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> 3388 3389<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>, 3390<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>, 3391<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete 3392list of <a href="#gravity">-gravity</a> settings available in your ImageMagick 3393installation.</p> 3394 3395<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> 3396 3397<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> 3398 3399<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> 3400 3401<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> 3402<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> 3403 3404<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> 3405 3406 3407<div style="margin: auto;"> 3408 <h4><a id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4> 3409</div> 3410 3411<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> 3412 3413 3414<div style="margin: auto;"> 3415 <h4><a id="hald-clut"></a>-hald-clut</h4> 3416</div> 3417 3418<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> 3419 3420<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2 3421dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You 3422can apply any color transformation to the Hald image and then use this option 3423to apply the transform to the image. </p> 3424 3425<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p> 3426<p>This option provides a convenient method for you to use Gimp or Photoshop 3427to make color corrections to the Hald CLUT image and subsequently apply them 3428to multiple images using an ImageMagick script. </p> 3429 3430<p>Note that the representation is only of the normal RGB color space and that 3431the whole color value triplet is used for the interpolated lookup of the 3432represented Hald color cube image. Because of this the operation is not <a 3433href="#channel" >-channel</a> setting effected, nor can it adjust or modify an 3434images transparency or alpha/matte channel.</p> 3435 3436<p>See also <a href="#clut" >-clut</a> which provides color value replacement 3437of the individual color channels, usally involving a simplier gray-scale 3438image. E.g: gray-scale to color replacement, or modification by a histogram 3439mapping. </p> 3440 3441 3442<div style="margin: auto;"> 3443 <h4><a id="help"></a>-help</h4> 3444</div> 3445 3446<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> 3447 3448<div style="margin: auto;"> 3449 <h4><a id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4> 3450</div> 3451 3452<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> 3453 3454<div style="margin: auto;"> 3455 <h4><a id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4> 3456</div> 3457 3458<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> 3459 3460<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> 3461 3462<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> 3463 3464<div style="margin: auto;"> 3465 <h4><a id="iconic"></a>-iconic</h4> 3466</div> 3467 3468<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> 3469 3470<div style="margin: auto;"> 3471 <h4><a id="identify"></a>-identify</h4> 3472</div> 3473 3474<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> 3475 3476<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> 3477 3478<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> 3479 3480<p>If <a href="#verbose">-verbose</a> precedes this option, copious 3481amounts of image properties are displayed including image statistics, profiles, 3482image histogram, and others.</p> 3483 3484<div style="margin: auto;"> 3485 <h4><a id="ift"></a>-ift</h4> 3486</div> 3487 3488<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> 3489 3490<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">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p> 3491 3492<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> 3493 3494<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p> 3495<p>or</p> 3496 3497<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> 3498 3499<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.</p> 3500 3501<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>.</p> 3502 3503<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.</p> 3504 3505<div style="margin: auto;"> 3506 <h4><a id="immutable"></a>-immutable</h4> 3507</div> 3508 3509<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> 3510 3511<div style="margin: auto;"> 3512 <h4><a id="implode"></a>-implode <em class="arg">factor</em></h4> 3513</div> 3514 3515<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> 3516 3517<div style="margin: auto;"> 3518 <h4><a id="insert"></a>-insert <em class="arg">index</em></h4> 3519</div> 3520 3521<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> 3522 3523<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> 3524 3525<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> 3526 3527<div style="margin: auto;"> 3528 <h4><a id="intent"></a>-intent <em class="arg">type</em></h4> 3529</div> 3530 3531<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> 3532 3533<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> 3534 3535<p>The default intent is undefined.</p> 3536 3537<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p> 3538 3539<div style="margin: auto;"> 3540 <h4><a id="interlace"></a>-interlace <em class="arg">type</em></h4> 3541</div> 3542 3543<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> 3544 3545<p>Choose from:</p> 3546 3547<pre class="text"> 3548 none 3549 line 3550 plane 3551 partition 3552 JPEG 3553 GIF 3554 PNG 3555</pre> 3556 3557<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> 3558 3559<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p> 3560 3561<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p> 3562 3563<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p> 3564 3565<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R, 3566image.G, and image.B).</p> 3567 3568<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> 3569image.</p> 3570 3571<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p> 3572 3573<div style="margin: auto;"> 3574 <h4><a id="interpolate"></a>-interpolate <em class="arg">type</em></h4> 3575</div> 3576 3577<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> 3578 3579<p>When looking up the color of a pixel using a non-integer floating point 3580value, you typically fall in between the pixel colors defined by the source 3581image. This setting determines how the color is determined from the colors of 3582the pixels surrounding that point. That is how to determine the color of a 3583point that falls between two, or even four different colored pixels. </p> 3584 3585<pre class="text"> 3586 integer The color of the top-left pixel (floor function) 3587 nearest-neighbor The nearest pixel to the lookup point (rounded function) 3588 average The average color of the surrounding four pixels 3589 bilinear A double linear interpolation of pixels (the default) 3590 mesh Divide area into two flat triangular interpolations 3591 bicubic Fitted bicubic-spines of surrounding 16 pixels 3592 spline Direct spline curves (colors are blurred) 3593 filter Use resize <a href="#filter">-filter</a> settings 3594</pre> 3595 3596<p>This most important for distortion operators such as <a href="#distort" 3597>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform" 3598>-transform</a> and <a href="#fx" >-fx</a>. </p> 3599 3600<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p> 3601 3602<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the 3603lookup for positions outside the boundaries of the image. </p> 3604 3605 3606<div style="margin: auto;"> 3607 <h4><a id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4> 3608</div> 3609 3610<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> 3611 3612<div style="margin: auto;"> 3613 <h4><a id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4> 3614</div> 3615 3616<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> 3617 3618<div style="margin: auto;"> 3619 <h4><a id="kerning"></a>-kerning <em class="arg">value</em></h4> 3620</div> 3621 3622<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> 3623 3624<div style="margin: auto;"> 3625 <h4><a id="label"></a>-label <em class="arg">name</em></h4> 3626</div> 3627 3628<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> 3629 3630<p>Use this option to assign a specific label to the image, as it is read in 3631or created. You can use the <a href="#set" >-set</a> operation to re-assign 3632a the labels of images already read in. Image formats such as TIFF, PNG, 3633MIFF, supports saving the label information with the image.</p> 3634 3635<p>When saving an image to a <em class="arg">PostScript</em> file, any label 3636assigned to an image is used as a header string to print above the postscript 3637image. </p> 3638 3639<p>You can include the image filename, type, width, height, or other image 3640attribute by embedding special format character. See <a href="/www/escape.html">Format and Print Image 3641Properties</a> for details of the percent escape codes.</p> 3642 3643<p>For example,</p> 3644 3645<p class="crtsnip"> 3646 -label "%m:%f %wx%h" bird.miff 3647</p> 3648 3649<p>assigns an image label of <kbd>MIFF:bird.miff 512x480</kbd> to the 3650"<kbd>bird.miff</kbd>" image and whose width is 512 and height is 480, as it 3651is read in. If a <a href="#label">+label</a> option was used instead, any 3652existing label present in the image would be used. You can remove all labels 3653from an image by assigning the empty string. </p> 3654 3655<p>A label is not drawn on the image, but is embedded in the image datastream 3656via <em>Label</em> tag or similar mechanism. If you want the label to be 3657visible on the image itself, use the <a href="#draw">-draw</a> option, or 3658during the final processing in the creation of a image montage.</p> 3659 3660<p>If the first character of <em class="arg">string</em> is <em 3661class="arg">@</em>, the image label is read from a file titled by the 3662remaining characters in the string. Labels in a file are literal, no embedded 3663formatting characters are recognized.</p> 3664 3665 3666<div style="margin: auto;"> 3667 <h4><a 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> 3668</div> 3669 3670<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> 3671 3672<p>Adaptively threshold each pixel based on the value of pixels in a 3673surrounding window. If the current pixel is lighter than this average plus 3674the optional <kbd>offset</kbd>, then it is made white, otherwise it is made 3675black. Small variations in pixel values such as found in scanned documents 3676can be ignored if offset is positive. A negative offset will make it more 3677sensitive to those small variations. </p> 3678 3679<p>This is commonly used to threshold images with an uneven background. It is 3680based on the assumption that average color of the small window is the 3681the local background color, from which to separate the forground color. </p> 3682 3683 3684<div style="margin: auto;"> 3685 <h4><a id="layers"></a>-layers <em class="arg">method</em></h4> 3686</div> 3687 3688<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> 3689 3690<p>Perform various image operation methods to a ordered sequence of images 3691which may represent either a set of overlaid 'image layers', a GIF disposal 3692animation, or a fully-'coalesced' animation sequence. </p> 3693 3694<table class="doc"> 3695 <tbody> 3696 <tr valign="top"> 3697 <th align="left" style="width: 8%">Method</th> 3698 <th align="left">Description</th> 3699 </tr> 3700 3701 <tr valign="top"> 3702 <td valign="top">compare-any</td> 3703 <td valign="top">Crop the second and later frames to the smallest rectangle 3704 that contains all the differences between the two images. No GIF <a 3705 href="#dispose" >-dispose</a> methods are taken into account. </td> 3706 </tr> 3707 3708 <tr><td></td><td>This exactly the same as the <a href="#deconstruct" 3709 >-deconstruct</a> operator, and does not preserve animations normal 3710 working, especially when animation used layer disposal methods such as 3711 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td> 3712 </tr> 3713 3714 <tr valign="top"> 3715 <td valign="top">compare-clear</td> 3716 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any 3717 opaque pixels which become transparent in the second frame. That is the 3718 smallest image needed to mask or erase pixels for the next frame. </td> 3719 </tr> 3720 3721 <tr valign="top"> 3722 <td valign="top">compare-overlay</td> 3723 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add 3724 extra color to the next image, as a result of overlaying color pixels. 3725 That is the smallest single overlaid image to add or change colors. </td> 3726 </tr> 3727 3728 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha 3729 composition method '<kbd>change-mask</kbd>', to reduce the image to 3730 just the pixels that need to be overlaid. </td> 3731 </tr> 3732 3733 <tr valign="top"> 3734 <td valign="top">coalesce</td> 3735 <td valign="top">Equivalent to a call to the <a href="#coalesce" 3736 >-coalesce</a> operator. Apply the layer disposal methods set in the 3737 current image sequence to form a fully defined animation sequence, as 3738 it should be displayed. Effectively converting a GIF animation into a 3739 'film strip'-like animation. </td> 3740 </tr> 3741 3742 <tr valign="top"> 3743 <td valign="top">composite</td> 3744 <td valign="top">Alpha Composition of two image lists, separated by a 3745 "<kbd>null:</kbd>" image, with the destination image list first, and 3746 the source images last. An image from each list are composited 3747 together until one list is finished. The separator image and source 3748 image lists are removed. </td> 3749 </tr> 3750 3751 3752 <tr><td></td> 3753 <td>The <a href="#geometry" >-geometry</a> offset is adjusted according 3754 to <a href="#gravity" >-gravity</a> in accordance of the virtual 3755 canvas size of the first image in each list. Unlike a normal <a 3756 href="#composite" >-composite</a> operation, the canvas offset is also 3757 added to the final composite positioning of each image. </td> </tr> 3758 3759 <tr><td></td> 3760 <td>If one of the image lists only contains one image, that image is 3761 applied to all the images in the other image list, regardless of which 3762 list it is. In this case it is the image meta-data of the list which 3763 preserved. </td> 3764 </tr> 3765 3766 3767 <tr valign="top"> 3768 <td valign="top">dispose</td> 3769 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of 3770 the animation after the layer disposal method has been applied, before 3771 the next sub-frame image is overlaid. That is the 'dispose' image that 3772 results from the application of the GIF <a href="#dispose" 3773 >-dispose</a> method. This allows you to check what 3774 is going wrong with a particular animation you may be developing. 3775 </td> 3776 </tr> 3777 3778 <tr valign="top"> 3779 <td valign="top">flatten</td> 3780 <td valign="top">Create a canvas the size of the first images virtual 3781 canvas using the current <a href="#background" >-background</a> color, 3782 and <a href="#compose" >-compose</a> each image in turn onto that 3783 canvas. Images falling outside that canvas is clipped. Final 3784 image will have a zero virtual canvas offset. </td> 3785 </tr> 3786 3787 <tr><td></td> 3788 <td>This usally used as one of the final 'image layering' operations 3789 overlaying all the prepared image layers into a final image. </td> 3790 </tr> 3791 3792 <tr><td></td> 3793 <td>For a single image this method can also be used to fillout a virtual 3794 canvas with real pixels, or to underlay a opaque color to remove 3795 transparency from an image.</td> 3796 </tr> 3797 3798 3799 <tr valign="top"> 3800 <td valign="top">merge</td> 3801 <td valign="top">As 'flatten' method but merging all the given image 3802 layers to create a new layer image just large enough to hold all the 3803 image without clipping or extra space. The new images virtual offset 3804 will preserve the position of the new layer, even if this offset is 3805 negative. The virtual canvas size of the first image is preserved. 3806 </td> 3807 </tr> 3808 3809 <tr><td></td><td>Caution is advised when handling image layers with 3810 negative offsets as few image file formats handle them correctly. 3811 Following this operation methd with <a href="#repage" >+repage</a> 3812 will remove the layer offset, and create a image in which all the 3813 overlaid image positions relative to each other is preserved, though 3814 not nessaraily exactly where you specified them. 3815 </td> 3816 </tr> 3817 3818 <tr><td></td><td>See also 'trim-bounds' below whcih is closely related but 3819 without doing the'flatten' to merge the images together. </td> 3820 </tr> 3821 3822 <tr valign="top"> 3823 <td valign="top">mosaic</td> 3824 <td valign="top">As 'flatten' method but expanding the initial canvas size 3825 of the first image in a positive direction only so as to hold all the 3826 image layers. However as a virtual canvas is 'locked' to the origin, 3827 by its own definition, image layers with a negative offsets will still 3828 become clipped by the top and left edges. See 'merge' or 'trim-bounds' 3829 if this could be a problem. </td> 3830 3831 </tr> 3832 3833 <tr><td></td><td>This method is commonly used to layout individual image 3834 using various offset but without knowing the final canvas size. The 3835 resulting image will, like 'flatten' not have any virtual offset, so 3836 can be saved to any image file format. </td> 3837 </tr> 3838 3839 3840 <tr valign="top"> 3841 <td valign="top">optimize</td> 3842 <td valign="top">Optimize a coalesced animation, into GIF animation using 3843 a number of general techniques. This currently a short cut to 3844 apply both the '<kbd>optimize-frame</kbd>', and 3845 '<kbd>optimize-transparency</kbd>' methods but may be expanded to 3846 include other optimization methods as they are developed. </td> 3847 </tr> 3848 3849 <tr valign="top"> 3850 <td valign="top">optimize-frame</td> 3851 <td valign="top">Optimize a coalesced animation, into GIF animation by 3852 reducing the number of pixels per frame as much as possible by 3853 attempting to pick the best layer disposal method to use, while ensuring 3854 the result will continue to animate properly. </td> 3855 </tr> 3856 3857 <tr><td></td><td> There is no guarantee that the best optimization is found. 3858 But then no reasonably fast GIF optimization algorithm can do this. 3859 However this does seem to do better than most other GIF frame 3860 optimizers seen. </td> 3861 </tr> 3862 3863 <tr valign="top"> 3864 <td valign="top">optimize-plus</td> 3865 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the 3866 overall optimization by adding extra frames to the animation, without 3867 changing the final look or timing of the animation. The frames are 3868 added to attempt to separate the clearing of pixels from the 3869 overlaying of new additional pixels from one animation frame to the 3870 next. If this does not improve the optimization (for the next frame 3871 only), it will fall back to the results of the previous normal 3872 '<kbd>optimize-frame</kbd>' technique. </td> 3873 </tr> 3874 3875 <tr><td></td><td>There is the possibility that the change in the disposal 3876 style will result in a worsening in the optimization of later frames, 3877 though this is unlikely. In other words there no guarantee that it is 3878 better than the normal '<kbd>optimize-frame</kbd>' technique. For some 3879 animations however you can get a vast improvement in the final 3880 animation size. </td> 3881 </tr> 3882 3883 <tr valign="top"> 3884 <td valign="top">optimize-transparency</td> 3885 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame 3886 overlay images with transparency, if it does not change the resulting 3887 animation by more than the current <a href="#fuzz" >-fuzz</a> factor. 3888 </td> 3889 </tr> 3890 3891 <tr><td></td><td>This should allow a existing frame optimized GIF animation 3892 to compress into a smaller file size due to larger areas of one 3893 (transparent) color rather than a pattern of multiple colors repeating 3894 the current disposed image of the last frame. </td> 3895 </tr> 3896 3897 <tr valign="top"> 3898 <td valign="top">remove-dups</td> 3899 <td valign="top">Remove (and merge time delays) of duplicate consecutive 3900 images, so as to simplify layer overlays of coalesced animations. 3901 </td> 3902 </tr> 3903 3904 <tr><td></td><td>Usually this a result of using a constant time delay 3905 across the whole animation, or after a larger animation was split into 3906 smaller sub-animations. The duplicate frames could also have been 3907 used as part of some frame optimization methods. </td> 3908 </tr> 3909 3910 <tr valign="top"> 3911 <td valign="top">remove-zero</td> 3912 <td valign="top">Remove any image with a zero time delay, unless ALL the 3913 images have a zero time delay (and is not a proper timed animation, a 3914 warning is then issued). </td> 3915 </tr> 3916 3917 <tr><td></td><td>In a GIF animation, such images are usually frames which 3918 provide partial intermediary updates between the frames that are 3919 actually displayed to users. These frames are usally added for 3920 improved frame optimization in GIF animations. </td> 3921 </tr> 3922 3923 <tr valign="top"> 3924 <td valign="top">trim-bounds</td> 3925 <td valign="top">Find the bounds of all the images in the current 3926 image sequence, then adjust the offsets so all images are contained on 3927 a minimal positive canvas. None of the image data is modified or 3928 merged, only the individual image virtual canvas size and offset. 3929 All the images is given the same canvas size, and and will have 3930 a positive offset, but will remain in the same position relative to 3931 each other. As a result of the minimal canvas size at least one image 3932 will touch every edge of that canvas. The image data touching those 3933 edges however may be transparent. </td> 3934 </tr> 3935 3936 <tr><td></td><td>The result is much like if you used 'merge' followed by a 3937 <a href="#repage" >+repage</a> option, except that all the images 3938 have been kept separate. If 'flatten' is used after using 3939 'trim-bounds' you will get the same result. </td> 3940 </tr> 3941 3942 </tbody> 3943</table> 3944 3945<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p> 3946 3947<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct" 3948>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic" 3949>-mosaic</a> are only aliases for the above methods and may be depreciated in 3950the future. Also see <a href="#page" >-page</a>, <a href="#repage" 3951>-repage</a> operators, the <a href="#compose" >-compose</a> setting, and the 3952GIF <a href="#dispose" >-dispose</a> and <a href="#delay" >-delay</a> 3953settings. </p> 3954 3955 3956<div style="margin: auto;"> 3957 <h4><a 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> 3958</div> 3959 3960<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> 3961 3962<p>Given one, two or three values delimited with commas: black-point, 3963white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and 3964white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white 3965point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center 3966contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string, 3967both black and white points are percentages of the full color range. Gamma 3968will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is 3969omitted, the default of 1.0 (no gamma correction) is assumed.</p> 3970 3971<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that 3972the given '<kbd>black_point</kbd>' value in the original image is set to 3973zero (or black), while the given '<kbd>white_point</kbd>' value is set to 3974<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments 3975to the image. The '<kbd>gamma</kbd>' of the resulting image will then be 3976adjusted. </p> 3977 3978<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or 3979adding the special '!' flag anywhere in the argument list, will cause the 3980operator to do the reverse of the level adjustment. That is a zero, or 3981<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is 3982adjusted to the given level values, allowing you to de-contrast, or compress 3983the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p> 3984 3985<p>Only the channels defined by the current <a href="#channel">-channel</a> 3986setting are adjusted (defaults to RGB color channels only), allowing you to 3987limit the effect of this operator. </p> 3988 3989<p>Please note that the transparency channel is treated as 'matte' 3990values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 3991 3992 3993<div style="margin: auto;"> 3994 <h4><a id="level-colors"></a>-level-colors {<em 3995 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4> 3996</div> 3997 3998<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> 3999 4000<p>This function is exactly like <a href="#level">-level</a>, except that the 4001value value for each color channel is determined by the 4002'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as 4003described under the <a href="#fill">-fill</a> option). </p> 4004 4005<p>This effectually means the colors provided to <kbd>-level-colors</kbd> 4006is mapped to become 'black' and 'white' respectively, with all the other 4007colors linearly adjusted (or clipped) to match that change. Each channel is 4008adjusted separately using the channel values of the colors specified. </p> 4009 4010<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>) 4011will map the image color 'black' and 'white' to the given colors 4012respectively, resulting in a gradient (de-contrasting) tint of the image to 4013those colors. This can also be used to convert a plain gray-scale image into a 4014one using the gradient of colors specified. </p> 4015 4016<p>By supplying a single color with a comma separator either before or after 4017that color, will just replace the respective 'black' or 'white' point 4018respectively. But if no comma separator is provided, the given color is 4019used for both the black and white color points, making the operator either 4020threshold the images around that color (- form) or set all colors to that 4021color (+ form). </p> 4022 4023 4024<div style="margin: auto;"> 4025 <h4><a id="limit"></a>-limit <em class="arg">type value</em></h4> 4026</div> 4027 4028<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> 4029 4030<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> 4031 4032<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> 4033 4034<p class="crtsnip"> 4035 -limit memory 32MiB -limit map 64MiB 4036</p> 4037 4038<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p> 4039 4040<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list resource</span><span class='crtout'></span></p><pre class="text"> 4041 File Area Memory Map Disk Thread Time 4042 ------------------------------------------------------------------------------ 4043 768 12.404GB 8.6642GiB 23.104GiB 18.446744EB 8 unlimited 4044</pre> 4045 4046<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> 4047 4048<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> 4049 4050<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> 4051 4052<p class="crtsnip"> 4053-limit area 10mb 4054</p> 4055 4056<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> 4057 4058<p class="crtsnip"> 4059-limit area 10mb -limit disk 500mb 4060</p> 4061 4062<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p> 4063 4064<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> 4065 4066<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. 4067</p> 4068 4069<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. 4070</p> 4071 4072<div style="margin: auto;"> 4073 <h4><a 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> 4074</div> 4075 4076<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> 4077 4078<p>This is very similar to <a href="#contrast-stretch" >-contrast-stretch</a>, 4079and uses a 'histogram bin' to determine the range of color values that needs to 4080be stretched. However it then stretchs those colors using the <a 4081href="#level" >-level</a> operator.</p> 4082 4083<p>As such while the initial determination may have 'binning' round off 4084effects, the image colors are stretched mathematically, rather than using the 4085histogram bins. This makes the operator more accurate. </p> 4086 4087<p>note however that a <a href="#linear-stretch" >-linear-stretch</a> of 4088'<kbd>0</kbd>' does nothing, while a value of '<kbd>1</kbd>' does a near 4089perfect stretch of the color range. </p> 4090 4091<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 4092normalization of mathematical images. </p> 4093 4094<p>This operator is under review for re-development. </p> 4095 4096 4097<div style="margin: auto;"> 4098 <h4><a id="linewidth"></a>-linewidth</h4> 4099</div> 4100 4101<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> 4102 4103<div style="margin: auto;"> 4104 <h4><a id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4> 4105</div> 4106 4107<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> 4108 4109<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> 4110 4111<div style="margin: auto;"> 4112 <h4><a id="list"></a>-list <em class="arg">type</em></h4> 4113</div> 4114 4115<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> 4116 4117<pre class="text"> 4118 Align Alpha Boolean Channel 4119 Class ClipPath Coder Color 4120 Colorspace Command Compose Compress 4121 Configure DataType Debug Decoration 4122 Delegate Direction Dispose Distort 4123 Dither Endian Evaluate FillRule 4124 Filter Font Format Function 4125 Gravity ImageList Intent Interlace 4126 Interpolate Kernel Layers LineCap 4127 LineJoin List Locale LogEvent 4128 Log Magic Method Metric 4129 Mime Mode Morphology Module 4130 Noise Orientation Policy PolicyDomain 4131 PolicyRights Preview Primitive QuantumFormat 4132 Resource SparseColor Storage Stretch 4133 Style Threshold Type Units 4134 Validate VirtualPixel 4135</pre> 4136 4137<p>These lists vary depending on your version of ImageMagick. Use "<kbd>-list 4138list</kbd>" to get a complete listing of all the "<kbd>-list</kbd>" arguments 4139available:</p> 4140 4141<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list list</span></p> 4142<div style="margin: auto;"> 4143 <h4><a id="log"></a>-log <em class="arg">string</em></h4> 4144</div> 4145 4146<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> 4147 4148<p>This option specifies the format for the log printed when the <a 4149href="#debug">-debug</a> option is active.</p> 4150 4151<p>You can display the following components by embedding special format 4152characters:</p> 4153 4154<pre class="text"> 4155 %d domain 4156 %e event 4157 %f function 4158 %l line 4159 %m module 4160 %p process ID 4161 %r real CPU time 4162 %t wall clock time 4163 %u user CPU time 4164 %% percent sign 4165 \n newline 4166 \r carriage return 4167</pre> 4168 4169<p>For example:</p> 4170 4171<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> 4172<p>The default behavior is to print all of the components.</p> 4173 4174<div style="margin: auto;"> 4175 <h4><a id="loop"></a>-loop <em class="arg">iterations</em></h4> 4176</div> 4177 4178<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> 4179 4180<p>Set iterations to zero to repeat the animation an infinite number of times, 4181otherwise the animation repeats itself up to <em class="arg">iterations</em> 4182times.</p> 4183 4184<div style="margin: auto;"> 4185 <h4><a id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4> 4186</div> 4187 4188<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> 4189 4190<div style="margin: auto;"> 4191 <h4><a id="magnify"></a>-magnify <em class="arg">factor</em></h4> 4192</div> 4193 4194<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> 4195 4196 4197<div style="margin: auto;"> 4198 <h4><a id="map"></a>-map <em class="arg">type</em></h4> 4199</div> 4200 4201<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> 4202 4203<p>Choose from these <em class="arg">Standard Colormap</em> types:</p> 4204 4205<pre class="text"> 4206 best 4207 default 4208 gray 4209 red 4210 green 4211 blue 4212</pre> 4213 4214<p>The <em class="arg">X server</em> must support the <em class="arg">Standard 4215Colormap</em> you choose, otherwise an error occurs. Use <kbd>list</kbd> as 4216the type and <kbd>display</kbd> searches the list of colormap types in 4217<kbd>top-to-bottom</kbd> order until one is located. See <em 4218class="arg">xstdcmap(1)</em> for one way of creating Standard Colormaps.</p> 4219 4220 4221<div style="margin: auto;"> 4222 <h4><a id="map_stream_"></a>-map <em class="arg">components</em></h4> 4223</div> 4224 4225<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> 4226 4227<p>Here are the valid components of a map:</p> 4228 4229<pre class="text"> 4230 r red pixel component 4231 g green pixel component 4232 b blue pixel component 4233 a alpha pixel component (0 is transparent) 4234 o opacity pixel component (0 is opaque) 4235 i grayscale intensity pixel component 4236 c cyan pixel component 4237 m magenta pixel component 4238 y yellow pixel component 4239 k black pixel component 4240 p pad component (always 0) 4241</pre> 4242 4243<p>You can specify as many of these components as needed in any order (e.g. 4244bgr). The components can repeat as well (e.g. rgbr).</p> 4245 4246 4247<div style="margin: auto;"> 4248 <h4><a id="mask"></a>-mask 4249<em class="arg">filename</em></h4> 4250</div> 4251 4252<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Prevent updates to image pixels specified by the mask.</td><td style='text-align:right;'></td></tr></table> 4253 4254<p>This the same as using a mask used for composite masking operations, with 4255grayscale values causing blended updates of the image the mask is attached to. 4256</P> 4257 4258<p>Use <a href="#mask">+mask</a> to remove the mask from images.</p> 4259 4260<p>Also see <a href="#clip-mask">-clip-mask</a> which work in the same way, 4261but with strict boolean masking. </p> 4262 4263<div style="margin: auto;"> 4264 <h4><a id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4> 4265</div> 4266 4267<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> 4268 4269<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 4270 4271<p>The default matte color is <kbd>#BDBDBD</kbd>, <span 4272style="background-color: #bdbdbd;">this shade of gray</span>.</p> 4273 4274<div style="margin: auto;"> 4275 <h4><a id="maximum"></a>-maximum</h4> 4276</div> 4277 4278<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> 4279 4280<p>Select the 'maximum' value from all the surrounding pixels. </p> 4281 4282<p>This is legacy option from the <a href="#statistic" >method</A> of the same 4283name. </p> 4284 4285<div style="margin: auto;"> 4286 <h4><a id="median"></a>-median <em class="arg">geometry</em></h4> 4287</div> 4288 4289<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> 4290 4291<p>Select the 'middle' value from all the surrounding pixels. </p> 4292 4293<p>This is legacy option from the <a href="#statistic" >method</A> of the same 4294name. </p> 4295 4296<div style="margin: auto;"> 4297 <h4><a id="metric"></a>-metric <em class="arg">type</em></h4> 4298</div> 4299 4300<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> 4301 4302<p>Choose from:</p> 4303 4304<pre class="text"> 4305 AE absolute error count, number of different pixels (-fuzz effected) 4306 FUZZ mean color distance 4307 MAE mean absolute error (normalized), average channel error distance 4308 MEPP mean error per pixel (normalized mean error, normalized peak error) 4309 MSE mean error squared, average of the channel error squared 4310 NCC normalized cross correlation 4311 PAE peak absolute (normalize peak absolute) 4312 PSNR peak signal to noise ratio 4313 RMSE root mean squared (normalized root mean squared) 4314</pre> 4315 4316<p>Control the '<kbd>AE</kbd>', or absolute count of pixels that are different, 4317with the <a href="#fuzz" >-fuzz</a> factor (ignore pixels which 4318only changed by a small amount). Use '<kbd>PAE</kbd>' to find the 4319size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels 4320'similar', while '<kbd>MAE</kbd>' dtermines the factor needed 4321for about half the pixels to be similar. </p> 4322 4323<p>The '<kbd>MEPP</kbd>' metric returns three different metrics 4324('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>' 4325normalized) from a single comparison run. </p> 4326 4327<p>To print a complete list of metrics, use the <a href="#list">-list 4328metrics</a> option.</p> 4329 4330 4331<div style="margin: auto;"> 4332 <h4><a id="minimum"></a>-minimum</h4> 4333</div> 4334 4335<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> 4336 4337<p>Select the 'minimal' value from all the surrounding pixels. </p> 4338 4339<p>This is legacy option from the <a href="#statistic" >method</A> of the same 4340name. </p> 4341 4342 4343 4344<div style="margin: auto;"> 4345 <h4><a id="mode"></a>-mode <em class="arg">geometry</em></h4> 4346</div> 4347 4348<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>make each pixel the 'predominate color' of the neighborhood.</td><td style='text-align:right;'>[<a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>]</td></tr></table> 4349 4350<div style="margin: auto;"> 4351 <h4>-mode <em class="arg">value</em></h4> 4352</div> 4353 4354<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> 4355 4356<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, 4357Unframe, or Concatenate</kbd></p> 4358 4359<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>' argument 4360for a list of <a href="#mode" >-mode</a> arguments available in your 4361ImageMagick installation.</p> 4362 4363 4364<div style="margin: auto;"> 4365 <h4><a id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4> 4366</div> 4367 4368<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 4369class="arg">saturation</em>, and <em class="arg">hue</em> of an image.</td><td style='text-align:right;'></td></tr></table> 4370 4371<p>The arguments are given as a percentages of variation. A value of 100 means 4372no change, and any missing values are taken to mean 100.</p> 4373 4374<p>The <em class="arg">brightness</em> is a multiplier of the overall 4375brightness of the image, so 0 means pure black, 50 is half as bright, 200 is 4376twice as bright. To invert its meaning <a href="#negate">-negate</a> the image 4377before and after. </p> 4378 4379<p>The <em class="arg">saturation</em> controls the amount of color in an 4380image. For example, 0 produce a grayscale image, while a large value such as 4381200 produce a very colorful, 'cartoonish' color.</p> 4382 4383<p>The <em class="arg">hue</em> argument causes a "rotation" of the colors 4384within the image by the amount specified. For example, 50 results in 4385a counter-clockwise rotation of 90, mapping red shades to purple, and so on. 4386A value of either 0 or 200 results in a complete 180 degree rotation of the 4387image. Using a value of 300 is a 360 degree rotation resulting in no change to 4388the original image. </p> 4389 4390<p>For example, to increase the color brightness by 20% and decrease the color 4391saturation by 10% and leave the hue unchanged, use <a 4392href="#modulate">-modulate 120,90</a>.</p> 4393 4394<p>Use <a href="#set">-set</a> attribute of '<kbd 4395class="arg">option:modulate:colorspace</kbd>' to specify which colorspace to 4396modulate. Choose from <kbd>HSB</kbd>, <kbd>HSL</kbd> (the default), or 4397<kbd>HWB</kbd>. For example,</p> 4398 4399<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> 4400 4401<div style="margin: auto;"> 4402 <h4><a id="monitor"></a>-monitor</h4> 4403</div> 4404 4405<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> 4406 4407 4408<div style="margin: auto;"> 4409 <h4><a id="monochrome"></a>-monochrome</h4> 4410</div> 4411 4412<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> 4413 4414 4415<div style="margin: auto;"> 4416 <h4><a id="morph"></a>-morph <em class="arg">frames</em></h4> 4417</div> 4418 4419<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> 4420 4421<p>Both the image pixels and size are linearly interpolated to give the 4422appearance of a meta-morphosis from one image to the next, over all the images 4423in the current image list. The added images are the equivalent of a <a 4424href="#blend">-blend</a> composition. The <em class="arg">frames</em> 4425argument determine how many images to interpolate between each image. </p> 4426 4427 4428<div style="margin: auto;"> 4429 <h4><a id="morphology"></a>-morphology</h4> 4430 <h4>-morphology <em class="arg">method</em> <em class="arg">kernel</em></h4> 4431</div> 4432 4433<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> 4434 4435<p>Until I get around to writing a option summary for this, see <a 4436href="http://www.imagemagick.org/Usage/morphology/" >IM Usage Examples, 4437Morphology</a>. </p> 4438 4439 4440<div style="margin: auto;"> 4441 <h4><a id="mosaic"></a>-mosaic</h4> 4442</div> 4443 4444<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> 4445 4446 4447<div style="margin: auto;"> 4448 <h4><a 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> 4449</div> 4450 4451<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> 4452 4453<p>Blur with the given radius, standard deviation (sigma), and angle. The 4454angle given is the angle toward which the image is blurred. That is the 4455direction people would consider the object is coming from. </p> 4456 4457<p>Note that the blur is not uniform distribution, giving the motion a 4458definite sense of direction of movement. </p> 4459 4460<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4461pixels which are outside the image proper are blurred into the final result. 4462</p> 4463 4464<div style="margin: auto;"> 4465 <h4><a id="name"></a>-name</h4> 4466</div> 4467 4468<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> 4469<div style="margin: auto;"> 4470 <h4><a id="negate"></a>-negate</h4> 4471</div> 4472 4473<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> 4474 4475<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> 4476 4477<div style="margin: auto;"> 4478 <h4><a id="noise"></a>-noise <em class="arg">geometry</em><br/> 4479 +noise <em class="arg">type</em></h4> 4480</div> 4481 4482<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> 4483 4484<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> 4485 4486<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> 4487 4488<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> 4489 4490<pre class="text"> 4491 Gaussian 4492 Impulse 4493 Laplacian 4494 Multiplicative 4495 Poisson 4496 Random 4497 Uniform 4498</pre> 4499 4500<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p> 4501 4502<p>Also see the <a href="#evaluate">-evaluate</a> noise functions that allos 4503the use of a controlling value to specify teh amount of noise that should be 4504added to an image. </p> 4505 4506 4507<div style="margin: auto;"> 4508 <h4><a id="normalize"></a>-normalize</h4> 4509</div> 4510 4511<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> 4512 4513<p>The intensity values are stretched to cover the entire range of possible 4514values. While doing so, black-out at most <em>2%</em> of the pixels and 4515white-out at most <em>1%</em> of the pixels.</p> 4516 4517<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a> 4518is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>. 4519(Before this version, it was equivalent to <a href="#contrast-stretch" 4520>-contrast-stretch 2%x99%</a>).</p> 4521 4522<p>All the channels are normalized in concert by the came amount so as to 4523preserve color integrity, when the default <a href="#channel" >+channel</a> 4524setting is in use. Specifying any other <a href="#channel" >-channel</a> 4525setting will normalize the RGB channels independently.</p> 4526 4527<p>See <a href="#contrast-stretch" >-contrast-stretch</a> for more details. 4528Also see <a href="#auto-level" >-auto-level</a> for a 'perfect' normalization 4529that is better suited to mathematically generated images. </p> 4530 4531<p>This operator is under review for re-development. </p> 4532 4533 4534<div style="margin: auto;"> 4535 <h4><a id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4> 4536</div> 4537 4538<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 4539class="arg">threshold map</em> specified, and a uniform color map with the 4540given number of <em class="arg">levels</em> per color channel . </td><td style='text-align:right;'></td></tr></table> 4541 4542<p>You can choose from these standard threshold maps:</p> 4543 4544<pre class="text"> 4545 threshold 1x1 Threshold 1x1 (non-dither) 4546 checks 2x1 Checkerboard 2x1 (dither) 4547 o2x2 2x2 Ordered 2x2 (dispersed) 4548 o3x3 3x3 Ordered 3x3 (dispersed) 4549 o4x4 4x4 Ordered 4x4 (dispersed) 4550 o8x8 8x8 Ordered 8x8 (dispersed) 4551 h4x4a 4x1 Halftone 4x4 (angled) 4552 h6x6a 6x1 Halftone 6x6 (angled) 4553 h8x8a 8x1 Halftone 8x8 (angled) 4554 h4x4o Halftone 4x4 (orthogonal) 4555 h6x6o Halftone 6x6 (orthogonal) 4556 h8x8o Halftone 8x8 (orthogonal) 4557 h16x16o Halftone 16x16 (orthogonal) 4558 c5x5b c5x5 Circles 5x5 (black) 4559 c5x5w Circles 5x5 (white) 4560 c6x6b c6x6 Circles 6x6 (black) 4561 c6x6w Circles 6x6 (white) 4562 c7x7b c7x7 Circles 7x7 (black) 4563 c7x7w Circles 7x7 (white) 4564</pre> 4565 4566<p> The <kbd>threshold</kbd> generated a simple 50% threshold of the image. 4567This could be used with <em class="arg" >level</em> to do the equivalent of <a 4568href="#posterize" >-posterize</a> to reduce an image to basic primary colors. 4569</p> 4570 4571<p>The <kbd>checks</kbd> pattern produces a 3 level checkerbord dither 4572pattern. That is a grayscale will become a pattern of solid black, solid 4573white, and mid-tone colors into a checkerboard pattern of black and white. 4574</p> 4575 4576<p>You can define your own <em class="arg" >threshold map</em> for ordered 4577dithering and halftoning your images, in either personal or system 4578<kbd>thresholds.xml</kbd> XML file. See <a href="resources.html" >Resources</A> 4579for more details of configuration files. </p> 4580 4581<p>To print a complete list of the thresholds that have been defined, use the 4582<a href="#list" >-list threshold</a> option.</p> 4583 4584<p>Note that at this time the same threshold dithering map is used for all 4585color channels, no attempt is made to offset or rotate the map for different 4586channels is made, to create an offset printing effect. Also as the maps are 4587simple threshold levels, the halftone and circle maps will create incomplete 4588circles along the edges of a colored area. Also all the effects are purely 4589on/off boolean effects, without anti-aliasing to make the circles smooth 4590looking. Large dots can be made to look better with a small amount of blurring 4591after being created. </p> 4592 4593 4594<div style="margin: auto;"> 4595 <h4><a id="opaque"></a>-opaque <em class="arg">color</em></h4> 4596</div> 4597 4598<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> 4599 4600<p>The <em class="arg">color</em> argument is defined using the format 4601described under the <a href="#fill" >-fill</a> option. The <a href="#fuzz" 4602>-fuzz</a> setting can be used to match and replace colors similar to the one 4603given.</p> 4604 4605<p>Use <a href="#opaque">+opaque</a> to paint any pixel that does not match 4606the target color. </p> 4607 4608<p>The <a href="#transparent">-transparent</a> operator is exactly the same 4609as <a href="#opaque" >-opaque</a> but replaces the matching color with 4610transparency rather than the current <a href="#fill">-fill</a> color setting. 4611To ensure that it can do this it also ensures that the image has an alpha 4612channel enabled, as per "<kbd><a href="#alpha" >-alpha</a> set</kbd>", for 4613the new transparent colors, and does not require you to modify the <a 4614href="#channel">-channel</a> to enable alpha channel handling. </p> 4615 4616 4617<div style="margin: auto;"> 4618 <h4><a id="orient"></a>-orient <em class="arg">image orientation</em></h4> 4619</div> 4620 4621<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> 4622 4623<p>Choose from these orientations:</p> 4624 4625<pre class="text"> 4626 bottom-left 4627 bottom-right 4628 left-bottom 4629 left-top 4630 right-bottom 4631 right-top 4632 top-left 4633 top-right 4634 undefined 4635</pre> 4636 4637<p>To print a complete list of orientations, use the <a href="#list" >-list 4638orientation</a> option.</p> 4639 4640 4641<div style="margin: auto;"> 4642 <h4><a id="page"></a>-page <em class="arg">geometry</em><br/> 4643 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!<></em>}]<br/> 4644 +page 4645 </h4> 4646</div> 4647 4648<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> 4649 4650<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> 4651 4652<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> 4653 4654<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> 4655<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;"> 4656<thead> 4657 <tr valign="top"> 4658 <th align="center"><em class="arg">media</em></th> 4659 <th align="center"><em class="arg">width</em></th> 4660 <th align="center"><em class="arg">height</em></th> 4661 </tr> 4662</thead> 4663<tbody> 4664<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr> 4665<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr> 4666<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr> 4667<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4668<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4669<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr> 4670<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr> 4671<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr> 4672<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr> 4673<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr> 4674<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr> 4675<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr> 4676<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr> 4677<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr> 4678<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4679<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4680<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr> 4681<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr> 4682<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr> 4683<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr> 4684<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr> 4685<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr> 4686<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr> 4687<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr> 4688<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr> 4689<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr> 4690<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr> 4691<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr> 4692<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr> 4693<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr> 4694<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr> 4695<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr> 4696<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr> 4697<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr> 4698<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr> 4699<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4700<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4701<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr> 4702</tbody> 4703</table> 4704 4705 4706 4707 4708<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> 4709 4710<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> 4711 4712<p>The default page dimensions for a TEXT image is 612x792.</p> 4713 4714<p>This option is used in concert with <a href="#density">-density</a>.</p> 4715 4716<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p> 4717 4718<div style="margin: auto;"> 4719 <h4><a id="paint"></a>-paint <em class="arg">radius</em></h4> 4720</div> 4721 4722<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> 4723 4724<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> 4725 4726<div style="margin: auto;"> 4727 <h4><a id="path"></a>-path <em class="arg">path</em></h4></div> 4728 4729<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> 4730 4731<div style="margin: auto;"> 4732 <h4><a id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4> 4733</div> 4734 4735<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> 4736 4737<p>Pause for the specified number of seconds before repeating the animation.</p> 4738 4739<div style="margin: auto;"> 4740 <h4><a id="pause_import_"></a>-pause <em class="arg">seconds</em></h4> 4741</div> 4742 4743<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> 4744 4745<p>Pause for the specified number of seconds before taking the next snapshot.</p> 4746 4747<div style="margin: auto;"> 4748 <h4><a id="ping"></a>-ping</h4> 4749</div> 4750 4751<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> 4752 4753<div style="margin: auto;"> 4754 <h4><a id="pointsize"></a>-pointsize <em class="arg">value</em></h4> 4755</div> 4756 4757<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> 4758 4759<div style="margin: auto;"> 4760 <h4><a id="polaroid"></a>-polaroid <em class="arg">angle</em></h4> 4761</div> 4762 4763<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> 4764 4765<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p> 4766 4767<div style="margin: auto;"> 4768 <h4><a id="posterize"></a>-posterize <em class="arg">levels</em></h4> 4769</div> 4770 4771<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> 4772 4773<div style="margin: auto;"> 4774 <h4><a id="precision"></a>-precision <em class="arg">value</em></h4> 4775</div> 4776 4777<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> 4778 4779<div style="margin: auto;"> 4780 <h4><a id="preview"></a>-preview <em class="arg">type</em></h4> 4781</div> 4782 4783<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> 4784 4785<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> 4786 4787<pre class="text"> 4788 Rotate Shear Roll Hue 4789 Saturation Brightness Gamma Spiff 4790 Dull Grayscale Quantize Despeckle 4791 ReduceNoise Add Noise Sharpen Blur 4792 Threshold EdgeDetect Spread Shade 4793 Raise Segment Solarize Swirl 4794 Implode Wave OilPaint CharcoalDrawing 4795 JPEG 4796</pre> 4797 4798<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p> 4799 4800<p>The default preview is <kbd>JPEG</kbd>.</p> 4801 4802<div style="margin: auto;"> 4803 <h4><a id="print"></a>-print <em class="arg">string</em></h4> 4804</div> 4805 4806<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> 4807 4808<div style="margin: auto;"> 4809 <h4><a id="process"></a>-process <em class="arg">command</em></h4> 4810</div> 4811 4812<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> 4813 4814<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> 4815 4816<div style="margin: auto;"> 4817 <h4><a id="profile"></a>-profile <em class="arg">filename</em><br/> 4818 +profile <em class="arg">profile_name</em></h4> 4819</div> 4820 4821<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> 4822 4823<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> 4824 4825<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> 4826 4827<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> 4828 4829<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> 4830 4831<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p> 4832 4833<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p> 4834<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> 4835 4836<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff</span></p> 4837<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results. 4838CMYK profiles are often very asymmetric since they involve 3−>4 and 4−>3 channel mapping. 4839</p> 4840 4841<p>The <a href="#profile">-profile</a> option can also be used to inject 4842previously-formatted ancillary chunks into the output PNG file, using 4843the commandline option as shown below or by setting the profile via a 4844programming interface:</p> 4845 4846<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>-profile PNG-chunk-x:<filename></span></p> 4847<p>where <em>x</em> is a location flag and 4848<em class="arg">filename</em> is a file containing the chunk 4849name in the first 4 bytes, then a colon (":"), followed by the chunk data. 4850This encoder will compute the chunk length and CRC, so those must not 4851be included in the file.</p> 4852 4853<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT), 4854or "e" (end, i.e., after IDAT). If you want to write multiple chunks 4855of the same type, then add a short unique string after the "x" to prevent 4856subsequent profiles from overwriting the preceding ones, e.g.,</p> 4857 4858 4859<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>-profile PNG-chunk-b01:file01 -profile PNG-chunk-b02:file02</span></p> 4860<div style="margin: auto;"> 4861 <h4><a id="quality"></a>-quality <em class="arg">value</em></h4> 4862</div> 4863 4864<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> 4865 4866<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> 4867 4868<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> 4869 4870<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> 4871 4872<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> 4873 4874<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p> 4875 4876<pre class="text"> 4877 0: none 4878 1: sub 4879 2: up 4880 3: average 4881 4: Paeth 4882</pre> 4883 4884<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> 4885 4886<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p> 4887 4888<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> 4889 4890<p>The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.</p> 4891 4892<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p> 4893 4894<div style="margin: auto;"> 4895 <h4><a id="quantize"></a>-quantize <em class="arg">colorspace</em></h4> 4896</div> 4897 4898<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> 4899 4900<p>This setting defines the colorspace used to sort out and reduce the number 4901of colors needed by an image (for later dithering) by operators such as <a 4902href="#colors" >-colors</a>, Note that color reducion also happens 4903automatically when saving images to color-limited image file formats, such as 4904GIF, and PNG8.</p> 4905 4906 4907<div style="margin: auto;"> 4908 <h4><a id="quiet"></a>-quiet</h4> 4909</div> 4910 4911<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> 4912 4913<div style="margin: auto;"> 4914 <h4><a id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4> 4915</div> 4916 4917<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> 4918 4919<p>Note that this is actually a rotational blur rather than a radial and as 4920such actually mis-named. </p> 4921 4922<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4923pixels which are outside the image proper are blurred into the final result. 4924</p> 4925 4926 4927<div style="margin: auto;"> 4928 <h4><a id="raise"></a>-raise <em class="arg">thickness</em></h4> 4929</div> 4930 4931<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> 4932 4933<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>. 4934</p> 4935 4936<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p> 4937 4938<div style="margin: auto;"> 4939 <h4><a id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4> 4940</div> 4941 4942<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> 4943 4944<div style="margin: auto;"> 4945 <h4><a id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4> 4946</div> 4947 4948<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> 4949 4950<div style="margin: auto;"> 4951 <h4><a id="regard-warnings"></a>-regard-warnings</h4> 4952</div> 4953 4954<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> 4955 4956<div style="margin: auto;"> 4957 <h4><a id="remap"></a>-remap <em class="arg">filename</em></h4> 4958</div> 4959 4960<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> 4961 4962<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then 4963the given colors are dithered over the image as necessary, otherwise the closest 4964color (in RGB colorspace) is selected to replace that pixel in the image. </p> 4965 4966<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all 4967images in the current image sequence, all the images will have the same color 4968table. That means that when saved to a file format such as GIF, it will use 4969that color table as a single common or global color table, for all the images, 4970without requiring extra local color tables. </p> 4971 4972<p>Use <a href="#remap">+remap</a> to reduce all images in the current image 4973sequence to use a common color map over all the images. This equivalent to 4974appending all the images together (without extra background colors) and color 4975reducing those images using <a href="#colors">-colors</a> with a 256 color 4976limit, then <a href="#remap">-remap</a> those colors over the original list of 4977images. This ensures all the images follow a single color map. </p> 4978 4979<p>If the number of colors over all the images is less than 256, then <a 4980href="#remap">+remap</a> should not perform any color reduction or dithering, as 4981no color changes are needed. In that case, its only effect is to force the use 4982of a global color table. This recommended after using either <a 4983href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to 4984reduce the number of colors in an animated image sequence. </p> 4985 4986<div style="margin: auto;"> 4987 <h4><a id="region"></a>-region <em class="arg">geometry</em></h4> 4988</div> 4989 4990<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> 4991 4992<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> 4993 4994<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> 4995 4996<div style="margin: auto;"> 4997 <h4><a id="remote"></a>-remote</h4> 4998</div> 4999 5000<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> 5001 5002<p>The only command recognized is the name of an image file to load.</p> 5003 5004<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> 5005 5006<div style="margin: auto;"> 5007 <h4><a id="render"></a>-render</h4> 5008</div> 5009 5010<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> 5011 5012<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> 5013 5014<div style="margin: auto;"> 5015<h4><a id="repage"></a>-repage <em class="arg">geometry</em></h4> 5016</div> 5017 5018<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> 5019 5020<p>This option is like <a href="#page">-page</a> but acts as an image operator 5021rather than a setting. You can separately set the canvas size or the offset 5022of the image on that canvas by only providing those components. </p> 5023 5024<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> 5025 5026<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing 5027offset to move the image relative to its previous position. This useful for 5028animation sequences. </p> 5029 5030<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to 5031recalculate the canvas size so the image (at its current offset) will appear 5032completely on that canvas (unless it has a negative offset).</p> 5033 5034<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual 5035canvas meta-data from the images. </p> 5036 5037<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to 5038directly assign virtual canvas meta-data. </p> 5039 5040 5041<div style="margin: auto;"> 5042 <h4><a id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4> 5043</div> 5044 5045<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> 5046 5047<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> 5048 5049<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> 5050 5051<div style="margin: auto;"> 5052 <h4><a id="resize"></a>-resize <em class="arg">geometry</em></h4> 5053</div> 5054 5055<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> 5056 5057<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> 5058 5059<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> 5060 5061<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> 5062 5063<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> 5064<div style="margin: auto;"> 5065 <h4><a id="respect-parentheses"></a>-respect-parentheses</h4> 5066</div> 5067 5068<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> 5069 5070<div style="margin: auto;"> 5071 <h4><a id="reverse"></a>-reverse</h4> 5072</div> 5073 5074<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> 5075 5076 5077<div style="margin: auto;"> 5078 <h4><a id="roll"></a>-roll {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 5079</div> 5080 5081<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> 5082 5083<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> 5084 5085 5086<div style="margin: auto;"> 5087 <h4><a id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg"><</em>}{<em class="arg">></em>}</h4> 5088</div> 5089 5090<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> 5091 5092<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> 5093 5094<p>Empty triangles in the corners, left over from rotating the image, are 5095filled with the <kbd>background</kbd> color. </p> 5096 5097<p>See also the <a href="#distort">-distort</a> operator and specifically the 5098'<kbd>ScaleRotateTranslate</kbd>' distort method. </p> 5099 5100 5101<div style="margin: auto;"> 5102 <h4><a id="sample"></a>-sample <em class="arg">geometry</em></h4> 5103</div> 5104 5105<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> 5106 5107<p>Change the image size simply by directly sampling the pixels original 5108image. When magnifying, pixels are replicated in blocks. When minifying, 5109pixels are sub-sampled (i.e., some rows and columns are skipped over). </p> 5110 5111<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 5112a <a href="#filter">-filter</a> setting of <kbd>point</kbd> (nearest 5113neighbour), though <a href="#sample">-sample</a> is a lot faster, as it 5114avoids all the filter processing of the image. As such it completely ignores 5115the current <a href="#filter">-filter</a> setting. </p> 5116 5117<p>The key feature of the <a href="#sample">-sample</a> is that no new colors 5118will be added to the resulting image, though some colors may disappear. </p> 5119 5120<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 5121ignored, unlike <a href="#resize">-resize</a>. </p> 5122 5123 5124<div style="margin: auto;"> 5125 <h4><a id="sampling-factor"></a>-sampling-factor <em class="arg">horizontal-factor</em>x<em class="arg">vertical-factor</em></h4> 5126</div> 5127 5128<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> 5129 5130<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> 5131 5132<div style="margin: auto;"> 5133 <h4><a id="scale"></a>-scale <em class="arg">geometry</em></h4> 5134</div> 5135 5136<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> 5137 5138<p>Change the image size simply by replacing pixels by averaging pixels 5139together when minifying, or replacing pixels when magnifing. </p> 5140 5141<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 5142a <a href="#filter">-filter</a> setting of <kbd>box</kbd>. Though it is a lot 5143faster, as it avoids all the filter processing of the image. As such it 5144completely ignores the current <a href="#filter">-filter</a> setting. </p> 5145 5146<p>If when shrinking (minifying) images the original image is some integer 5147multiple of the new image size, the number of pixels avergaed together to 5148produce the new pixel color is the same across the whole image. This is 5149a special case known as 'binning' and is often used as a method of reducing 5150noise in image such as those generated by digital cameras, especially in low 5151light conditions. </p> 5152 5153 5154<div style="margin: auto;"> 5155 <h4><a id="scene"></a>-scene <em class="arg">value</em></h4> 5156</div> 5157 5158<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> 5159 5160<p>This option sets the scene number of an image or the first image in an image sequence.</p> 5161 5162<div style="margin: auto;"> 5163 <h4><a id="screen"></a>-screen</h4> 5164</div> 5165 5166<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> 5167 5168<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> 5169 5170<div style="margin: auto;"> 5171 <h4><a id="seed"></a>-seed</h4> 5172</div> 5173 5174<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> 5175 5176<div style="margin: auto;"> 5177 <h4><a id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4> 5178</div> 5179 5180<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> 5181 5182<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> 5183 5184<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> 5185 5186<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report 5187of the color clusters is returned.</p> 5188 5189 5190<div style="margin: auto;"> 5191 <h4><a id="selective-blur"></a>-selective-blur <em class="arg">radius</em><br />-selective-blur <em class="arg">radius</em>x<em class="arg">sigma</em>{<em class="arg">+threshold</em>}</h4> 5192</div> 5193 5194<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> 5195 5196<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> 5197 5198<div style="margin: auto;"> 5199 <h4><a id="separate"></a>-separate</h4> 5200</div> 5201 5202<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> 5203 5204<div style="margin: auto;"> 5205 <h4><a id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</em></h4> 5206</div> 5207 5208<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> 5209 5210<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p> 5211 5212<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> 5213 5214 5215 5216<div style="margin: auto;"> 5217 <h4><a id="set"></a>-set <em class="arg">key value</em></h4> 5218 <h4>+set <em class="arg">key</em></h4> 5219</div> 5220 5221<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 5222image sequence.</td><td style='text-align:right;'></td></tr></table> 5223 5224<p>This will assign (or modify) specific settings attached to all the images 5225in the current image sequence. Using the <a href="#set">+set</a> form of the 5226option will either remove, or reset that setting to a default state, as 5227appropriate. </p> 5228 5229<p>For example, it will modify specific well known image meta-data 5230'attributes' such as those normally overridden by: the options <a 5231href="#delay" >-delay</a>, <a href="#dispose" >-dispose</a>, and <a 5232href="#page" >-page</a>, <a href="#colorspace" >-colorspace</a>; generally 5233assigned before the image is read in, by using a <em class="arg">key</em> of 5234the same name. </p> 5235 5236<p>If the given <em class="arg">key</em> does not match a specific known 5237'attribute ', such as shown above, the setting is stored as a a free form 5238'property' string. Such settings are listed in <a href="#verbose" 5239>-verbose</a> information ("<kbd>info:</kbd>" output format) as "Properties". 5240</p> 5241 5242<p>This includes string 'properities' that are set by and assigned to images 5243using the options <a href="#comment" >-comment</a>, <a href="#label" 5244>-label</a>, <a href="#caption" >-caption</a>. These options actually assign 5245a global 'artifact' which are automatically assigned (and any <a href="/www/escape.html" >Format Percent 5246Escapes</a> expanded) to images as they are read in. For example:</p> 5247 5248<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> 5249<p>The set value can also make use of <a href="/www/escape.html" >Format and Print Image 5250Properties</a> in the defined value. For example:</p> 5251 5252<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> 5253<p>Other well known 'properities' that can be include: 5254'<kbd>date:create</kbd>' and '<kbd>date:modify</kbd>' and 5255'<kbd>signature</kbd>'. </p> 5256 5257<p>The <a href="#repage">-repage</a> operator will also allow you to modify 5258the '<kbd>page</kbd>' attribute of an image for images already in memory (also 5259see <a href="#repage">-page</a>). However it is designed to provide a finer 5260control of the sub-parts of this 'attribute'. The <a href="#set">-set page</a> 5261option will only provide a direct, unmodified assignment of '<kbd>page</kbd>' 5262attribute. </p> 5263 5264<p>This option can also associate a colorspace or profile with your image. 5265For example,</p> 5266 5267<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> 5268<p>Some 'properties' must be defined in a specific way to be used. For 5269example only 'properties' prefixed with "<kbd>filename:</kbd>" can be used to 5270modify the output filename of an image. For example</p> 5271 5272<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'</span></p> 5273<p>If the setting value is prefixed with "<kbd>option:</kbd>" the setting will 5274be saved as a global "Artifact" exactly as if it was set using the <a 5275href="#define" >-define</a> option. As such settings are global in scope, they 5276can be used to pass 'attributes' and 'properities' of one specific image, 5277in a way that allows you to use them in a completely different image, even if 5278the original image has long since been modified or destroyed. For example: </p> 5279 5280<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> 5281<p>Note that <a href="/www/escape.html" >Format Percent Escapes</a> will only match 5282a 'artifact' if the given <em class="arg">key</em> does not match an existing 5283'attribute' or 'property'. </p> 5284 5285<p>You can set the attributes of the image registry by prefixing the value 5286with <kbd>registry:</kbd>.</p> 5287 5288 5289 5290<div style="margin: auto;"> 5291 <h4><a id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4> 5292</div> 5293 5294<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> 5295 5296<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> 5297 5298<div style="margin: auto;"> 5299 <h4><a 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> 5300</div> 5301 5302<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> 5303 5304<div style="margin: auto;"> 5305 <h4><a 5306id="shared-memory"></a>-shared-memory</h4> 5307</div> 5308 5309<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> 5310 5311<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> 5312 5313<div style="margin: auto;"> 5314 <h4><a id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4> 5315</div> 5316 5317<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> 5318 5319<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p> 5320 5321<div style="margin: auto;"> 5322 <h4><a id="shave"></a>-shave <em class="arg">geometry</em></h4> 5323</div> 5324 5325<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> 5326 5327<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> 5328 5329<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> 5330 5331<div style="margin: auto;"> 5332 <h4><a id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4> 5333</div> 5334 5335<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> 5336 5337<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> 5338 5339<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> 5340 5341<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> 5342 5343<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> 5344 5345<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> 5346<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> 5347 5348<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p> 5349<div style="margin: auto;"> 5350 <h4><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4> 5351</div> 5352 5353<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> 5354 5355<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> 5356 5357<div style="margin: auto;"> 5358 <h4><a id="silent"></a>-silent</h4> 5359</div> 5360 5361<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> 5362 5363<div style="margin: auto;"> 5364 <h4><a id="size"></a>-size <em class="arg">width</em>[x<em class="arg">height</em>][<em class="arg">+offset</em>]</h4> 5365</div> 5366 5367<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> 5368 5369<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> 5370 5371<p>For Photo CD images, choose from these sizes:</p> 5372 5373<pre class="text"> 5374 192x128 5375 384x256 5376 768x512 5377 1536x1024 5378 3072x2048 5379</pre> 5380 5381<div style="margin: auto;"> 5382 <h4><a 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> 5383</div> 5384 5385<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> 5386 5387<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> 5388 5389<div style="margin: auto;"> 5390 <h4><a id="smush"></a>-smush <em class="arg">offset</em></h4> 5391</div> 5392 5393<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>smush an image sequence together.</td><td style='text-align:right;'></td></tr></table> 5394 5395<div style="margin: auto;"> 5396 <h4><a id="snaps"></a>-snaps <em class="arg">value</em></h4> 5397</div> 5398 5399<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> 5400 5401<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p> 5402 5403<div style="margin: auto;"> 5404 <h4><a id="solarize"></a>-solarize <em class="arg">threshold</em></h4> 5405</div> 5406 5407<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> 5408 5409<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p> 5410 5411<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p> 5412 5413<div style="margin: auto;"> 5414 <h4><a id="sparse-color"></a>-sparse-color <em 5415 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4> 5416</div> 5417 5418<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> 5419 5420 5421<table class="doc"> 5422 <tbody> 5423 <tr valign="top"> 5424 <th align="left" style="width: 8%">Method</th> 5425 <th align="left">Description</th> 5426 </tr> 5427 5428 <tr valign="top"> 5429 <td valign="top">barycentric</td> 5430 <td valign="top">three point triangle of color given 3 points. 5431 Giving only 2 points will form a linear gradient between those points. 5432 The gradient generated extends beyond the triangle created by those 5433 3 points. </td> 5434 </tr> 5435 5436 <tr valign="top"> 5437 <td valign="top">bilinear</td> 5438 <td valign="top">Like barycentric but for 4 points. Less than 4 points 5439 fall back to barycentric. </td> 5440 </tr> 5441 <tr valign="top"> 5442 <td valign="top">voronoi</td> 5443 <td valign="top">Simply map each pixel to the to nearest color point 5444 given. The result are polygonal 'cells' of solid color. </td> 5445 </tr> 5446 5447 <tr valign="top"> 5448 <td valign="top">shepards</td> 5449 <td valign="top">Colors points biased on the ratio of inverse distance 5450 squared. Generating spots of color in a sea of the average of 5451 colors. </td> 5452 </tr> 5453 5454 <tr valign="top"> 5455 <td valign="top">inverse</td> 5456 <td valign="top">Colors points biased on the ratio of inverse distance. 5457 This generates sharper points of color rather than rounded spots of 5458 '<kbd>shepards</kbd>' Generating spots of color in a sea of the 5459 average of colors. </td> 5460 </tr> 5461 5462 </tbody> 5463</table> 5464 5465<p>The points are placed according to the images location on the virtual 5466canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a> 5467offset), and do not actually have to exist on the given image, but may be 5468some point beyond the edge of the image. All points are floating point values. 5469</p> 5470 5471<p>Only the color channels defined by the <a href="#channel" >-channel</a> are 5472modified, which means that by default matte/alpha transparency channel is not 5473effected. Typically transparency channel is turned off either before or after 5474the operation. </P> 5475 5476Of course if some color points are transparent to generate a transparent 5477gradient, then the image also requires transparency enabled to store the 5478values. </p> 5479 5480<p>All the above methods when given a single point of color will replace all 5481the colors in the image with the color given, regardless of the point. This is 5482logical, and provides an alternative technique to recolor a image to some 5483default value. </p> 5484 5485 5486<div style="margin: auto;"> 5487 <h4><a id="splice"></a>-splice <em class="arg">geometry</em></h4> 5488</div> 5489 5490<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> 5491 5492<p>This will add rows and columns of the current <a 5493href="#background">-background</a> color into the given image according to the 5494given <a href="#gravity">-gravity</a> effectd geometry setting. >See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Essentually <a href="#splice">-splice</a> will divide the 5495image into four quadrants, separating them by the inserted rows and columns. 5496</P> 5497 5498If a dimension of geometry is zero no rows or columns will be added for that 5499dimension. Similarly using a zero offset with the appropriate <a 5500href="#gravity">-gravity</a> setting will add rows and columns to the edges of 5501the image, padding the image only along that one edge. Edge padding is what <a 5502href="#splice">-splice</a> is most commonly used for. </p> 5503 5504<p>If the exact same <em class="arg">geometry</em> and <a 5505href="#gravity">-gravity</a> is later used with <a href="#chop">-chop</a> the 5506added added all splices removed. </p> 5507 5508<div style="margin: auto;"> 5509 <h4><a id="spread"></a>-spread <em class="arg">amount</em></h4> 5510</div> 5511 5512<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> 5513 5514<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> 5515 5516<div style="margin: auto;"> 5517 <h4><a id="statistic"></a>-statistic <em class="arg">type</em> <em class="arg">geometry</em></h4> 5518</div> 5519 5520<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>replace each pixel with corresponding statistic from the neighborhood.</td><td style='text-align:right;'>[<a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>]</td></tr></table> 5521 5522<p>Choose from these statistic types:</p> 5523<pre class="text"> 5524 Gradient maximum difference in area 5525 Maximum maximum value per channel in neighborhood 5526 Minimum minimum value per channel in neighborhood 5527 Mean average value per channel in neighborhood 5528 Median median value per channel in neighborhood 5529 Mode mode (most frequent) value per channel in neighborhood 5530 Nonpeak value just before or after the median value per channel in neighborhood 5531</pre> 5532 5533<div style="margin: auto;"> 5534 <h4><a id="stegano"></a>-stegano <em class="arg">offset</em></h4> 5535</div> 5536 5537<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> 5538 5539<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> 5540 5541<div style="margin: auto;"> 5542 <h4><a id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4> 5543</div> 5544 5545<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> 5546 5547<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> 5548 5549<div style="margin: auto;"> 5550 <h4><a id="storage-type"></a>-storage-type <em class="arg">type</em></h4> 5551</div> 5552 5553<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> 5554 5555<pre class="text"> 5556 char unsigned characters 5557 double doubles 5558 float floats 5559 integer integers 5560 long longs 5561 quantum pixels in the native depth of your ImageMagick distribution 5562 short unsigned shorts 5563</pre> 5564 5565<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels 5566values range from 0 to the maximum value the storage type can support.</p> 5567 5568<div style="margin: auto;"> 5569 <h4><a id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4> 5570</div> 5571 5572<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> 5573 5574<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> 5575 5576<pre class="text"> 5577 Any 5578 Condensed 5579 Expanded 5580 ExtraCondensed 5581 ExtraExpanded 5582 Normal 5583 SemiCondensed 5584 SemiExpanded 5585 UltraCondensed 5586 UltraExpanded 5587</pre> 5588 5589<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p> 5590 5591<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> 5592 5593<div style="margin: auto;"> 5594 <h4><a id="strip"></a>-strip</h4> 5595</div> 5596 5597<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> 5598 5599<div style="margin: auto;"> 5600 <h4><a id="stroke"></a>-stroke <em class="arg">color</em></h4> 5601</div> 5602 5603<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> 5604 5605<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5606 5607<p>See <a href="#draw">-draw</a> for further details.</p> 5608 5609<div style="margin: auto;"> 5610 <h4><a id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4> 5611</div> 5612 5613<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> 5614 5615<p>See <a href="#draw">-draw</a> for further details.</p> 5616 5617<div style="margin: auto;"> 5618 <h4><a id="style"></a>-style <em class="arg">fontStyle</em></h4> 5619</div> 5620 5621<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> 5622 5623<p>This setting suggests a font style that ImageMagick should try to apply to 5624the currently selected font family. Select <em class="arg">fontStyle</em> from 5625the following.</p> 5626 5627<pre class="text"> 5628 Any 5629 Italic 5630 Normal 5631 Oblique 5632</pre> 5633 5634<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> 5635 5636<div style="margin: auto;"> 5637 <h4><a id="subimage-search"></a>-subimage-search</h4> 5638</div> 5639 5640<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> 5641 5642<p>This option is required to have compare search for the best match location 5643of a small image within a larger image. This search will produce two images 5644(or two frames). The first is the "difference" image and the second will 5645be the "match score" image.</p> 5646 5647<p>The "match-score" image is smaller containing a pixel for ever possible 5648position of the top-left corner of the given sub-image. that is its size will 5649be the size of the larger_image - sub_image + 1. The brightest location in 5650this image is the location s the locate on the best match that is also 5651reported. Note that this may or may nor be a perfect match, and the actual 5652brightness will reflect this. Other bright 'peaks' can be used to locate other 5653possible matching loctions. </p> 5654 5655<p>Note that the search will try to compare teh sub-image at every possible 5656location in the larger image, as such it can be very slow. The smaller the 5657sub-image the faster this search is. </p> 5658 5659 5660<div style="margin: auto;"> 5661 <h4><a id="swap"></a>-swap <em class="arg">index,index</em></h4> 5662</div> 5663 5664<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> 5665 5666<p>For example, <a href="#swap">-swap 0,2</a> swaps the first and the third 5667images in the current image sequence. Use <a href="#swap">+swap</a> to switch 5668the last two images in the sequence.</p> 5669 5670<div style="margin: auto;"> 5671 <h4><a id="swirl"></a>-swirl <em class="arg">degrees</em></h4> 5672</div> 5673 5674<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> 5675 5676<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p> 5677 5678<div style="margin: auto;"> 5679 <h4><a id="synchronize"></a>-synchronize</h4> 5680</div> 5681 5682<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>synchronize image to storage device.</td><td style='text-align:right;'></td></tr></table> 5683 5684<div style="margin: auto;"> 5685 <h4><a id="taint"></a>-taint</h4> 5686</div> 5687 5688<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mark the image as modified.</td><td style='text-align:right;'></td></tr></table> 5689 5690<div style="margin: auto;"> 5691 <h4><a id="text-font"></a>-text-font <em class="arg">name</em></h4> 5692</div> 5693 5694<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> 5695 5696<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> 5697 5698<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> 5699 5700<div style="margin: auto;"> 5701 <h4><a id="texture"></a>-texture <em class="arg">filename</em></h4> 5702</div> 5703 5704<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> 5705 5706<div style="margin: auto;"> 5707 <h4><a id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5708</div> 5709 5710<!-- {<em class="arg">green,blue,opacity</em>} 5711<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> 5712--> 5713 5714<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> 5715 5716<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> 5717 5718<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. 5719</p> 5720 5721<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> 5722 5723<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p> 5724<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> 5725 5726 5727<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> 5728<p>Note that the values of the transparency channel is treated as 'matte' 5729values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 5730 5731<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>. 5732</p> 5733 5734<div style="margin: auto;"> 5735 <h4><a id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4> 5736</div> 5737 5738<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> 5739 5740<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> 5741 5742<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> 5743 5744<div style="margin: auto;"> 5745 <h4><a id="tile"></a>-tile <em class="arg">filename</em></h4> 5746</div> 5747 5748<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> 5749 5750<div style="margin: auto;"> 5751 <h4>-tile <em class="arg">geometry</em></h4> 5752</div> 5753 5754<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> 5755 5756<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> 5757 5758<div style="margin: auto;"> 5759 <h4>-tile</h4> 5760</div> 5761 5762<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> 5763 5764<div style="margin: auto;"> 5765 <h4><a 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> 5766</div> 5767 5768<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> 5769 5770<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> 5771 5772<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> 5773 5774<div style="margin: auto;"> 5775 <h4><a id="tint"></a>-tint <em class="arg">value</em></h4> 5776</div> 5777 5778<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> 5779 5780<p>Tint the image with the fill color.</p> 5781 5782<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> 5783 5784<div style="margin: auto;"> 5785 <h4><a id="title"></a>-title <em class="arg">string</em></h4> 5786</div> 5787 5788<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> 5789 5790<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> 5791 5792<p>For example,</p> 5793 5794<p class="crtsnip"> 5795 -title "%m:%f %wx%h" 5796</p> 5797 5798<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> 5799 5800 5801<div style="margin: auto;"> 5802 <h4><a id="transform"></a>-transform</h4> 5803</div> 5804 5805<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> 5806 5807<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p> 5808 5809<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> 5810 5811<p>This operator has been now been superseded by the <a 5812href="#distort">-distort</a> '<kbd>AffineProjection</kbd>' method. </p> 5813 5814 5815<div style="margin: auto;"> 5816 <h4><a id="transparent"></a>-transparent <em class="arg">color</em></h4> 5817</div> 5818 5819<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> 5820 5821<p>The <em class="arg">color</em> argument is defined using the format 5822described under the <a href="#fill">-fill</a> option. The <a href="#fuzz" 5823>-fuzz</a> setting can be used to match and replace colors similar to the one 5824given. </p> 5825 5826<p>Use <a href="#transparent" >+transparent</a> to invert the pixels matched. 5827that is make all non-matching colors transparent. </p> 5828 5829<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a 5830href="#transparent" >-transparent</a> but replaces the matching color with the 5831current <a href="#fill">-fill</a> color setting, rather than transparent. 5832However the <a href="#transparent" >-transparent</a> operator also ensures 5833that the image has an alpha channel enabled, as per "<kbd><a href="#alpha" 5834>-alpha</a> set</kbd>", and does not require you to modify the <a 5835href="#channel">-channel</a> to enable alpha channel handling. </p> 5836 5837<p>Note that this does not define the color as being the 'transparency color' 5838used for color-mapped image formats, such as GIF. For that use <a 5839href="#transparent-color" >-transparent-color</a> </p> 5840 5841 5842<div style="margin: auto;"> 5843 <h4><a id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4> 5844</div> 5845 5846<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> 5847 5848<p>Sometimes this is used for saving to image formats such as 5849GIF and PNG8 which uses this color to represent boolean transparency. This 5850does not make a color transparent, it only defines what color the transparent 5851color is in the color palette of the saved image. Use <a 5852href="#transparent">-transparent</a> to make an opaque color transparent.</p> 5853 5854<p>This option allows you to have both an opaque visible color, as well as a 5855transparent color of the same color value without conflict. That is, you can 5856use the same color for both the transparent and opaque color areas within an 5857image. This, in turn, frees to you to select a transparent color that is 5858appropriate when an image is displayed by an application that does not handle a 5859transparent color index, while allowing ImageMagick to correctly handle images of this 5860type. </p> 5861 5862<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p> 5863 5864<div style="margin: auto;"> 5865 <h4><a id="transpose"></a>-transpose</h4> 5866</div> 5867 5868<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> 5869 5870<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>. 5871</p> 5872 5873<div style="margin: auto;"> 5874 <h4><a id="transverse"></a>-transverse</h4> 5875</div> 5876 5877<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> 5878 5879 5880<div style="margin: auto;"> 5881 <h4><a id="treedepth"></a>-treedepth <em class="arg">value</em></h4> 5882</div> 5883 5884<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> 5885 5886<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> 5887 5888<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> 5889 5890<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> 5891 5892<div style="margin: auto;"> 5893 <h4><a id="trim"></a>-trim</h4> 5894</div> 5895 5896<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> 5897 5898<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> 5899 5900<p>The page or virtual canvas information of the image is preserved allowing 5901you to extract the result of the <a href="#trim">-trim</a> operation from the 5902image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page 5903information if it is unwanted.</p> 5904 5905<p>If the trimmed image 'disappears' an warning is produced, and a special 5906single pixel transparent 'missed' image is returned, in the same way as when a 5907<a href="#crop">-crop</a> operation 'misses' the image proper. </p> 5908 5909 5910<div style="margin: auto;"> 5911 <h4><a id="type"></a>-type <em class="arg">type</em></h4> 5912</div> 5913 5914<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> 5915 <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>, or <kbd>ColorSeparationMatte</kbd>.</p> 5916 5917<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> 5918 5919<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p> 5920<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> 5921 5922<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p> 5923 5924<div style="margin: auto;"> 5925 <h4><a id="undercolor"></a>-undercolor <em class="arg">color</em></h4> 5926</div> 5927 5928<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> 5929 5930<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5931 5932<p>See <a href="#draw">-draw</a> for further details.</p> 5933 5934 5935<div style="margin: auto;"> 5936 <h4><a id="update"></a>-update <em class="arg">seconds</em></h4> 5937</div> 5938 5939<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> 5940 5941<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> 5942 5943 5944<div style="margin: auto;"> 5945 <h4><a id="unique-colors"></a>-unique-colors</h4> 5946</div> 5947 5948<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> 5949 5950 5951<div style="margin: auto;"> 5952 <h4><a id="units"></a>-units <em class="arg">type</em></h4> 5953</div> 5954 5955<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> 5956 5957<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> 5958 5959 5960<div style="margin: auto;"> 5961 <h4><a 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> 5962</div> 5963 5964<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> 5965 5966<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> 5967 5968<p>The parameters are:</p> 5969 5970<pre class="text"> 5971 radius The radius of the Gaussian, in pixels, not counting the center 5972 pixel (default 0). 5973 sigma The standard deviation of the Gaussian, in pixels (default 1.0). 5974 amount The fraction of the difference between the original and the blur 5975 image that is added back into the original (default 1.0). 5976 threshold The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the 5977 difference amount (default 0.05). 5978</pre> 5979 5980 5981<div style="margin: auto;"> 5982 <h4><a id="verbose"></a>-verbose</h4> 5983</div> 5984 5985<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> 5986 5987 5988<div style="margin: auto;"> 5989 <h4><a id="version"></a>-version</h4> 5990</div> 5991 5992<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> 5993 5994 5995<div style="margin: auto;"> 5996 <h4><a id="view"></a>-view <em class="arg">string</em></h4> 5997</div> 5998 5999<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> 6000 6001 6002<div style="margin: auto;"> 6003 <h4><a 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> 6004</div> 6005 6006<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> 6007 6008 6009<div style="margin: auto;"> 6010 <h4><a id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4> 6011</div> 6012 6013<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> 6014 6015<p>This option defines what color source should be used if and when a color 6016lookup completely 'misses' the source image. The color(s) that appear to 6017surround the source image. Generally this color is derived from the source 6018image, but could also be set to a specify background color. </p> 6019 6020<p>Choose from these methods:</p> 6021 6022<pre class="text"> 6023 background the area surrounding the image is the background color 6024 black the area surrounding the image is black 6025 checker-tile alternate squares with image and background color 6026 dither non-random 32x32 dithered pattern 6027 edge extend the edge pixel toward infinity 6028 gray the area surrounding the image is gray 6029 horizontal-tile horizontally tile the image, background color above/below 6030 horizontal-tile-edge horizontally tile the image and replicate the side edge pixels 6031 mirror mirror tile the image 6032 random choose a random pixel from the image 6033 tile tile the image (default) 6034 transparent the area surrounding the image is transparent blackness 6035 vertical-tile vertically tile the image, sides are background color 6036 vertical-tile-edge vertically tile the image and replicate the side edge pixels 6037 white the area surrounding the image is white 6038</pre> 6039 6040<p>The default value is "edge".</p> 6041 6042<p>This most important for distortion operators such as <a href="#distort" 6043>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>. 6044However it also effects operations that may access pixels just outside the 6045image proper, such as <a href="#convolve">-convolve</a>, <a 6046href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p> 6047 6048<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p> 6049 6050 6051<div style="margin: auto;"> 6052 <h4><a id="visual"></a>-visual <em class="arg">type</em></h4> 6053</div> 6054 6055<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> 6056 6057<p>Choose from these visual classes:</p> 6058 6059<pre class="text"> 6060 StaticGray 6061 GrayScale 6062 StaticColor 6063 PseudoColor 6064 TrueColor 6065 DirectColor 6066 default 6067 visual id 6068</pre> 6069 6070<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> 6071 6072 6073<div style="margin: auto;"> 6074 <h4><a id="watermark"></a>-watermark <em 6075 class="arg">brightness</em>x<em class="arg">saturation</em></h4> 6076</div> 6077 6078<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 6079saturation.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 6080 6081<p>Take a grayscale image (with alpha mask) and modify the destination image's 6082brightness according to watermark image's grayscale value and the <em 6083class="arg">brightness</em> percentage. The destinations color saturation 6084attribute is just direct modified by the <em class="arg">saturation</em> 6085percentage, which defaults to 100 percent (no color change). </p> 6086 6087 6088<div style="margin: auto;"> 6089 <h4><a id="wave"></a>-wave <em class="arg">amplitude</em><br />-wave <em class="arg">amplitude</em>x<em class="arg">wavelength</em></h4> 6090</div> 6091 6092<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> 6093 6094<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p> 6095 6096<div style="margin: auto;"> 6097 <h4><a id="weight"></a>-weight <em class="arg">fontWeight</em></h4> 6098</div> 6099 6100<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> 6101 6102<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> 6103 6104<table class="doc"> 6105 <col width="25%" /> 6106 <col width="75%" /> 6107 <thead> 6108 <tr> 6109 <th><em class="arg">fontWeight</em></th> 6110 <th>Description</th> 6111 </tr> 6112 </thead> 6113 <tbody> 6114 <tr><td>All </td> <td>No effect. </td></tr> 6115 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr> 6116 <tr><td>Bolder </td> <td>Add 100 to font weight if currently ≤ 800.</td></tr> 6117 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently ≤ 100.</td></tr> 6118 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr> 6119 </tbody> 6120 </table> 6121 6122<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p> 6123 6124<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> 6125 6126<div style="margin: auto;"> 6127 <h4><a id="white-point"></a>-white-point <em class="arg">x,y</em></h4> 6128</div> 6129 6130<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> 6131 6132<div style="margin: auto;"> 6133 <h4><a id="white-threshold"></a>-white-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 6134</div> 6135 6136<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> 6137 6138<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. 6139</p> 6140 6141<div style="margin: auto;"> 6142 <h4><a id="window"></a>-window <em class="arg">id</em></h4> 6143</div> 6144 6145<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> 6146 6147<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> 6148 6149<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> 6150 6151<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> 6152 6153<div style="margin: auto;"> 6154 <h4><a id="window-group"></a>-window-group</h4> 6155</div> 6156 6157<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> 6158 6159<div style="margin: auto;"> 6160 <h4><a id="write"></a>-write <em class="arg">filename</em></h4> 6161</div> 6162 6163<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> 6164 <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> 6165 6166<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p> 6167</div> 6168</div> 6169 6170</div> 6171 6172<div id="linkbar"> 6173 <span id="linkbar-west"> </span> 6174 <span id="linkbar-center"> 6175 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> • 6176 <a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi">Studio</a> 6177 </span> 6178 <span id="linkbar-east"> </span> 6179 </div> 6180 <div class="footer"> 6181 <span id="footer-west">© 1999-2011 ImageMagick Studio LLC</span> 6182 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span> 6183 </div> 6184 <div style="clear: both; margin: 0; width: 100%; "></div> 6185 <script type="text/javascript"> 6186 var _gaq = _gaq || []; 6187 _gaq.push(['_setAccount', 'UA-17690367-1']); 6188 _gaq.push(['_trackPageview']); 6189 6190 (function() { 6191 var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; 6192 ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; 6193 var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); 6194 })(); 6195 </script> 6196</body> 6197</html> 6198
