blob: 5b0c52ba26042206ff44797d5998f78d64e1de8b [file] [log] [blame]
Cristy594d2772015-11-15 10:47:42 -05001
2
3
4
cristy29dc8652015-05-12 16:26:21 +00005<!DOCTYPE html>
cristyd2432012015-05-04 23:15:15 +00006<html lang="en">
cristyad41c0c2012-10-31 00:49:28 +00007<head>
cristy29f2c972015-07-28 13:37:46 +00008 <title>ImageMagick: Command-line Options</title>
Cristy912a9222016-06-17 15:37:28 -04009 <meta charset="utf-8" />
10 <meta http-equiv="X-UA-Compatible" content="IE=edge" />
11 <meta name="viewport" content="width=device-width, initial-scale=1" />
Cristy594d2772015-11-15 10:47:42 -050012 <meta http-equiv="content-type" content="text/html; charset=utf-8"/>
13 <meta name="application-name" content="ImageMagick"/>
14 <meta name="description" content="ImageMagick® is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, JPEG-2000, GIF, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves."/>
15 <meta name="application-url" content="http://www.imagemagick.org"/>
16 <meta name="generator" content="PHP"/>
17 <meta name="keywords" content="command-line, options, ImageMagick, PerlMagick, image processing, image, photo, software, Magick++, OpenMP, convert"/>
18 <meta name="rating" content="GENERAL"/>
19 <meta name="robots" content="INDEX, FOLLOW"/>
20 <meta name="generator" content="ImageMagick Studio LLC"/>
21 <meta name="author" content="ImageMagick Studio LLC"/>
22 <meta name="revisit-after" content="2 DAYS"/>
23 <meta name="resource-type" content="document"/>
Cristy912a9222016-06-17 15:37:28 -040024 <meta name="copyright" content="Copyright (c) 1999-2016 ImageMagick Studio LLC"/>
Cristy594d2772015-11-15 10:47:42 -050025 <meta name="distribution" content="Global"/>
26 <meta name="magick-serial" content="P131-S030410-R485315270133-P82224-A6668-G1245-1"/>
Cristy912a9222016-06-17 15:37:28 -040027 <meta name="google-site-verification" content="_bMOCDpkx9ZAzBwb2kF3PRHbfUUdFj2uO8Jd1AXArz4" />
Cristy594d2772015-11-15 10:47:42 -050028 <link rel="icon" href="../images/wand.png"/>
29 <link rel="shortcut icon" href="../images/wand.ico"/>
Cristy912a9222016-06-17 15:37:28 -040030 <link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Roboto:900,400,400italic,700,700italic,300,300italic|Open+Sans:300italic,400italic,700italic,300,400,600,700">
Cristyce4a3552015-12-14 13:53:35 -050031 <link rel="stylesheet" href="css/magick.css"/>
cristyad41c0c2012-10-31 00:49:28 +000032</head>
cristyd2432012015-05-04 23:15:15 +000033<body>
cristyad41c0c2012-10-31 00:49:28 +000034<div class="main">
cristyd2432012015-05-04 23:15:15 +000035<div class="magick-masthead">
36 <div class="container">
Cristy594d2772015-11-15 10:47:42 -050037 <script async="async" src="http://localhost/pagead/js/adsbygoogle.js"></script> <ins class="adsbygoogle"
38 style="display:block"
39 data-ad-client="ca-pub-3129977114552745"
40 data-ad-slot="6345125851"
41 data-ad-format="auto"></ins>
cristy29f2c972015-07-28 13:37:46 +000042 <script>
Cristy542697a2015-10-12 20:10:32 -040043 (adsbygoogle = window.adsbygoogle || []).push({});
cristyd2432012015-05-04 23:15:15 +000044 </script>
cristyd2432012015-05-04 23:15:15 +000045 <nav class="magick-nav">
cristy44443b92015-05-05 00:06:07 +000046 <a class="magick-nav-item " href="../index.html">Home</a>
cristyea2793e2015-05-31 16:52:26 +000047 <a class="magick-nav-item " href="binary-releases.html">Download</a>
cristyd2432012015-05-04 23:15:15 +000048 <a class="magick-nav-item " href="command-line-tools.html">Tools</a>
Cristye93be682015-11-26 09:07:51 -050049 <a class="magick-nav-item " href="command-line-processing.html">Command-line</a>
cristyea2793e2015-05-31 16:52:26 +000050 <a class="magick-nav-item " href="resources.html">Resources</a>
51 <a class="magick-nav-item " href="api.html">Develop</a>
Cristy1f1f3a02016-06-01 07:25:42 -040052 <a class="magick-nav-item " href="http://www.imagemagick.org/script/search.php">Search</a>
Cristye09ed312016-03-06 08:07:39 -050053 <a class="magick-nav-item pull-right" href="https://www.imagemagick.org/discourse-server/">Community</a>
cristyd2432012015-05-04 23:15:15 +000054 </nav>
55 </div>
56</div>
57<div class="container">
Cristy882d9f42015-10-29 16:48:39 -040058<div class="magick-header">
Cristye0779712016-07-30 17:25:22 -040059<p class="text-center"><a href="command-line-options.html#adaptive-blur">&#x2011;adaptive&#x2011;blur</a><a href="command-line-options.html#adaptive-resize">&#x2011;adaptive&#x2011;resize</a><a href="command-line-options.html#adaptive-sharpen">&#x2011;adaptive&#x2011;sharpen</a><a href="command-line-options.html#adjoin">&#x2011;adjoin</a><a href="command-line-options.html#affine">&#x2011;affine</a><a href="command-line-options.html#alpha">&#x2011;alpha</a><a href="command-line-options.html#alpha-color">&#x2011;alpha&#x2011;color</a><a href="command-line-options.html#annotate">&#x2011;annotate</a><a href="command-line-options.html#antialias">&#x2011;antialias</a><a href="command-line-options.html#append">&#x2011;append</a><a href="command-line-options.html#attenuate">&#x2011;attenuate</a><a href="command-line-options.html#authenticate">&#x2011;authenticate</a><a href="command-line-options.html#auto-gamma">&#x2011;auto&#x2011;gamma</a><a href="command-line-options.html#auto-level">&#x2011;auto&#x2011;level</a><a href="command-line-options.html#auto-orient">&#x2011;auto&#x2011;orient</a><a href="command-line-options.html#backdrop">&#x2011;backdrop</a><a href="command-line-options.html#background">&#x2011;background</a><a href="command-line-options.html#bench">&#x2011;bench</a><a href="command-line-options.html#bias">&#x2011;bias</a><a href="command-line-options.html#black-point-compensation">&#x2011;black&#x2011;point&#x2011;compensation</a><a href="command-line-options.html#black-threshold">&#x2011;black&#x2011;threshold</a><a href="command-line-options.html#blend">&#x2011;blend</a><a href="command-line-options.html#blue-primary">&#x2011;blue&#x2011;primary</a><a href="command-line-options.html#blue-shift">&#x2011;blue&#x2011;shift</a><a href="command-line-options.html#blur">&#x2011;blur</a><a href="command-line-options.html#border">&#x2011;border</a><a href="command-line-options.html#bordercolor">&#x2011;bordercolor</a><a href="command-line-options.html#borderwidth">&#x2011;borderwidth</a><a href="command-line-options.html#brightness-contrast">&#x2011;brightness&#x2011;contrast</a><a href="command-line-options.html#cache">&#x2011;cache</a><a href="command-line-options.html#canny">&#x2011;canny</a><a href="command-line-options.html#caption">&#x2011;caption</a><a href="command-line-options.html#cdl">&#x2011;cdl</a><a href="command-line-options.html#channel">&#x2011;channel</a><a href="command-line-options.html#charcoal">&#x2011;charcoal</a><a href="command-line-options.html#chop">&#x2011;chop</a><a href="command-line-options.html#clamp">&#x2011;clamp</a><a href="command-line-options.html#clip">&#x2011;clip</a><a href="command-line-options.html#clip-mask">&#x2011;clip&#x2011;mask</a><a href="command-line-options.html#clip-path">&#x2011;clip&#x2011;path</a><a href="command-line-options.html#clone">&#x2011;clone</a><a href="command-line-options.html#clut">&#x2011;clut</a><a href="command-line-options.html#coalesce">&#x2011;coalesce</a><a href="command-line-options.html#colorize">&#x2011;colorize</a><a href="command-line-options.html#colormap">&#x2011;colormap</a><a href="command-line-options.html#color-matrix">&#x2011;color&#x2011;matrix</a><a href="command-line-options.html#colors">&#x2011;colors</a><a href="command-line-options.html#colorspace">&#x2011;colorspace</a><a href="command-line-options.html#combine">&#x2011;combine</a><a href="command-line-options.html#comment">&#x2011;comment</a><a href="command-line-options.html#compare">&#x2011;compare</a><a href="command-line-options.html#complex">&#x2011;complex</a><a href="command-line-options.html#compose">&#x2011;compose</a><a href="command-line-options.html#composite">&#x2011;composite</a><a href="command-line-options.html#compress">&#x2011;compress</a><a href="command-line-options.html#connected-components">&#x2011;connected&#x2011;components</a><a href="command-line-options.html#contrast">&#x2011;contrast</a><a href="command-line-options.html#contrast-stretch">&#x2011;contrast&#x2011;stretch</a><a href="command-line-options.html#convolve">&#x2011;convolve</a><a href="command-line-options.html#copy">&#x2011;copy</a><a href="command-line-options.html#crop">&#x2011;crop</a><a href="command-line-options.html#cycle">&#x2011;cycle</a><a href="command-line-options.html#debug">&#x2011;debug</a><a href="command-line-options.html#decipher">&#x2011;decipher</a><a href="command-line-options.html#deconstruct">&#x2011;deconstruct</a><a href="command-line-options.html#define">&#x2011;define</a><a href="command-line-options.html#delay">&#x2011;delay</a><a href="command-line-options.html#delete">&#x2011;delete</a><a href="command-line-options.html#density">&#x2011;density</a><a href="command-line-options.html#depth">&#x2011;depth</a><a href="command-line-options.html#descend">&#x2011;descend</a><a href="command-line-options.html#deskew">&#x2011;deskew</a><a href="command-line-options.html#despeckle">&#x2011;despeckle</a><a href="command-line-options.html#direction">&#x2011;direction</a><a href="command-line-options.html#displace">&#x2011;displace</a><a href="command-line-options.html#display">&#x2011;display</a><a href="command-line-options.html#dispose">&#x2011;dispose</a><a href="command-line-options.html#dissimilarity-threshold">&#x2011;dissimilarity&#x2011;threshold</a><a href="command-line-options.html#dissolve">&#x2011;dissolve</a><a href="command-line-options.html#distort">&#x2011;distort</a><a href="command-line-options.html#distribute-cache">&#x2011;distribute&#x2011;cache</a><a href="command-line-options.html#dither">&#x2011;dither</a><a href="command-line-options.html#draw">&#x2011;draw</a><a href="command-line-options.html#duplicate">&#x2011;duplicate</a><a href="command-line-options.html#edge">&#x2011;edge</a><a href="command-line-options.html#emboss">&#x2011;emboss</a><a href="command-line-options.html#encipher">&#x2011;encipher</a><a href="command-line-options.html#encoding">&#x2011;encoding</a><a href="command-line-options.html#endian">&#x2011;endian</a><a href="command-line-options.html#enhance">&#x2011;enhance</a><a href="command-line-options.html#equalize">&#x2011;equalize</a><a href="command-line-options.html#evaluate">&#x2011;evaluate</a><a href="command-line-options.html#evaluate-sequence">&#x2011;evaluate&#x2011;sequence</a><a href="command-line-options.html#extent">&#x2011;extent</a><a href="command-line-options.html#extract">&#x2011;extract</a><a href="command-line-options.html#family">&#x2011;family</a><a href="command-line-options.html#features">&#x2011;features</a><a href="command-line-options.html#fft">&#x2011;fft</a><a href="command-line-options.html#fill">&#x2011;fill</a><a href="command-line-options.html#filter">&#x2011;filter</a><a href="command-line-options.html#flatten">&#x2011;flatten</a><a href="command-line-options.html#flip">&#x2011;flip</a><a href="command-line-options.html#floodfill">&#x2011;floodfill</a><a href="command-line-options.html#flop">&#x2011;flop</a><a href="command-line-options.html#font">&#x2011;font</a><a href="command-line-options.html#foreground">&#x2011;foreground</a><a href="command-line-options.html#format">&#x2011;format</a><a href="command-line-options.html#format_identify_">&#x2011;format[identify]</a><a href="command-line-options.html#frame">&#x2011;frame</a><a href="command-line-options.html#frame_import_">&#x2011;frame[import]</a><a href="command-line-options.html#function">&#x2011;function</a><a href="command-line-options.html#fuzz">&#x2011;fuzz</a><a href="command-line-options.html#fx">&#x2011;fx</a><a href="command-line-options.html#gamma">&#x2011;gamma</a><a href="command-line-options.html#gaussian-blur">&#x2011;gaussian&#x2011;blur</a><a href="command-line-options.html#geometry">&#x2011;geometry</a><a href="command-line-options.html#gravity">&#x2011;gravity</a><a href="command-line-options.html#grayscale">&#x2011;grayscale</a><a href="command-line-options.html#green-primary">&#x2011;green&#x2011;primary</a><a href="command-line-options.html#hald-clut">&#x2011;hald&#x2011;clut</a><a href="command-line-options.html#help">&#x2011;help</a><a href="command-line-options.html#highlight-color">&#x2011;highlight&#x2011;color</a><a href="command-line-options.html#hough-lines">&#x2011;hough&#x2011;lines</a><a href="command-line-options.html#iconGeometry">&#x2011;iconGeometry</a><a href="command-line-options.html#iconic">&#x2011;iconic</a><a href="command-line-options.html#identify">&#x2011;identify</a><a href="command-line-options.html#ift">&#x2011;ift</a><a href="command-line-options.html#immutable">&#x2011;immutable</a><a href="command-line-options.html#implode">&#x2011;implode</a><a href="command-line-options.html#insert">&#x2011;insert</a><a href="command-line-options.html#intensity">&#x2011;intensity</a><a href="command-line-options.html#intent">&#x2011;intent</a><a href="command-line-options.html#interlace">&#x2011;interlace</a><a href="command-line-options.html#interpolate">&#x2011;interpolate</a><a href="command-line-options.html#interline-spacing">&#x2011;interline&#x2011;spacing</a><a href="command-line-options.html#interword-spacing">&#x2011;interword&#x2011;spacing</a><a href="command-line-options.html#kerning">&#x2011;kerning</a><a href="command-line-options.html#kuwahara">&#x2011;kuwahara</a><a href="command-line-options.html#label">&#x2011;label</a><a href="command-line-options.html#lat">&#x2011;lat</a><a href="command-line-options.html#layers">&#x2011;layers</a><a href="command-line-options.html#level">&#x2011;level</a><a href="command-line-options.html#level-colors">&#x2011;level&#x2011;colors</a><a href="command-line-options.html#limit">&#x2011;limit</a><a href="command-line-options.html#linear-stretch">&#x2011;linear&#x2011;stretch</a><a href="command-line-options.html#linewidth">&#x2011;linewidth</a><a href="command-line-options.html#liquid-rescale">&#x2011;liquid&#x2011;rescale</a><a href="command-line-options.html#list">&#x2011;list</a><a href="command-line-options.html#log">&#x2011;log</a><a href="command-line-options.html#loop">&#x2011;loop</a><a href="command-line-options.html#lowlight-color">&#x2011;lowlight&#x2011;color</a><a href="command-line-options.html#magnify">&#x2011;magnify</a><a href="command-line-options.html#map">&#x2011;map</a><a href="command-line-options.html#map_stream_">&#x2011;map[stream]</a><a href="command-line-options.html#mattecolor">&#x2011;mattecolor</a><a href="command-line-options.html#median">&#x2011;median</a><a href="command-line-options.html#mean-shift">&#x2011;mean&#x2011;shift</a><a href="command-line-options.html#metric">&#x2011;metric</a><a href="command-line-options.html#mode">&#x2011;mode</a><a href="command-line-options.html#modulate">&#x2011;modulate</a><a href="command-line-options.html#moments">&#x2011;moments</a><a href="command-line-options.html#monitor">&#x2011;monitor</a><a href="command-line-options.html#monochrome">&#x2011;monochrome</a><a href="command-line-options.html#morph">&#x2011;morph</a><a href="command-line-options.html#morphology">&#x2011;morphology</a><a href="command-line-options.html#mosaic">&#x2011;mosaic</a><a href="command-line-options.html#motion-blur">&#x2011;motion&#x2011;blur</a><a href="command-line-options.html#name">&#x2011;name</a><a href="command-line-options.html#negate">&#x2011;negate</a><a href="command-line-options.html#noise">&#x2011;noise</a><a href="command-line-options.html#normalize">&#x2011;normalize</a><a href="command-line-options.html#opaque">&#x2011;opaque</a><a href="command-line-options.html#ordered-dither">&#x2011;ordered&#x2011;dither</a><a href="command-line-options.html#orient">&#x2011;orient</a><a href="command-line-options.html#page">&#x2011;page</a><a href="command-line-options.html#paint">&#x2011;paint</a><a href="command-line-options.html#path">&#x2011;path</a><a href="command-line-options.html#pause_animate_">&#x2011;pause[animate]</a><a href="command-line-options.html#pause_import_">&#x2011;pause[import]</a><a href="command-line-options.html#perceptible">&#x2011;perceptible</a><a href="command-line-options.html#ping">&#x2011;ping</a><a href="command-line-options.html#pointsize">&#x2011;pointsize</a><a href="command-line-options.html#polaroid">&#x2011;polaroid</a><a href="command-line-options.html#poly">&#x2011;poly</a><a href="command-line-options.html#posterize">&#x2011;posterize</a><a href="command-line-options.html#precision">&#x2011;precision</a><a href="command-line-options.html#preview">&#x2011;preview</a><a href="command-line-options.html#print">&#x2011;print</a><a href="command-line-options.html#process">&#x2011;process</a><a href="command-line-options.html#profile">&#x2011;profile</a><a href="command-line-options.html#quality">&#x2011;quality</a><a href="command-line-options.html#quantize">&#x2011;quantize</a><a href="command-line-options.html#quiet">&#x2011;quiet</a><a href="command-line-options.html#radial-blur">&#x2011;radial&#x2011;blur</a><a href="command-line-options.html#raise">&#x2011;raise</a><a href="command-line-options.html#random-threshold">&#x2011;random&#x2011;threshold</a><a href="command-line-options.html#read-mask">&#x2011;read&#x2011;mask</a><a href="command-line-options.html#red-primary">&#x2011;red&#x2011;primary</a><a href="command-line-options.html#regard-warnings">&#x2011;regard&#x2011;warnings</a><a href="command-line-options.html#region">&#x2011;region</a><a href="command-line-options.html#remap">&#x2011;remap</a><a href="command-line-options.html#remote">&#x2011;remote</a><a href="command-line-options.html#render">&#x2011;render</a><a href="command-line-options.html#repage">&#x2011;repage</a><a href="command-line-options.html#resample">&#x2011;resample</a><a href="command-line-options.html#resize">&#x2011;resize</a><a href="command-line-options.html#respect-parentheses">&#x2011;respect&#x2011;parentheses</a><a href="command-line-options.html#reverse">&#x2011;reverse</a><a href="command-line-options.html#roll">&#x2011;roll</a><a href="command-line-options.html#rotate">&#x2011;rotate</a><a href="command-line-options.html#sample">&#x2011;sample</a><a href="command-line-options.html#sampling-factor">&#x2011;sampling&#x2011;factor</a><a href="command-line-options.html#scale">&#x2011;scale</a><a href="command-line-options.html#scene">&#x2011;scene</a><a href="command-line-options.html#screen">&#x2011;screen</a><a href="command-line-options.html#seed">&#x2011;seed</a><a href="command-line-options.html#segment">&#x2011;segment</a><a href="command-line-options.html#selective-blur">&#x2011;selective&#x2011;blur</a><a href="command-line-options.html#separate">&#x2011;separate</a><a href="command-line-options.html#sepia-tone">&#x2011;sepia&#x2011;tone</a><a href="command-line-options.html#set">&#x2011;set</a><a href="command-line-options.html#shade">&#x2011;shade</a><a href="command-line-options.html#shadow">&#x2011;shadow</a><a href="command-line-options.html#shared-memory">&#x2011;shared&#x2011;memory</a><a href="command-line-options.html#sharpen">&#x2011;sharpen</a><a href="command-line-options.html#shave">&#x2011;shave</a><a href="command-line-options.html#shear">&#x2011;shear</a><a href="command-line-options.html#sigmoidal-contrast">&#x2011;sigmoidal&#x2011;contrast</a><a href="command-line-options.html#silent">&#x2011;silent</a><a href="command-line-options.html#similarity-threshold">&#x2011;similarity&#x2011;threshold</a><a href="command-line-options.html#size">&#x2011;size</a><a href="command-line-options.html#sketch">&#x2011;sketch</a><a href="command-line-options.html#smush">&#x2011;smush</a><a href="command-line-options.html#snaps">&#x2011;snaps</a><a href="command-line-options.html#solarize">&#x2011;solarize</a><a href="command-line-options.html#sparse-color">&#x2011;sparse&#x2011;color</a><a href="command-line-options.html#splice">&#x2011;splice</a><a href="command-line-options.html#spread">&#x2011;spread</a><a href="command-line-options.html#statistic">&#x2011;statistic</a><a href="command-line-options.html#stegano">&#x2011;stegano</a><a href="command-line-options.html#stereo">&#x2011;stereo</a><a href="command-line-options.html#storage-type">&#x2011;storage&#x2011;type</a><a href="command-line-options.html#stretch">&#x2011;stretch</a><a href="command-line-options.html#strip">&#x2011;strip</a><a href="command-line-options.html#stroke">&#x2011;stroke</a><a href="command-line-options.html#strokewidth">&#x2011;strokewidth</a><a href="command-line-options.html#style">&#x2011;style</a><a href="command-line-options.html#subimage-search">&#x2011;subimage&#x2011;search</a><a href="command-line-options.html#swap">&#x2011;swap</a><a href="command-line-options.html#swirl">&#x2011;swirl</a><a href="command-line-options.html#synchronize">&#x2011;synchronize</a><a href="command-line-options.html#taint">&#x2011;taint</a><a href="command-line-options.html#text-font">&#x2011;text&#x2011;font</a><a href="command-line-options.html#texture">&#x2011;texture</a><a href="command-line-options.html#threshold">&#x2011;threshold</a><a href="command-line-options.html#thumbnail">&#x2011;thumbnail</a><a href="command-line-options.html#tile">&#x2011;tile</a><a href="command-line-options.html#tile-offset">&#x2011;tile&#x2011;offset</a><a href="command-line-options.html#tint">&#x2011;tint</a><a href="command-line-options.html#title">&#x2011;title</a><a href="command-line-options.html#transform">&#x2011;transform</a><a href="command-line-options.html#transparent">&#x2011;transparent</a><a href="command-line-options.html#transparent-color">&#x2011;transparent&#x2011;color</a><a href="command-line-options.html#transpose">&#x2011;transpose</a><a href="command-line-options.html#transverse">&#x2011;transverse</a><a href="command-line-options.html#treedepth">&#x2011;treedepth</a><a href="command-line-options.html#trim">&#x2011;trim</a><a href="command-line-options.html#type">&#x2011;type</a><a href="command-line-options.html#undercolor">&#x2011;undercolor</a><a href="command-line-options.html#unique-colors">&#x2011;unique&#x2011;colors</a><a href="command-line-options.html#units">&#x2011;units</a><a href="command-line-options.html#unsharp">&#x2011;unsharp</a><a href="command-line-options.html#update">&#x2011;update</a><a href="command-line-options.html#verbose">&#x2011;verbose</a><a href="command-line-options.html#version">&#x2011;version</a><a href="command-line-options.html#view">&#x2011;view</a><a href="command-line-options.html#vignette">&#x2011;vignette</a><a href="command-line-options.html#virtual-pixel">&#x2011;virtual&#x2011;pixel</a><a href="command-line-options.html#visual">&#x2011;visual</a><a href="command-line-options.html#watermark">&#x2011;watermark</a><a href="command-line-options.html#wave">&#x2011;wave</a><a href="command-line-options.html#wavelet-denoise">&#x2011;wavelet&#x2011;denoise</a><a href="command-line-options.html#weight">&#x2011;weight</a><a href="command-line-options.html#white-point">&#x2011;white&#x2011;point</a><a href="command-line-options.html#white-threshold">&#x2011;white&#x2011;threshold</a><a href="command-line-options.html#window">&#x2011;window</a><a href="command-line-options.html#window-group">&#x2011;window&#x2011;group</a><a href="command-line-options.html#write">&#x2011;write</a><a href="command-line-options.html#write-mask">&#x2011;write&#x2011;mask</a> </p>
Cristy882d9f42015-10-29 16:48:39 -040060
61<p class="lead magick-description">Below is list of command-line options recognized by the ImageMagick <a href="command-line-tools.html">command-line tools</a>. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it. Unless otherwise noted, each option is recognized by the commands: <a href="convert.html">convert</a> and <a href="mogrify.html">mogrify</a>.</p>
62
63<div style="margin: auto;">
64 <h3 class="magick-header"><a id="adaptive-blur"></a>-adaptive-blur <var>radius</var>[x<var>sigma</var>]</h3>
65</div>
66
67<p class="magick-description">Adaptively blur pixels, with decreasing effect near edges.</p>
68
69<p>A Gaussian operator of the given radius and standard deviation (<var>sigma</var>) is used. If <var>sigma</var> is not given it
70defaults to 1.</p>
71
72<div style="margin: auto;">
73 <h3 class="magick-header"><a id="adaptive-resize"></a>-adaptive-resize <var>geometry</var></h3>
74</div>
75
76<p class="magick-description">Resize the image using data-dependent triangulation.</p>
77
78<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <a href="command-line-options.html#adaptive-resize">-adaptive-resize</a>
Cristy594d2772015-11-15 10:47:42 -050079option defaults to data-dependent triangulation. Use the <a
80href="command-line-options.html#filter">-filter</a> to choose a different resampling algorithm.
81Offsets, if present in the geometry string, are ignored, and the <a
82href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
Cristy882d9f42015-10-29 16:48:39 -040083
84<div style="margin: auto;">
85 <h3 class="magick-header"><a id="adaptive-sharpen"></a>-adaptive-sharpen <var>radius</var>[x<var>sigma</var>]</h3>
86</div>
87
88<p class="magick-description">Adaptively sharpen pixels, with increasing effect near edges.</p>
89
90<p>A Gaussian operator of the given radius and standard deviation
91(<var>sigma</var>) is used. If <var>sigma</var> is not given it
92defaults to 1.</p>
93
94<div style="margin: auto;">
95 <h3 class="magick-header"><a id="adjoin"></a>-adjoin</h3>
96</div>
97
98<p class="magick-description">Join images into a single multi-image file.</p>
99
100<p>This option is enabled by default. An attempt is made to save all images of
101an image sequence into the given output file. However, some formats, such as
102JPEG and PNG, do not support more than one image per file, and in that case
103ImageMagick is forced to write each image as a separate file. As such, if
104more than one image needs to be written, the filename given is modified by
105adding a <a href="command-line-options.html#scene">-scene</a> number before the suffix, in order to
106make distinct names for each image. </p>
107
108<p>Use <a href="command-line-options.html#adjoin">+adjoin</a> to force each image to be written to
109separate files, whether or not the file format allows multiple images per file
110(for example, GIF, MIFF, and TIFF). </p>
111
112<p>Including a C-style integer format string in the output filename will
113automagically enable <a href="command-line-options.html#adjoin">+adjoin</a> and are used to specify
114where the <a href="command-line-options.html#scene">-scene</a> number is placed in the filenames. These
115strings, such as '<code>%d</code>' or '<code>%03d</code>', are familiar to those
116who have used the standard <code>printf()</code>' C-library function. As an
117example, the command</p>
118
119<pre>
120convert logo: rose: -morph 15 my%02dmorph.jpg
121</pre>
122
123<p>will create a sequence of 17 images (the two given plus 15 more created by
124<a href="command-line-options.html#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg,
125my02morph.jpg, ..., my16morph.jpg. </p>
126
127<p>In summary, ImageMagick tries to write all images to one file, but will
128save to multiple files, if any of the following conditions exist...</p>
129<ol>
130<li>the output image's file format does not allow multi-image files,</li>
131<li>the <a href="command-line-options.html#adjoin">+adjoin</a> option is given, or</li>
132<li>a printf() integer format string (eg: "%d") is present in the output
133 filename.</li>
134</ol>
135
136
137<div style="margin: auto;">
138 <h3 class="magick-header"><a id="affine"></a>-affine
139 <var>s<sub>x</sub></var>,<var>r<sub>x</sub></var>,<var>r<sub>y</sub></var>,<var>s<sub>y</sub></var>[,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>]</h3>
140</div>
141
142<p class="magick-description">Set the drawing transformation matrix for combined rotating and scaling.</p>
143
Cristy594d2772015-11-15 10:47:42 -0500144<p>This option sets a transformation matrix, for use by subsequent <a
145href="command-line-options.html#draw">-draw</a> or <a href="command-line-options.html#transform">-transform</a> options. </p>
Cristy882d9f42015-10-29 16:48:39 -0400146
147<p>The matrix entries are entered as comma-separated numeric values either in
148quotes or without spaces. </p>
149
150<p>Internally, the transformation matrix has 3x3 elements, but three of them
151are omitted from the input because they are constant. The new (transformed)
152coordinates (<var>x'</var>, <var>y'</var>) of a pixel at
153position (<var>x</var>, <var>y</var>) in the original
154image are calculated using the following matrix equation.</p>
155
Cristy594d2772015-11-15 10:47:42 -0500156<p class="text-center"><img class="img-thumbnail" alt="affine transformation" src="../images/affine.png"/> </p>
Cristy882d9f42015-10-29 16:48:39 -0400157
158<p> The size of the resulting image is that of the smallest rectangle that
159contains the transformed source image. The parameters
160<var>t<sub>x</sub></var> and <var>t<sub>y</sub></var>
161subsequently shift the image pixels so that those that are moved out of the
162image area are cut off.</p>
163
164<p>The transformation matrix complies with the left-handed pixel coordinate
165system: positive <var>x</var> and <var>y</var> directions
166are rightward and downward, resp.; positive rotation is clockwise.</p>
167
168<p> If the translation coefficients <var>t<sub>x</sub></var> and
169<var>t<sub>y</sub></var> are omitted they default to 0,0. Therefore,
170four parameters suffice for rotation and scaling without translation.</p>
171
172<p>Scaling by the factors <var>s<sub>x</sub></var> and
173<var>s<sub>y</sub></var> in the <var>x</var> and <var>y</var> directions,
174respectively, is accomplished with the following.</p>
175
Cristy594d2772015-11-15 10:47:42 -0500176<p>See <a href="command-line-options.html#transform">-transform</a>, and the <a
177href="command-line-options.html#distort">-distort</a> method '<code>Affineprojection</code> for more
Cristy882d9f42015-10-29 16:48:39 -0400178information </p>
179
180
181<pre>
182-affine <var>s<sub>x</sub></var>,0,0,<var>s<sub>y</sub></var>
183</pre>
184
185<p>Translation by a displacement (<var>t<sub>x</sub></var>, <var>t<sub>y</sub></var>) is accomplished like so:</p>
186
187<pre>
188-affine 1,0,0,1,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>
189</pre>
190
191<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle
192<var>a</var> by letting <var>c</var> = cos(<var>a</var>), <var>s</var>
193= sin(<var>a</var>), and using the following.</p>
194
195<pre>
196-affine <var>c</var>,<var>s</var>,-<var>s</var>,<var>c</var>
197</pre>
198
Cristy594d2772015-11-15 10:47:42 -0500199<p>The cumulative effect of a sequence of <a href="command-line-options.html#affine" >-affine</a>
200transformations can be accomplished by instead by a single <a href="command-line-options.html#affine"
201>-affine</a> operation using the matrix equal to the product of the matrices
Cristy882d9f42015-10-29 16:48:39 -0400202of the individual transformations.</p>
203
204<p>An attempt is made to detect near-singular transformation matrices. If the
205matrix determinant has a sufficiently small absolute value it is rejected.</p>
206
207<div style="margin: auto;">
208 <h3 class="magick-header"><a id="alpha"></a>-alpha <var>type</var></h3>
209</div>
210
211<p class="magick-description">Gives control of the alpha/matte channel of an image.</p>
212
213<p>Used to set a flag on an image indicating whether or not to use existing alpha
214channel data, to create an alpha channel, or to perform other operations on the alpha channel. Choose the argument <var>type</var> from the list below.</p>
215
216<dl class="dl-horizontal">
217 <dt>Activate</dt>
218 <dd>
219 Enable the image's transparency channel. Note normally Set
220 should be used instead of this, unless you specifically need to
221 preserve existing (but specifically turned Off) transparency
222 channel. </dd>
223
224 <dt>Associate</dt>
225 <dd>
226 associate the alpha channel with the image.</dd>
227
228 <dt>Deactivate</dt>
229 <dd>
230 Disables the image's transparency channel. Does not delete or change the
231 existing data, just turns off the use of that data.</dd>
232
233 <dt>Disassociate</dt>
234 <dd>
235 disassociate the alpha channel from the image.</dd>
236
237 <dt>Set</dt>
238 <dd>
239 Activates the alpha/matte channel. If it was previously turned off
240 then it also resets the channel to opaque. If the image already had
241 the alpha channel turned on, it will have no effect.</dd>
242
243 <dt>Opaque</dt>
244 <dd>
245 Enables the alpha/matte channel and forces it to be fully opaque.
246 </dd>
247
248 <dt>Transparent</dt>
249 <dd>
250 Activates the alpha/matte channel and forces it to be fully
251 transparent. This effectively creates a fully transparent image the
252 same size as the original and with all its original RGB data still
253 intact, but fully transparent. </dd>
254
255 <dt>Extract</dt>
256 <dd>
257 Copies the alpha channel values into all the color channels and turns
258 'Off' the the image's transparency, so as to generate
Cristy769d8892016-01-19 18:11:14 -0500259 a grayscale mask of the image's shape. The alpha channel data is left
Cristy882d9f42015-10-29 16:48:39 -0400260 intact just deactivated. This is the inverse of 'Copy'.
261 </dd>
262
263 <dt>Copy</dt>
264 <dd>
265 Turns 'On' the alpha/matte channel, then copies the
Cristy769d8892016-01-19 18:11:14 -0500266 grayscale intensity of the image, into the alpha channel, converting
267 a grayscale mask into a transparent shaped mask ready to be colored
Cristy882d9f42015-10-29 16:48:39 -0400268 appropriately. The color channels are not modified. </dd>
269
270 <dt>Shape</dt>
271 <dd>
272 As per 'Copy' but also colors the resulting shape mask with
273 the current background color. That is the RGB color channels is
274 replaced, with appropriate alpha shape.
275 </dd>
276
277 <dt>Remove</dt>
278 <dd>
279 Composite the image over the background color.
280 </dd>
281
282 <dt>Background</dt>
283 <dd>
284 Set any fully-transparent pixel to the background color, while leaving
285 it fully-transparent. This can make some image file formats, such as
286 PNG, smaller as the RGB values of transparent pixels are more uniform,
287 and thus can compress better.
288 </dd>
289</dl>
290
291<p>Note that while the obsolete <code>+matte</code> operation was the
Cristy594d2772015-11-15 10:47:42 -0500292same as "<code><a href="command-line-options.html#alpha" >-alpha</a> Off</code>", the <code>
293>-matte</code> operation was the same as "<code><a href="command-line-options.html#alpha" >-alpha</a>
294Set</code>" and not "<code><a href="command-line-options.html#alpha" >-alpha</a> On</code>". </p>
Cristy882d9f42015-10-29 16:48:39 -0400295
Cristyf650f4f2016-04-01 10:53:07 -0400296<div style="margin: auto;">
297 <h3 class="magick-header"><a id="alpha-color"></a>-alpha-color <var>color</var></h3>
298</div>
299
300<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p>
301
302<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
303
304<p>The default matte color is <code>#BDBDBD</code>, <span
305style="background-color: #bdbdbd;">this shade of gray</span>.</p>
306
307<p>This is an IMv7 option, use <a href="command-line-options.html#mattecolor">mattecolor</a> with IMv6.</p>
308
Cristy882d9f42015-10-29 16:48:39 -0400309
310<div style="margin: auto;">
311 <h3 class="magick-header"><a id="annotate"></a>
Cristy594d2772015-11-15 10:47:42 -0500312 -annotate <var>degrees</var> <var>text</var><br />
313 -annotate <var>Xdegrees</var>x<var>Ydegrees</var> <var>text</var><br /> -annotate <var>Xdegrees</var>x<var>Ydegrees</var> {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var><br /> -annotate {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400314</div>
315
316<p class="magick-description">Annotate an image with text</p>
317
318<p>This is a convenience for annotating an image with text. For more precise
319control over text annotations, use <a href="command-line-options.html#draw">-draw</a>.</p>
320
321
322<p>The values <var>Xdegrees</var> and <var>Ydegrees</var>
Cristy594d2772015-11-15 10:47:42 -0500323control the shears applied to the text, while <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are offsets that give the location of the text relative any <a href="command-line-options.html#gravity" >-gravity</a> setting and defaults to the upper left corner of the image.</p>
Cristy882d9f42015-10-29 16:48:39 -0400324
325<p>Using <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>
326or <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>x<var>degrees</var> produces an unsheared rotation of the text. The
327direction of the rotation is positive, which means a clockwise rotation if <var>degrees</var> is positive. (This conforms to the usual mathematical
328convention once it is realized that the positive <var>y</var>–direction is
329conventionally considered to be <var>downward</var> for images.)</p>
330
331<p>The new (transformed) coordinates (<var>x'</var>, <var>y'</var>) of a pixel at position (<var>x</var>, <var>y</var>) in the image are calculated using the following matrix
332equation.</p>
333
Cristy594d2772015-11-15 10:47:42 -0500334<p class="text-center"><img class="img-thumbnail" alt="annotate transformation" src="../images/annotate.png"/></p>
Cristy882d9f42015-10-29 16:48:39 -0400335
336<p>If <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are omitted, they default to 0. This makes the
337bottom-left of the text becomes the upper-left corner of the image, which is
Cristy594d2772015-11-15 10:47:42 -0500338probably undesirable. Adding a <a href="command-line-options.html#gravity" >-gravity</a> option in this
Cristy882d9f42015-10-29 16:48:39 -0400339case leads to nice results.</p>
340
341<p>Text is any UTF-8 encoded character sequence. If <var>text</var>
342is of the form '@mytext.txt', the text is read from the file
343<code>mytext.txt</code>. Text in a file is taken literally; no embedded
344formatting characters are recognized.</p>
345
346<div style="margin: auto;">
347 <h3 class="magick-header"><a id="antialias"></a>-antialias</h3>
348</div>
349
350<p class="magick-description">Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines.</p>
351
352<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when
353drawn. Use <a href="command-line-options.html#antialias">+antialias</a> to disable the addition of
354antialiasing edge pixels. This will then reduce the number of colors added to
355an image to just the colors being directly drawn. That is, no mixed colors
356are added when drawing such objects. </p>
357
358<div style="margin: auto;">
359 <h3 class="magick-header"><a id="append"></a>-append</h3>
360</div>
361
362<p class="magick-description">Join current images vertically or horizontally.</p>
363
364<p>This option creates a single longer image, by joining all the current
365images in sequence top-to-bottom. Use <a href="command-line-options.html#append">+append</a> to
366stack images left-to-right. </p>
367
368<p>If they are not of the same width, narrower images are padded with the
369current <a href="command-line-options.html#background">-background</a> color setting, and their
Cristy594d2772015-11-15 10:47:42 -0500370position relative to each other can be controlled by the current <a
371href="command-line-options.html#gravity">-gravity</a> setting. </p>
Cristy882d9f42015-10-29 16:48:39 -0400372
373
374<div style="margin: auto;">
375 <h3 class="magick-header"><a id="attenuate"></a>-attenuate <var>value</var></h3>
376</div>
377
378<p class="magick-description">Lessen (or intensify) when adding noise to an image.</p>
379
380<p>If unset the value is equivalent to 1.0, or a maximum noise addition</p>
381
382<div style="margin: auto;">
383 <h3 class="magick-header"><a id="authenticate"></a>-authenticate <var>password</var></h3>
384</div>
385
386<p class="magick-description">Decrypt a PDF with a password.</p>
387
388<p>Use this option to supply a <var>password</var> for decrypting
389a PDF that has been encrypted using Microsoft Crypto API (MSC API). The
390encrypting using the MSC API is not supported.</p>
391
392<p>For a different encryption method, see <a href="command-line-options.html#encipher">-encipher</a>
393and <a href="command-line-options.html#decipher">-decipher</a>. </p>
394
395
396<div style="margin: auto;">
397 <h3 class="magick-header"><a id="auto-gamma"></a>-auto-gamma</h3>
398</div>
399
400<p class="magick-description">Automagically adjust gamma level of image.</p>
401
Cristy594d2772015-11-15 10:47:42 -0500402<p>This calculates the mean values of an image, then applies a calculated <a
403href="command-line-options.html#gamma" >-gamma</a> adjustment so that is the mean color exists in the
Cristy882d9f42015-10-29 16:48:39 -0400404image it will get a have a value of 50%. </p>
405
406<p>This means that any solid 'gray' image becomes 50% gray. </p>
407
408<p>This works well for real-life images with little or no extreme dark and
409light areas, but tend to fail for images with large amounts of bright sky or
410dark shadows. It also does not work well for diagrams or cartoon like images.
411</p>
412
Cristy594d2772015-11-15 10:47:42 -0500413<p>It uses the <a href="command-line-options.html#channel" >-channel</a> setting, (including the
Cristy882d9f42015-10-29 16:48:39 -0400414'<var>sync</var>' flag for channel synchronization), to determine which color
Cristy594d2772015-11-15 10:47:42 -0500415values is used and modified. As the default <a href="command-line-options.html#channel"
416>-channel</a> setting is '<var>RGB,sync</var>', channels are modified
Cristy882d9f42015-10-29 16:48:39 -0400417together by the same gamma value, preserving colors. </p>
418
419
420
421<div style="margin: auto;">
422 <h3 class="magick-header"><a id="auto-level"></a>-auto-level</h3>
423</div>
424
425<p class="magick-description">Automagically adjust color levels of image.</p>
426
427<p>This is a 'perfect' image normalization operator. It finds the exact
Cristy594d2772015-11-15 10:47:42 -0500428minimum and maximum color values in the image and then applies a <a
429href="command-line-options.html#level" >-level</a> operator to stretch the values to the full range of
Cristy882d9f42015-10-29 16:48:39 -0400430values. </p>
431
432<p>The operator is not typically used for real-life images, image scans, or
433JPEG format images, as a single 'out-rider' pixel can set a bad min/max values
Cristy594d2772015-11-15 10:47:42 -0500434for the <a href="command-line-options.html#level" >-level</a> operation. On the other hand it is the
Cristy882d9f42015-10-29 16:48:39 -0400435right operator to use for color stretching gradient images being used to
436generate Color lookup tables, distortion maps, or other 'mathematically'
437defined images. </p>
438
Cristy594d2772015-11-15 10:47:42 -0500439<p>The operator is very similar to the <a href="command-line-options.html#normalize">-normalize</a>, <a
440href="command-line-options.html#contrast-stretch" >-contrast-stretch</a>, and <a href="command-line-options.html#linear-stretch"
441>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping'
442problems that these operators may have. That is <a href="command-line-options.html#auto-level"
443>-auto-level</a> is the perfect or ideal version these operators. </p>
Cristy882d9f42015-10-29 16:48:39 -0400444
Cristy594d2772015-11-15 10:47:42 -0500445<p>It uses the <a href="command-line-options.html#channel" >-channel</a> setting, (including the
Cristy882d9f42015-10-29 16:48:39 -0400446special '<var>sync</var>' flag for channel synchronization), to determine
Cristy594d2772015-11-15 10:47:42 -0500447which color values are used and modified. As the default <a
448href="command-line-options.html#channel" >+channel</a> setting is '<var>RGB,sync</var>', the
Cristy882d9f42015-10-29 16:48:39 -0400449'<var>sync</var>' ensures that the color channels will are modified
450together by the same gamma value, preserving colors, and ignoring
451transparency. </p>
452
453
454<div style="margin: auto;">
455 <h3 class="magick-header"><a id="auto-orient"></a>-auto-orient</h3>
456</div>
457
458<p class="magick-description">adjusts an image so that its orientation is suitable for viewing (i.e. top-left orientation).</p>
459
460<p>This operator reads and resets the EXIF image profile setting 'Orientation'
461and then performs the appropriate 90 degree rotation on the image to orient
462the image, for correct viewing. </p>
463
464<p>This EXIF profile setting is usually set using a gravity sensor in digital
465camera, however photos taken directly downward or upward may not have an
466appropriate value. Also images that have been orientation 'corrected' without
467reseting this setting, may be 'corrected' again resulting in a incorrect
Cristy594d2772015-11-15 10:47:42 -0500468result. If the EXIF profile was previously stripped, the <a
469href="command-line-options.html#auto-orient" >-auto-orient</a> operator will do nothing. </p>
Cristy882d9f42015-10-29 16:48:39 -0400470
471
472<div style="margin: auto;">
473 <h3 class="magick-header"><a id="average"></a>-average</h3>
474</div>
475
476<p class="magick-description">Average a set of images.</p>
477
478<p>An error results if the images are not identically sized.</p>
479
480
481<div style="margin: auto;">
482 <h3 class="magick-header"><a id="backdrop"></a>-backdrop</h3>
483</div>
484
485<p class="magick-description">Display the image centered on a backdrop.</p>
486
487<p>This backdrop covers the entire workstation screen and is useful for hiding
488other X window activity while viewing the image. The color of the backdrop is
489specified as the background color. The color is specified using the format
490described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
491
492<div style="margin: auto;">
493 <h3 class="magick-header"><a id="background"></a>-background <var>color</var></h3>
494</div>
495
496<p class="magick-description">Set the background color.</p>
497
Cristy594d2772015-11-15 10:47:42 -0500498<p>The color is specified using the format described under the <a
499href="command-line-options.html#fill">-fill</a> option. The default background color (if none is
Cristy882d9f42015-10-29 16:48:39 -0400500specified or found in the image) is white.</p>
501
502<div style="margin: auto;">
503 <h3 class="magick-header"><a id="bench"></a>-bench <var>iterations</var></h3>
504</div>
505
506<p class="magick-description">Measure performance.</p>
507
508<p>Repeat the entire command for the given number of <var>iterations</var> and report the user-time and elapsed time. For instance,
509consider the following command and its output. Modify the benchmark with the
510-duration to run the benchmark for a fixed number of seconds and -concurrent
511to run the benchmark in parallel (requires the OpenMP feature).</p>
512
513<pre>
Cristye09ed312016-03-06 08:07:39 -0500514-> convert logo: -resize 200% -bench 5 logo.png
515Performance[1]: 5i 1.344ips 1.000e 3.710u 0:03.720
516Performance[2]: 5i 1.634ips 0.549e 3.890u 0:03.060
517Performance[3]: 5i 2.174ips 0.618e 3.190u 0:02.300
518Performance[4]: 5i 1.678ips 0.555e 3.810u 0:02.980
Cristy882d9f42015-10-29 16:48:39 -0400519Performance[4]: 5i 0.875657ips 6.880u 0:05.710
520</pre>
521
Cristye09ed312016-03-06 08:07:39 -0500522<p>In this example, 5 iterations were completed at 2.174 iterations per
523second, using 3 threads and 3.190 seconds of the user allotted time, for
524a total elapsed time of 2.300 seconds.</p>
Cristy882d9f42015-10-29 16:48:39 -0400525
526<div style="margin: auto;">
527 <h3 class="magick-header"><a id="bias"></a>-bias <var>value</var>{<var>%</var>}</h3>
528</div>
529
530<p class="magick-description">Add bias when convolving an image.</p>
531
Cristy594d2772015-11-15 10:47:42 -0500532<p>This option shifts the output of <a href="command-line-options.html#convolve">&#x2011;convolve</a> so that
Cristy882d9f42015-10-29 16:48:39 -0400533positive and negative results are relative to the specified bias value. </p>
534
535<p>This is important for non-HDRI compilations of ImageMagick when dealing
536with convolutions that contain negative as well as positive values. This is
537especially the case with convolutions involving high pass filters or edge
538detection. Without an output bias, the negative values are clipped at
539zero.</p>
540
Cristy594d2772015-11-15 10:47:42 -0500541<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
Cristy882d9f42015-10-29 16:48:39 -0400542negative results without clipping to the color value range
543(0..QuantumRange).</p>
544
Cristy594d2772015-11-15 10:47:42 -0500545<p>See the discussion on HDRI implementations of ImageMagick on the page <a
546href="high-dynamic-range.html" >High Dynamic-Range Images</a>. For more
547about HDRI go the ImageMagick <a
548href="http://www.imagemagick.org/Usage/basics/#hdri" >Usage</a> pages or this
549<a
550href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
Cristy882d9f42015-10-29 16:48:39 -0400551entry. </p>
552
553<div style="margin: auto;">
554 <h3 class="magick-header"><a id="black-point-compensation"></a>-black-point-compensation</h3>
555</div>
556
557<p class="magick-description">Use black point compensation.</p>
558
559<div style="margin: auto;">
560 <h3 class="magick-header"><a id="black-threshold"></a>-black-threshold <var>value</var>{<var>%</var>}</h3>
561</div>
562
563<p class="magick-description">Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</p>
564
565<p> The threshold value can be given as a percentage or as an absolute integer
566value within [0, <var>QuantumRange</var>] corresponding to the
Cristy594d2772015-11-15 10:47:42 -0500567desired <a href="command-line-options.html#channel">&#x2011;channel</a> value. See <a href="command-line-options.html#threshold">&#x2011;threshold</a>for more details on thresholds and resulting values. </p>
Cristy882d9f42015-10-29 16:48:39 -0400568
569
570<div style="margin: auto;">
571 <h3 class="magick-header"><a id="blend"></a>-blend <var>geometry</var></h3>
572</div>
573
574<p class="magick-description">blend an image into another by the given absolute value or percent.</p>
575
576<p>Blend will average the images together ('plus') according to the
577percentages given and each pixels transparency. If only a single percentage
578value is given it sets the weight of the composite or 'source' image, while
579the background image is weighted by the exact opposite amount. That is a
580<code>-blend 30%</code> merges 30% of the 'source' image with 70% of the
581'destination' image. Thus it is equivalent to <code>-blend 30x70%</code>.</p>
582
583
584<div style="margin: auto;">
585 <h3 class="magick-header"><a id="blue-primary"></a>-blue-primary <var>x</var>,<var>y</var></h3>
586</div>
587
588<p class="magick-description">Set the blue chromaticity primary point.</p>
589
590<div style="margin: auto;">
591 <h3 class="magick-header"><a id="blue-shift"></a>-blue-shift <var>factor</var></h3>
592</div>
593
594<p class="magick-description">simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</p>
595
596<div style="margin: auto;">
597
598<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -0500599 <h3 class="magick-header"><a id="blur"></a>-blur <var>radius</var><br />-blur <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400600</div>
601
602<p class="magick-description">Reduce image noise and reduce detail levels.</p>
603
604<p>Convolve the image with a Gaussian or normal distribution using the given
Cristy594d2772015-11-15 10:47:42 -0500605<var >Sigma</var> value. The formula is:</p>
Cristy882d9f42015-10-29 16:48:39 -0400606
Cristy594d2772015-11-15 10:47:42 -0500607<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/></p>
Cristy882d9f42015-10-29 16:48:39 -0400608
Cristy594d2772015-11-15 10:47:42 -0500609<p>The <var >Sigma</var> value is the important argument, and
Cristy882d9f42015-10-29 16:48:39 -0400610determines the actual amount of blurring that will take place. </p>
611
Cristy594d2772015-11-15 10:47:42 -0500612<p>The <var >Radius</var> is only used to determine the size of the
Cristy882d9f42015-10-29 16:48:39 -0400613array which will hold the calculated Gaussian distribution. It should be an
614integer. If not given, or set to zero, IM will calculate the largest possible
615radius that will provide meaningful results for the Gaussian distribution.
616</p>
617
Cristy594d2772015-11-15 10:47:42 -0500618<p>The larger the <var >Radius</var> the slower the
619operation is. However too small a <var >Radius</var>, and sever
620aliasing effects may result. As a guideline, <var >Radius</var>
621should be at least twice the <var >Sigma</var> value, though three
Cristy882d9f42015-10-29 16:48:39 -0400622times will produce a more accurate result. </p>
623
624<p>This option differs from <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a> simply
625by taking advantage of the separability properties of the distribution. Here
626we apply a single-dimensional Gaussian matrix in the horizontal direction,
627then repeat the process in the vertical direction.</p>
628
629<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
630pixels which are outside the image proper are blurred into the final result.
631</p>
632
633
634<div style="margin: auto;">
635 <h3 class="magick-header">-blur <var>Width</var>[x<var>Height</var>[+<var>Angle</var>]]</h3>
636</div>
637
638<p class="magick-description">Variably blur an image according to the overlay mapping.</p>
639
640<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted
641Average (EWA) of the source image, scaled according to the grayscale
642mapping. </p>
643
Cristy594d2772015-11-15 10:47:42 -0500644<p>The ellipse is weighted with sigma set to the given <var>Width</var> and <var >Height</var>. The <var >Height</var>
645defaults to the <var >Width</var> for a normal circular Gaussian
646weighting. The <var >Angle</var> will rotate the ellipse from
Cristy882d9f42015-10-29 16:48:39 -0400647horizontal clock-wise. </p>
648
649<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
650pixels which are outside the image proper are blurred into the final result.
651</p>
652
653
654<div style="margin: auto;">
655 <h3 class="magick-header"><a id="border"></a>-border <var>geometry</var></h3>
656</div>
657
658<p class="magick-description">Surround the image with a border of color. </p>
659
660<p>Set the width and height using the <var>size</var> portion of the
661<var>geometry</var> argument. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets are
662ignored. </p>
663
664<p>As of IM 6.7.8-8, the <var>geometry</var> arguments behave as follows:</p>
665
666<dl class="dl-horizontal">
667<dt><var>value</var></dt>
668<dd>value is added to both left/right and top/bottom</dd>
669<dt><var>value-x</var><kbd>x</kbd></dt>
670<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
671<dt><kbd>x</kbd><var>value-y</var></dt>
672<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
673<dt><var>value-x</var><kbd>x</kbd><var>value-y</var></dt>
674<dd>value-x is added to left/right and value-y added to top/bottom</dd>
675<dt><var>value-x</var><kbd>x</kbd>0</dt>
676<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
677<dt>0<kbd>x</kbd><var>value-y</var></dt>
678<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
679<dt><var>value</var>%</dt>
680<dd>value % of width is added to left/right and value % of height is added to top/bottom</dd>
681<dt><var>value-x</var><kbd>x</kbd>%</dt>
682<dd>value-x % of width is added to left/right and to top/bottom</dd>
683<dt>x<var>value-y</var>%</dt>
684<dd>value-y % of height is added to top/bottom and to left/right</dd>
685<dt><var>value-x</var>%<kbd>x</kbd><var>value-y</var>%</dt>
686<dd>value-x % of width is added to left/right and value-y % of height is added to top/bottom</dd>
687<dt><var>value-x</var>%<kbd>x</kbd>0%</dt>
688<dd>value-x % of width is added to left/right and top/bottom are unchanged</dd>
689<dt>0%<kbd>x</kbd><var>value-y</var>%</dt>
690<dd>value-y % of height is added to top/bottom and left/right are unchanged</dd>
691</dl>
692
Cristy594d2772015-11-15 10:47:42 -0500693<p>Set the border color by preceding with the <a
694href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -0400695
Cristy594d2772015-11-15 10:47:42 -0500696<p>The <a href="command-line-options.html#border">-border</a> operation is affected by the current <a
697href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
Cristy882d9f42015-10-29 16:48:39 -0400698'<code>Over</code>' composition method. It generates an image of the appropriate
699size colors by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> before
700overlaying the original image in the center of this net image. This means that
701with the default compose method of '<code>Over</code>' any transparent parts may
702be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
703<p>See also the <a href="command-line-options.html#frame">-frame</a> option, which has more
704functionality.</p>
705
706<div style="margin: auto;">
707 <h3 class="magick-header"><a id="bordercolor"></a>-bordercolor <var>color</var></h3>
708</div>
709
710<p class="magick-description">Set the border color.</p>
711
712<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
713
714<p>The default border color is <code>#DFDFDF</code>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p>
715
716<div style="margin: auto;">
717 <h3 class="magick-header"><a id="borderwidth"></a>-borderwidth <var>geometry</var> </h3>
718</div>
719
720<p class="magick-description">Set the border width.</p>
721
722<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -0500723 <h3 class="magick-header"><a id="brightness-contrast"></a>-brightness-contrast <var>brightness</var><br />-brightness-contrast <var>brightness</var>{x<var>contrast</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400724</div>
725
726<p class="magick-description">Adjust the brightness and/or contrast of the image.</p>
727
728<p>Brightness and Contrast values apply changes to the input image. They are
729not absolute settings. A brightness or contrast value of zero means no change.
730The range of values is -100 to +100 on each. Positive values increase the
731brightness or contrast and negative values decrease the brightness or contrast.
732To control only contrast, set the brightness=0. To control only brightness,
733set contrast=0 or just leave it off.</p>
734
735<p>You may also use <a href="command-line-options.html#fill">-channel</a> to control which channels to
736apply the brightness and/or contrast change. The default is to apply the same
737transformation to all channels.</p>
738
739<p>Brightness and Contrast arguments are converted to offset and slope of a
740linear transform and applied
741using <a href="command-line-options.html#fill">-function polynomial "slope,offset"</a>.</p>
742
743<p>The slope varies from 0 at contrast=-100 to almost vertical at
744contrast=+100. For brightness=0 and contrast=-100, the result are totally
745midgray. For brightness=0 and contrast=+100, the result will approach but
746not quite reach a threshold at midgray; that is the linear transformation
747is a very steep vertical line at mid gray.</p>
748
749<p>Negative slopes, i.e. negating the image, are not possible with this
750function. All achievable slopes are zero or positive.</p>
751
752<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5
753at brightness=+100. Thus, when contrast=0 and brightness=100, the result is
754totally white. Similarly, when contrast=0 and brightness=-100, the result is
755totally black.</p>
756
757<p>As the range of values for the arguments are -100 to +100, adding the '%'
758symbol is no different than leaving it off.</p>
759
760<div style="margin: auto;">
761 <h3 class="magick-header"><a id="cache"></a>-cache <var>threshold</var></h3>
762</div>
763
Cristy594d2772015-11-15 10:47:42 -0500764<p class="magick-description">(This option has been replaced by the <a href='command-line-options.html#limit'>-limit</a> option).</p>
Cristy882d9f42015-10-29 16:48:39 -0400765
766<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -0500767 <h3 class="magick-header"><a id="canny"></a>-canny <var>radius</var><br/>-canny <var>radius</var>x<var>sigma</var>{<var>+lower-percent</var>}{<var>+upper-percent</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400768</div>
769
770<p class="magick-description">Canny edge detector uses a multi-stage algorithm to detect a wide range of edges in the image.</p>
771
772<p>The thresholds range from 0 to 100% (e.g. -canny 0x1+10%+30%) with {<var>+lower-percent</var>} &lt; {<var>+upper-percent</var>}. If {<var>+upper-percent</var>} is increased but {<var>+lower-percent</var>} remains the same, lesser edge components will be detected, but their lengths will be the same. If {<var>+lower-percent</var>} is increased but {<var>+upper-percent</var>} is the same, the same number of edge components will be detected but their lengths will be shorter. The default thresholds are shown. The <var>radius</var>x<var>sigma</var> controls a gaussian blur applied to the input image to reduce noise and smooth the edges.</p>
773
774<div style="margin: auto;">
775 <h3 class="magick-header"><a id="caption"></a>-caption <var>string</var></h3>
776</div>
777
778<p class="magick-description">Assign a caption to an image.</p>
779
780<p>This option sets the caption meta-data of an image read in after this
781option has been given. To modify a caption of images already in memory use
782"<code><a href="command-line-options.html#set">-set</a> caption</code>". </p>
783
Cristy594d2772015-11-15 10:47:42 -0500784<p>The caption can contain special format characters listed in the <a
785href="escape.html">Format and
Cristy882d9f42015-10-29 16:48:39 -0400786Print Image Properties</a>. These attributes are expanded when the caption
787is finally assigned to the individual images. </p>
788
789<p>If the first character of <var>string</var> is <var>@</var>, the image caption is read from a file titled by the
790remaining characters in the string. Comments read in from a file are literal;
791no embedded formatting characters are recognized.</p>
792
793<p>Caption meta-data is not visible on the image itself. To do that use the
794<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
795instead.</p>
796
797<p>For example,</p>
798
799<pre>
800-caption "%m:%f %wx%h" bird.miff
801</pre>
802
803<p>produces an image caption of <code>MIFF:bird.miff 512x480</code> (assuming
804that the image <code>bird.miff</code> has a width of 512 and a height of
805480.</p>
806
807
808<div style="margin: auto;">
809 <h3 class="magick-header"><a id="cdl"></a>-cdl <var>filename</var></h3>
810</div>
811
812<p class="magick-description">color correct with a color decision list.</p>
813
814<p>Here is an example color correction collection:</p>
815
816<pre>
817&lt;?xml version="1.0" encoding="UTF-8"?&gt;
818&lt;ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"&gt;
819 &lt;ColorCorrection id="cc06668"&gt;
820 &lt;SOPNode&gt;
821 &lt;Slope&gt; 0.9 1.2 0.5 &lt;/Slope&gt;
822 &lt;Offset&gt; 0.4 -0.5 0.6 &lt;/Offset&gt;
823 &lt;Power&gt; 1.0 0.8 1.5 &lt;/Power&gt;
824 &lt;/SOPNode&gt;
825 &lt;SATNode&gt;
826 &lt;Saturation&gt; 0.85 &lt;/Saturation&gt;
827 &lt;/SATNode&gt;
828 &lt;/ColorCorrection&gt;
829&lt;/ColorCorrectionCollection&gt;
830</pre>
831
832<div style="margin: auto;">
833 <h3 class="magick-header"><a id="channel"></a>-channel <var>type</var></h3>
834</div>
835
836<p class="magick-description">Specify those image color channels to which subsequent operators are limited.</p>
837
838<p>Choose from: <code>Red</code>, <code>Green</code>, <code>Blue</code>,
839<code>Alpha</code>, <code>Gray</code>, <code>Cyan</code>, <code>Magenta</code>,
840<code>Yellow</code>, <code>Black</code>, <code>Opacity</code>,
841<code>Index</code>, <code>RGB</code>, <code>RGBA</code>, <code>CMYK</code>, or
842<code>CMYKA</code>.</p>
843
844<p>The channels above can also be specified as a comma-separated list or can be
845abbreviated as a concatenation of the letters '<code>R</code>', '<code>G</code>',
846'<code>B</code>', '<code>A</code>', '<code>O</code>', '<code>C</code>',
847'<code>M</code>', '<code>Y</code>', '<code>K</code>'.
848
849For example, to only select the <code>Red</code> and <code>Blue</code> channels
850you can either use </p>
851<pre>
852-channel Red,Blue
853</pre>
854<p>or you can use the short hand form</p>
855<pre>
856-channel RB
857</pre>
858
859<p>All the channels that are present in an image can be specified using the
860special channel type <code>All</code>. Not all operators are 'channel capable',
861but generally any operators that are generally 'grey-scale' image operators,
862will understand this setting. See individual operator documentation. </p>
863
Cristy594d2772015-11-15 10:47:42 -0500864<br/>
Cristy882d9f42015-10-29 16:48:39 -0400865
866<p>On top of the normal channel selection an extra flag can be specified,
867'<code>Sync</code>'. This is turned on by default and if set means that
868operators that understand this flag should perform: cross-channel
869synchronization of the channels. If not specified, then most grey-scale
870operators will apply their image processing operations to each individual
871channel (as specified by the rest of the <a href="command-line-options.html#channel">-channel</a>
872setting) completely independently from each other. </p>
873
874<p>For example for operators such as <a href="command-line-options.html#auto-level">-auto-level</a> and
875<a href="command-line-options.html#auto-gamma">-auto-gamma</a> the color channels are modified
876together in exactly the same way so that colors will remain in-sync. Without
877it being set, then each channel is modified separately and
878independently, which may produce color distortion. </p>
879
880<p>The <a href="command-line-options.html#morphology">-morphology</a> '<code>Convolve</code>' method
881and the <a href="command-line-options.html#compose">-compose</a> mathematical methods, also understands
882the '<code>Sync</code>' flag to modify the behavior of pixel colors according
883to the alpha channel (if present). That is to say it will modify the image
884processing with the understanding that fully-transparent colors should not
885contribute to the final result. </p>
886
887<p>Basically, by default, operators work with color channels in synchronous, and
888treats transparency as special, unless the <a href="command-line-options.html#channel">-channel</a>
889setting is modified so as to remove the effect of the '<code>Sync</code>' flag.
890How each operator does this depends on that operators current implementation.
891Not all operators understands this flag at this time, but that is changing.
892</p>
893
894<p>To print a complete list of channel types, use <a href="command-line-options.html#list">-list
895channel</a>.</p>
896
897<p>By default, ImageMagick sets <a href="command-line-options.html#channel">-channel</a> to the value
898'<code>RGBK,sync</code>', which specifies that operators act on all color
899channels except the transparency channel, and that all the color channels are
900to be modified in exactly the same way, with an understanding of transparency
Cristy594d2772015-11-15 10:47:42 -0500901(depending on the operation being applied). The 'plus' form <a
902href="command-line-options.html#channel" >+channel</a> will reset the value back to this default. </p>
Cristy882d9f42015-10-29 16:48:39 -0400903
Cristy594d2772015-11-15 10:47:42 -0500904<p>Options that are affected by the <a href="command-line-options.html#channel" >-channel</a> setting
Cristy882d9f42015-10-29 16:48:39 -0400905include the following.
906
907<a href="command-line-options.html#auto-gamma">-auto-gamma</a>,
908<a href="command-line-options.html#auto-level">-auto-level</a>,
909<a href="command-line-options.html#black-threshold">-black-threshold</a>,
910<a href="command-line-options.html#blur">-blur</a>,
911<a href="command-line-options.html#clamp">-clamp</a>,
912<a href="command-line-options.html#clut">-clut</a>,
913<a href="command-line-options.html#combine">-combine</a>,
914<a href="command-line-options.html#composite">-composite</a> (Mathematical compose methods only),
915<a href="command-line-options.html#convolve">-convolve</a>,
916<a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
917<a href="command-line-options.html#evaluate">-evaluate</a>,
918<a href="command-line-options.html#function">-function</a>,
919<a href="command-line-options.html#fx">-fx</a>,
920<a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>,
921<a href="command-line-options.html#hald-clut">-hald-clut</a>,
922<a href="command-line-options.html#motion-blur">-motion-blur</a>,
923<a href="command-line-options.html#morphology">-morphology</a>,
924<a href="command-line-options.html#negate">-negate</a>,
925<a href="command-line-options.html#normalize">-normalize</a>,
926<a href="command-line-options.html#ordered-dither">-ordered-dither</a>,
927<a href="command-line-options.html#radial-blur">-radial-blur</a>,
928<a href="command-line-options.html#random-threshold">-random-threshold</a>,
929<a href="command-line-options.html#separate">-separate</a>,
930<a href="command-line-options.html#threshold">-threshold</a>, and
931<a href="command-line-options.html#white-threshold">-white-threshold</a>.
932</p>
933
Cristy594d2772015-11-15 10:47:42 -0500934<p>Warning, some operators behave differently when the <a href="command-line-options.html#channel"
935>+channel</a> default setting is in effect, verses ANY user defined <a
936href="command-line-options.html#channel" >-channel</a> setting (including the equivalent of the
Cristy882d9f42015-10-29 16:48:39 -0400937default). These operators have yet to be made to understand the newer 'Sync'
938flag. </p>
939
Cristy769d8892016-01-19 18:11:14 -0500940<p>For example <a href="command-line-options.html#threshold">-threshold</a> will by default grayscale
Cristy594d2772015-11-15 10:47:42 -0500941the image before thresholding, if no <a href="command-line-options.html#channel" >-channel</a> setting
Cristy882d9f42015-10-29 16:48:39 -0400942has been defined. This is not 'Sync flag controlled, yet. </p>
943
Cristy594d2772015-11-15 10:47:42 -0500944<p>Also some operators such as <a href="command-line-options.html#blur">-blur</a>, <a
945href="command-line-options.html#gaussian-blur">-gaussian-blur</a>, will modify their handling of the
946color channels if the '<code>alpha</code>' channel is also enabled by <a
947href="command-line-options.html#channel" >-channel</a>. Generally this done to ensure that
Cristy882d9f42015-10-29 16:48:39 -0400948fully-transparent colors are treated as being fully-transparent, and thus any
949underlying 'hidden' color has no effect on the final results. Typically
950resulting in 'halo' effects. The newer <a href="command-line-options.html#morphology">-morphology</a>
951convolution equivalents however does have a understanding of the 'Sync' flag
952and will thus handle transparency correctly by default. </p>
953
954<p>As a alpha channel is optional within images, some operators will read the
955color channels of an image as a greyscale alpha mask, when the image has no
Cristy594d2772015-11-15 10:47:42 -0500956alpha channel present, and the <a href="command-line-options.html#channel" >-channel</a> setting tells
957the operator to apply the operation using alpha channels. The <a
958href="command-line-options.html#clut">-clut</a> operator is a good example of this. </p>
Cristy882d9f42015-10-29 16:48:39 -0400959
960
961
962<div style="margin: auto;">
963 <h3 class="magick-header"><a id="charcoal"></a>-charcoal <var>factor</var></h3>
964</div>
965
966<p class="magick-description">Simulate a charcoal drawing.</p>
967
968<div style="margin: auto;">
969 <h3 class="magick-header"><a id="chop"></a>-chop <var>geometry</var></h3>
970</div>
971
972<p class="magick-description">Remove pixels from the interior of an image.</p>
973
974<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>width</var>
975and <var>height</var> given in the of the <var>size</var>
976portion of the <var>geometry</var> argument give the number of
977columns and rows to remove. The <var>offset</var> portion of
978the <var>geometry</var> argument is influenced by
979a <a href="command-line-options.html#gravity">-gravity</a> setting, if present.</p>
980
981<p>The <a href="command-line-options.html#chop">-chop</a> option removes entire rows and columns,
982and moves the remaining corner blocks leftward and upward to close the gaps.</p>
983
984<p>While it can remove internal rows and columns of pixels, it is more
985typically used with as <a href="command-line-options.html#gravity">-gravity</a> setting and zero
Cristy594d2772015-11-15 10:47:42 -0500986offsets so as to remove a single edge from an image. Compare this to <a
987href="command-line-options.html#shave" >-shave</a> which removes equal numbers of pixels from opposite
Cristy882d9f42015-10-29 16:48:39 -0400988sides of the image. </p>
989
Cristy594d2772015-11-15 10:47:42 -0500990<p>Using <a href="command-line-options.html#chop">-chop</a> effectively undoes the results of a <a
991href="command-line-options.html#splice">-splice</a> that was given the same <var>geometry</var> and <a href="command-line-options.html#gravity">-gravity</a> settings. </p>
Cristy882d9f42015-10-29 16:48:39 -0400992
993<div style="margin: auto;">
994 <h3 class="magick-header"><a id="clamp"></a>-clamp</h3>
995</div>
996
997<p class="magick-description">set each pixel whose value is below zero to zero and any the pixel whose value is above the quantum range to the quantum range (e.g. 65535) otherwise the pixel value remains unchanged.</p>
998
999<div style="margin: auto;">
1000 <h3 class="magick-header"><a id="clip"></a>-clip</h3>
1001</div>
1002
1003<p class="magick-description">Apply the clipping path if one is present.</p>
1004
1005<p>If a clipping path is present, it is applied to subsequent operations.</p>
1006
1007<p>For example, in the command</p>
1008
1009<pre>
1010convert cockatoo.tif -clip -negate negated.tif
1011</pre>
1012
1013<p>only the pixels within the clipping path are negated.</p>
1014
1015<p>The <a href="command-line-options.html#clip">-clip</a> feature requires SVG support. If the SVG
1016delegate library is not present, the option is ignored.</p>
1017
1018<p>Use <a href="command-line-options.html#clip">+clip</a> to disable clipping for subsequent operations.</p>
1019
1020<div style="margin: auto;">
1021 <h3 class="magick-header"><a id="clip-mask"></a>-clip-mask</h3>
1022</div>
1023
1024<p class="magick-description">Clip the image as defined by this mask.</p>
1025
1026<p>Use the alpha channel of the current image as a mask. Any areas that is
1027white is not modified by any of the 'image processing operators' that follow,
1028until the mask is removed. Pixels in the black areas of the clip mask are
1029modified per the requirements of the operator. </p>
1030
1031<p>In some ways this is similar to (though not the same) as defining
Cristy594d2772015-11-15 10:47:42 -05001032a rectangular <a href="command-line-options.html#region" >-region</a>, or using the negative of the
1033mask (third) image in a three image <a href="command-line-options.html#composite" >-composite</a>,
Cristy882d9f42015-10-29 16:48:39 -04001034operation. </p>
1035
1036<p>Use <a href="command-line-options.html#clip-mask">+clip-mask</a> to disable clipping for subsequent operations.</p>
1037
1038<div style="margin: auto;">
1039 <h3 class="magick-header"><a id="clip-path"></a>-clip-path <var>id</var></h3>
1040</div>
1041
1042<p class="magick-description">Clip along a named path from the 8BIM profile.</p>
1043
1044<p>This is identical to <a href="command-line-options.html#clip">-clip</a> except choose a specific clip path in the event the image has more than one path available. </p>
1045
1046<p>Use <a href="command-line-options.html#clip-path">+clip-path</a> to disable clipping for subsequent operations.</p>
1047
1048<div style="margin: auto;">
1049 <h3 class="magick-header"><a id="clone"></a>-clone <var>index(s)</var></h3>
1050</div>
1051
1052<p class="magick-description">make a clone of an image (or images).</p>
1053
1054<p>Inside parenthesis (where the operator is normally used) it will make a
1055clone of the images from the last 'pushed' image sequence, and adds them to
1056the end of the current image sequence. Outside parenthesis
1057(not recommended) it clones the images from the current image sequence. </p>
1058
1059<p>Specify the image by its index in the sequence. The first image is index
10600. Negative indexes are relative to the end of the sequence; for
1061example, <code>−1</code>
1062represents the last image of the sequence. Specify a range of images with a
1063dash (e.g. <code>0−4</code>). Separate multiple indexes with commas but no
1064spaces (e.g. <code>0,2,5</code>). A value of '<code>0−−1</code> will
1065effectively clone all the images. </p>
1066
1067<p>The <a href="command-line-options.html#clone">+clone</a> will simply make a copy of the last image
1068in the image sequence, and is thus equivalent to using a argument of
1069'<code>−1</code>'. </p>
1070
1071<div style="margin: auto;">
1072 <h3 class="magick-header"><a id="clut"></a>-clut</h3>
1073</div>
1074
1075<p class="magick-description">Replace the channel values in the first image using each corresponding channel in the second image as a <b>c</b>olor <b>l</b>ook<b>u</b>p <b>t</b>able.</p>
1076
1077<p>The second (LUT) image is ordinarily a gradient image containing the
1078histogram mapping of how each channel should be modified. Typically it is a
1079either a single row or column image of replacement color values. If larger
1080than a single row or column, values are taken from a diagonal line from
1081top-left to bottom-right corners.</p>
1082
Cristy594d2772015-11-15 10:47:42 -05001083<p>The lookup is further controlled by the <a
1084href="command-line-options.html#interpolate">-interpolate</a> setting, which is especially handy for an
Cristy882d9f42015-10-29 16:48:39 -04001085LUT which is not the full length needed by the ImageMagick installed Quality
1086(Q) level. Good settings for this are the '<code>bilinear</code>' and
1087'<code>bicubic</code>' interpolation settings, which give smooth color
1088gradients, and the '<code>integer</code>' setting for a direct, unsmoothed
1089lookup of color values. </p>
1090
1091<p>This operator is especially suited to replacing a grayscale image with a
1092specific color gradient from the CLUT image. </p>
1093
1094<p>Only the channel values defined by the <a href="command-line-options.html#channel">-channel</a>
Cristy594d2772015-11-15 10:47:42 -05001095setting will have their values replaced. In particular, since the default <a
1096href="command-line-options.html#channel">-channel</a> setting is <code>RGB</code>, this means that
1097transparency (alpha/matte channel) is not affected, unless the <a
1098href="command-line-options.html#channel">-channel</a> setting is modified. When the alpha channel is
1099set, it is treated by the <a href="command-line-options.html#clut" >-clut</a> operator in the same way
Cristy882d9f42015-10-29 16:48:39 -04001100as the other channels, implying that alpha/matte values are replaced using the
1101alpha/matte values of the original image. </p>
1102
1103<p>If either the image being modified, or the lookup image, contains no
Cristy594d2772015-11-15 10:47:42 -05001104transparency (i.e. <a href="command-line-options.html#alpha" >-alpha</a> is turned 'off') but the <a
1105href="command-line-options.html#channel">-channel</a> setting includes alpha replacement, then it is
Cristy769d8892016-01-19 18:11:14 -05001106assumed that image represents a grayscale gradient which is used for the
1107replacement alpha values. That is you can use a grayscale CLUT image to
1108adjust a existing images alpha channel, or you can color a grayscale image
Cristy882d9f42015-10-29 16:48:39 -04001109using colors form CLUT containing the desired colors, including transparency.
1110</p>
1111
Cristy594d2772015-11-15 10:47:42 -05001112<p>See also <a href="command-line-options.html#hald-clut" >-hald-clut</a> which replaces colors
Cristy882d9f42015-10-29 16:48:39 -04001113according to the lookup of the full color RGB value from a 2D representation
1114of a 3D color cube. </p>
1115
1116
1117<div style="margin: auto;">
1118 <h3 class="magick-header"><a id="coalesce"></a>-coalesce</h3>
1119</div>
1120
1121<p class="magick-description">Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</p>
1122
1123<p>Overlay each image in an image sequence according to
1124its <a href="command-line-options.html#dispose">-dispose</a> meta-data, to reproduce the look of
1125an animation at each point in the animation sequence. All images should be
1126the same size, and are assigned appropriate GIF disposal settings for the
1127animation to continue working as expected as a GIF animation. Such frames
1128are more easily viewed and processed than the highly optimized GIF overlay
1129images. </p>
1130
1131<p>The animation can be re-optimized after processing using
1132the <a href="command-line-options.html#layers">-layers</a> method '<code>optimize</code>', although
1133there is no guarantee that the restored GIF animation optimization is
1134better than the original. </p>
1135
1136
1137<div style="margin: auto;">
1138 <h3 class="magick-header"><a id="colorize"></a>-colorize <var>value</var></h3>
1139</div>
1140
Cristy594d2772015-11-15 10:47:42 -05001141<p class="magick-description">Colorize the image by an amount specified by <var>value</var> using the color specified by the most recent <a href="command-line-options.html#fill" >-fill</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04001142
1143<p>Specify the amount of colorization as a percentage. Separate colorization
1144values can be applied to the red, green, and blue channels of the image with
1145a comma-delimited list of colorization
1146values (e.g., <code>-colorize 0,0,50</code>).</p>
1147
1148<div style="margin: auto;">
1149 <h3 class="magick-header"><a id="colormap"></a>-colormap <var>type</var></h3>
1150</div>
1151
1152<p class="magick-description">Define the colormap type.</p>
1153
1154<p>The <var>type</var> can be <code>shared</code> or <code>private</code>.</p>
1155
1156<p>This option only applies when the default X server visual
1157is <code>PseudoColor</code> or <code>GrayScale</code>. Refer
1158to <a href="command-line-options.html#visual">-visual</a> for more details. By default,
1159a shared colormap is allocated. The image shares colors with
1160other X clients. Some image colors could be approximated,
1161therefore your image may look very different than intended.
1162If <code>private</code> is chosen, the image colors appear exactly
1163as they are defined. However, other clients may go <var>technicolor</var>
1164when the image colormap is installed.</p>
1165
1166<div style="margin: auto;">
1167 <h3 class="magick-header"><a id="colors"></a>-colors <var>value</var></h3>
1168</div>
1169
1170<p class="magick-description">Set the preferred number of colors in the image.</p>
1171
1172<p>The actual number of colors in the image may be less than your request,
1173but never more. Note that this a color reduction option. Images with fewer
1174unique colors than specified by <var>value</var> will have any
1175duplicate or unused colors removed. The ordering of an existing color
1176palette may be altered. When converting an image from color to grayscale,
1177it is more efficient to convert the image to the gray colorspace before
1178reducing the number of colors. Refer to
1179the <a href="quantize.html">
1180color reduction algorithm</a> for more details.</p>
1181
1182<div style="margin: auto;">
1183 <h3 class="magick-header"><a id="color-matrix"></a>-color-matrix <var>matrix</var></h3>
1184</div>
1185
1186<p class="magick-description">apply color correction to the image.</p>
1187
1188<p>This option permits saturation changes, hue rotation, luminance to alpha,
1189and various other effects. Although variable-sized transformation matrices
1190can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6
1191for CMYKA (or RGBA with offsets). The matrix is similar to those used by
1192Adobe Flash except offsets are in column 6 rather than 5 (in support of
1193CMYKA images) and offsets are normalized (divide Flash offset by 255).</p>
1194
1195<p>As an example, to add contrast to an image with offsets, try this command:</p>
1196
1197<pre>
1198convert kittens.jpg -color-matrix \
1199 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \
1200 0.0 1.5 0.0 0.0, 0.0, -0.157 \
1201 0.0 0.0 1.5 0.0, 0.0, -0.157 \
1202 0.0 0.0 0.0 1.0, 0.0, 0.0 \
1203 0.0 0.0 0.0 0.0, 1.0, 0.0 \
1204 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png
1205</pre>
1206<div style="margin: auto;">
1207 <h3 class="magick-header"><a id="colorspace"></a>-colorspace <var>value</var></h3>
1208</div>
1209
1210<p class="magick-description">Set the image colorspace.</p>
1211
1212<p>Choices are:</p>
1213
1214<pre>
1215CMY CMYK Gray HCL
1216HCLp HSB HSI HSL
1217HSV HWB Lab LCHab
1218LCHuv LMS Log Luv
1219OHTA Rec601YCbCr Rec709YCbCr RGB
1220scRGB sRGB Transparent xyY
1221XYZ YCbCr YCC YDbDr
1222YIQ YPbPr YUV
1223</pre>
1224
1225<p>To print a complete list of colorspaces, use <a href="command-line-options.html#list">-list colorspace</a>.</p>
1226
1227<p>For a more accurate color conversion to or from the linear RGB, CMYK, or grayscale colorspaces, use the <a href="command-line-options.html#profile">-profile</a> option. Note, ImageMagick assumes the sRGB colorspace if the image format does not indicate otherwise. For colorspace conversion, the gamma function is first removed to produce linear RGB.</p>
1228
1229<table class="table table-condensed table-striped">
1230 <caption>Conversion of RGB to Other Color Spaces</caption>
1231 <tr><th valign="middle">CMY</th></tr>
1232 <tr><td valign="middle">C=<var>QuantumRange</var>−R</td></tr>
1233 <tr><td valign="middle">M=<var>QuantumRange</var>−G</td></tr>
1234 <tr><td valign="middle">Y=<var>QuantumRange</var>−B</td></tr>
1235 <tr><th valign="middle">CMYK — starts with CMY from above</th></tr>
1236 <tr><td valign="middle">K=min(C,Y,M)</td></tr>
1237 <tr><td valign="middle">C=<var>QuantumRange</var>*(C−K)/(<var>QuantumRange</var>−K)</td></tr>
1238 <tr><td valign="middle">M=<var>QuantumRange</var>*(M−K)/(<var>QuantumRange</var>−K)</td></tr>
1239 <tr><td valign="middle">Y=<var>QuantumRange</var>*(Y−K)/(<var>QuantumRange</var>−K)</td></tr>
1240
1241 <tr><th valign="middle">Gray</th></tr>
1242 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1243
1244 <tr><th valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr>
1245 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1246 <tr><td valign="middle">S=distance from axis outward</td></tr>
1247 <tr><td valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <var>intensity-like</var></td></tr>
1248
1249 <tr><th valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr>
1250 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1251 <tr><td valign="middle">S=distance from axis outward</td></tr>
1252 <tr><td valign="middle">L=distance along axis from bottom upward; L=0.5*max(R,G,B) + 0.5*min(R,G,B); <var>intensity-like</var></td></tr>
1253
1254 <tr><th valign="middle">HWB — Hue, Whiteness, Blackness</th></tr>
1255 <tr><td valign="middle">Hue (complicated equation)</td></tr>
1256 <tr><td valign="middle">Whiteness (complicated equation)</td></tr>
1257 <tr><td valign="middle">Blackness (complicated equation)</td></tr>
1258
1259 <tr><th valign="middle">LAB</th></tr>
1260 <tr><td valign="middle">L (complicated equation relating X,Y,Z)</td></tr>
1261 <tr><td valign="middle">A (complicated equation relating X,Y,Z)</td></tr>
1262 <tr><td valign="middle">B (complicated equation relating X,Y,Z)</td></tr>
1263
1264 <tr><th valign="middle">LOG</th></tr>
1265 <tr><td valign="middle">I1 (complicated equation involving logarithm of R)</td></tr>
1266 <tr><td valign="middle">I2 (complicated equation involving logarithm of G)</td></tr>
1267 <tr><td valign="middle">I3 (complicated equation involving logarithm of B)</td></tr>
1268
1269 <tr><th valign="middle">OHTA — approximates principal components transformation</th></tr>
1270 <tr><td valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <var>intensity-like</var></td></tr>
1271 <tr><td valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1272 <tr><td valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1273
1274 <tr><th valign="middle">Rec601Luma</th></tr>
1275 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1276
1277 <tr><th valign="middle">Rec601YCbCr</th></tr>
1278 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1279 <tr><td valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1280 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1281
1282 <tr><th valign="middle">Rec709Luma</th></tr>
1283 <tr><td valign="middle">Gray=0.212656*R+0.715158*G+0.072186*B</td></tr>
1284
1285 <tr><th valign="middle">Rec709YCbCr</th></tr>
1286 <tr><td valign="middle">Y=0.212656*R+0.715158*G+0.072186*B; <var>intensity-like</var></td></tr>
1287 <tr><td valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1288 <tr><td valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1289
1290 <tr><th valign="middle">sRGB</th></tr>
1291 <tr><td valign="middle">if R ≤ .0.0031308 then Rs=R/12.92 else Rs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1292 <tr><td valign="middle">if G ≤ .0.0031308 then Gs=B/12.92 else Gs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1293 <tr><td valign="middle">if B ≤ .0.0031308 then Bs=B/12.92 else Bs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1294
1295 <tr><th valign="middle">XYZ</th></tr>
1296 <tr><td valign="middle">X=0.4124564*R+0.3575761*G+0.1804375*B</td></tr>
1297 <tr><td valign="middle">Y=0.2126729*R+0.7151522*G+0.0721750*B</td></tr>
1298 <tr><td valign="middle">Z=0.0193339*R+0.1191920*G+0.9503041*B</td></tr>
1299
1300 <tr><th valign="middle">YCC</th></tr>
1301 <tr><td valign="middle">Y=(0.298839*R+0.586811*G+0.114350*B) (with complicated scaling); <var>intensity-like</var></td></tr>
1302 <tr><td valign="middle">C1=(−0.298839*R−0.586811*G+0.88600*B) (with complicated scaling)</td></tr>
1303 <tr><td valign="middle">C2=(0.70100*R−0.586811*G−0.114350*B) (with complicated scaling)</td></tr>
1304
1305 <tr><th valign="middle">YCbCr</th></tr>
1306 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1307 <tr><td valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1308 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1309
1310 <tr><th valign="middle">YIQ</th></tr>
1311 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1312 <tr><td valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1313 <tr><td valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1314
1315 <tr><th valign="middle">YPbPr</th></tr>
1316 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1317 <tr><td valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1318 <tr><td valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1319
1320 <tr><th valign="middle">YUV</th></tr>
1321 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1322 <tr><td valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1323 <tr><td valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1324</table>
1325
1326<p>Note the scRGB colorspace requires HDRI support otherwise it behaves just like linear RGB.</p>
1327
1328<div style="margin: auto;">
1329 <h3 class="magick-header"><a id="combine"></a>-combine</h3>
1330</div>
1331
1332<p class="magick-description">Combine one or more images into a single image.</p>
1333
1334<p>The channels (previously set by <a href="command-line-options.html#channel">-channel</a>) of the
1335combined image are taken from the grayscale values of each image in the
1336sequence, in order. For the default -channel setting of <code>RGB</code>, this
1337means the first image is assigned to the <code>Red</code> channel, the second
1338to the <code>Green</code> channel, the third to the <code>Blue</code>.</p>
1339
Cristy594d2772015-11-15 10:47:42 -05001340<p>This option can be thought of as the inverse to <a
1341href="command-line-options.html#separate">-separate</a>, so long as the channel settings are the same.
Cristy882d9f42015-10-29 16:48:39 -04001342Thus, in the following example, the final image should be a copy of the
1343original. </p>
1344
1345<pre>
1346convert original.png -channel RGB -separate sepimage.png
1347convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \
1348 -combine imagecopy.png
1349</pre>
1350
1351<div style="margin: auto;">
1352 <h3 class="magick-header"><a id="comment"></a>-comment <var>string</var></h3>
1353</div>
1354
1355<p class="magick-description">Embed a comment in an image.</p>
1356
1357<p>This option sets the comment meta-data of an image read in after this
1358option has been given. To modify a comment of images already in memory use
1359"<code><a href="command-line-options.html#set">-set</a> comment</code>". </p>
1360
Cristy594d2772015-11-15 10:47:42 -05001361<p>The comment can contain special format characters listed in the <a
1362href="escape.html">Format and
Cristy882d9f42015-10-29 16:48:39 -04001363Print Image Properties</a>. These attributes are expanded when the comment
1364is finally assigned to the individual images. </p>
1365
1366<p>If the first character of <var>string</var> is <var>@</var>, the image comment is read from a file titled by the
1367remaining characters in the string. Comments read in from a file are literal;
1368no embedded formatting characters are recognized.</p>
1369
1370<p>Comment meta-data are not visible on the image itself. To do that use the
1371<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
1372instead.</p>
1373
1374<p>For example,</p>
1375
1376<pre>
1377-comment "%m:%f %wx%h" bird.miff
1378</pre>
1379
1380<p>produces an image comment of <code>MIFF:bird.miff 512x480</code> (assuming
1381that the image <code>bird.miff</code> has a width of 512 and a height of
1382480.</p>
1383
1384<div style="margin: auto;">
1385 <h3 class="magick-header"><a id="compare"></a>-compare</h3>
1386</div>
1387
1388<p class="magick-description">mathematically and visually annotate the difference between an image and its reconstruction</p>
1389
1390<p>This is a convert version of "<code>compare</code>" for two same sized images. The syntax is as follows, but other metrics are allowed.</p>
1391
1392<pre>
Cristy594d2772015-11-15 10:47:42 -05001393convert image.png reference.png -metric RMSE -compare \ <br/> difference.png
Cristy882d9f42015-10-29 16:48:39 -04001394</pre>
1395
1396<p>To get the metric value use the string format "%[distortion]".</p>
1397
1398<pre>
1399convert image.png reference.png -metric RMSE -compare -format \
1400 "%[distortion]" info:
1401</pre>
1402
1403<div style="margin: auto;">
1404 <h3 class="magick-header"><a id="complex"></a>-complex <var>operator</var></h3>
1405</div>
1406
1407<p class="magick-description">perform complex mathematics on an image sequence</p>
1408
1409Choose from these operators:
1410
1411<pre>
1412add
1413conjugate
1414divide
1415magnitude-phase
1416multiply
1417real-imaginary
1418subtract
1419</pre>
1420
1421<p>Optionally specify the <code>divide</code> operator SNR with <code><a href="command-line-options.html#define">-define</a> complex:snr=float</code>.</p>
1422
1423<div style="margin: auto;">
1424 <h3 class="magick-header"><a id="compose"></a>-compose <var>operator</var></h3>
1425</div>
1426
1427<p class="magick-description">Set the type of image composition.</p>
1428
1429<p>See <a href="compose.html">Alpha Compositing</a> for
1430a detailed discussion of alpha compositing.</p>
1431
1432<p>This setting effects image processing operators that merge two (or more)
1433images together in some way. This includes the operators,
1434<a href="command-line-options.html#composite">-compare</a>,
1435<a href="command-line-options.html#composite">-composite</a>,
1436<a href="command-line-options.html#layers">-layers</a> composite,
1437<a href="command-line-options.html#flatten">-flatten</a>,
1438<a href="command-line-options.html#mosaic">-mosaic</a>,
1439<a href="command-line-options.html#layers">-layers</a> merge,
1440<a href="command-line-options.html#border">-border</a>,
1441<a href="command-line-options.html#frame">-frame</a>,
1442and <a href="command-line-options.html#extent">-extent</a>. </p>
1443
1444<p>It is also one of the primary options for the "<code>composite</code>"
1445command. </p>
1446
1447
1448<div style="margin: auto;">
1449 <h3 class="magick-header"><a id="composite"></a>-composite</h3>
1450</div>
1451
1452<p class="magick-description">Perform alpha composition on two images and an optional mask</p>
1453
1454<p>Take the first image 'destination' and overlay the second 'source' image
1455according to the current <a href="command-line-options.html#compose">-compose</a> setting. The location
Cristy594d2772015-11-15 10:47:42 -05001456of the 'source' or 'overlay' image is controlled according to <a
Cristye93be682015-11-26 09:07:51 -05001457href="command-line-options.html#gravity" >-gravity</a>, and <a href="command-line-options.html#geometry" >-geometry</a>
Cristy882d9f42015-10-29 16:48:39 -04001458settings. </p>
1459
Cristy769d8892016-01-19 18:11:14 -05001460<p>If a third image is given this is treated as a grayscale blending 'mask' image
Cristy882d9f42015-10-29 16:48:39 -04001461relative to the first 'destination' image. This mask is blended with the
1462source image. However for the '<code>displace</code>' compose method, the
1463mask is used to provide a separate Y-displacement image instead. </p>
1464
1465<p>If a <a href="command-line-options.html#compose">-compose</a> method requires extra numerical
Cristy594d2772015-11-15 10:47:42 -05001466arguments or flags these can be provided by setting the <a
1467href="command-line-options.html#set">-set</a> '<code>option:compose:args</code>'
Cristy882d9f42015-10-29 16:48:39 -04001468appropriately for the compose method. </p>
1469
1470<p>Some <a href="command-line-options.html#compose">-compose</a> methods can modify the 'destination'
Cristy594d2772015-11-15 10:47:42 -05001471image outside the overlay area. You can disable this by setting the special <a
1472href="command-line-options.html#set">-set</a> '<code>option:compose:outside-overlay</code>'
Cristy882d9f42015-10-29 16:48:39 -04001473to '<code>false</code>'. </p>
1474
1475<p>The SVG compositing specification requires that color and opacity values range between zero and QuantumRange inclusive. You can permit values outside this range with this option: <a href="command-line-options.html#set">-set</a> '<code>option:compose:clamp=false</code></p>
1476
1477
1478<div style="margin: auto;">
1479 <h3 class="magick-header"><a id="compress"></a>-compress <var>type</var></h3>
1480</div>
1481
1482<p class="magick-description">Use pixel compression specified by <var>type</var> when writing the image.</p>
1483
Cristy594d2772015-11-15 10:47:42 -05001484<p>Choices are: <code>None</code>, <code>BZip</code>, <code
1485>Fax</code>, <code>Group4</code>, <code
1486>JPEG</code>, <code>JPEG2000</code>, <code
1487>Lossless</code>, <code>LZW</code>, <code
1488>RLE</code> or <code>Zip</code>.</p>
Cristy882d9f42015-10-29 16:48:39 -04001489
1490<p>To print a complete list of compression types, use <a href="command-line-options.html#list">-list
1491compress</a>.</p>
1492
1493<p>Specify <a href="command-line-options.html#compress">+compress</a> to store the binary image in an
1494uncompressed format. The default is the compression type of the specified
1495image file.</p>
1496
1497<p>If <code>LZW</code> compression is specified but LZW compression has not been
1498enabled, the image data is written in an uncompressed LZW format that can be
1499read by LZW decoders. This may result in larger-than-expected GIF files.</p>
1500
1501<p><code>Lossless</code> refers to lossless JPEG, which is only available if the
1502JPEG library has been patched to support it. Use of lossless JPEG is generally
1503not recommended.</p>
1504
1505<p>
1506When writing an ICO file, you may request that the images be encoded in
1507PNG format, by specifying <code>Zip</code> compression.</p>
1508
1509<p>
1510When writing a JNG file, specify <code>Zip</code> compression to request that
1511the alpha channel be encoded in PNG "IDAT" format, or <code>JPEG</code>
1512to request that it be encoded in JPG "JDAA" format.</p>
1513
1514<p>Use the <a href="command-line-options.html#quality">-quality</a> option to set the compression level
1515to be used by JPEG, PNG, MIFF, and MPEG encoders.
1516Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to set the
1517sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling
1518the chroma channels.</p>
1519
1520<div style="margin: auto;">
1521 <h3 class="magick-header"><a id="connected-components"></a>-connected-components <var>connectivity</var></h3>
1522</div>
1523
Cristyce4a3552015-12-14 13:53:35 -05001524<p class="magick-description"><a href="connected-components.html">connected-components</a> labeling detects connected regions in an image, choose from 4 or 8 way connectivity.</p>
Cristy882d9f42015-10-29 16:48:39 -04001525
Cristy594d2772015-11-15 10:47:42 -05001526<p>Use <code><a href="command-line-options.html#define" >-define</a> connected-components:verbose=true</code> to output statistics associated with each unique label.</p>
Cristy882d9f42015-10-29 16:48:39 -04001527
1528<div style="margin: auto;">
1529 <h3 class="magick-header"><a id="contrast"></a>-contrast</h3>
1530</div>
1531
1532<p class="magick-description">Enhance or reduce the image contrast.</p>
1533
1534<p>This option enhances the intensity differences between the lighter and
1535darker elements of the image. Use <a href="command-line-options.html#contrast">-contrast</a> to enhance
1536the image or <a href="command-line-options.html#contrast">+contrast</a> to reduce the image
1537contrast.</p>
1538
1539<p>For a more pronounced effect you can repeat the option:</p>
1540
1541<pre>
1542convert rose: -contrast -contrast rose_c2.png
1543</pre>
1544
1545<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05001546 <h3 class="magick-header"><a id="contrast-stretch"></a>-contrast-stretch <var>black-point</var><br />-contrast-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04001547</div>
1548
1549<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
1550
1551<p>While performing the stretch, black-out at most <var>black-point</var> pixels and white-out at most <var>white-point</var> pixels. Or, if percent is used, black-out at most
Cristy594d2772015-11-15 10:47:42 -05001552<var >black-point %</var> pixels and white-out at most <var>white-point %</var> pixels.</p>
Cristy882d9f42015-10-29 16:48:39 -04001553
Cristy594d2772015-11-15 10:47:42 -05001554<p>Prior to ImageMagick 6.4.7-0, <a href="command-line-options.html#contrast-stretch"
1555>-contrast-stretch</a> will black-out at most <var>black-point</var> pixels and white-out at most <var >total pixels
Cristy882d9f42015-10-29 16:48:39 -04001556minus white-point</var> pixels. Or, if percent is used, black-out at most <var>black-point %</var> pixels and white-out at most <var>100% minus white-point %</var> pixels.</p>
1557
1558<p>Note that <code>-contrast-stretch 0</code> will modify the image such that
1559the image's min and max values are stretched to 0 and <var>QuantumRange</var>, respectively, without any loss of data due to burn-out or
Cristy594d2772015-11-15 10:47:42 -05001560clipping at either end. This is not the same as <a href="command-line-options.html#normalize"
1561>-normalize</a>, which is equivalent to <code>-contrast-stretch 0.15x0.05%</code> (or
Cristy882d9f42015-10-29 16:48:39 -04001562prior to ImageMagick 6.4.7-0, <code>-contrast-stretch 2%x99%</code>).</p>
1563
1564<p>Internally operator works by creating a histogram bin, and then uses that
1565bin to modify the image. As such some colors may be merged together when they
1566originally fell into the same 'bin'. </p>
1567
Cristy769d8892016-01-19 18:11:14 -05001568<p>All the channels are normalized in concert by the same amount so as to
Cristy594d2772015-11-15 10:47:42 -05001569preserve color integrity, when the default <a href="command-line-options.html#channel" >+channel</a>
1570setting is in use. Specifying any other <a href="command-line-options.html#channel" >-channel</a>
Cristy882d9f42015-10-29 16:48:39 -04001571setting will normalize the RGB channels independently.</p>
1572
Cristy594d2772015-11-15 10:47:42 -05001573<p>See also <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect'
Cristy882d9f42015-10-29 16:48:39 -04001574normalization of mathematical images. </p>
1575
1576<p>This operator is under review for re-development. </p>
1577
1578
1579<div style="margin: auto;">
1580 <h3 class="magick-header"><a id="convolve"></a>-convolve <var>kernel</var></h3>
1581</div>
1582
1583<p class="magick-description">Convolve an image with a user-supplied convolution kernel.</p>
1584
1585<p>The <var>kernel</var> is a matrix specified as
1586a comma-separated list of integers (with no spaces), ordered left-to right,
1587starting with the top row. Presently, only odd-dimensioned kernels are
1588supported, and therefore the number of entries in the specified <var>kernel</var> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25,
15897<sup>2</sup>=49, etc. </p>
1590
Cristy594d2772015-11-15 10:47:42 -05001591<p>Note that the <a href="command-line-options.html#convolve">&#x2011;convolve</a> operator supports the <a href="command-line-options.html#bias">&#x2011;bias</a> setting. This option shifts the convolution so that
Cristy882d9f42015-10-29 16:48:39 -04001592positive and negative results are relative to a user-specified bias value.
1593This is important for non-HDRI compilations of ImageMagick when dealing with
1594convolutions that contain negative as well as positive values. This is
1595especially the case with convolutions involving high pass filters or edge
1596detection. Without an output bias, the negative values is clipped at zero.
1597</p>
1598
Cristy594d2772015-11-15 10:47:42 -05001599<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
Cristy882d9f42015-10-29 16:48:39 -04001600negative results without clipping to the color value range (0..QuantumRange).
Cristy594d2772015-11-15 10:47:42 -05001601See the discussion on HDRI implementations of ImageMagick on the page <a
1602href="high-dynamic-range.html">High
1603Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a
1604href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
Cristy882d9f42015-10-29 16:48:39 -04001605<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
1606entry. </p>
1607
1608
1609<div style="margin: auto;">
1610 <h3 class="magick-header"><a id="copy"></a>-copy <var>geometry</var> <var>offset</var></h3>
1611</div>
1612
1613<p class="magick-description">copy pixels from one area of an image to another.</p>
1614
1615<div style="margin: auto;">
1616 <h3 class="magick-header"><a id="crop"></a>-crop <var>geometry</var>{<var>@</var>}{<var>!</var>}</h3>
1617</div>
1618
1619<p class="magick-description">Cut out one or more rectangular regions of the image.</p>
1620
1621<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
1622
1623<p>The <var>width</var> and <var>height</var> of the <var>geometry</var> argument give the size of the image that remains
1624after cropping, and <var>x</var> and <var>y</var> in the
1625<var>offset</var> (if present) gives the location of the top left
1626corner of the cropped image with respect to the original image. To specify the
1627amount to be removed, use <a href="command-line-options.html#shave">-shave</a> instead.</p>
1628
1629<p>If the <var>x</var> and <var>y</var> offsets are
1630present, a single image is generated, consisting of the pixels from the
1631cropping region. The offsets specify the location of the upper left corner of
1632the cropping region measured downward and rightward with respect to the upper
1633left corner of the image. If the <a href="command-line-options.html#gravity">-gravity</a> option is
1634present with <code>NorthEast</code>, <code>East</code>, or <code>SouthEast</code>
1635gravity, it gives the distance leftward from the right edge of the image to
Cristy594d2772015-11-15 10:47:42 -05001636the right edge of the cropping region. Similarly, if the <a
1637href="command-line-options.html#gravity">-gravity</a> option is present with <code>SouthWest</code>,
Cristy882d9f42015-10-29 16:48:39 -04001638<code>South</code>, or <code>SouthEast</code> gravity, the distance is measured
1639upward between the bottom edges.</p>
1640
1641<p>If the <var>x</var> and <var>y</var> offsets are
1642omitted, a set of tiles of the specified geometry, covering the entire input
1643image, is generated. The rightmost tiles and the bottom tiles are smaller if
1644the specified geometry extends beyond the dimensions of the input image.</p>
1645
1646<p>You can add the <var>@</var> to the geometry argument to equally divide the image into the number of tiles generated.</p>
1647
1648<p>By adding a exclamation character flag to the geometry argument, the
1649cropped images virtual canvas page size and offset is set as if the
1650geometry argument was a viewport or window. This means the canvas page size
1651is set to exactly the same size you specified, the image offset set
1652relative top left corner of the region cropped. </p>
1653
1654<p>If the cropped image 'missed' the actual image on its virtual canvas, a
1655special single pixel transparent 'missed' image is returned, and a 'crop
1656missed' warning given. </p>
1657
Cristy594d2772015-11-15 10:47:42 -05001658<p>It might be necessary to <a href="command-line-options.html#repage" >+repage</a> the image prior to
Cristy882d9f42015-10-29 16:48:39 -04001659cropping the image to ensure the crop coordinate frame is relocated to the
1660upper-left corner of the visible image.
1661
Cristy594d2772015-11-15 10:47:42 -05001662Similarly you may want to use <a href="command-line-options.html#repage" >+repage</a> after cropping to
Cristy882d9f42015-10-29 16:48:39 -04001663remove the page offset that will be left behind. This is especially true when
1664you are going to write to an image format such as PNG that supports an image
1665offset.</p>
1666
1667<div style="margin: auto;">
1668 <h3 class="magick-header"><a id="cycle"></a>-cycle <var>amount</var></h3>
1669</div>
1670
1671<p class="magick-description">displace image colormap by amount.</p>
1672
1673<p><var>Amount</var> defines the number of positions each
1674colormap entry is shifted.</p>
1675
1676
1677<div style="margin: auto;">
1678 <h3 class="magick-header"><a id="debug"></a>-debug <var>events</var></h3>
1679</div>
1680
1681<p class="magick-description">enable debug printout.</p>
1682
1683<p>The <code>events</code> parameter specifies which events are to be logged. It
1684can be either <code>None</code>, <code>All</code>, <code>Trace</code>, or
1685a comma-separated list consisting of one or more of the following domains:
1686<code>Accelerate</code>, <code>Annotate</code>, <code>Blob</code>, <code>Cache</code>,
1687<code>Coder</code>, <code>Configure</code>, <code>Deprecate</code>,
1688<code>Exception</code>, <code>Locale</code>, <code>Render</code>,
1689<code>Resource</code>, <code>Security</code>, <code>TemporaryFile</code>,
1690<code>Transform</code>, <code>X11</code>, or <code>User</code>. </p>
1691
1692
1693<p>For example, to log cache and blob events, use.</p>
1694
1695<pre>
1696convert -debug "Cache,Blob" rose: rose.png
1697</pre>
1698
1699<p>The <code>User</code> domain is normally empty, but developers can log user
1700events in their private copy of ImageMagick.</p>
1701
1702<p>To print the complete list of debug methods, use <a href="command-line-options.html#list">-list
1703debug</a>.</p>
1704
1705<p>Use the <a href="command-line-options.html#log">-log</a> option to specify the format for debugging
1706output.</p>
1707
1708<p>Use <a href="command-line-options.html#debug">+debug</a> to turn off all logging.</p>
1709
Cristy594d2772015-11-15 10:47:42 -05001710<p>Debugging may also be set using the <code>MAGICK_DEBUG</code> <a href="resources.html#environment"
1711>environment variable</a>. The allowed values for the <code>MAGICK_DEBUG</code>
Cristy882d9f42015-10-29 16:48:39 -04001712environment variable are the same as for the <a href="command-line-options.html#debug">-debug</a>
1713option.</p>
1714
1715
1716<div style="margin: auto;">
1717 <h3 class="magick-header"><a id="decipher"></a>-decipher <var>filename</var></h3>
1718</div>
1719
1720<p class="magick-description">Decipher and restore pixels that were previously transformed by <a href="command-line-options.html#encipher">-encipher</a>.</p>
1721
1722<p>Get the passphrase from the file specified by <var>filename</var>.</p>
1723
Cristy594d2772015-11-15 10:47:42 -05001724<p>For more information, see the webpage, <a
1725href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or
Cristy882d9f42015-10-29 16:48:39 -04001726Decipher an Image</a>.</p>
1727
1728
1729<div style="margin: auto;">
1730 <h3 class="magick-header"><a id="deconstruct"></a>-deconstruct</h3>
1731</div>
1732
1733<p class="magick-description">find areas that has changed between images </p>
1734
Cristy594d2772015-11-15 10:47:42 -05001735<p>Given a sequence of images all the same size, such as produced by <a
1736href="command-line-options.html#coalesce">-coalesce</a>, replace the second and later images, with
Cristy882d9f42015-10-29 16:48:39 -04001737a smaller image of just the area that changed relative to the previous image.
1738</p>
1739
1740<p>The resulting sequence of images can be used to optimize an animation
1741sequence, though will not work correctly for GIF animations when parts of the
1742animation can go from opaque to transparent. </p>
1743
1744<p>This option is actually equivalent to the <a href="command-line-options.html#layers">-layers</a>
1745method '<code>compare-any</code>'. </p>
1746
1747
1748<div style="margin: auto;">
1749 <h3 class="magick-header"><a id="define"></a>-define <var>key</var>{<var>=value</var>}<var>...</var></h3>
1750</div>
1751
1752<p class="magick-description">add specific global settings generally used to control coders and image processing operations.</p>
1753
1754<p>This option creates one or more definitions for coders and decoders to use
1755while reading and writing image data. Definitions are generally used to
1756control image file format coder modules, and image processing operations,
Cristy594d2772015-11-15 10:47:42 -05001757beyond what is provided by normal means. Defined settings are listed in <a
1758href="command-line-options.html#verbose" >-verbose</a> information ("<code>info:</code>" output format)
Cristy882d9f42015-10-29 16:48:39 -04001759as "Artifacts". </p>
1760
1761<p>If <var>value</var> is missing for a definition, an empty-valued
1762definition of a flag is created with that name. This used to control on/off
1763options. Use <a href="command-line-options.html#define">+define key</a> to remove definitions
1764previously created. Use <a href="command-line-options.html#define">+define "*"</a> to remove all
1765existing definitions.</p>
1766
Cristy594d2772015-11-15 10:47:42 -05001767<p>The same 'artifact' settings can also be defined using the <a
1768href="command-line-options.html#set" >-set "option:<var>key</var>" "<var>value</var>"</a> option, which also allows the use of <a href="escape.html" >Format and Print Image
Cristy882d9f42015-10-29 16:48:39 -04001769Properties</a> in the defined value. </p>
1770
1771<p>The <var>option</var> and <var>key</var> are case-independent (they are
1772converted to lowercase for use within the decoders) while the <var>value</var>
1773is case-dependent.</p>
1774
1775<p>Such settings are global in scope, and affect all images and operations. </p>
1776
1777<p>The following definitions are just some of the artifacts that are
1778available:</p>
1779
1780<table class="table table-condensed table-striped">
1781 <tr>
Cristye0779712016-07-30 17:25:22 -04001782 <td>bmp:alpha=<var>true|false</var></td>
1783 <td>include any alpha channel when writing in the BMP image format.</td>
1784 </tr>
1785
1786 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001787 <td>bmp:format=<var>value</var></td>
1788 <td> valid values are <var>bmp2</var>, <var>bmp3</var>,
1789 and <var>bmp4</var>. This option can be useful when the
1790 method of prepending "BMP2:" to the output filename is inconvenient or
1791 is not available, such as when using the <a href="mogrify.html">mogrify</a> utility.</td>
1792 </tr>
1793
1794 <tr>
1795 <td>colorspace:auto-grayscale=<var>on|off</var></td>
1796 <td>prevent automatic conversion to grayscale inside coders that support
1797 grayscale. This should be accompanied by -type truecolor. PNG and TIF do
1798 not need this define. With PNG, just use PNG24:image. With TIF, just use
1799 -type truecolor. JPG and PSD will need this define.</td>
1800 </tr>
1801
1802 <tr>
1803 <td>complex:snr=<var>value</var></td>
1804 <td>Set the divide SNR constant<a href="command-line-options.html#complex">-complex</a></td>
1805 </tr>
1806
1807 <tr>
1808 <td>compose:args=<var>arguments</var></td>
1809 <td>Sets certain compose argument values when using convert ... -compose ...
Cristy1f1f3a02016-06-01 07:25:42 -04001810 -composite. See <a href="compose.html"
Cristy594d2772015-11-15 10:47:42 -05001811 >Image Composition</a></td>
Cristy882d9f42015-10-29 16:48:39 -04001812 </tr>
1813
1814 <tr>
1815 <td>compose:clamp=<var>on|off</var></td>
1816 <td>set each pixel whose value is below zero to zero and any the pixel whose value is above the quantum range to the quantum range (e.g. 65535) otherwise the pixel value remains unchanged. Define supported in ImageMagick 6.9.1-3 and above.</td>
1817 </tr>
1818
1819 <tr>
Cristyde27d762016-01-02 12:56:44 -05001820 <td>connected-components:area-threshold=<var>value</var></td>
1821 <td>Merges any region with area smaller than <var>value</var> into its surrounding region or largest neighbor.</td>
1822 </tr>
1823
1824 <tr>
1825 <td>connected-components:keep=<var>list-of-ids</var></td>
Cristye0779712016-07-30 17:25:22 -04001826 <td>Comma and/or hyphenated list of id values to keep in the output. Supported in Imagemagick 6.9.3-0.</td>
Cristyde27d762016-01-02 12:56:44 -05001827 </tr>
1828
1829 <tr>
1830 <td>connected-components:mean-color=<var>true</var></td>
1831 <td>Changes the output image from id values to mean color values. Supported in Imagemagick 6.9.2-8.</td>
1832 </tr>
1833
1834 <tr>
1835 <td>connected-components:remove=<var>list-of-ids</var></td>
Cristye0779712016-07-30 17:25:22 -04001836 <td>Comma and/or hyphenated list of id values to remove from the output. Supported in Imagemagick 6.9.2-9.</td>
Cristyde27d762016-01-02 12:56:44 -05001837 </tr>
1838
1839 <tr>
1840 <td>connected-components:verbose=<var>true</var></td>
1841 <td>Lists id, bounding box, centroid, area, mean color for each region.</td>
1842 </tr>
1843
1844 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001845 <td>convolve:scale=<var>{kernel_scale}[!^] [,{origin_addition}] [%]</var></td>
1846 <td>Defines the kernel scaling. The special flag ! automatically scales to
1847 full dynamic range. The ! flag can be used in combination with a factor or
1848 percent. The factor or percent is then applied after the automatic scaling.
1849 An example is 50%!. This produces a result 50% darker than full dynamic
1850 range scaling. The ^ flag assures the kernel is 'zero-summing', for
1851 example when some values are positive and some are negative as in edge
1852 detection kernels. The origin addition adds that value to the center
1853 pixel of the kernel. This produces and effect that is like adding the image
1854 that many times to the result of the filtered image. The typical value
1855 is 1 so that the original image is added to the result of the convolution.
1856 The default is 0.</td>
1857 </tr>
1858
1859 <tr>
1860 <td>convolve:showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05001861 <td>Outputs (to 'standard error') all the information about a specified <a
1862 href="command-line-options.html#morphology" >-morphology convolve</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04001863 </tr>
1864
1865 <tr>
1866 <td>dcm:display-range=<var>reset</var></td>
1867 <td>Sets the display range to the minimum and maximum pixel values for the
1868 DCM image format.</td>
1869 </tr>
1870
1871 <tr>
1872 <td>dds:cluster-fit=<var>true|false</var></td>
1873 <td>Enables the dds cluster-fit.</td>
1874 </tr>
1875
1876 <tr>
1877 <td>dds:compression=<var>dxt1|dxt5|none</var></td>
1878 <td>Sets the dds compression.</td>
1879 </tr>
1880
1881 <tr>
1882 <td>dds:mipmaps=<var>value</var></td>
1883 <td>Sets the dds number of mipmaps.</td>
1884 </tr>
1885
1886 <tr>
1887 <td>dds:weight-by-alpha=<var>true|false</var></td>
1888 <td>Enables the dds alpha weighting.</td>
1889 </tr>
1890
1891 <tr>
1892 <td>delegate:bimodal=<var>true</var></td>
1893 <td>Specifies direct conversion from Postscript to PDF.</td>
1894 </tr>
1895
1896 <tr>
1897 <td>distort:scale=<var>value</var></td>
Cristy594d2772015-11-15 10:47:42 -05001898 <td>Sets the output scaling factor for use with <a href="command-line-options.html#distort"
1899 >-distort</a></td>
Cristy882d9f42015-10-29 16:48:39 -04001900 </tr>
1901
1902 <tr>
1903 <td>distort:viewport=<var>WxH+X+Y</var></td>
1904 <td>Sets the viewport for use with <a href="command-line-options.html#distort">-distort</a></td>
1905 </tr>
1906
1907 <tr>
1908 <td>dot:layout-engine=<var>value</var></td>
1909 <td>Specifies the layout engine for the DOT image format (e.g.
1910 <code>neato</code>).</td>
1911 </tr>
1912
1913 <tr>
1914 <td>filter:option=<var>value</var></td>
1915 <td>Set a filter option for use with <a href="command-line-options.html#resize">-resize</a>.
1916 See <a href="command-line-options.html#filter">-filter</a> for details.</td>
1917 </tr>
1918
1919 <tr>
1920 <td>fourier:normalize=<var>inverse</var></td>
1921 <td>Sets the location for the FFT/IFT normalization as use by
1922 <a href="command-line-options.html#fft">+-fft</a> and <a href="command-line-options.html#ift">+-ift</a>. The default is
1923 <var>forward</var>.</td>
1924 </tr>
1925
1926 <tr>
1927 <td>h:format=<var>value</var></td>
1928 <td>Set the image encoding format use when writing a C-style header.
1929 <var>format</var> can be any output format supported by ImageMagick
1930 except for <var>h</var> and <var>magick</var></td>. If this
1931 option is omitted, the default is <var>GIF</var> for PseudoClass
1932 images and <var>PNM</var> for DirectClass images.
1933 </tr>
1934
1935 <tr>
1936 <td>icon:auto-resize</td>
1937 <td>Automatically stores multiple sizes when writing an ico image
1938 (requires a 256x256 input image).</td>
1939 </tr>
1940
1941 <tr>
1942 <td>jp2:layer-number=<var>value</var></td>
1943 <td>Sets the maximum number of quality layers to decode. Same for JPT, JC2,
1944 and J2K</td>
1945 </tr>
1946
1947 <tr>
1948 <td>jp2:number-resolutions=<var>value</var></td>
1949 <td>Sets the number of resolutions to encode.Same for JPT, JC2, and J2K</td>
1950 </tr>
1951
1952 <tr>
1953 <td>jp2:progression-order=<var>value</var></td>
1954 <td>choose from LRCP, RLCP, RPCL, PCRL or CPRL. Same for JPT, JC2, and
1955 J2K</td>
1956 </tr>
1957
1958 <tr>
1959 <td>jp2:quality=<var>value,value...</var></td>
1960 <td>Sets the quality layer PSNR, given in dB. The order is from left to
1961 right in ascending order. The default is a single lossless quality layer.
1962 Same for JPT, JC2, and J2K</td>
1963 </tr>
1964
1965 <tr>
1966 <td>jp2:rate=<var>value</var></td>
1967 <td>Specify the compression factor to use while writing JPEG-2000 files. The
1968 compression factor is the reciprocal of the compression ratio. The valid
1969 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined,
1970 this value overrides the -quality setting. A quality setting of 75
1971 results in a rate value of 0.06641. Same for JPT, JC2, and J2K</td>
1972 </tr>
1973
1974 <tr>
1975 <td>jp2:reduce-factor=<var>value</var></td>
1976 <td>Sets the number of highest resolution levels to be discarded.Same for
1977 JPT, JC2, and J2K</td>
1978 </tr>
1979
1980 <tr>
1981 <td>jpeg:block-smoothing=<var>on|off</var></td>
Cristy594d2772015-11-15 10:47:42 -05001982 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04001983 </tr>
1984
1985 <tr>
1986 <td>jpeg:colors=<var>value</var></td>
1987 <td>Set the desired number of colors and let the JPEG encoder do the
1988 quantizing.</td>
1989 </tr>
1990
1991 <tr>
1992 <td>jpeg:dct-method=<var>value</var></td>
1993 <td>Choose from <code>default</code>, <code>fastest</code>,
1994 <code>float</code>, <code>ifast</code>, and <code>islow</code>.</td>
1995 </tr>
1996
1997 <tr>
1998 <td>jpeg:extent=<var>value</var></td>
1999 <td>Restrict the maximum JPEG file size, for example <code>-define
2000 jpeg:extent=400KB</code>. The JPEG encoder will search for the highest
2001 compression quality level that results in an output file that does not
Cristye93be682015-11-26 09:07:51 -05002002 exceed the value. The <code>-quality</code> option also will be respected
2003 starting with version 6.9.2-5. Between 6.9.1-0 and 6.9.2-4, add -quality
2004 100 in order for the jpeg:extent to work properly. Prior to 6.9.1-0, the
2005 -quality setting was ignored.</td>
Cristy882d9f42015-10-29 16:48:39 -04002006 </tr>
2007
2008 <tr>
2009 <td>jpeg:fancy-upsampling=<var>on|off</var></td>
Cristy594d2772015-11-15 10:47:42 -05002010 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002011 </tr>
2012
2013 <tr>
2014 <td>jpeg:optimize-coding=<var>on|off</var></td>
Cristy594d2772015-11-15 10:47:42 -05002015 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002016 </tr>
2017
2018 <tr>
2019 <td>jpeg:q-table=<var>table</var></td>
Cristy594d2772015-11-15 10:47:42 -05002020 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002021 </tr>
2022
2023 <tr>
2024 <td>jpeg:sampling-factor=<var>sampling-factor-string</var></td>
Cristy594d2772015-11-15 10:47:42 -05002025 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002026 </tr>
2027
2028 <tr>
2029 <td>jpeg:size=<var>geometry</var></td>
2030 <td>Set the size hint of a JPEG image, for
2031 example, <code>-define jpeg:size=128x128</code>.
2032 It is most useful for increasing performance and reducing the memory
2033 requirements when reducing the size of a large JPEG image.</td>
2034 </tr>
2035
2036 <tr>
2037 <td>json:features</td>
2038 <td>includes features in verbose information</td>
2039 </tr>
2040
2041 <tr>
2042 <td>json:limit</td>
Cristy594d2772015-11-15 10:47:42 -05002043 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002044 </tr>
2045
2046 <tr>
2047 <td>json:locate</td>
Cristy594d2772015-11-15 10:47:42 -05002048 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002049 </tr>
2050
2051 <tr>
2052 <td>json:moments</td>
2053 <td>includes image moments in verbose information</td>
2054 </tr>
2055
2056 <tr>
2057 <td>magick:format=<var>value</var></td>
2058 <td>Set the image encoding format use when writing a C-style header.
2059 This is the same as "h:format=format" described above.</td>.
2060 </tr>
2061
2062 <tr>
2063 <td>mng:need-cacheoff</td>
2064 <td>turn playback caching off for streaming MNG.</td>
2065 </tr>
2066
2067 <tr>
2068 <td>morphology:compose=<var>compose-method</var></td>
Cristy594d2772015-11-15 10:47:42 -05002069 <td>Specifies how to merge results generated by multiple<a
2070 href="command-line-options.html#morphology" >-morphology</a> kernel. The default is none. One
Cristy882d9f42015-10-29 16:48:39 -04002071 typical value is 'lighten' as used, for example, with the sobel edge
2072 kernels. </td>
2073 </tr>
2074
2075 <tr>
2076 <td>morphology:showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05002077 <td>Outputs (to 'standard error') all the information about a generated <a
2078 href="command-line-options.html#morphology" >-morphology</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04002079 </tr>
2080
2081 <tr>
2082 <td>pcl:fit-to-page=<var>true</var></td>
2083
Cristy594d2772015-11-15 10:47:42 -05002084 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002085 <td>pdf:fit-page=<var>geometry</var></td>
2086 <td> geometry specifies the scaling dimensions for resizing when the PDF is
2087 being read. The geometry is either WxH{%} or page size. No offsets are
2088 allowed. (introduced in IM 6.8.8-8)</td>
2089 </tr>
2090
2091 <tr>
2092 <td>pdf:fit-to-page=<var>true</var></td>
Cristy594d2772015-11-15 10:47:42 -05002093 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002094 </tr>
2095
2096 <tr>
2097 <td>pdf:use-cropbox=<var>true</var></td>
Cristy594d2772015-11-15 10:47:42 -05002098 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002099 </tr>
2100
2101 <tr>
2102 <td>pdf:use-trimbox=<var>true</var></td>
Cristy594d2772015-11-15 10:47:42 -05002103 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002104 </tr>
2105
2106 <tr>
2107 <td>png:bit-depth=<var>value</var></td>
Cristy594d2772015-11-15 10:47:42 -05002108 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002109 </tr>
2110 <tr>
2111 <td>png:color-type=<var>value</var></td>
2112 <td>desired bit-depth and color-type for PNG output. You can force the PNG
2113 encoder to use a different bit-depth and color-type than it would have
2114 normally selected, but only if this does not cause any loss of image
2115 quality. Any attempt to reduce image quality is treated as an error and no
2116 PNG file is written. E.g., if you have a 1-bit black-and-white image, you
2117 can use these "defines" to cause it to be written as an 8-bit grayscale,
2118 indexed, or even a 64-bit RGBA. But if you have a 16-million color image,
2119 you cannot force it to be written as a grayscale or indexed PNG. If you
2120 wish to do this, you must use the appropriate <a href="command-line-options.html#depth">-depth</a>,
2121 <a href="command-line-options.html#colors">-colors</a>, or <a href="command-line-options.html#type">-type</a> directives to
2122 reduce the image quality prior to using the PNG encoder. Note that in
2123 indexed PNG files, "bit-depth" refers to the number of bits per index,
2124 which can be 1, 2, 4, or 8. In such files, the color samples always have
2125 8-bit depth.</td>
2126 </tr>
2127
2128 <tr>
2129 <td>png:compression-filter=<var>value</var></td>
2130 <td> valid values are 0 through 9. 0-4 are the corresponding PNG filters,
2131 5 means adaptive filtering except for images with a colormap, 6 means
2132 adaptive filtering for all images, 7 means MNG "loco" compression, 8 means
2133 Z_RLE strategy with adaptive filtering, and 9 means Z_RLE strategy with no
2134 filtering.</td>
2135 </tr>
2136
2137 <tr>
2138 <td>png:compression-level=<var>value</var></td>
2139 <td> valid values are 0 through 9, with 0 providing the least but fastest
2140 compression and 9 usually providing the best and always the slowest.</td>
2141 </tr>
2142
2143 <tr>
2144 <td>png:compression-strategy=<var>value</var></td>
2145 <td> valid values are 0 through 4, meaning default, filtered, huffman_only,
2146 rle, and fixed ZLIB compression strategy. If you are using an old zlib
2147 that does not support Z_RLE (before 1.2.0) or Z_FIXED (before 1.2.2.2),
2148 values 3 and 4, respectively, will use the zlib default strategy
2149 instead.</td>
2150 </tr>
2151
2152 <tr>
2153 <td>png:format=<var>value</var></td>
2154 <td> valid values are <var>png8</var>, <var>png24</var>,
2155 <var>png32</var>, <var>png48</var>,
2156 <var>png64</var>, and <var>png00</var>.
2157 This property can be useful for specifying
2158 the specific PNG format to be used, when the usual method of prepending the
2159 format name to the output filename is inconvenient, such as when writing
2160 a PNG-encoded ICO file or when using <a href="mogrify.html">mogrify</a>.
2161 Value = <var>png8</var> reduces the number of colors to 256,
2162 only one of which may be fully transparent, if necessary. The other
2163 values do not force any reduction of quality; it is an error to request
2164 a format that cannot represent the image data without loss (except that
2165 it is allowed to reduce the bit-depth from 16 to 8 for all formats).
2166 Value = <var>png24</var> and <var>png48</var>
2167 allow transparency, only if a single color is fully transparent and that
2168 color does not also appear in an opaque pixel; such transparency is
2169 written in a PNG <code>tRNS</code> chunk.
2170 Value = <var>png00</var> causes the image to inherit its
2171 color-type and bit-depth from the input image, if the input was also
2172 a PNG.</td>
2173 </tr>
2174
2175 <tr>
2176 <td>png:exclude-chunk=<var>value</var></td>
2177
Cristy594d2772015-11-15 10:47:42 -05002178 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002179 <td>png:include-chunk=<var>value</var></td>
2180 <td>ancillary chunks to be excluded from or included in PNG output.
2181
2182 <p>The <var>value</var> can be the name of a PNG chunk-type such
2183 as <var>bKGD</var>, a comma-separated list of chunk-names
2184 (which can include the word <var>date</var>, the word
2185 <var>all</var>, or the word <var>none</var>).
2186 Although PNG chunk-names are case-dependent, you can use all lowercase
2187 names if you prefer.</p>
2188
2189 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior
2190 of the PNG encoder and have no effect on the PNG decoder.</p>
2191
2192 <p>As a special case, if the <code>sRGB</code> chunk is excluded and
2193 the <code>gAMA</code> chunk is included, the <code>gAMA</code> chunk will
2194 only be written if gamma is not 1/2.2, since most decoders assume
2195 sRGB and gamma=1/2.2 when no colorspace information is included in
2196 the PNG file. Because the list is processed from left to right, you
2197 can achieve this with a single define:</p>
2198
2199<pre>
2200-define png:include-chunk=none,gAMA
2201</pre>
2202
2203 <p>As a special case, if the <code>sRGB</code> chunk is not excluded and
2204 the PNG encoder recognizes that the image contains the sRGB ICC profile,
2205 the PNG encoder will write the <code>sRGB</code> chunk instead of the
2206 entire ICC profile. To force the PNG encoder to write the sRGB
2207 profile as an <code>iCCP</code> chunk in the output PNG instead of the
2208 <code>sRGB</code> chunk, exclude the <code>sRGB</code> chunk.</p>
2209
2210 <p>The critical PNG chunks <code>IHDR</code>, <code>PLTE</code>,
2211 <code>IDAT</code>, and <code>IEND</code> cannot be excluded. Any such
2212 entries appearing in the list will be ignored.</p>
2213
2214 <p>If the ancillary PNG <code>tRNS</code> chunk is excluded and the
2215 image has transparency, the PNG colortype is forced to be 4 or 6
2216 (GRAY_ALPHA or RGBA). If the image is not transparent, then the
2217 <code>tRNS</code> chunk isn't written anyhow, and there is no effect
2218 on the PNG colortype of the output image.</p>
2219
2220 <p>The <a href="command-line-options.html#strip">-strip</a> option does the equivalent of the
2221 following for PNG output:</p>
2222
2223<pre>
2224-define png:exclude-chunk=EXIF,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date
2225</pre>
2226
2227 <p>The default behavior is to include all known PNG ancillary chunks
2228 plus ImageMagick's private <code>vpAg</code> ("virtual page") chunk,
2229 and to exclude all PNG chunks that are unknown to ImageMagick,
2230 regardless of their PNG "copy-safe" status as described in the
2231 PNG specification.</p>
2232
2233 <p>Any chunk names that are not known to ImageMagick are ignored
2234 if they appear in either the "include-chunk" or "exclude-chunk" list.
2235 The ancillary chunks currently known to ImageMagick are
2236 <code>bKGD</code>, <code>cHRM</code>, <code>gAMA</code>, <code>iCCP</code>,
2237 <code>oFFs</code>, <code>pHYs</code>, <code>sRGB</code>, <code>tEXt</code>,
2238 <code>tRNS</code>, <code>vpAg</code>, and <code>zTXt</code>.</p>
2239
2240 <p>You can also put <code>date</code> in the list to include or exclude
2241 the "Date:create" and "Date:modify" text chunks that ImageMagick normally
2242 inserts in the output PNG.</p></td>
2243 </tr>
2244
2245 <tr>
2246 <td>png:preserve-colormap[=<var>true</var>]</td>
Cristy594d2772015-11-15 10:47:42 -05002247 <td>Use the existing image->colormap. Normally the PNG encoder will
Cristy882d9f42015-10-29 16:48:39 -04002248 try to optimize the palette, eliminating unused entries and putting
2249 the transparent colors first. If this flag is set, that behavior
2250 is suppressed.</td>
2251 </tr>
2252
2253 <tr>
2254 <td>png:preserve-iCCP[=<var>true</var>]</td>
2255 <td>By default, the PNG decoder and encoder examine any ICC profile
2256 that is present, either from an <code>iCCP</code> chunk in the PNG
2257 input or supplied via an option, and if the profile is recognized
2258 to be the sRGB profile, converts it to the <code>sRGB</code> chunk.
2259 You can use <code>-define png:preserve-iCCP</code> to prevent
2260 this from happening; in such cases the <code>iCCP</code> chunk
2261 will be read or written and no <code>sRGB</code> chunk will be
2262 written. There are some ICC profiles that claim to be sRGB but
2263 have various errors that cause them to be rejected by libpng16; such
2264 profiles are recognized anyhow and converted to the <code>sRGB</code>
2265 chunk, but are rejected if the <code>-define png:preserve-iCCP</code>
2266 is present. Note that not all "sRGB" ICC profiles are recognized
2267 yet; we will add them to the list as we encounter them.</td>
2268 </tr>
2269
2270 <tr>
2271 <td>png:swap-bytes[=<var>true</var>]</td>
2272 <td>The PNG specification requires that any multi-byte integers be stored in
2273 network byte order (MSB-LSB endian). This option allows you to
2274 fix any invalid PNG files that have 16-bit samples stored incorrectly
2275 in little-endian order (LSB-MSB). The "-define png:swap-bytes" option
2276 must appear before the input filename on the commandline. The swapping
2277 is done during the libpng decoding operation.</td>
2278 </tr>
2279
2280 <tr>
2281 <td>profile:skip=<var>name1,name2,...</var></td>
2282 <td>Skip the named profile[s] when reading the image. Use skip="*" to
2283 skip all named profiles in the image. Many named profiles exist,
2284 including ICC, EXIF, APP1, IPTC, XMP, and others.</td>
2285 </tr>
2286
2287 <tr>
2288 <td>ps:imagemask</td>
2289 <td>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will
2290 create Postscript files that render bilevel images with the Postscript
2291 imagemask operator instead of the image operator.</td>
2292 </tr>
2293
2294 <tr>
2295 <td>psd:alpha-unblend=off</td>
2296 <td>Disables new automatic un-blending of transparency with the base image
2297 for the flattened layer 0 before adding the alpha channel to the output
2298 image. This define must be placed before the input psd image. (Available
2299 as of IM 6.9.2.5). The automatic un-blending is new to IM 6.9.2.5 and
2300 prevents the transparency from being applied twice in the output
2301 image.</td>
2302 </tr>
2303
2304 <tr>
Cristy1f1f3a02016-06-01 07:25:42 -04002305 <td>preserve-timestamp=<var>{True, False}</var></td>
2306 <td>Preserve file timestamp (<code>mogrify</code> only).</td>
2307 </tr>
2308
2309 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002310 <td>quantum:format=<var>type</var></td>
2311 <td>Set the type to <code>floating-point</code> to specify a floating-point
2312 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode
2313 to preserve negative values. If <a href="command-line-options.html#depth">-depth</a> 16 is
2314 included, the result is a single precision floating point format.
2315 If <a href="command-line-options.html#depth">-depth</a> 32 is included, the result is
2316 double precision floating point format.</td>
2317 </tr>
2318
2319 <tr>
2320 <td>quantum:polarity=<var>photometric-interpretation</var></td>
2321 <td>Set the photometric-interpretation of an image (typically for TIFF image
2322 file format) to either <code>min-is-black</code> (default) or
2323 <code>min-is-white</code>.</td>
2324 </tr>
2325
2326 <tr>
2327 <td>sample:offset=<var>geometry</var></td>
2328 <td>Location of the sampling point within the sub-region being sampled,
Cristy594d2772015-11-15 10:47:42 -05002329 expressed as percentages (see <a href="command-line-options.html#sample" >-sample</a>).</td>
Cristy882d9f42015-10-29 16:48:39 -04002330 </tr>
2331
2332 <tr>
2333 <td>showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05002334 <td>Outputs (to 'standard error') all the information about a generated <a
2335 href="command-line-options.html#morphology" >-morphology</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04002336 </tr>
2337
2338 <tr>
2339 <td>stream:buffer-size=<var>value</var></td>
2340 <td>Set the stream buffer size. Select 0 for unbuffered I/O.</td>
2341 </tr>
2342
2343 <tr>
2344 <td>tiff:alpha=<var>associated|unassociated|unspecified</var></td>
2345 <td>Specify the alpha extra samples as associated, unassociated or unspecified </td>
2346 </tr>
2347
2348 <tr>
2349 <td>tiff:endian=<var>msb|lsb</var></td>
Cristy594d2772015-11-15 10:47:42 -05002350 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002351 </tr>
2352
2353 <tr>
2354 <td>tiff:exif-properties=<var>false</var></td>
2355 <td>Skips reading the EXIF properties.</td>
2356 </tr>
2357
2358 <tr>
2359 <td>tiff:fill-order=<var>msb|lsb</var></td>
Cristy594d2772015-11-15 10:47:42 -05002360 <td>&nbsp</td>
Cristy882d9f42015-10-29 16:48:39 -04002361 </tr>
2362
2363 <tr>
2364 <td>tiff:ignore-layers=<var>true</var></td>
2365 <td>Ignores the photoshop layers.</td>
2366 </tr>
2367
2368 <tr>
2369 <td>tiff:ignore-tags=<var>comma-separate-list-of-tag-IDs</var></td>
2370 <td>Allows one or more tag ID values to be ignored.</td>
2371 </tr>
2372
2373 <tr>
2374 <td>tiff:rows-per-strip=<var>value</var></td>
2375 <td>Sets the number of rows per strip</td>
2376 </tr>
2377
2378 <tr>
2379 <td>tiff:tile-geometry=<var>WxH</var></td>
2380 <td>Sets the tile size for pyramid tiffs. Requires the suffix
2381 PTIF: before the outputname</td>
2382 </tr>
Cristye09ed312016-03-06 08:07:39 -05002383
2384 <tr>
2385 <td>type:features=<var>string</var></td>
2386 <td>&nbsp</td>
2387 </tr>
2388
2389 <tr>
2390 <td>type:hinting=<var>off</var></td>
2391 <td>&nbsp</td>
2392 </tr>
Cristy882d9f42015-10-29 16:48:39 -04002393</table>
2394
2395<p>For example, to create a postscript file that will render only the black
2396pixels of a bilevel image, use:</p>
2397
2398<pre>
2399convert bilevel.tif -define ps:imagemask eps3:stencil.ps
2400</pre>
2401
2402<p>Set attributes of the image registry by prefixing the value with
2403<code>registry:</code>. For example, to set a temporary path to put work files,
2404use:</p>
2405
2406<pre>
2407-define registry:temporary-path=/data/tmp
2408</pre>
2409
2410<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05002411 <h3 class="magick-header"><a id="delay"></a>-delay <var>ticks</var> <br />-delay <var>ticks</var>x<var>ticks-per-second</var> {<var>&lt;</var>} {<var>&gt;</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04002412</div>
2413
2414<p class="magick-description">display the next image after pausing.</p>
2415
2416<p>This option is useful for regulating the animation of image sequences
2417<var>ticks/ticks-per-second</var> seconds must expire before the display of the
2418next image. The default is no delay between each showing of the image
2419sequence. The default ticks-per-second is 100.</p>
2420
2421<p>Use <code>&gt;</code> to change the image delay <var>only</var> if its current
2422value exceeds the given delay. <code>&lt;</code> changes the image delay
2423<var>only</var> if current value is less than the given delay. For example, if
2424you specify <code>30&gt;</code> and the image delay is 20, the image delay does
2425not change. However, if the image delay is 40 or 50, the delay it is changed
2426to 30. Enclose the given delay in quotation marks to prevent the
2427<code>&lt;</code> or <code>&gt;</code> from being interpreted by your shell as
2428a file redirection.</p>
2429
2430
2431<div style="margin: auto;">
2432 <h3 class="magick-header"><a id="delete"></a>-delete <var>indexes</var></h3>
2433</div>
2434
2435<p class="magick-description">delete the images specified by index, from the image sequence.</p>
2436
2437<p>Specify the image by its index in the sequence. The first image is index
24380. Negative indexes are relative to the end of the sequence, for example, -1
2439represents the last image of the sequence. Specify a range of images with
2440a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use
Cristy912a9222016-06-17 15:37:28 -04002441<code>+delete</code> to delete the last image in the current image sequence. Use <code>-delete 0--1</code> to delete the entire image sequence.</p>
Cristy882d9f42015-10-29 16:48:39 -04002442
2443
2444<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05002445 <h3 class="magick-header"><a id="density"></a>-density <var>width</var><br />-density <var>width</var>x<var>height</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002446</div>
2447
2448<p class="magick-description">Set the horizontal and vertical resolution of an image for rendering to devices.</p>
2449
2450<p>This option specifies the image resolution to store while encoding a raster
2451image or the canvas resolution while rendering (reading) vector formats such
2452as Postscript, PDF, WMF, and SVG into a raster image. Image resolution
2453provides the unit of measure to apply when rendering to an output device or
Cristy594d2772015-11-15 10:47:42 -05002454raster image. The default unit of measure is in dots per inch (DPI). The <a
2455href="command-line-options.html#units">-units</a> option may be used to select dots per centimeter
Cristy882d9f42015-10-29 16:48:39 -04002456instead.</p>
2457
2458<p>The default resolution is 72 dots per inch, which is equivalent to one
2459point per pixel (Macintosh and Postscript standard). Computer screens are
2460normally 72 or 96 dots per inch, while printers typically support 150, 300,
2461600, or 1200 dots per inch. To determine the resolution of your display, use
2462a ruler to measure the width of your screen in inches, and divide by the
2463number of horizontal pixels (1024 on a 1024x768 display).</p>
2464
2465<p>If the file format supports it, this option may be used to update the
2466stored image resolution. Note that Photoshop stores and obtains image
2467resolution from a proprietary embedded profile. If this profile is not
2468stripped from the image, then Photoshop will continue to treat the image using
2469its former resolution, ignoring the image resolution specified in the standard
2470file header.</p>
2471
2472<p>The <a href="command-line-options.html#density">-density</a> option sets an <var>attribute</var> and
2473does not alter the underlying raster image. It may be used to adjust the
2474rendered size for desktop publishing purposes by adjusting the scale applied
2475to the pixels. To resize the image so that it is the same size at a different
2476resolution, use the <a href="command-line-options.html#resample">-resample</a> option.</p>
2477
2478<div style="margin: auto;">
2479 <h3 class="magick-header"><a id="depth"></a>-depth <var>value</var></h3>
2480</div>
2481
2482<p class="magick-description">depth of the image.</p>
2483
2484<p>This the number of bits in a color sample within a pixel. Use this option
2485to specify the depth of raw images whose depth is unknown such as GRAY, RGB,
2486or CMYK, or to change the depth of any image after it has been read.</p>
2487
2488<div style="margin: auto;">
2489 <h3 class="magick-header"><a id="descend"></a>-descend</h3>
2490</div>
2491
2492<p class="magick-description">obtain image by descending window hierarchy.</p>
2493
2494<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05002495 <h3 class="magick-header"><a id="deskew"></a>-deskew <var>threshold{%}</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002496</div>
2497
2498<p class="magick-description">straighten an image. A threshold of 40% works for most images.</p>
2499
2500<p>Use <a href="command-line-options.html#set">-set</a> <code>option:deskew:auto-crop
2501<var>width</var></code> to auto crop the image. The set argument is the pixel
2502width of the image background (e.g 40).</p>
2503
2504<div style="margin: auto;">
2505 <h3 class="magick-header"><a id="despeckle"></a>-despeckle</h3>
2506</div>
2507
2508<p class="magick-description">reduce the speckles within an image.</p>
2509
2510<div style="margin: auto;">
2511 <h3 class="magick-header"><a id="direction"></a>-direction <var>type</var></h3>
2512</div>
2513
2514<p class="magick-description">render text right-to-left or left-to-right.</p>
2515
2516<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05002517 <h3 class="magick-header"><a id="displace"></a>-displace <var>horizontal-scale</var>{%}{!}<br />-displace <var>horizontal-scale</var>x<var>vertical-scale</var>{%}{!}</h3>
Cristy882d9f42015-10-29 16:48:39 -04002518</div>
2519
2520<p class="magick-description">shift image pixels as defined by a displacement map.</p>
2521
2522<p>With this option, the 'overlay' image, and optionally the 'mask' image,
2523is used as a displacement map, which is used to displace the lookup of
2524what part of the 'background' image is seen at each point of the overlaid
2525area. Much like the displacement map is a 'lens' that redirects light shining
2526through it so as to present a distorted view the original 'background' image
2527behind it. </p>
2528
2529<p>Any perfect grey areas of the displacement map produce a zero
2530displacement of the image. Black areas produce the given maximum negative
2531displacement of the lookup point, while white produce a maximum positive
2532displacement of the lookup. </p>
2533
2534<p>Note that it is the lookup of the 'background' that is displaced, not a
2535displacement of the image itself. As such an area of the displacement map
2536containing 'white' will have the lookup point 'shifted' by a positive amount,
2537and thus generating a copy of the destination image to the right/downward from
2538the correct position. That is the image will look like it may have been
2539'shifted' in a negative left/upward direction. Understanding this is a very
2540important in understanding how displacement maps work. </p>
2541
2542<p>The given arguments define the maximum amount of displacement in pixels
2543that a particular map can produce. If the displacement scale is large enough
2544it is also possible to lookup parts of the 'background' image that lie well
2545outside the bounds of the displacement map itself. That is you could very
2546easily copy a section of the original image from outside the overlay area
2547into the overlay area. </p>
2548
2549<p>The '%' flag makes the displacement scale relative to the size of the
2550overlay image (100% = half width/height of image). Using '!' switches
2551percentage arguments to refer to the destination image size instead.
2552these flags were added as of IM v6.5.3-5.</p>
2553
2554<p>Normally a single grayscale displacement map is provided, which with the
2555given scaling values will determine a single direction (vector) in which
2556displacements can occur (positively or negatively). However, if you also
2557specify a third image which is normally used as a <var>mask</var>,
2558the <var>composite image</var> is used for horizontal X
2559displacement, while the <var>mask image</var> is used for vertical Y
2560displacement. This allows you to define completely different displacement
2561values for the X and Y directions, and allowing you to lookup any point within
2562the <var>scale</var> bounds. In other words each pixel can lookup
2563any other nearby pixel, producing complex 2 dimensional displacements, rather
2564than a simple 1 dimensional vector displacements. </p>
2565
2566<p>Alternatively rather than supplying two separate images, as of IM v6.4.4-0,
2567you can use the 'red' channel of the overlay image to specify the horizontal
2568or X displacement, and the 'green' channel for the vertical or Y displacement.
2569</p>
2570
2571<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a
2572mask the transparency of the destination image. However areas outside the
2573overlaid areas will not be effected. </p>
2574
2575
2576<div style="margin: auto;">
2577 <h3 class="magick-header"><a id="display"></a>-display <var>host:display[.screen]</var></h3>
2578</div>
2579
2580<p class="magick-description">Specifies the X server to contact.</p>
2581
2582<p>This option is used with convert for obtaining image or font from this
2583X server. See <var>X(1)</var>.</p>
2584
2585<div style="margin: auto;">
2586 <h3 class="magick-header"><a id="dispose"></a>-dispose <var>method</var></h3>
2587</div>
2588
2589<p class="magick-description">define the GIF disposal image setting for images that are being created or read in. </p>
2590
2591<p>The layer disposal method defines the way each the displayed image is to be
2592modified after the current 'frame' of an animation has finished being
2593displayed (after its 'delay' period), but before the next frame on an
2594animation is to be overlaid onto the display. </p>
2595
2596<p>Here are the valid methods:</p>
2597
2598<dl class="dl-horizontal">
2599<dt>Undefined</dt><dd>0: No disposal specified (equivalent to '<code>none</code>').</dd>
2600<dt>None</dt><dd>1: Do not dispose, just overlay next frame image.</dd>
2601<dt>Background</dt><dd>2: Clear the frame area with the background color.</dd>
2602<dt>Previous</dt><dd>3: Clear to the image prior to this frames overlay.</dd>
2603</dl>
2604
2605<p>You can also use the numbers given above, which is what the GIF format
2606uses internally to represent the above settings. </p>
2607
2608<p>To print a complete list of dispose methods, use <a href="command-line-options.html#list">-list dispose</a>.</p>
2609
Cristy594d2772015-11-15 10:47:42 -05002610<p>Use <a href="command-line-options.html#dispose" >+dispose</a>, turn off the setting and prevent
Cristy882d9f42015-10-29 16:48:39 -04002611resetting the layer disposal methods of images being read in. </p>
2612
2613<p>Use <a href="command-line-options.html#set">-set</a> '<code>dispose</code>' method to set the image
2614disposal method for images already in memory.</p>
2615
2616<div style="margin: auto;">
2617 <h3 class="magick-header"><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <var>value</var></h3>
2618</div>
2619
2620<p class="magick-description">maximum RMSE for subimage match (default 0.2).</p>
2621
2622
2623<div style="margin: auto;">
2624 <h3 class="magick-header"><a id="dissolve"></a>-dissolve <var>src_percent</var>[x<var>dst_percent</var>]</h3>
2625</div>
2626
2627<p class="magick-description">dissolve an image into another by the given percent.</p>
2628
2629<p>The opacity of the composite image is multiplied by the given percent, then
2630it is composited 'over' the main image. If <var>src_percent</var>
2631is greater than 100, start dissolving the main image so it becomes
2632transparent at a value of '<code>200</code>'. If both percentages
2633are given, each image are dissolved to the percentages given. </p>
2634
2635<p>Note that dissolve percentages do not add, two opaque images dissolved
2636'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2637images, you would need to use dissolve values of '50,100'. </p>
2638
2639<div style="margin: auto;">
2640 <h3 class="magick-header"><a id="distort"></a>-distort <var>method arguments</var></h3>
2641</div>
2642
2643<p class="magick-description">distort an image, using the given <var>method</var> and its required <var>arguments</var>.</p>
2644
2645<p>The <var>arguments</var> is a single string containing a list
2646of floating point numbers separated by commas or spaces. The number of
2647and meaning of the floating point values depends on the distortion <var>method</var> being used. </p>
2648
2649<p>Choose from these distortion types:</p>
2650
2651<table class="table table-condensed table-striped">
2652 <tr>
2653 <th style="width: 8%">Method</th>
2654 <th>Description</th>
2655 </tr>
2656
2657 <tr>
Cristy594d2772015-11-15 10:47:42 -05002658 <td>ScaleRotateTranslate <br/> SRT</td>
Cristy882d9f42015-10-29 16:48:39 -04002659 <td>
2660 Distort image by first scaling and rotating about a given 'center',
2661 before translating that 'center' to the new location, in that order. It
2662 is an alternative method of specifying a 'Affine' type of
2663 distortion, but without shearing effects. It also provides a good way
2664 of rotating and displacing a smaller image for tiling onto a larger
Cristy594d2772015-11-15 10:47:42 -05002665 background (IE 2-dimensional animations). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002666
2667 The number of arguments determine the specific meaning of each
Cristy594d2772015-11-15 10:47:42 -05002668 argument for the scales, rotation, and translation operations. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002669
2670 <dl class="dl-horizontal">
2671 <dt>2:</dt><dd><var>Scale Angle</var></dd>
2672 <dt>3:</dt><dd><var>X,Y Angle</var></dd>
2673 <dt>4:</dt><dd><var>X,Y Scale Angle</var></dd>
2674 <dt>5:</dt> <dd><var>X,Y ScaleX,ScaleY Angle</var></dd>
2675 <dt>6:</dt> <dd><var>X,Y Scale Angle NewX,NewY</var></dd>
2676 <dt>7:</dt> <dd><var>X,Y ScaleX,ScaleY Angle NewX,NewY</var></dd>
2677 </dl>
2678
2679 This is actually an alternative way of specifying a 2 dimensional linear
2680 'Affine' or 'AffineProjection' distortion. </td> </tr>
2681
2682 <tr>
2683 <td>Affine</td>
2684 <td>
2685 Distort the image linearly by moving a list of at least 3 or more sets
2686 of control points (as defined below). Ideally 3 sets or 12 floating
2687 point values are given allowing the image to be linearly scaled,
2688 rotated, sheared, and translated, according to those three points. See
2689 also the related 'AffineProjection' and 'SRT'
Cristy594d2772015-11-15 10:47:42 -05002690 distortions. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002691
2692 More than 3 sets given control point pairs (12 numbers) is least
2693 squares fitted to best match a linear affine distortion. If only 2
2694 control point pairs (8 numbers) are given a two point image translation
2695 rotation and scaling is performed, without any possible shearing,
2696 flipping or changes in aspect ratio to the resulting image. If only one
2697 control point pair is provides the image is only translated, (which may
Cristy594d2772015-11-15 10:47:42 -05002698 be a floating point non-integer translation). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002699
2700 This distortion does not include any form of perspective distortion.
2701 </td>
2702
2703 </tr>
2704
2705 <tr>
2706 <td>AffineProjection</td>
2707 <td>
2708 Linearly distort an image using the given Affine Matrix of 6
2709 pre-calculated coefficients forming a set of Affine Equations to map
2710 the source image to the destination image.
2711
2712 <p class="text-center"><var>
2713 s<sub>x</sub>, r<sub>x</sub>,
2714 r<sub>y</sub>, s<sub>y</sub>,
2715 t<sub>x</sub>, t<sub>y</sub>
2716 </var></p>
2717
Cristy594d2772015-11-15 10:47:42 -05002718 See <a href="command-line-options.html#affine" >-affine</a> setting for more detail, and
2719 meanings of these coefficients. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002720
2721 The distortions 'Affine' and 'SRT' provide
2722 alternative methods of defining this distortion, with ImageMagick doing
2723 the calculations needed to generate the required coefficients. You can
Cristy594d2772015-11-15 10:47:42 -05002724 see the internally generated coefficients, by using a <a
2725 href="command-line-options.html#verbose" >-verbose</a> setting with those other variants. </td>
Cristy882d9f42015-10-29 16:48:39 -04002726
2727 </tr>
2728
2729 <tr>
Cristy594d2772015-11-15 10:47:42 -05002730 <td>BilinearForward<br/>
Cristy882d9f42015-10-29 16:48:39 -04002731 BilinearReverse</td>
2732 <td>
2733 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or
2734 16 values (see below). Not that lines may not appear straight after
2735 distortion, though the distance between coordinates will remain
Cristy594d2772015-11-15 10:47:42 -05002736 consistent. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002737
2738 The 'BilinearForward' is used to map rectangles to any
2739 quadrilateral, while the 'BilinearReverse' form maps any
2740 quadrilateral to a rectangle, while preserving the straight line edges
Cristy594d2772015-11-15 10:47:42 -05002741 in each case. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002742
2743 Note that 'BilinearForward' can generate invalid pixels
Cristyf650f4f2016-04-01 10:53:07 -04002744 which will be colored using the <a href="command-line-options.html#alpha-color" >-alpha-color</a>
Cristy882d9f42015-10-29 16:48:39 -04002745 color setting. Also if the quadrilateral becomes 'flipped' the image
Cristy594d2772015-11-15 10:47:42 -05002746 may disappear. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002747
2748 There are future plans to produce a true Bilinear distortion that will
2749 attempt to map any quadrilateral to any other quadrilateral, while
2750 preserving edges (and edge distance ratios).
2751
2752 </td>
2753 </tr>
2754
2755 <tr>
2756 <td>Perspective</td>
2757 <td>
2758 Perspective distort the images, using a list of 4 or more sets of
2759 control points (as defined below). More that 4 sets (16 numbers) of
2760 control points provide least squares fitting for more accurate
2761 distortions (for the purposes of image registration and panorama
2762 effects). Less than 4 sets will fall back to a 'Affine'
Cristy594d2772015-11-15 10:47:42 -05002763 linear distortion. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002764
2765 Perspective Distorted images ensures that straight lines remain
2766 straight, but the scale of the distorted image will vary. The horizon
2767 is anti-aliased, and the 'sky' color may be set using the
Cristyf650f4f2016-04-01 10:53:07 -04002768 <a href="command-line-options.html#alpha-color" >-alpha-color</a> setting. </td>
Cristy882d9f42015-10-29 16:48:39 -04002769 </tr>
2770
2771 <tr>
2772 <td>PerspectiveProjection </td>
2773 <td>
2774 Do a 'Perspective' distortion biased on a set of 8
2775 pre-calculated coefficients. You can get these coefficients by looking
Cristy594d2772015-11-15 10:47:42 -05002776 at the <a href="command-line-options.html#verbose" >-verbose</a> output of a
Cristy882d9f42015-10-29 16:48:39 -04002777 'Perspective' distortion, or by calculating them yourself.
2778 If the last two perspective scaling coefficients are zero, the
2779 remaining 6 represents a transposed 'Affine Matrix'. </td>
2780
2781 </tr>
2782
2783 <tr>
2784 <td>Arc</td>
2785 <td>
2786 Arc the image (variation of polar mapping) over the angle given around
2787 a circle.
2788
Cristy594d2772015-11-15 10:47:42 -05002789 <p><dl class="dl-horizontal">
Cristy882d9f42015-10-29 16:48:39 -04002790 <dt>arc_angle</dt>
2791 <dd>The angle over which to arc the image side-to-side</dd>
2792 <dt>rotate_angle</dt>
2793 <dd>Angle to rotate resulting image from vertical center</dd>
2794 <dt>top_radius</dt>
2795 <dd>Set top edge of source image at this radius</dd>
2796 <dt>bottom_radius </dt>
2797 <dd>Set bottom edge to this radius (radial scaling)</dd>
Cristy594d2772015-11-15 10:47:42 -05002798 </dl></p>
Cristy882d9f42015-10-29 16:48:39 -04002799
2800 The resulting image is always resized to best fit the resulting image,
Cristy594d2772015-11-15 10:47:42 -05002801 (as if using <a href="command-line-options.html#distort" >+distort</a>) while attempting to
Cristy882d9f42015-10-29 16:48:39 -04002802 preserve scale and aspect ratio of the original image as much as
2803 possible with the arguments given by the user. All four arguments will
Cristy594d2772015-11-15 10:47:42 -05002804 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002805
2806 This a variation of a polar distortion designed to try to preserve the
2807 aspect ratio of the image rather than direct Cartesian to Polar
2808 conversion. </td>
2809 </tr>
2810
2811 <tr>
2812 <td>Polar</td>
2813 <td>
2814 Like 'Arc' but do a complete Cartesian to Polar mapping of
2815 the image. that is the height of the input image is mapped to the
2816 radius limits, while the width is wrapped around between the
Cristy594d2772015-11-15 10:47:42 -05002817 angle limits. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002818
Cristy594d2772015-11-15 10:47:42 -05002819 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br/>
Cristy882d9f42015-10-29 16:48:39 -04002820
2821 All arguments are optional. With <var>Rmin</var> defaulting to zero, the
2822 center to the center of the image, and the angles going from -180 (top)
2823 to +180 (top). If <var>Rmax</var> is given the special value of
2824 '0', the the distance from the center to the nearest edge
2825 is used for the radius of the output image, which will ensure the whole
2826 image is visible (though scaled smaller). However a special value of
2827 '-1' will use the distance from the center to the furthest
2828 corner, This may 'clip' the corners from the input rectangular image,
2829 but will generate the exact reverse of a 'DePolar' with
Cristy594d2772015-11-15 10:47:42 -05002830 the same arguments. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002831
Cristy594d2772015-11-15 10:47:42 -05002832 If the plus form of distort (<a href="command-line-options.html#distort" >+distort</a>) is used
Cristy882d9f42015-10-29 16:48:39 -04002833 output image center will default to 0,0 of the virtual
2834 canvas, and the image size adjusted to ensure the whole input image is
2835 made visible in the output image on the virtual canvas. </td>
2836
2837 </tr>
2838
2839 <tr>
2840 <td>DePolar</td>
2841 <td>
2842 Uses the same arguments and meanings as a 'Polar' distortion
Cristy594d2772015-11-15 10:47:42 -05002843 but generates the reverse Polar to Cartesian distortion. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002844
2845 The special <var>Rmax</var> setting of '0' may however clip
2846 the corners of the input image. However using the special
2847 <var>Rmax</var> setting of '-1' (maximum center to corner
2848 distance) will ensure the whole distorted image is preserved in the
2849 generated result, so that the same argument to 'Polar' will
2850 reverse the distortion re-producing the original.
2851
2852 Note that as this distortion requires the area resampling of a circular
2853 arc, which can not be handled by the builtin EWA resampling function.
2854 As such the normal EWA filters are turned off. It is recommended some
2855 form of 'super-sampling' image processing technique be used to produce
2856 a high quality result. </td>
2857
2858 </tr>
2859
2860 <tr>
2861 <td>Barrel</td>
2862 <td>
Cristy594d2772015-11-15 10:47:42 -05002863 Given the four coefficients (A,B,C,D) as defined by <a
2864 href="http://wiki.panotools.org/Lens_correction_model" >Helmut
Cristy882d9f42015-10-29 16:48:39 -04002865 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to
2866 correct radial lens distortions. That is in photographs, make straight
Cristy594d2772015-11-15 10:47:42 -05002867 lines straight again. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002868
2869 <p class="text-center">Arguments: <var>A B C</var> [ <var>D</var> [
Cristy594d2772015-11-15 10:47:42 -05002870 <var>X</var> , <var>Y</var> ] ] <br/>
Cristy882d9f42015-10-29 16:48:39 -04002871 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub>
2872 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var>
2873 [ <var>X</var> , <var>Y</var> ] </p>
2874 So that it forms the function
2875 <p class="text-center">Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2876 <var>C</var>*r + <var>D</var> )</p>
2877
2878 Where <var>X</var>,<var>Y</var> is the optional center of the distortion
Cristy594d2772015-11-15 10:47:42 -05002879 (defaulting to the center of the image). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002880 The second form is typically used to distort images, rather than
Cristy594d2772015-11-15 10:47:42 -05002881 correct lens distortions. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002882 </td>
2883
2884 </tr>
2885
2886 <tr>
2887 <td>BarrelInverse</td>
2888 <td>
2889 This is very similar to 'Barrel' with the same set of
2890 arguments, and argument handling. However it uses the inverse
2891 of the radial polynomial,
2892 so that it forms the function
2893 <p class="text-center">Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2894 <var>C</var>*r + <var>D</var> )</p>
2895 Note that this is not the reverse of the 'Barrel'
2896 distortion, just a different barrel-like radial distortion method.
2897
2898 </td>
2899 </tr>
2900
2901 <tr>
2902 <td>Shepards</td>
2903 <td>
2904 Distort the given list control points (any number) using an Inverse
Cristy594d2772015-11-15 10:47:42 -05002905 Squared Distance Interpolation Method (<a
2906 href="http://en.wikipedia.org/wiki/Shepard%27s_method" >Shepards
Cristy882d9f42015-10-29 16:48:39 -04002907 Method</a>). The control points in effect do 'localized' displacement
2908 of the image around the given control point (preserving the look and
2909 the rotation of the area near the control points. For best results
2910 extra control points should be added to 'lock' the positions of the
2911 corners, edges and other unchanging parts of the image, to prevent
Cristy594d2772015-11-15 10:47:42 -05002912 their movement. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002913
2914 The distortion has been likened to 'taffy pulling' using nails, or
2915 pins' stuck in a block of 'jelly' which is then moved to the new
Cristy594d2772015-11-15 10:47:42 -05002916 position, distorting the surface of the jelly. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002917
Cristy594d2772015-11-15 10:47:42 -05002918 Internally it is equivalent to generating a displacement map (see <a
2919 href="command-line-options.html#displace" >-displace</a>) for source image color look-up using
2920 the <a href="command-line-options.html#sparse-color" >-sparse-color</a> method of the same name.
Cristy882d9f42015-10-29 16:48:39 -04002921
2922 </td>
2923 </tr>
2924
2925</table>
2926
2927<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list
2928distort</a>.</p>
2929
2930<p>Many of the above distortion methods such as '<code>Affine</code>',
2931'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points
2932defining how these points in the given image should be distorted in the
2933destination image. Each set of four floating point values represent a source
2934image coordinate, followed immediately by the destination image coordinate.
2935This produces a list of values such as...</p>
2936<p class="text-center"><var>
2937 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub>
2938 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub>
2939 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub>
2940 ...
2941 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub>
2942</var></p>
2943<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the
2944destination image. </p>
2945
2946<p>For example, to warp an image using '<code>perspective</code>' distortion,
2947needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
2948perspective distortion of the built-in "rose:" image. Note how spaces were
2949used to group the 4 sets of coordinate pairs, to make it easier to read and
2950understand.</p>
2951
2952<pre>
2953convert rose: -virtual-pixel black \
2954 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \
2955 rose_3d_rotated.gif"
2956</pre>
2957
2958<p>If more that the required number of coordinate pairs are given for
2959a distortion, the distortion method is 'least squares' fitted to produce the
2960best result for all the coordinate pairs given. If less than the ideal number
2961of points are given, the distort will generally fall back to a simpler form of
2962distortion that can handles the smaller number of coordinates (usually a linear
2963'<code>Affine</code>' distortion). </p>
2964
2965<p>By using more coordinates you can make use of image registration tool to
2966find matching coordinate pairs in overlapping images, so as to improve the
2967'fit' of the distortion. Of course a bad coordinate pair can also make the
2968'fit' worse. Caution is always advised. </p>
2969
2970<p>Colors are acquired from the source image according to a cylindrical
Cristy594d2772015-11-15 10:47:42 -05002971resampling <a href="command-line-options.html#filter" >-filter</a>, using a special technique known as
Cristy882d9f42015-10-29 16:48:39 -04002972EWA resampling. This produces very high quality results, especially when
2973images become smaller (minified) in the output, which is very common when
2974using '<code>perspective</code>' distortion. For example here we view
2975a infinitely tiled 'plane' all the way to the horizon. </p>
2976
2977<pre>
2978convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \
2979 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \
2980 checks_tiled.jpg
2981</pre>
2982
2983<p>Note that a infinitely tiled perspective images involving the horizon can
2984be very slow, because of the number of pixels that are compressed to generate
2985each individual pixel close to the 'horizon'. You can turn off EWA
Cristy594d2772015-11-15 10:47:42 -05002986resampling, by specifying the special <a href="command-line-options.html#filter" >-filter</a> setting of
Cristy882d9f42015-10-29 16:48:39 -04002987'<code>point</code>' (recommended if you plan to use super-sampling instead).
2988</p>
2989
2990<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
Cristy594d2772015-11-15 10:47:42 -05002991example, <a href="command-line-options.html#distort" >-distort</a> will use the current <a
Cristyf650f4f2016-04-01 10:53:07 -04002992href="command-line-options.html#alpha-color" >-alpha-color</a> setting for these pixels. If you do not
Cristy882d9f42015-10-29 16:48:39 -04002993what these pixels to be visible, set the color to match the rest of the
2994ground. </p>
2995
2996<p>The output image size will by default be the same as the input image. This
2997means that if the part of the distorted image falls outside the viewed area of
2998the 'distorted space', those parts is clipped and lost. However if you use
Cristy594d2772015-11-15 10:47:42 -05002999the plus form of the operator (<a href="command-line-options.html#distort" >+distort</a>) the operator
Cristy882d9f42015-10-29 16:48:39 -04003000will attempt (if possible) to show the whole of the distorted image, while
3001retaining a correct 'virtual canvas' offset, for image layering. This offset
Cristy594d2772015-11-15 10:47:42 -05003002may need to be removed using <a href="command-line-options.html#repage" >+repage</a>, to remove if it
Cristy882d9f42015-10-29 16:48:39 -04003003is unwanted. </p>
3004
Cristy594d2772015-11-15 10:47:42 -05003005<p>Setting <a href="command-line-options.html#verbose" >-verbose</a> setting, will cause <a
3006href="command-line-options.html#distort" >-distort</a> to attempt to output the internal coefficients,
3007and the <a href="command-line-options.html#fx" >-fx</a> equivalent to the distortion, for expert study,
Cristy882d9f42015-10-29 16:48:39 -04003008and debugging purposes. This many not be available for all distorts. </p>
3009
Cristy594d2772015-11-15 10:47:42 -05003010<p>You can alternatively specify a special "<code><a href="command-line-options.html#define"
3011>-define</a> distort:viewport={geometry_string}</code>" setting which will
Cristy882d9f42015-10-29 16:48:39 -04003012specify the size and the offset of the generated 'viewport' image of the
3013distorted image space.</p>
3014
Cristy594d2772015-11-15 10:47:42 -05003015<p>Setting a "<code><a href="command-line-options.html#define" >-define</a>
Cristy769d8892016-01-19 18:11:14 -05003016distort:scale=<var>scale_factor</var></code>" will scale the output image (viewport or
Cristy882d9f42015-10-29 16:48:39 -04003017otherwise) by that factor without changing the viewed contents of the
3018distorted image. This can be used either for 'super-sampling' the image for
3019a higher quality result, or for panning and zooming around the image (with
3020appropriate viewport changes, or post-distort cropping and resizing). </p>
3021
Cristy594d2772015-11-15 10:47:42 -05003022<p>Setting "<code><a href="command-line-options.html#define" >-define</a> resample:verbose=1</code>"
Cristy882d9f42015-10-29 16:48:39 -04003023will output the cylindrical filter lookup table created by the EWA (Elliptical
3024Weighted Average) resampling algorithm. Note this table uses a squared radius
3025lookup value. This is typically only used for debugging EWA resampling. </p>
3026
3027
3028<div style="margin: auto;">
3029 <h3 class="magick-header"><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3>
3030</div>
3031
3032<p class="magick-description">launch a distributed pixel cache server. </p>
3033
3034<div style="margin: auto;">
3035 <h3 class="magick-header"><a id="dither"></a>-dither <var>method</var></h3>
3036</div>
3037
3038<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to
3039images when general color reduction is applied via an option, or automagically
3040when saving to specific formats. This enabled by default.</p>
3041
3042<p>Dithering places two or more colors in neighboring pixels so that to the
3043eye a closer approximation of the images original color is reproduced. This
3044reduces the number of colors needed to reproduce the image but at the cost of
3045a lower level pattern of colors. Error diffusion dithers can use any set of
3046colors (generated or user defined) to an image. </p>
3047
3048<p>Dithering is turned on by default, to turn it off use the plus form of the
3049setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript
3050without text or graphic aliasing. Disabling dithering often (but not always)
3051leads to faster process, a smaller number of colors, but more cartoon like
3052image coloring. Generally resulting in 'color banding' effects in areas with
3053color gradients. </p>
3054
Cristy594d2772015-11-15 10:47:42 -05003055<p>The color reduction operators <a href="command-line-options.html#colors">-colors</a>, <a
3056href="command-line-options.html#monochrome">-monochrome</a>, <a href="command-line-options.html#remap ">-remap</a>, and <a
3057href="command-line-options.html#posterize">-posterize</a>, apply dithering to images using the reduced
Cristy882d9f42015-10-29 16:48:39 -04003058color set they created. These operators are also used as part of automatic
3059color reduction when saving images to formats with limited color support, such
3060as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used
3061in these cases. </p>
3062
3063<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a>
Cristy594d2772015-11-15 10:47:42 -05003064to generate purely random dither. Or use <a
3065href="command-line-options.html#ordered-dither">-ordered-dither</a> to apply threshold mapped dither
Cristy882d9f42015-10-29 16:48:39 -04003066patterns, using uniform color maps, rather than specific color maps. </p>
3067
3068
3069<div style="margin: auto;">
3070 <h3 class="magick-header"><a id="draw"></a>-draw <var>string</var></h3>
3071</div>
3072
3073<p class="magick-description">Annotate an image with one or more graphic primitives.</p>
3074
3075<p>Use this option to annotate or decorate an image with one or more graphic
3076primitives. The primitives include shapes, text, transformations, and pixel
3077operations.</p>
3078
3079<p>The shape primitives:</p>
3080
3081<dl class="dl-horizontal">
3082<dt>point</dt><dd> x,y</dd>
3083<dt>line</dt><dd> x0,y0 x1,y1</dd>
3084<dt>rectangle</dt><dd> x0,y0 x1,y1</dd>
3085<dt>roundRectangle</dt><dd> x0,y0 x1,y1 wc,hc</dd>
3086<dt>arc</dt><dd> x0,y0 x1,y1 a0,a1</dd>
3087<dt>ellipse</dt><dd> x0,y0 rx,ry a0,a1</dd>
3088<dt>circle</dt><dd> x0,y0 x1,y1</dd>
3089<dt>polyline</dt><dd> x0,y0 ... xn,yn</dd>
3090<dt>polygon</dt><dd> x0,y0 ... xn,yn</dd>
3091<dt>bezier</dt><dd> x0,y0 ... xn,yn</dd>
3092<dt>path</dt><dd>specification </dd>
3093<dt>image</dt><dd> operator x0,y0 w,h filename</dd>
3094</dl>
3095
3096<p>The text primitive:</p>
3097
3098<dl class="dl-horizontal">
3099<dt>text</dt><dd>x0,y0 string</dd>
3100</dl>
3101<p>The text gravity primitive:</p>
3102
3103<dl class="dl-horizontal">
3104<dt>gravity</dt><dd>NorthWest, North, NorthEast, West, Center, East, SouthWest, South, or SouthEast</dd>
3105</dl>
3106
3107<p>The text gravity primitive only affects the placement of text and does not
Cristy594d2772015-11-15 10:47:42 -05003108interact with the other primitives. It is equivalent to using the <a
3109href="command-line-options.html#gravity">-gravity</a> command-line option, except that it is limited in
Cristy882d9f42015-10-29 16:48:39 -04003110scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p>
3111
3112<p>The transformation primitives:</p>
3113
3114<dl class="dl-horizontal">
3115<dt>rotate</dt><dd>degrees</dd>
3116<dt>translate</dt><dd>dx,dy</dd>
3117<dt>scale</dt><dd>sx,sy</dd>
3118<dt>skewX</dt><dd>degrees</dd>
3119<dt>skewY</dt><dd>degrees</dd>
3120</dl>
3121
3122<p>The pixel operation primitives:</p>
3123
3124<dl class="dl-horizontal">
3125<dt>color</dt><dd>x0,y0 method</dd>
3126<dt>matte</dt><dd>x0,y0 method</dd>
3127</dl>
3128
Cristy594d2772015-11-15 10:47:42 -05003129<p>The shape primitives are drawn in the color specified by the preceding <a
3130href="command-line-options.html#fill">-fill</a> setting. For unfilled shapes, use <a
3131href="command-line-options.html#fill">-fill none</a>. You can optionally control the stroke (the
3132"outline" of a shape) with the <a href="command-line-options.html#stroke">-stroke</a> and <a
3133href="command-line-options.html#strokewidth">-strokewidth</a> settings.</p>
Cristy882d9f42015-10-29 16:48:39 -04003134
3135<p>A <code>point</code> primitive is specified by a single <var>point</var> in the
3136pixel plane, that is, by an ordered pair of integer coordinates,
3137<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code>
Cristy594d2772015-11-15 10:47:42 -05003138primitive is not affected by <a href="command-line-options.html#stroke">-stroke</a> or <a
3139href="command-line-options.html#strokewidth">-strokewidth</a>.)</p>
Cristy882d9f42015-10-29 16:48:39 -04003140
3141<p>A <code>line</code> primitive requires a start point and end point.</p>
3142
3143<p>A <code>rectangle</code> primitive is specified by the pair of points at the
3144upper left and lower right corners.</p>
3145
3146<p>A <code>roundRectangle</code> primitive takes the same corner points as
3147a <code>rectangle</code> followed by the width and height of the rounded corners
3148to be removed.</p>
3149
3150<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled).
3151Give the center and any point on the perimeter (boundary).</p>
3152
3153<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in
3154to a given rectangle. An <code>arc</code> requires the two corners used for
3155<code>rectangle</code> (see above) followed by the start and end angles of the
3156arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end
3157points produced are then joined with a line segment and the resulting segment
3158of an ellipse is filled.</p>
3159
3160<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the
3161center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of
3162the ellipse) and start and end angles in degrees (e.g. 100,100 100,150
31630,360).</p>
3164
3165<p>The <code>polyline</code> and <code>polygon</code> primitives require three or
3166more points to define their perimeters. A <code>polyline</code> is simply
3167a <code>polygon</code> in which the final point is not stroked to the start
Cristy594d2772015-11-15 10:47:42 -05003168point. When unfilled, this is a <var>polygonal line</var>. If the <a
3169href="command-line-options.html#stroke">-stroke</a> setting is <code>none</code> (the default), then
Cristy882d9f42015-10-29 16:48:39 -04003170a <code>polyline</code> is identical to a <code>polygon</code>. </p>
3171
3172<p>A <var>coordinate</var> is a pair of integers separated by a space or
3173optional comma. </p>
3174
3175<p>As an example, to define a circle centered at 100,100 that extends to
3176150,150 use:</p>
3177
3178<pre>
3179-draw 'circle 100,100 150,150'
3180</pre>
3181
3182<p>The <code>Bezier</code> primitive creates a spline curve and requires three
3183or points to define its shape. The first and last points are the
3184<var>knots</var> and these points are attained by the curve, while any
3185intermediate coordinates are <var>control points</var>. If two control points
3186are specified, the line between each end knot and its sequentially respective
3187control point determines the tangent direction of the curve at that end. If
3188one control point is specified, the lines from the end knots to the one
3189control point determines the tangent directions of the curve at each end. If
3190more than two control points are specified, then the additional control points
3191act in combination to determine the intermediate shape of the curve. In order
3192to draw complex curves, it is highly recommended either to use the
3193<code>path</code> primitive or to draw multiple four-point bezier segments with
3194the start and end knots of each successive segment repeated. For example:</p>
3195
3196<pre>
3197-draw 'bezier 20,50 45,100 45,0 70,50'
3198-draw 'bezier 70,50 95,100 95,0 120,50'
3199</pre>
3200
3201<p>A <code>path</code> represents an outline of an object, defined in terms of
3202moveto (set a new current point), lineto (draw a straight line), curveto (draw
3203a Bezier curve), arc (elliptical or circular arc) and closepath (close the
3204current shape by drawing a line to the last moveto) elements. Compound paths
3205(i.e., a path with subpaths, each consisting of a single moveto followed by
3206one or more line or curve operations) are possible to allow effects such as
Cristy594d2772015-11-15 10:47:42 -05003207<var>donut holes</var> in objects. (See <a
3208href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p>
Cristy882d9f42015-10-29 16:48:39 -04003209
3210<p>Use <code>image</code> to composite an image with another image. Follow the
3211image keyword with the composite operator, image location, image size, and
3212filename:</p>
3213
3214<pre>
3215-draw 'image SrcOver 100,100 225,225 image.jpg'
3216</pre>
3217
3218<p>You can use 0,0 for the image size, which means to use the actual
3219dimensions found in the image header. Otherwise, it is scaled to the given
3220dimensions. See <a href="compose.html">Alpha Compositing</a> for
3221a detailed discussion of alpha composition methods that are available. </p>
3222
3223<p>The "special augmented compose operators" such as "dissolve" that require
3224arguments cannot be used at present with the <code>-draw image</code> option.
3225 </p>
3226
3227<p>Use <code>text</code> to annotate an image with text. Follow the text
3228coordinates with a string. If the string has embedded spaces, enclose it in
3229single or double quotes.</p>
3230
3231<p>For example, the following annotates the image with <code>Works like
3232magick!</code> for an image titled <code>bird.miff</code>. </p>
3233
3234<pre>
3235-draw "text 100,100 'Works like magick!' "
3236</pre>
3237
3238<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way
3239to annotate an image with text.</p>
3240
3241<p>The <code>rotate</code> primitive rotates subsequent shape primitives and
Cristy594d2772015-11-15 10:47:42 -05003242text primitives about the origin of the main image. If the <a
3243href="command-line-options.html#region">-region</a> option precedes the <a href="command-line-options.html#draw">-draw</a>
Cristy882d9f42015-10-29 16:48:39 -04003244option, the origin for transformations is the upper left corner of the
3245region.</p>
3246
3247<p>The <code>translate</code> primitive translates subsequent shape and text
3248primitives.</p>
3249
3250<p>The <code>scale</code> primitive scales them.</p>
3251
3252<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect
3253to the origin of the main image or the region.</p>
3254
3255<p>The transformations modify the current affine matrix, which is initialized
3256from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a>
3257option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a>
3258option. The initial affine matrix is not affected; that matrix is only changed
3259by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another
3260<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is
3261reinitialized from the initial affine matrix.</p>
3262
3263<p>Use the <code>color</code> primitive to change the color of a pixel to the
3264fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with
3265a method:</p>
3266
3267<pre>
3268point
3269replace
3270floodfill
3271filltoborder
3272reset
3273</pre>
3274
3275<p>Consider the target pixel as that specified by your coordinate. The
3276<code>point</code> method recolors the target pixel. The <code>replace</code>
3277method recolors any pixel that matches the color of the target pixel.
3278<code>Floodfill</code> recolors any pixel that matches the color of the target
3279pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor
3280pixel that is not the border color. Finally, <code>reset</code> recolors all
3281pixels.</p>
3282
3283<p>Use <code>matte</code> to the change the pixel matte value to transparent.
3284Follow the pixel coordinate with a method (see the <code>color</code> primitive
3285for a description of methods). The <code>point</code> method changes the matte
3286value of the target pixel. The <code>replace</code> method changes the matte
3287value of any pixel that matches the color of the target pixel.
3288<code>Floodfill</code> changes the matte value of any pixel that matches the
3289color of the target pixel and is a neighbor, whereas <code>filltoborder</code>
Cristy594d2772015-11-15 10:47:42 -05003290changes the matte value of any neighbor pixel that is not the border color (<a
3291href="command-line-options.html#bordercolor">-bordercolor</a>). Finally <code>reset</code> changes the
Cristy882d9f42015-10-29 16:48:39 -04003292matte value of all pixels.</p>
3293
Cristy594d2772015-11-15 10:47:42 -05003294<p>You can set the primitive color, font, and font bounding box color with <a
3295href="command-line-options.html#fill">-fill</a>, <a href="command-line-options.html#font">-font</a>, and <a href="command-line-options.html#box">-box</a>
Cristy882d9f42015-10-29 16:48:39 -04003296respectively. Options are processed in command line order so be sure to use
3297these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p>
3298
3299<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather
3300than 1.png).</p>
3301
Cristy594d2772015-11-15 10:47:42 -05003302<p>Drawing primitives conform to the <a href="magick-vector-graphics.html" >Magick
Cristy882d9f42015-10-29 16:48:39 -04003303Vector Graphics</a> format.</p>
3304
3305
3306<div style="margin: auto;">
3307 <h3 class="magick-header"><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3>
3308</div>
3309
3310<p class="magick-description">duplicate an image one or more times.</p>
3311
3312<p>Specify the count and the image to duplicate by its index in the sequence.
3313The first image is index 0. Negative indexes are relative to the end of the
3314sequence, for example, -1 represents the last image of the sequence. Specify
3315a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g.
33160,2). Use <code>+duplicate</code> to duplicate the last image in the current
3317image sequence.</p>
3318
3319<div style="margin: auto;">
3320 <h3 class="magick-header"><a id="edge"></a>-edge <var>radius</var></h3>
3321</div>
3322
3323<p class="magick-description">detect edges within an image.</p>
3324
3325<div style="margin: auto;">
3326 <h3 class="magick-header"><a id="emboss"></a>-emboss <var>radius</var></h3>
3327</div>
3328
3329<p class="magick-description">emboss an image.</p>
3330
3331<div style="margin: auto;">
3332 <h3 class="magick-header"><a id="encipher"></a>-encipher <var>filename</var></h3>
3333</div>
3334
3335<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p>
3336
3337<p>Get the passphrase from the file specified by <var>filename</var>.</p>
3338
Cristy594d2772015-11-15 10:47:42 -05003339<p>For more information, see the webpage, <a
3340href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or
Cristy882d9f42015-10-29 16:48:39 -04003341Decipher an Image</a>.</p>
3342
3343
3344
3345<div style="margin: auto;">
3346 <h3 class="magick-header"><a id="encoding"></a>-encoding <var>type</var></h3>
3347</div>
3348
3349<p class="magick-description">specify the text encoding.</p>
3350
3351<p>Choose from</p>
3352
3353<pre>
3354AdobeCustom AdobeExpert
3355AdobeStandard AppleRoman
3356BIG5 GB2312
3357Latin 2 None
3358SJIScode Symbol
3359Unicode Wansung
3360</pre>
3361
3362<div style="margin: auto;">
3363 <h3 class="magick-header"><a id="endian"></a>-endian <var>type</var></h3>
3364</div>
3365
3366<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p>
3367
3368<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p>
3369
3370<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p>
3371
3372
3373<div style="margin: auto;">
3374 <h3 class="magick-header"><a id="enhance"></a>-enhance</h3>
3375</div>
3376
3377<p class="magick-description">Apply a digital filter to enhance a noisy image.</p>
3378
3379
3380<div style="margin: auto;">
3381 <h3 class="magick-header"><a id="equalize"></a>-equalize</h3>
3382</div>
3383
3384<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p>
3385
3386<p>To perform histogram equalization on all channels in concert, transform the
3387image into some other color space, such as HSL, OHTA, YIQ or YUV, then
3388equalize the appropriate intensity-like channel, then convert back to RGB.</p>
3389
3390<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness
3391-equalize -colorspace RGB</code> ...</p>
3392
3393<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal
3394components transformation that puts most of the information in the first
3395channel. Here we have ... <code>-colorspace OHTA -channel red -equalize
3396-colorspace RGB</code> ...</p>
3397
3398<div style="margin: auto;">
3399 <h3 class="magick-header"><a id="evaluate"></a>-evaluate <var>operator value</var></h3>
3400</div>
3401
3402<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p>
3403
Cristy594d2772015-11-15 10:47:42 -05003404<p>(See the <a href="command-line-options.html#function" >-function</a> operator for some
3405multi-parameter functions. See the <a href="command-line-options.html#fx" >-fx</a> operator if more
Cristy882d9f42015-10-29 16:48:39 -04003406elaborate calculations are needed.)</p>
3407
3408<p>The behaviors of each <var>operator</var> are summarized in the
3409following list. For brevity, the numerical value of a "pixel" referred to
3410below is the value of the corresponding channel of that pixel, while
3411a "normalized pixel" is that number divided by the maximum
3412(installation-dependent) value <var>QuantumRange</var>. (If
3413normalized pixels are used, they are restored, following the other
3414calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p>
3415
3416<table class="table table-condensed table-striped">
Cristy594d2772015-11-15 10:47:42 -05003417 <col width="25%" />
3418 <col width="75%" />
Cristy882d9f42015-10-29 16:48:39 -04003419 <thead>
3420 <tr>
3421 <th><var>operator</var></th>
3422 <th>Summary (see further below for details)</th>
3423 </tr>
3424 </thead>
3425 <tbody>
3426
3427 <tr><td>Abs </td> <td>Add <var>value</var> to pixels and return absolute value. </td></tr>
3428 <tr><td>Add </td> <td>Add <var>value</var> to pixels. </td></tr>
3429 <tr><td>AddModulus </td> <td>Add <var>value</var> to pixels modulo <var>QuantumRange</var>.</td></tr>
3430 <tr><td>And </td> <td>Binary AND of pixels with <var>value</var>.</td></tr>
3431 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3432 <tr><td>Divide </td> <td>Divide pixels by <var>value</var>.</td></tr>
3433 <tr><td>Exp </td> <td>base-e exponential function</td></tr>
3434 <tr><td>Exponential </td> <td>base-e exponential function</td></tr>
3435 <tr><td>LeftShift </td> <td>Shift the pixel values left by <var>value</var> bits (i.e., multiply pixels by 2<sup><var>value</var></sup>).</td></tr>
3436 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
3437 <tr><td>Max </td> <td>Set pixels to maximum of <var>value</var> and current pixel <var>value</var> (i.e. set any pixels currently less than <var>value</var> to <var>value</var>).</td></tr>
3438 <tr><td>Mean </td> <td>Add the <var>value</var> and divide by 2.</td></tr>
3439 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr>
3440 <tr><td>Min </td> <td>Set pixels to minimum of <var>value</var> and current pixel <var>value</var> (i.e. set any pixels currently greater than <var>value</var> to <var>value</var>).</td></tr>
3441 <tr><td>Multiply </td> <td>Multiply pixels by <var>value</var>.</td></tr>
3442 <tr><td>Or </td> <td>Binary OR of pixels with <var>value</var>.</td></tr>
3443 <tr><td>Pow </td> <td>Raise normalized pixels to the power <var>value</var>.</td></tr>
3444 <tr><td>RightShift </td> <td>Shift the pixel values right by <var>value</var> bits (i.e., divide pixels by 2<sup><var>value</var></sup>).</td></tr>
3445 <tr><td>RMS</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3446 <tr><td>RootMeanSquare</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3447 <tr><td>Set </td> <td>Set pixel equal to <var>value</var>.</td></tr>
3448 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3449 <tr><td>Subtract </td> <td>Subtract <var>value</var> from pixels.</td></tr>
3450 <tr><td>Xor </td> <td>Binary XOR of pixels with <var>value.</var></td></tr>
3451
3452 <tr><td> </td><td> </td></tr>
3453
3454 <tr><td>Gaussian-noise</td><td> </td></tr>
3455 <tr><td>Impulse-noise</td><td> </td></tr>
3456 <tr><td>Laplacian-noise</td><td> </td></tr>
Cristy594d2772015-11-15 10:47:42 -05003457 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="command-line-options.html#noise" >-noise</a> operators.)</td></tr>
Cristy882d9f42015-10-29 16:48:39 -04003458 <tr><td>PoissonNoise</td><td> </td></tr>
3459 <tr><td>Uniform-noise</td><td> </td></tr>
3460
3461 <tr><td> </td><td> </td></tr>
3462
3463 <tr><td>Threshold </td> <td>Threshold pixels larger than <var>value</var>.</td></tr>
3464 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <var>value</var>.</td></tr>
3465 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <var>value</var>. </td></tr>
3466 </tbody>
3467 </table>
3468
Cristy594d2772015-11-15 10:47:42 -05003469<p>The specified functions are applied only to each previously set <a
3470href="command-line-options.html#channel" >-channel</a> in the image. If necessary, the results of the
Cristy882d9f42015-10-29 16:48:39 -04003471calculations are truncated (clipped) to fit in the interval [0, <var>QuantumRange</var>]. The transparency channel of the image is
3472represented as a 'alpha' values (0 = fully transparent), so, for example, a
3473<code>Divide</code> by 2 of the alpha channel will make the image
3474semi-transparent. Append the percent symbol '<code>%</code>' to specify a value
3475as a percentage of the <var>QuantumRange</var>.</p>
3476
3477<p>To print a complete list of <a href="command-line-options.html#evaluate">-evaluate</a> operators, use
3478<a href="command-line-options.html#list">-list evaluate</a>.</p>
3479
3480<p>The results of the <code>Add</code>, <code>Subtract</code> and
Cristy594d2772015-11-15 10:47:42 -05003481<code>Multiply</code> methods can also be achieved using either the <a
3482href="command-line-options.html#level" >-level</a> or the <a href="command-line-options.html#level" >+level</a> operator, with
Cristy882d9f42015-10-29 16:48:39 -04003483appropriate argument, to linearly modify the overall range of color values.
Cristy594d2772015-11-15 10:47:42 -05003484Please note, however, that <a href="command-line-options.html#level" >-level</a> treats transparency as
3485'matte' values (0 = opaque), while <a href="command-line-options.html#level" >-evaluate</a> works with
Cristy882d9f42015-10-29 16:48:39 -04003486'alpha' values.</p>
3487
3488<p><code>AddModulus</code> has been added as of ImageMagick 6.4.8-4 and provides
3489addition modulo the <var>QuantumRange</var>. It is therefore
3490equivalent to <code>Add</code> unless the resulting pixel value is outside the
3491interval [0, <var>QuantumRange</var>]. </p>
3492
3493<p><code>Exp or Exponential</code> has been added as of ImageMagick 6.6.5-1 and
3494works on normalized pixel values. The <var>value</var> used with
3495<code>Exp</code> should be negative so as to produce a decaying exponential
3496function. Non-negative values will always produce results larger unity and
3497thus outside the interval [0, <var>QuantumRange</var>]. The
3498formula is expressed below. </p>
3499
3500<p class="text-center">
3501exp(<var>value</var> × <b><var>u</var></b>)
3502</p>
3503
Cristy594d2772015-11-15 10:47:42 -05003504<p> If the input image is squared, for example, using <a href="command-line-options.html#-function"
3505>-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be
Cristy882d9f42015-10-29 16:48:39 -04003506the result.</p>
3507
3508<p><code>Log</code> has been added as of ImageMagick 6.4.2-1 and works on
3509normalized pixel values. This a <var>scaled</var> log function. The <var>value</var> used with <code>Log</code> provides a <var>scaling
3510factor</var> that adjusts the curvature in the graph of the log function. The
3511formula applied to a normalized value <b><var>u</var></b> is below. </p>
3512
3513<p class="text-center">
3514log(<var>value</var> × <b><var>u</var></b> + 1) / log(<var>value</var> + 1)
3515</p>
3516
3517<p><code>Pow</code> has been added as of ImageMagick 6.4.1-9, and works on
Cristy594d2772015-11-15 10:47:42 -05003518normalized pixel values. Note that <code>Pow</code> is related to the <a
3519href="command-line-options.html#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent
Cristy882d9f42015-10-29 16:48:39 -04003520to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
Cristy594d2772015-11-15 10:47:42 -05003521with <a href="command-line-options.html#gamma" >-gamma</a> is simply the reciprocal of the value used
Cristy882d9f42015-10-29 16:48:39 -04003522with <code>Pow</code>.</p>
3523
3524<p><code>Cosine</code> and <code>Sine</code> was added as of IM v6.4.8-8 and
3525converts the image values into a value according to a (co)sine wave function.
3526The synonyms <code>Cos</code> and <code>Sin</code> may also be used. The output
3527is biased 50% and normalized by 50% so as to fit in the respective color value
3528range. The <var>value</var> scaling of the <var>period</var> of the
3529function (its frequency), and thus determines the number of 'waves' that will
3530be generated over the input color range. For example, if the <var>value</var> is 1, the effective period is simply the <var>QuantumRange</var>; but if the <var>value</var> is 2,
3531then the effective period is the <var>half</var> the <var>QuantumRange</var>.</p>
3532
3533<p class="text-center">
35340.5 + 0.5 × cos(2 π <b><var>u</var></b> × <var>value</var>).
3535</p>
3536
Cristy594d2772015-11-15 10:47:42 -05003537<p>See also the <a href="command-line-options.html#function" >-function</a> operator, which is a
Cristy882d9f42015-10-29 16:48:39 -04003538multi-value version of evaluate. </p>
3539
3540<div style="margin: auto;">
3541 <h3 class="magick-header"><a id="evaluate-sequence"></a>-evaluate-sequence <var>operator</var></h3>
3542</div>
3543
3544<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or
3545logical expression over a sequence of images.</p>
3546
Cristy594d2772015-11-15 10:47:42 -05003547<p>To print a complete list of <a
3548href="command-line-options.html#evaluate-sequence">-evaluate-sequence</a> operators, use <a
3549href="command-line-options.html#list">-list evaluate</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003550
3551<div style="margin: auto;">
3552 <h3 class="magick-header"><a id="extent"></a>-extent <var>geometry</var></h3>
3553</div>
3554
3555<p class="magick-description">Set the image size and offset.</p>
3556
3557<p>If the image is enlarged, unfilled areas are set to the background color.
3558To position the image, use offsets in the <var>geometry</var>
3559specification or precede with a <a href="command-line-options.html#gravity">-gravity</a> setting. To
Cristy594d2772015-11-15 10:47:42 -05003560specify how to compose the image with the background, use <a href="command-line-options.html#compose"
3561>-compose</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003562
3563<p>This command reduces or expands a JPEG image to fit on an 800x600
3564display. If the aspect ratio of the input image isn't exactly 4:3, then the
3565image is centered on an 800x600 black canvas: </p>
3566
3567<pre>
3568convert input.jpg -resize 800x600 -background black -compose Copy \
3569 -gravity center -extent 800x600 -quality 92 output.jpg
3570</pre>
3571
3572<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3573
3574<div style="margin: auto;">
3575 <h3 class="magick-header"><a id="extract"></a>-extract <var>geometry</var></h3>
3576</div>
3577
3578<p class="magick-description">Extract the specified area from image.</p>
3579
3580<p>This option is most useful for extracting a subregion of a very large raw
3581image. Note that these two commands are equivalent:</p>
3582
3583<pre>
3584convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \
3585 image.rgb image.png",
3586convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \
3587 image.rgb image.png"
3588</pre>
3589
3590<p>If you omit the offsets, as in</p>
3591
3592<pre>
3593convert -size 16000x16000 -depth 8 -extract 640x480 \
3594 image.rgb image.png
3595</pre>
3596
3597<p>the image is <var>resized</var> to the specified dimensions instead,
3598equivalent to:</p>
3599
3600<pre>
3601convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png
3602</pre>
3603
3604<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3605
3606<div style="margin: auto;">
3607 <h3 class="magick-header"><a id="family"></a>-family <var>fontFamily</var></h3>
3608</div>
3609
3610<p class="magick-description">Set a font family for text.</p>
3611
3612<p>This setting suggests a font family that ImageMagick should try to use for
3613rendering text. If the family can be found it is used; if not, a default font
3614(e.g., "Arial") or a family known to be similar is substituted (e.g.,
3615"Courier" might be used if "System" is requested but not found). </p>
3616
Cristy594d2772015-11-15 10:47:42 -05003617<p>For other settings that affect fonts, see the options <a
3618href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a
3619href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04003620
3621<div style="margin: auto;">
3622 <h3 class="magick-header"><a id="features"></a>-features <var>distance</var></h3>
3623</div>
3624
3625<p class="magick-description">display (co-occurrence matrix) texture measure features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</p>
3626
3627<pre>
3628Angular Second Moment Sum Entropy
3629Contrast Entropy
3630Correlation Difference Variance
3631Sum of Squares Variance Difference Entropy
3632Inverse Difference Moment Information Measure of Correlation 1
3633Sum Average Information Measure of Correlation 2
3634Sum Variance Maximum Correlation Coefficient
3635</pre>
3636
3637<div style="margin: auto;">
3638 <h3 class="magick-header"><a id="fft"></a>-fft</h3>
3639</div>
3640
3641<p class="magick-description">implements the forward discrete Fourier transform (DFT).</p>
3642
3643<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
3644users in ImageMagick 6.6.0-9). It transforms an image from the normal
3645(spatial) domain to the frequency domain. In the frequency domain, an image is
3646represented as a superposition of complex sinusoidal waves of varying
3647amplitudes. The image x and y coordinates are the possible frequencies along
3648the x and y directions, respectively, and the pixel intensity values are
3649complex numbers that correspond to the sinusoidal wave amplitudes. See for
3650example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier
3651Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier
3652Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier
3653Transform</a>.</p>
3654
3655<p>A single image name is provided as output for this option. However, the
3656output result will have two components. It is either a two-frame image or two
3657separate images, depending upon whether the image format specified supports
3658multi-frame images. The reason that we get a dual output result is because the
3659frequency domain represents an image using complex numbers, which cannot be
3660visualized directly. Therefore, the complex values are automagically separated
3661into a two-component image representation. The first component is the
3662magnitude of the complex number and the second is the phase of the complex
Cristy594d2772015-11-15 10:47:42 -05003663number. See for example, <a
3664href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003665
3666<p>The magnitude and phase component images must be specified using image
3667formats that do not limit the color or compress the image. Thus, MIFF, TIF,
3668PFM, EXR and PNG are the recommended image formats to use. All of these
3669formats, except PNG support multi-frame images. So for example,</p>
3670
3671<pre>
3672convert image.png -fft fft_image.miff
3673</pre>
3674
3675<p>generates a magnitude image as <code>fft_image.miff[0]</code> and a phase
3676image as <code>fft_image.miff[1]</code>. Similarly,</p>
3677
3678<pre>
3679convert image.png -fft fft_image.png
3680</pre>
3681
3682<p>generates a magnitude image as <code>fft_image-0.png</code> and a phase image
3683as <code>fft_image-1.png</code>. If you prefer this representation, then you can
Cristy594d2772015-11-15 10:47:42 -05003684force any of the other formats to produce two output images by including <a
3685href="command-line-options.html#adjoin">+adjoin</a> following -fft in the command line.</p>
Cristy882d9f42015-10-29 16:48:39 -04003686
3687<p>The input image can be any size, but if not square and even-dimensioned, it
3688is padded automagically to the larger of the width or height of the input
3689image and to an even number of pixels. The padding will occur at the bottom
3690and/or right sides of the input image. The resulting output magnitude and
Cristy594d2772015-11-15 10:47:42 -05003691phase images is square at this size. The kind of padding relies on the <a
3692href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04003693
3694<p>Both output components will have dynamic ranges that fit within
3695[0, <var>QuantumRange</var>], so that HDRI need not be enabled.
3696Phase values nominally range from 0 to 2*π, but is scaled to span the full
3697dynamic range. (The first few releases had non-HDRI scaled but HDRI not
3698scaled). The magnitude image is not scaled and thus generally will contain
3699very small values. As such, the image normally will appear totally black. In
3700order to view any detail, the magnitude image typically is enhanced with a log
3701function into what is usually called the spectrum. A log function is used to
3702enhance the darker values more in comparison to the lighter values. This can
3703be done, for example, as follows:</p>
3704
3705<pre>
3706convert fft_image.miff[0] -contrast-stretch 0 \
3707 -evaluate log 1000 fft_image_spectrum.png"
3708</pre>
3709
Cristy594d2772015-11-15 10:47:42 -05003710<p>where either <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> 0 or <a
3711href="command-line-options.html#auto-level">-auto-level</a> is used to scale the image to full dynamic
Cristy882d9f42015-10-29 16:48:39 -04003712range, first. The argument to the <a href="command-line-options.html#evaluate">-evaluate</a> log
3713typically is specified between 100 and 10,000, depending upon the amount of
3714detail that one wants to bring out in the spectrum. Larger values produce more
3715visible detail. Too much detail, however, may hide the important features.</p>
3716
3717<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
3718use <a href="command-line-options.html#fft">-fft</a>.</p>
3719
3720<p>Use <a href="command-line-options.html#fft">+fft</a> to produce two output images that are the real
3721and imaginary components of the complex valued Fourier transform.</p>
3722
3723<p>However, as the real and imaginary components can contain negative values,
3724this requires that IM be configured with HDRI enabled. In this case, you must
3725use either MIFF, TIF, PFM or MPC formats for the real and imaginary component
3726results, since they are formats that preserve both negative and fractional
3727values without clipping them or truncating the fractional part. With either
3728MIFF or TIF, one should add -define quantum:format=32, to allow those image
3729types to work properly in HDRI mode without clipping.</p>
3730
Cristy594d2772015-11-15 10:47:42 -05003731<p>The real and imaginary component images resulting from <a
3732href="command-line-options.html#fft">+fft</a> are also square, even dimensioned images due to the same
Cristy882d9f42015-10-29 16:48:39 -04003733padding that was discussed above for the magnitude and phase component
3734images.</p>
3735
Cristy594d2772015-11-15 10:47:42 -05003736<p>See the discussion on HDRI implementations of ImageMagick on the page <a
3737href="high-dynamic-range.html" >High Dynamic-Range Images</a>. For more
3738about HDRI go the ImageMagick <a
3739href="http://www.imagemagick.org/Usage/basics/#hdri" >Usage</a> pages, <a
3740href="http://www.fmwconcepts.com/imagemagick/fourier_transforms/fourier.html"
3741>Fred's Fourier Processing With ImageMagick page</a> or this <a
3742 href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging" >Wikipedia</a>
Cristy882d9f42015-10-29 16:48:39 -04003743 entry. </p>
3744
Cristy594d2772015-11-15 10:47:42 -05003745<p>By default the FFT is normalized (and the IFT is not). Use "<code><a href="command-line-options.html#define" >-define</a> fourier:normalize=forward</code> to explicitly normalize the FFT and unnormalize the IFT.</p>
Cristy882d9f42015-10-29 16:48:39 -04003746
3747
3748<div style="margin: auto;">
3749 <h3 class="magick-header"><a id="fill"></a>-fill <var>color</var></h3>
3750</div>
3751
3752<p class="magick-description">color to use when filling a graphic primitive.</p>
3753
3754<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA,
Cristy594d2772015-11-15 10:47:42 -05003755HSL, HSLA, CMYK, or CMYKA specification. See <a href="color.html" >Color Names</a> for
Cristy882d9f42015-10-29 16:48:39 -04003756a description of how to properly specify the color argument.</p>
3757
3758<p>Enclose the color specification in quotation marks to prevent the "#" or
3759the parentheses from being interpreted by your shell.</p>
3760
3761<p>For example,</p>
3762
3763<pre>
3764-fill blue
3765-fill "#ddddff"
3766-fill "rgb(255,255,255)"
3767</pre>
3768
3769<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
3770
3771<p>To print a complete list of color names, use the <a href="command-line-options.html#list">-list color</a> option.</p>
3772
3773<div style="margin: auto;">
3774 <h3 class="magick-header"><a id="filter"></a>-filter <var>type</var></h3>
3775</div>
3776
3777<p class="magick-description">Use this <var>type</var> of filter when resizing or distorting an image.</p>
3778
3779<p>Use this option to affect the resizing operation of an image during
Cristy594d2772015-11-15 10:47:42 -05003780operations such as <a href="command-line-options.html#resize">-resize</a> and <a href="command-line-options.html#distort"
3781>-distort</a>. For example you can use a simple resize filter such as:</p>
Cristy882d9f42015-10-29 16:48:39 -04003782
3783<pre>
3784Point Hermite Cubic
3785Box Gaussian Catrom
3786Triangle Quadratic Mitchell
3787</pre>
3788
3789<p>The <code>Bessel</code> and <code>Sinc</code> filter is also provided (as well
3790as a faster <code>SincFast</code> equivalent form). However these filters are
3791generally useless on their own as they are infinite filters that are being
3792clipped to the filters support size. Their direct use is not recommended
3793except via expert settings (see below). </p>
3794
3795<p>Instead these special filter functions are typically windowed by a windowing
Cristy594d2772015-11-15 10:47:42 -05003796function that the <a href="command-line-options.html#filter" >-filter</a> setting defines. That is
Cristy882d9f42015-10-29 16:48:39 -04003797using these functions will define a 'Windowed' filter, appropriate to the
3798operator involved. Windowed filters include: </p>
3799
3800<pre>
3801Lanczos Hamming Parzen
3802Blackman Kaiser Welsh
3803Hanning Bartlett Bohman
3804</pre>
3805
3806<p>Also one special self-windowing filter is also provided
3807<code>Lagrange</code>, which will automagically re-adjust its function depending
3808on the current 'support' or 'lobes' expert settings (see below).</p>
3809
3810<p>If you do not select a filter with this option, the filter defaults to
3811<code>Mitchell</code> for a colormapped image, an image with a matte channel, or
3812if the image is enlarged. Otherwise the filter default to
3813<code>Lanczos</code>.</p>
3814
3815<p>To print a complete list of resize filters, use the <a href="command-line-options.html#list">-list
3816filter</a> option.</p>
3817
3818<p>You can modify how the filter behaves as it scales your image through the
Cristy594d2772015-11-15 10:47:42 -05003819use of these expert settings (see also <a href="command-line-options.html#define" >-define</a> and <a
3820href="command-line-options.html#set" >-set</a>):-</p>
Cristy882d9f42015-10-29 16:48:39 -04003821
3822<table class="table table-condensed table-striped">
3823 <tr>
3824 <td>-define filter:blur=<var>factor</var></td>
3825 <td>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
3826 blurry or &lt; 1.0 for sharp. This should only be used with Gaussian and
3827 Gaussian-like filters simple filters, or you may not get the expected
3828 results. </td>
3829 </tr>
3830
3831 <tr>
3832 <td>-define filter:support=<var>radius</var></td>
3833 <td>Set the filter support radius. Defines how large the filter should be and
3834 thus directly defines how slow the filtered resampling process is. All
3835 filters have a default 'preferred' support size. Some filters like
3836 <code>Lagrange</code> and windowed filters adjust themselves depending on
3837 this value. With simple filters this value either does nothing (but slow
3838 the resampling), or will clip the filter function in a detrimental way.
3839 </td>
3840 </tr>
3841
3842 <tr>
3843 <td>-define filter:lobes=<var>count</var></td>
3844 <td>Set the number of lobes to use for the Sinc/Bessel filter. This an
3845 alternative way of specifying the 'support' range of the filter, that is
3846 designed to be more suited to windowed filters, especially when used for
3847 image distorts.</td>
3848 </tr>
3849
3850 <tr>
3851 <td>-define filter:sigma=<var>value</var></td>
3852 <td>The 'sigma' value used to define the <code>Gaussian</code> filter. Default
3853 sigma value is '<code>0.5</code>'. It only effects <code>Gaussian</code> but
3854 does not shrink (but may enlarge) the filter's 'support'. It can be used
3855 to generate very small blurs but without the filter 'missing' pixels due
3856 to using a small support setting. A larger value of '<code>0.707</code>'
3857 (a value of '1/sqrt(2)') is another common setting. </td>
3858 </tr>
3859
3860 <tr>
3861 <td>-define filter:b=<var>b-spline_factor</var></td>
Cristy594d2772015-11-15 10:47:42 -05003862 <tr>
Cristy882d9f42015-10-29 16:48:39 -04003863 <td>-define filter:c=<var>keys_alpha_factor</var></td>
3864 <td>Redefine the values used for cubic filters such as <code>Cubic</code>,
3865 <code>Catrom</code>, <code>Mitchel</code>, and <code>Hermite</code>, as well as
3866 the <code>Parzen</code> cubic windowing function. If only one of the values
3867 are defined, the other is set so as to generate a 'Cubic-Keys' filter.
3868 The values meaning was defined by a research paper by
3869 Mitchell-Netravali.</td>
3870 </tr>
3871
3872 <tr>
3873 <td>-define filter:kaiser-beta=<var>value</var></td>
3874 <td>The 'alpha' value used to as part of the Kaiser Windowing function.
3875 Default value is '6.5'. It only effects Kaiser windowing function, and
3876 does not effect any other attributes.
3877 Before ImageMagick v6.7.6-10, this option was known as "filter:alpha", (an
3878 inheritance from the very old "zoom" program). It was changed to bring the
3879 function in line with more modern academic research usage, and better
3880 assign it be more definitive. </td>
3881 </tr>
3882
3883 <tr>
3884 <td>-define filter:kaiser-alpha=<var>value</var></td>
3885 <td>This value when multiplied by 'PI' is equivalent to "kaiser-beta", and
3886 will override that setting. It only effects Kaiser windowing function,
3887 and does not effect any other attributes. </td>
3888 </tr>
3889
3890 <tr>
3891 <td>-define filter:filter=<var>filter_function</var></td>
3892 <td>Use this function directly as the weighting filter. This will allow
3893 you to directly use a windowing function such as <code>Blackman</code>,
3894 as a resampling filter, rather than as its normal usage as a windowing
3895 function. If defined, no windowing function also defined, the window function is set
3896 to <code>Box</code>). Directly specifying <code>Sinc</code> or <code>Jinc</code>
3897 as a filter will also do this. </td>
3898 </tr>
3899
3900 <tr>
3901 <td>-define filter:window=<var>filter_function</var></td>
3902 <td>The IIR (infinite impulse response) filters <code>Sinc</code> and
3903 <code>Jinc</code> are windowed (brought down to zero over the defined
3904 support range) with the given filter. This allows you to specify a filter
3905 function to be used as a windowing function for these IIR filters.
3906 Many of the defined filters are actually windowing functions for these IIR
3907 filters. A typical choices is <code>Box</code>, (which effectively turns
3908 off the windowing function). </td>
3909 </tr>
3910
3911 <tr>
3912 <td>-define filter:win-support=<var>radius</var></td>
3913 <td>Scale windowing function to this size instead. This causes the windowing
3914 (or self-windowing Lagrange filter) to act is if the support window is
3915 larger than what is actually supplied to the calling operator. The filter
3916 however is still clipped to the real support size given. If unset this
3917 will equal the normal filter support size. </td>
3918 </tr>
3919
3920 <tr>
3921 <td>-define filter:verbose=<var>1</var></td>
3922 <td>This causes IM to print information on the final internal filter
3923 selection to standard output. This includes a commented header on the
3924 filter settings being used, and data allowing the filter weights to be
3925 easily graphed. Note however that some filters are internally defined in terms of other filters. The <code>Lanczos</code> filter for example is defined in terms of
3926 a <code>SincFast</code> windowed <code>SincFast</code> filter, while
3927 <code>Mitchell</code> is defined as a general <code>Cubic</code> family filter
3928 with specific 'B' and 'C' settings. </td>
3929 </tr>
3930
3931</table>
3932
3933<p>For example, to get a 8 lobe jinc windowed sinc filter (Genseng filter?):</p>
3934
3935<pre>
3936convert image.png \
3937 -filter sinc \
3938 -set filter:window=jinc \
3939 -set filter:lobes=8 \
3940 -resize 150% image.jpg"
3941</pre>
3942
3943<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
3944
3945<pre>
3946convert image.png \
3947 -set filter:filter=sinc \
3948 -set filter:lobes=4 \
3949 -resize 150% image.jpg"
3950</pre>
3951
3952<p>To extract the data for a raw windowing function, combine it with
3953a '<code>Box</code>' filter. For example the '<code>Welch</code> parabolic
3954windowing function. </p>
3955
3956<pre>
3957convert null: -define filter:filter=Box \
3958 -define filter:window=Welch \
3959 -define filter:support=1.0 \
3960 -define filter:verbose=1 \
Cristy594d2772015-11-15 10:47:42 -05003961 -resize 2 null: > window_welch.dat
Cristy882d9f42015-10-29 16:48:39 -04003962gnuplot
3963 set grid
3964 plot \"window_welch.dat\" with lines
3965</pre>
3966
3967<p>Note that the use of expert options is provided for image processing experts
3968who have studied and understand how resize filters work. Without this
3969knowledge, and an understanding of the definition of the actual filters
3970involved, using expert settings are more likely to be detrimental to your image
3971resizing.</p>
3972
3973
3974<div style="margin: auto;">
3975 <h3 class="magick-header"><a id="flatten"></a>-flatten</h3>
3976</div>
3977
Cristy594d2772015-11-15 10:47:42 -05003978<p class="magick-description">This is a simple alias for the <a href="command-line-options.html#layers" >-layers</a> method "flatten".</p>
Cristy882d9f42015-10-29 16:48:39 -04003979
3980
3981<div style="margin: auto;">
3982 <h3 class="magick-header"><a id="flip"></a>-flip</h3>
3983</div>
3984
3985<p class="magick-description">create a <var>mirror image</var></p>
3986
3987<p>reflect the scanlines in the vertical direction. The image will be mirrored
3988upside-down. </p>
3989
3990
3991<div style="margin: auto;">
3992 <h3 class="magick-header"><a id="floodfill"></a>-floodfill {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var> <var>color</var></h3>
3993</div>
3994
3995<p class="magick-description">floodfill the image with color at the specified offset.</p>
3996
3997<p>Flood fill starts from the given 'seed point' which is not gravity effected.
Cristy594d2772015-11-15 10:47:42 -05003998Any color that matches within <a href="command-line-options.html#fuzz" >-fuzz</a> color distance of the
Cristy882d9f42015-10-29 16:48:39 -04003999given <var>color</var> argument, connected to that 'seed point'
Cristy594d2772015-11-15 10:47:42 -05004000will be replaced with the current <a href="command-line-options.html#fill" >-fill</a> color. </p>
Cristy882d9f42015-10-29 16:48:39 -04004001
4002<p>Note that if the pixel at the 'seed point' does not itself match the given
Cristy594d2772015-11-15 10:47:42 -05004003<var>color</var> (according to <a href="command-line-options.html#fuzz" >-fuzz</a>), then no
Cristy882d9f42015-10-29 16:48:39 -04004004action will be taken. </p>
4005
Cristy594d2772015-11-15 10:47:42 -05004006<p>This operator works more like the <a href="command-line-options.html#opaque" >-opaque</a> option, than
Cristy882d9f42015-10-29 16:48:39 -04004007a more general flood fill that reads the matching color directly at the 'seed
Cristy594d2772015-11-15 10:47:42 -05004008point'. For this form of flood fill, look at <a href="command-line-options.html#draw" >-draw</a> and
Cristy882d9f42015-10-29 16:48:39 -04004009its 'color floodfill' drawing method. </p>
4010
4011
4012<div style="margin: auto;">
4013 <h3 class="magick-header"><a id="flop"></a>-flop</h3>
4014</div>
4015
4016<p class="magick-description">create a <var>mirror image</var>.</p>
4017
4018<p>Reflect the scanlines in the horizontal direction, just like the image in
4019a vertical mirror. </p>
4020
4021
4022<div style="margin: auto;">
4023 <h3 class="magick-header"><a id="font"></a>-font <var>name</var></h3>
4024</div>
4025
4026<p class="magick-description">set the font to use when annotating images with text, or creating labels.</p>
4027
4028<p>To print a complete list of fonts, use the <a href="command-line-options.html#list">-list font</a>
4029option (for versions prior to 6.3.6, use 'type' instead of 'font').</p>
4030
4031<p>In addition to the fonts specified by the above pre-defined list, you can
4032also specify a font from a specific source. For example <code>Arial.ttf</code>
4033is a TrueType font file, <code>ps:helvetica</code> is PostScript font, and
4034<code>x:fixed</code> is X11 font.</p>
4035
Cristy594d2772015-11-15 10:47:42 -05004036<p>For other settings that affect fonts, see the options <a
4037href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a
4038href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04004039
4040
4041<div style="margin: auto;">
4042 <h3 class="magick-header"><a id="foreground"></a>-foreground <var>color</var></h3>
4043</div>
4044
4045<p class="magick-description">Define the foreground color for menus.", "display</p>
4046
Cristy594d2772015-11-15 10:47:42 -05004047<p>The color is specified using the format described under the <a
4048href="command-line-options.html#fill">-fill</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04004049
4050<p>The default foreground color is black.</p>
4051
4052<div style="margin: auto;">
4053 <h3 class="magick-header"><a id="format"></a>-format <var>type</var></h3>
4054</div>
4055
4056<p class="magick-description">the image format type.</p>
4057
4058<p>When used with the <code>mogrify</code> utility, this option converts any
4059image to the image <a href="formats.html">format</a> you specify.
Cristy594d2772015-11-15 10:47:42 -05004060For a list of image format types supported by ImageMagick, use <a
4061href="command-line-options.html#list">-list format</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04004062
4063<p>By default the file is written to its original name. However, if the
4064filename extension matches a supported format, the extension is replaced with
4065the image format type specified with <a href="command-line-options.html#format">-format</a>. For
4066example, if you specify <var>tiff</var> as the format type and the
4067input image filename is <var>image.gif</var>, the output image
4068filename becomes <var>image.tiff</var>.</p>
4069
4070<div style="margin: auto;">
4071 <h3 class="magick-header"><a id="format_identify_"></a>-format <var>string</var></h3>
4072</div>
4073
4074<p class="magick-description">output formatted image characteristics.</p>
4075
4076<p>See <a href="escape.html">Format and Print Image
4077Properties</a> for an explanation on how to specify the argument to this
4078option.</p>
4079
4080<div style="margin: auto;">
4081 <h3 class="magick-header"><a id="frame"></a>-frame <var>geometry</var></h3>
4082</div>
4083
4084<p class="magick-description">Surround the image with a border or beveled frame.</p>
4085
Cristyf650f4f2016-04-01 10:53:07 -04004086<p>The color of the border is specified with the <a href="command-line-options.html#alpha-color"
4087>-alpha-color</a> command line option. </p>
Cristy882d9f42015-10-29 16:48:39 -04004088
4089<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>size</var> portion of the <var>geometry</var> argument indicates the amount of extra width and
4090height that is added to the dimensions of the image. If no offsets are given
4091in the <var>geometry</var> argument, then the border added is
4092a solid color. Offsets <var>x</var> and <var>y</var>, if present, specify that
4093the width and height of the border is partitioned to form an outer bevel of
4094thickness <var>x</var> pixels and an inner bevel of thickness
4095<var>y</var> pixels. Negative offsets make no sense as frame arguments.
4096</p>
4097
Cristy594d2772015-11-15 10:47:42 -05004098<p>The <a href="command-line-options.html#frame">-frame</a> option is affected by the current <a
4099href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
Cristy882d9f42015-10-29 16:48:39 -04004100'<code>Over</code>' composition method. It generates an image of the appropriate
4101size with the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting, and then
Cristy594d2772015-11-15 10:47:42 -05004102draws the frame of four distinct colors close to the current <a
Cristyf650f4f2016-04-01 10:53:07 -04004103href="command-line-options.html#alpha-color">-alpha-color</a>. The original image is then overlaid onto
Cristy882d9f42015-10-29 16:48:39 -04004104center of this image. This means that with the default compose method of
Cristy594d2772015-11-15 10:47:42 -05004105'<code>Over</code>' any transparent parts may be replaced by the current <a
4106href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04004107
4108<p>The image composition is not
4109affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p>
4110
4111
4112<div style="margin: auto;">
4113 <h3 class="magick-header"><a id="frame_import_"></a>-frame</h3>
4114</div>
4115
4116<p class="magick-description">include the X window frame in the imported image. </p>
4117<div style="margin: auto;">
4118 <h3 class="magick-header"><a id="function"></a>-function <var>function</var> <var>parameters</var></h3>
4119</div>
4120
4121<p class="magick-description">Apply a function to channel values.</p>
4122
4123<p>This operator performs calculations based on the given arguments to modify
Cristy594d2772015-11-15 10:47:42 -05004124each of the color values for each previously set <a
4125href="command-line-options.html#channel">-channel</a> in the image. See <a
4126href="command-line-options.html#evaluate">-evaluate</a> for details concerning how the results of the
Cristy882d9f42015-10-29 16:48:39 -04004127calculations are handled.</p>
4128
Cristy594d2772015-11-15 10:47:42 -05004129<p>This is can be considered a multi-argument version of the <a
4130href="command-line-options.html#evaluate">-evaluate</a> operator. (Added in
Cristy882d9f42015-10-29 16:48:39 -04004131ImageMagick 6.4.8−8.)</p>
4132
4133<p>Here, <var>parameters</var> is a comma-separated list of
4134numerical values. The number of values varies depending on which <var>function</var> is selected. Choose the <var>function</var> from:</p>
4135
4136<pre>
4137Polynomial
4138Sinusoid
4139Arcsin
4140Arctan
4141</pre>
4142
4143<p>To print a complete list of <a href="command-line-options.html#function">-function</a> operators,
4144use <a href="command-line-options.html#list">-list function</a>. Descriptions follow.</p>
4145
4146<dl class="dl-horizontal">
4147 <dt>Polynomial</dt>
4148 <dd><p>The <code>Polynomial</code> function takes an arbitrary number of parameters,
4149these being the coefficients of a polynomial, in decreasing order of degree.
4150That is, entering</p>
4151
4152<pre>
4153-function Polynomial <var>a</var><sub><var>n</var></sub>,<var>a</var><sub><var>n</var>-1</sub>,...<var>a</var><sub>1</sub>,<var>a</var><sub>0</sub>
4154</pre>
4155
4156<p>will invoke a polynomial function given by</p>
4157
4158<pre>
4159<var>a</var><sub><var>n</var></sub> <b><var>u</var></b><sup><var>n</var></sup> + <var>a</var><sub><var>n</var>-1</sub> <b><var>u</var></b><sup><var>n</var>-1</sup> + ··· <var>a</var><sub>1</sub> <b><var>u</var></b> + <var>a</var><sub>0</sub>,
4160</pre>
4161
4162<p>where <b><var>u</var></b> is pixel's original normalized channel value.</p>
4163
4164<p>The <code>Polynomial</code> function can be used in place of <code>Set</code>
4165(the <var>constant</var> polynomial) and <code>Add</code>, <code>Divide</code>,
4166<code>Multiply</code>, and <code>Subtract</code> (some <var>linear</var>
Cristy594d2772015-11-15 10:47:42 -05004167polynomials) of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. The <a
4168href="command-line-options.html#level">-level</a> operator also affects channels linearly. Some
Cristy882d9f42015-10-29 16:48:39 -04004169correspondences follow.</p>
4170
4171<table class="table table-condensed table-striped">
4172 <tr>
4173 <td>-evaluate Set <var>value</var> </td>
4174 <td>-function Polynomial <var>value</var></td>
4175 <td>(Constant functions; set <var>value</var>×100% gray when channels are RGB.)</td>
4176 </tr>
4177 <tr>
4178 <td>-evaluate Add <var>value</var> </td>
4179 <td>-function Polynomial 1,<var>value</var></td>
4180 </tr>
4181 <tr>
4182 <td>-evaluate Subtract <var>value</var> </td>
4183 <td>-function Polynomial 1,−<var>value</var></td>
4184 </tr>
4185 <tr>
4186 <td>-evaluate Multiply <var>value</var> </td>
4187 <td>-function Polynomial <var>value</var>,0</td>
4188 </tr>
4189 <tr>
4190 <td>+level black% x white%</td>
4191 <td>-function Polynomial A,B</td>
4192 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
4193 </tr>
4194</table>
4195
4196<p>The <code>Polynomial</code> function gives great versatility, since
4197polynomials can be used to fit any continuous curve to any degree of accuracy
4198desired.</p>
4199
4200</dd>
4201<dt>Sinusoid</dt>
4202<dd>
4203<p>The <code>Sinusoid</code> function can be used to vary the channel values
4204sinusoidally by setting frequency, phase shift, amplitude, and a bias. These
4205values are given as one to four parameters, as follows,</p>
4206
4207<pre>
4208-function <code>Sinusoid</code> <var>freq</var>,[<var>phase</var>,[<var>amp</var>,[<var>bias</var>]]]
4209</pre>
4210
4211<p>where <var>phase</var> is in degrees. (The domain [0,1] of the function
4212corresponds to 0 through <var>freq</var>×360 degrees.)
4213The result is that if a pixel's normalized channel value is originally
4214<b><var>u</var></b>, its resulting normalized value is given by </p>
4215
4216<pre>
4217<var>amp</var> * sin(2*π* (<var>freq</var> * <b><var>u</var></b> + <var>phase</var> / 360)) + <var>bias</var>
4218</pre>
4219
4220<p> For example, the following generates a curve that starts and ends at 0.9
4221(when <b><var>u</var></b>=0 and 1, resp.), oscillating three times between
4222.7−.2=.5 and .7+.2=.9. </p>
4223
4224<pre>
4225-function Sinusoid 3,-90,.2,.7
4226</pre>
4227
4228<p>The default values of <var>amp</var> and <var>bias</var> are both .5. The default for <var>phase</var>
4229is 0.</p>
4230
4231<p>The <code>Sinusoid</code> function generalizes <code>Sin</code> and
4232<code>Cos</code> of the <a href="command-line-options.html#evaluate">-evaluate</a> operator by allowing
4233varying amplitude, phase and bias. The correspondence is as follows.</p>
4234
4235<table class="table table-condensed table-striped">
4236 <tr>
4237 <td>-evaluate Sin <var>freq</var> </td>
4238 <td>-function Sinusoid <var>freq</var>,0 </td>
4239 </tr>
4240 <tr>
4241 <td>-evaluate Cos <var>freq</var> </td>
4242 <td>-function Sinusoid <var>freq</var>,90 </td>
4243 </tr>
4244</table>
4245 </dd>
4246<dt>ArcSin</dt>
4247<dd>
4248<p>The <code>ArcSin</code> function generates the inverse curve of a Sinusoid,
4249and can be used to generate cylindrical distortion and displacement maps.
4250The curve can be adjusted relative to both the input values and output range
4251of values.</p>
4252
4253<pre>
4254-function <code>ArcSin</code> <var>width</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4255</pre>
4256
4257<p>with all values given in terms of normalized color values (0.0 for black,
42581.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
4259for bout input (<var>width</var>), and output (<var>width</var>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
4260
4261<pre>
4262<var>range</var>/π * asin( 2/<var>width</var> * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
4263</pre>
4264
4265</dd>
4266<dt>ArcTan</dt>
4267<dd>
4268<p>The <code>ArcTan</code> function generates a curve that smooth crosses from
4269limit values at infinities, though a center using the given slope value.
4270All these values can be adjusted via the arguments.</p>
4271
4272<pre>
4273-function <code>ArcTan</code> <var>slope</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4274</pre>
4275
4276<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
4277</p>
4278
4279<pre>
4280<var>range</var>/π * atan( <var>slope</var>*π * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
4281</pre>
4282 </dd>
Cristy594d2772015-11-15 10:47:42 -05004283 </tr>
Cristy882d9f42015-10-29 16:48:39 -04004284</dl>
4285
4286
4287
4288<div style="margin: auto;">
4289 <h3 class="magick-header"><a id="fuzz"></a>-fuzz <var>distance</var>{<var>%</var>}</h3>
4290</div>
4291
4292<p class="magick-description">Colors within this <var>distance</var> are considered equal.</p>
4293
4294<p>A number of algorithms search for a target color. By default the color must
4295be exact. Use this option to match colors that are close to the target color
4296in RGB space. For example, if you want to automagically trim the edges of an
4297image with <a href="command-line-options.html#trim">-trim</a> but the image was scanned and the target
4298background color may differ by a small amount. This option can account for
4299these differences.</p>
4300
4301<p>The <var>distance</var> can be in absolute intensity units or, by
4302appending <code>%</code> as a percentage of the maximum possible intensity (255,
430365535, or 4294967295).</p>
4304
Cristy594d2772015-11-15 10:47:42 -05004305<p>Use <a href="command-line-options.html#fuzz" >+fuzz</a> to reset the fuzz value to 0.</p>
Cristy882d9f42015-10-29 16:48:39 -04004306
4307
4308<div style="margin: auto;">
4309 <h3 class="magick-header"><a id="fx"></a>-fx <var>expression</var></h3>
4310</div>
4311
4312<p class="magick-description">apply a mathematical expression to an image or image channels.</p>
4313
4314<p>If the first character of <var>expression</var> is <code>@</code>,
4315the expression is read from a file titled by the remaining characters in the
4316string.</p>
4317
4318<p>See <a href="fx.html">FX,
4319The Special Effects Image Operator</a> for a detailed discussion of this
4320option.</p>
4321
4322
4323<div style="margin: auto;">
4324 <h3 class="magick-header"><a id="gamma"></a>-gamma <var>value</var></h3>
4325</div>
4326
4327<p class="magick-description">level of gamma correction.</p>
4328
4329<p>The same color image displayed on two different workstations may look
4330different due to differences in the display monitor. Use gamma correction to
4331adjust for this color difference. Reasonable values extend from
4332<code>0.8</code> to <code>2.3</code>. Gamma less than 1.0 darkens the image and
4333gamma greater than 1.0 lightens it. Large adjustments to image gamma may
4334result in the loss of some image information if the pixel quantum size is only
4335eight bits (quantum range 0 to 255).</p>
4336
4337<p>Gamma adjusts the image's channel values pixel-by-pixel according to
4338a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the
4339normalized or 0 to 1 color value. For example, using a value of gamma=2 is the
4340same as taking the square root of the image.</p>
4341
4342<p>You can apply separate gamma values to the red, green, and blue channels of
4343the image with a gamma value list delimited with commas (e.g.,
4344<code>1.7,2.3,1.2</code>).</p>
4345
4346<p>Use <a href="command-line-options.html#gamma">+gamma <var>value</var></a> to set the
4347image gamma level without actually adjusting the image pixels. This option
4348is useful if the image is of a known gamma but not set as an image attribute
4349(e.g. PNG images). Write the "file gamma" which is the reciprocal of the
4350display gamma; e.g., if your image is sRGB and you want to write a PNG gAMA
4351chunk, use</p>
4352
4353<pre>
4354convert input.png +gamma .45455 output.png
4355</pre>
4356
4357<p>(0.45455 is 1/2.2)</p>
4358
4359<p>Note that gamma adjustments are also available via the <a href="command-line-options.html#level">-level</a> operator.</p>
4360
4361<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05004362 <h3 class="magick-header"><a id="gaussian-blur"></a>-gaussian-blur <var>radius</var><br />-gaussian-blur <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004363</div>
4364
4365<p class="magick-description">Blur the image with a Gaussian operator.</p>
4366
4367<p>Convolve the image with a Gaussian or normal distribution using the given
Cristy594d2772015-11-15 10:47:42 -05004368<var >Sigma</var> value. The formula is:</p>
Cristy882d9f42015-10-29 16:48:39 -04004369
Cristy594d2772015-11-15 10:47:42 -05004370<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/> </p>
Cristy882d9f42015-10-29 16:48:39 -04004371
Cristy594d2772015-11-15 10:47:42 -05004372<p>The <var >Sigma</var> value is the important argument, and
Cristy882d9f42015-10-29 16:48:39 -04004373determines the actual amount of blurring that will take place. </p>
4374
Cristy594d2772015-11-15 10:47:42 -05004375<p>The <var >Radius</var> is only used to determine the size of the
Cristy882d9f42015-10-29 16:48:39 -04004376array which will hold the calculated Gaussian distribution. It should be an
4377integer. If not given, or set to zero, IM will calculate the largest possible
4378radius that will provide meaningful results for the Gaussian distribution.
4379</p>
4380
Cristy594d2772015-11-15 10:47:42 -05004381<p>The larger the <var >Radius</var> the radius the slower the
4382operation is. However too small a <var >Radius</var>, and sever
4383aliasing effects may result. As a guideline, <var >Radius</var>
4384should be at least twice the <var >Sigma</var> value, though three
Cristy882d9f42015-10-29 16:48:39 -04004385times will produce a more accurate result. </p>
4386
4387<p>This differs from the faster <a href="command-line-options.html#blur">-blur</a> operator in that a
4388full 2-dimensional convolution is used to generate the weighted average of the
4389neighboring pixels. </p>
4390
4391<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
4392pixels which are outside the image proper are blurred into the final result.
4393</p>
4394
4395
4396<div style="margin: auto;">
4397 <h3 class="magick-header"><a id="geometry"></a>-geometry <var>geometry</var></h3>
4398</div>
4399
4400<p class="magick-description">Set the preferred size and location of the image.</p>
4401
4402<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4403
4404<div style="margin: auto;">
4405 <h3 class="magick-header"><a id="gravity"></a>-gravity <var>type</var></h3>
4406</div>
4407
4408<p class="magick-description">Sets the current gravity suggestion for various other settings and options.</p>
4409
4410<p>Choices include: <code>NorthWest</code>, <code>North</code>,
4411<code>NorthEast</code>, <code>West</code>, <code>Center</code>, <code>East</code>,
Cristy594d2772015-11-15 10:47:42 -05004412<code>SouthWest</code>, <code>South</code>, <code>SouthEast</code>. Use <a
4413href="command-line-options.html#list">-list gravity</a> to get a complete list of <a
4414href="command-line-options.html#gravity">-gravity</a> settings available in your ImageMagick
Cristy882d9f42015-10-29 16:48:39 -04004415installation.</p>
4416
4417<p>The direction you choose specifies where to position text or subimages. For
4418example, a gravity of <code>Center</code> forces the text to be centered within
Cristy776113a2016-04-29 12:01:19 -04004419the image. By default, the image gravity is <code>undefined</code>. See <a
Cristy594d2772015-11-15 10:47:42 -05004420href="command-line-options.html#draw">-draw</a> for more details about graphic primitives. Only the
4421text primitive of <a href="command-line-options.html#draw">-draw</a> is affected by the <a
4422href="command-line-options.html#gravity">-gravity</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04004423
4424<p>The <a href="command-line-options.html#gravity">-gravity</a> option is also used in concert with the
4425<a href="command-line-options.html#geometry">-geometry</a> setting and other settings or options that
Cristy594d2772015-11-15 10:47:42 -05004426take <var>geometry</var> as an argument, such as the <a
4427href="command-line-options.html#crop">-crop</a> option. </p>
Cristy882d9f42015-10-29 16:48:39 -04004428
4429<p>If a <a href="command-line-options.html#gravity">-gravity</a> setting occurs before another option
4430or setting having a <var>geometry</var> argument that specifies an
4431offset, the offset is usually applied to the point within the image suggested
4432by the <a href="command-line-options.html#gravity">-gravity</a> argument. Thus, in the following
4433command, for example, suppose the file <code>image.png</code> has dimensions
4434200x100. The offset specified by the argument to <a href="command-line-options.html#region">-region</a>
4435is (−40,+20). The argument to <a href="command-line-options.html#gravity">-gravity</a> is
4436<code>Center</code>, which suggests the midpoint of the image, at the point
4437(100,50). The offset (−40,20) is applied to that point, giving
4438(100−40,50+20)=(60,70), so the specified 10x10 region is located at
4439that point. (In addition, the <a href="command-line-options.html#gravity">-gravity</a> affects the
4440region itself, which is <var>centered</var> at the pixel
4441coordinate (60,70). (See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.)</p>
4442
4443<pre>
4444convert image.png -gravity Center -region 10x10-40+20 \
4445 -negate output.png
4446</pre>
4447
Cristy594d2772015-11-15 10:47:42 -05004448<p>When used as an option to <a href="composite.html">composite</a>, <a
4449href="command-line-options.html#gravity">-gravity</a> gives the direction that the image gravitates
Cristy882d9f42015-10-29 16:48:39 -04004450within the composite.</p>
4451
Cristy594d2772015-11-15 10:47:42 -05004452<p>When used as an option to <a href="montage.html">montage</a>, <a
4453href="command-line-options.html#gravity">-gravity</a> gives the direction that an image gravitates
Cristy882d9f42015-10-29 16:48:39 -04004454within a tile. The default gravity is <code>Center</code> for this purpose.</p>
4455
4456
4457<div style="margin: auto;">
4458 <h3 class="magick-header"><a id="grayscale"></a>-grayscale <var>method</var></h3>
4459</div>
4460
4461<p class="magick-description">convert image to grayscale.</p>
4462
Cristy594d2772015-11-15 10:47:42 -05004463<p>This will use one of the <a href="command-line-options.html#intensity" >-intensity</a> methods to
Cristy882d9f42015-10-29 16:48:39 -04004464convert the given image into a linear-grayscale image. </p>
4465
4466<p>For example, to convert an image to (linear) Rec709Luminance grayscale, type:</p>
4467
4468<pre>
4469convert in.png -grayscale Rec709Luminance out.png
4470</pre>
4471
4472<p>which is equivalent to:</p>
4473
4474<pre>
4475convert in.png -colorspace gray out.png
4476</pre>
4477
4478<p>Similarly, to convert an image to (non-linear) Rec709Luma grayscale, type:</p>
4479
4480<pre>
4481convert in.png -grayscale Rec709Luma out.png
4482</pre>
4483
4484<p>which is equivalent to:</p>
4485
4486<pre>
4487convert in.png -set colorspace RGB -colorspace gray out.png
4488</pre>
4489
4490<p>Note that a 'colorspace' intensity method will produce the same result
4491regardless of the current colorpsace of the image. But a 'mathematical'
4492intensity method will depend on the current colorspace the image is currently
4493using. </p>
4494
Cristy594d2772015-11-15 10:47:42 -05004495<p>While this operation uses an <a href="command-line-options.html#intensity" >-intensity</a> method,
4496it does not use or set the <a href="command-line-options.html#intensity" >-intensity</a> setting, so
Cristy882d9f42015-10-29 16:48:39 -04004497will not effect other operations that may use that setting.</p>
4498
4499
4500<div style="margin: auto;">
4501 <h3 class="magick-header"><a id="green-primary"></a>-green-primary <var>x,y</var></h3>
4502</div>
4503
4504<p class="magick-description">green chromaticity primary point.</p>
4505
4506
4507<div style="margin: auto;">
4508 <h3 class="magick-header"><a id="hald-clut"></a>-hald-clut</h3>
4509</div>
4510
4511<p class="magick-description">apply a Hald color lookup table to the image.</p>
4512
4513<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
4514dimensions. Create it with the <code>HALD:</code> prefix (e.g. HALD:8). You
4515can apply any color transformation to the Hald image and then use this option
4516to apply the transform to the image. </p>
4517
4518<pre>
4519convert image.png hald.png -hald-clut transform.png
4520</pre>
4521
4522<p>This option provides a convenient method for you to use Gimp or Photoshop
4523to make color corrections to the Hald CLUT image and subsequently apply them
4524to multiple images using an ImageMagick script. </p>
4525
4526<p>Note that the representation is only of the normal RGB color space and that
4527the whole color value triplet is used for the interpolated lookup of the
Cristy594d2772015-11-15 10:47:42 -05004528represented Hald color cube image. Because of this the operation is not <a
4529href="command-line-options.html#channel" >-channel</a> setting effected, nor can it adjust or modify an
Cristy882d9f42015-10-29 16:48:39 -04004530images transparency or alpha/matte channel.</p>
4531
Cristy594d2772015-11-15 10:47:42 -05004532<p>See also <a href="command-line-options.html#clut" >-clut</a> which provides color value replacement
Cristy769d8892016-01-19 18:11:14 -05004533of the individual color channels, usually involving a simpler grayscale
4534image. E.g: grayscale to color replacement, or modification by a histogram
Cristy882d9f42015-10-29 16:48:39 -04004535mapping. </p>
4536
4537
4538<div style="margin: auto;">
4539 <h3 class="magick-header"><a id="help"></a>-help</h3>
4540</div>
4541
4542<p class="magick-description">print usage instructions.</p>
4543
4544<div style="margin: auto;">
4545 <h3 class="magick-header"><a id="highlight-color"></a>-highlight-color <var>color</var></h3>
4546</div>
4547
4548<p class="magick-description">when comparing images, emphasize pixel differences with this color.</p>
4549
4550<div style="margin: auto;">
4551 <h3 class="magick-header"><a id="hough-lines"></a>-hough-lines <var>width</var>x<var>height</var>{<var>+threshold</var>}</h3>
4552</div>
4553
4554<p class="magick-description">identify straight lines in the image (e.g. -hough-lines 9x9+195).</p>
4555
4556<p>Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds.</p>
4557
4558<p>The process accumulates counts for every white pixel in the binary edge image for every possible orientation (for angles from 0 to 179 in 1 deg increments) and distance from the center of the image to the corners (in 1 px increments). It stores the counts in an accumulator matrix of angle vs distance. The size of the accumulator will be 180x(diagonal/2). Next it searches the accumulator for peaks in counts and converts the locations of the peaks to slope and intercept in the normal x,y input image space. The algorithm uses slope/intercepts to find the endpoints clipped to the bounds of the image. The lines are drawn from the given endpoints. The counts are a measure of the length of the lines.</p>.
4559
4560<p>The WxH arguments specify the filter size for locating the peaks in the Hough accumulator. The threshold excludes lines whose counts are less than the threshold value.</p>
4561
Cristy594d2772015-11-15 10:47:42 -05004562<p>Use <code><a href="command-line-options.html#background" >-background</a></code> to specify the color of the background onto which the lines will be drawn. The default is black.</p>
Cristy882d9f42015-10-29 16:48:39 -04004563
Cristy594d2772015-11-15 10:47:42 -05004564<p>Use <code><a href="command-line-options.html#fill" >-fill</a></code> to specify the color of the lines. The default is black.</p>
Cristy882d9f42015-10-29 16:48:39 -04004565
Cristy594d2772015-11-15 10:47:42 -05004566<p>Use <code><a href="command-line-options.html#stroke" >-stroke</a></code> and <code><a href="command-line-options.html#strokewidth" >-strokewidth</a></code> to specify the thickness of the lines. The default is black and no strokewidth.</p>
Cristy882d9f42015-10-29 16:48:39 -04004567
4568<p>A text file listing the endpoints and counts may be created by using the suffix, .mvg, for the output image.</p>
4569
Cristy594d2772015-11-15 10:47:42 -05004570<p>Use <code><a href="command-line-options.html#define" >-define</a> hough-lines:accumulator=true</code> to return the accumulator image in addition to the lines image.</p>
Cristy882d9f42015-10-29 16:48:39 -04004571
4572<div style="margin: auto;">
4573 <h3 class="magick-header"><a id="iconGeometry"></a>-iconGeometry <var>geometry</var></h3>
4574</div>
4575
4576<p class="magick-description">specify the icon geometry.</p>
4577
4578<p>Offsets, if present in the geometry specification, are handled in the same
4579manner as the <a href="command-line-options.html#geometry">-geometry</a> option, using X11 style to
4580handle negative offsets.</p>
4581
4582<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4583
4584<div style="margin: auto;">
4585 <h3 class="magick-header"><a id="iconic"></a>-iconic</h3>
4586</div>
4587
4588<p class="magick-description">start in icon mode in X Windows", 'animate', 'display</p>
4589
4590<div style="margin: auto;">
4591 <h3 class="magick-header"><a id="identify"></a>-identify</h3>
4592</div>
4593
4594<p class="magick-description">identify the format and characteristics of the image.</p>
4595
4596<p>This information is printed: image scene number; image name; image size;
4597the image class (<var>DirectClass</var> or <var>PseudoClass</var>); the total number of unique colors; and the
4598number of seconds to read and transform the image. Refer to <a href="miff.html">MIFF</a> for
4599a description of the image class.</p>
4600
4601<p>If <a href="command-line-options.html#colors">-colors</a> is also specified, the total unique colors
Cristy594d2772015-11-15 10:47:42 -05004602in the image and color reduction error values are printed. Refer to <a
4603href="quantize.html">color
Cristy882d9f42015-10-29 16:48:39 -04004604reduction algorithm</a> for a description of these values.</p>
4605
4606<p>If <a href="command-line-options.html#verbose">-verbose</a> precedes this option, copious
4607amounts of image properties are displayed including image statistics, profiles,
4608image histogram, and others.</p>
4609
4610<div style="margin: auto;">
4611 <h3 class="magick-header"><a id="ift"></a>-ift</h3>
4612</div>
4613
4614<p class="magick-description">implements the inverse discrete Fourier transform (DFT).</p>
4615
4616<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
4617users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase
4618images from the frequency domain to a single image in the normal or spatial
Cristy594d2772015-11-15 10:47:42 -05004619domain. See for example, <a
4620href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>,
Cristy882d9f42015-10-29 16:48:39 -04004621<a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and
4622<a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p>
4623
4624<p>For example, depending upon the image format used to store the result of
4625the <a href="command-line-options.html#fft">-fft</a>, one would use either</p>
4626
4627<pre>
4628convert fft_image.miff -ift fft_image_ift.png
4629</pre>
4630
4631<p>or</p>
4632
4633<pre>
4634convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png
4635</pre>
4636
4637<p>The resulting image may need to be cropped due to padding introduced when
Cristy594d2772015-11-15 10:47:42 -05004638the original image, prior to the <a href="command-line-options.html#fft">-fft</a> or <a
4639href="command-line-options.html#fft">+fft</a>, was not square or even dimensioned. Any padding is at
Cristy882d9f42015-10-29 16:48:39 -04004640the right and/or bottom sides of the image.</p>
4641
4642<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
4643use <a href="command-line-options.html#ift">-ift</a>.</p>
4644
4645<p>Use <a href="command-line-options.html#ift">+ift</a> (with HDRI enabled) to transform a pair of real
4646and imaginary images from the frequency domain to a single image in the normal
4647(spatial) domain.</p>
4648
Cristy594d2772015-11-15 10:47:42 -05004649<p>By default the IFT is not normalized (and the FFT is). Use "<code><a href="command-line-options.html#define" >-define</a> fourier:normalize=inverse</code> to explicitly normalize the IFT and unnormalize the FFT.</p>
Cristy882d9f42015-10-29 16:48:39 -04004650
4651<div style="margin: auto;">
4652 <h3 class="magick-header"><a id="immutable"></a>-immutable</h3>
4653</div>
4654
4655<p class="magick-description">make image immutable.</p>
4656
4657<div style="margin: auto;">
4658 <h3 class="magick-header"><a id="implode"></a>-implode <var>factor</var></h3>
4659</div>
4660
4661<p class="magick-description">implode image pixels about the center.</p>
4662
4663<div style="margin: auto;">
4664 <h3 class="magick-header"><a id="insert"></a>-insert <var>index</var></h3>
4665</div>
4666
4667<p class="magick-description">insert the last image into the image sequence.</p>
4668
4669<p>This option takes last image in the current image sequence and inserts it
4670at the given index. If a negative index is used, the insert position is
4671calculated before the last image is removed from the sequence. As such
4672<code>-insert -1</code> will result in no change to the image sequence.</p>
4673
4674<p>The <code>+insert</code> option is equivalent to <code>-insert -1</code>. In
4675other words, insert the last image, at the end of the current image sequence.
4676Consequently this has no effect on the image sequence order.</p>
4677
4678<div style="margin: auto;">
4679 <h3 class="magick-header"><a id="intensity"></a>-intensity <var>method</var></h3>
4680</div>
4681
4682<p class="magick-description">method to generate intensity value from pixel.</p>
4683
4684<p>ImageMagick provides a number of methods used in situations where an
4685operator needs to determine a single grayscale value for some purpose, from
4686an image with red, green, and blue pixel components. Typically the linear
4687<code>Rec709Luminance</code> formula is used, which is the same formula used when
4688converting images to <code>-colorspace gray</code>. </p>
4689
4690<p>The following formulas are currently provided, and will first convert
4691the pixel values to linear-RGB or non-linear sRGB colorspace before
4692being applied to calculate the final greyscale value. </p>
4693
4694<dl class="dl-horizontal">
4695<dt>Rec601Luma</dt><dd> 0.298839R' + 0.586811G'+ 0.114350B'</dd>
4696<dt>Rec601Luminance</dt><dd> 0.298839R + 0.586811G + 0.114350B</dd>
4697<dt>Rec709Luma</dt><dd> 0.212656R' + 0.715158G' + 0.072186B'</dd>
4698<dt>Rec709Luminance</dt><dd> 0.212656R + 0.715158G + 0.072186B</dd>
4699<dt>Brightness</dt><dd> max(R', G', B')</dd>
4700<dt>Lightness</dt><dd> (min(R', G', B') + max(R', G', B')) / 2.0</dd>
4701</dl>
4702
4703<p>Note that the above R,G,B values is the image's linear-RGB values, while
4704R',G',B' are sRGB non-linear values. </p>
4705
4706<p>These intensity methods are mathematical in nature and will use the
4707current value in the images respective R,G,B channel regardless of
4708what that is, or what colorspace the image is currently using.</p>
4709
4710<dl class="dl-horizontal">
4711<dt>Average</dt><dd>(R + G + B) / 3.0</dd>
4712<dt>MS</dt><dd>(R^2 + G^2 + B^2) / 3.0</dd>
4713<dt>RMS</dt><dd>sqrt( (R^2 + G^2 + B^2) / 3.0 )</dd>
4714</dl>
4715
4716<p>These methods are often used for other purposes, such as generating a
Cristy594d2772015-11-15 10:47:42 -05004717grayscale difference image between two color images (using <a href="command-line-options.html#compose"
4718>-compose</a> '<code>Difference</code>' composition. </p>
Cristy882d9f42015-10-29 16:48:39 -04004719
4720<p> For example The 'MS' (Mean Squared) setting is good for minimizing color
4721error comparisions. While... The method 'RMS' (Root Mean Squared) for
4722example is appropriate for calculating color vector distance, from a color
Cristy594d2772015-11-15 10:47:42 -05004723difference image. This is equivalent to the color only component of the <a
4724href="command-line-options.html#fuzz" >-fuzz</a> factor color compare setting. </p>
Cristy882d9f42015-10-29 16:48:39 -04004725
Cristy594d2772015-11-15 10:47:42 -05004726<p>See also <a href="command-line-options.html#grayscale" >-grayscale</a> which applies one of the above
4727grayscaling formula directly to an image without setting the <a
4728href="command-line-options.html#intensity" >-intensity</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04004729
Cristy594d2772015-11-15 10:47:42 -05004730<p>The <a href="command-line-options.html#colorspace" >-colorspace gray</a> image conversion also uses
Cristy882d9f42015-10-29 16:48:39 -04004731the current intensity setting, but will always convert the image to the
4732appropriate sRGB or linear-RGB colorspace before appling the above
4733function.</p>
4734
4735<p>To print a complete list of possible pixel intensity setting methods, use <a href="command-line-options.html#list">-list intensity</a>.</p>
4736
Cristy594d2772015-11-15 10:47:42 -05004737<p>Operators affected by the <a href="command-line-options.html#intensity" >-intensity</a> setting include:</p>
Cristy882d9f42015-10-29 16:48:39 -04004738
4739<pre>
4740-adaptive-blur
4741-adaptive-sharpen
4742-black-threshold
4743-clut (when mapping greyscale CLUT image to alpha channel if set by -channels)
4744-colors for gray colorspace
4745-compose {LightenIntensity, DarkenIntensity, CopyOpacity, CopyBlack}
4746-contrast-stretch
4747-distort {ErodeIntensity, DilateIntensity}
4748-normalize
4749-random-threshold
4750-selective-blur
4751-shade
4752-threshold
4753-tint
4754-white-threshold
4755</pre>
4756
4757<div style="margin: auto;">
4758 <h3 class="magick-header"><a id="intent"></a>-intent <var>type</var></h3>
4759</div>
4760
4761<p class="magick-description">use this type of rendering intent when managing the image color.</p>
4762
4763<p>Use this option to affect the color management operation of an image (see
4764<a href="command-line-options.html#profile">-profile</a>). Choose from these intents: <code>Absolute,
4765Perceptual, Relative, Saturation</code>.</p>
4766
4767<p>The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces.</p>
4768
4769<p>To print a complete list of rendering intents, use <a href="command-line-options.html#list">-list intent</a>.</p>
4770
4771<div style="margin: auto;">
4772 <h3 class="magick-header"><a id="interlace"></a>-interlace <var>type</var></h3>
4773</div>
4774
4775<p class="magick-description">the type of interlacing scheme.</p>
4776
4777<p>Choose from:</p>
4778
4779<pre>
4780none
4781line
4782plane
4783partition
4784JPEG
4785GIF
4786PNG
4787</pre>
4788
4789<p>This option is used to specify the type of interlacing scheme for raw image
4790formats such as <code>RGB</code> or <code>YUV</code>.</p>
4791
4792<p><code>None</code> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
4793
4794<p><code>Line</code> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
4795
4796<p><code>Plane</code> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
4797
4798<p><code>Partition</code> is like plane except the different planes are saved to
4799individual files (e.g. image.R, image.G, and image.B).</p>
4800
4801<p>Use <code>Line</code> or <code>Plane</code> to create an <code>interlaced
4802PNG</code> or <code>GIF</code> or <code>progressive JPEG</code> image.</p>
4803
4804<p>To print a complete list of interlacing schemes, use <a href="command-line-options.html#list">-list
4805interlace</a>.</p>
4806
4807<div style="margin: auto;">
4808 <h3 class="magick-header"><a id="interpolate"></a>-interpolate <var>type</var></h3>
4809</div>
4810
4811<p class="magick-description">Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.</p>
4812
4813<p>When looking up the color of a pixel using a non-integer floating point
4814value, you typically fall in between the pixel colors defined by the source
4815image. This setting determines how the color is determined from the colors of
4816the pixels surrounding that point. That is how to determine the color of a
4817point that falls between two, or even four different colored pixels. </p>
4818
4819<dl class="dl-horizontal">
4820 <dt>integer</dt>
4821 <dd>The color of the top-left pixel (floor function)</dd>
4822 <dt>nearest-neighbor</dt>
4823 <dd>The nearest pixel to the lookup point (rounded function)</dd>
4824 <dt>average</dt>
4825 <dd>The average color of the surrounding four pixels</dd>
4826 <dt>bilinear</dt>
4827 <dd>A double linear interpolation of pixels (the default)</dd>
4828 <dt>mesh</dt>
4829 <dd>Divide area into two flat triangular interpolations</dd>
4830 <dt>bicubic</dt>
4831 <dd>Fitted bicubic-spines of surrounding 16 pixels</dd>
4832 <dt>spline</dt>
4833 <dd>Direct spline curves (colors are blurred)</dd>
4834 <dt>filter</dt>
4835 <dd>Use resize <a href="command-line-options.html#filter">-filter</a> settings</dd>
4836</dl>
4837
Cristy594d2772015-11-15 10:47:42 -05004838<p>This most important for distortion operators such as <a href="command-line-options.html#distort"
4839>-distort</a>, <a href="command-line-options.html#implode" >-implode</a>, <a href="command-line-options.html#transform"
4840>-transform</a> and <a href="command-line-options.html#fx" >-fx</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04004841
4842<p>To print a complete list of interpolation methods, use <a href="command-line-options.html#list">-list interpolate</a>.</p>
4843
Cristy594d2772015-11-15 10:47:42 -05004844<p>See also <a href="command-line-options.html#virtual-pixel" >-virtual-pixel</a>, for control of the
Cristy882d9f42015-10-29 16:48:39 -04004845lookup for positions outside the boundaries of the image. </p>
4846
4847
4848<div style="margin: auto;">
4849 <h3 class="magick-header"><a id="interline-spacing"></a>-interline-spacing <var>value</var></h3>
4850</div>
4851
4852<p class="magick-description">the space between two text lines.</p>
4853
4854<div style="margin: auto;">
4855 <h3 class="magick-header"><a id="interword-spacing"></a>-interword-spacing <var>value</var></h3>
4856</div>
4857
4858<p class="magick-description">the space between two words.</p>
4859
4860<div style="margin: auto;">
4861 <h3 class="magick-header"><a id="kerning"></a>-kerning <var>value</var></h3>
4862</div>
4863
4864<p class="magick-description">the space between two letters.</p>
4865
4866<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05004867 <h3 class="magick-header"><a id="kuwahara"></a>-kuwahara <var>radius</var><br />-kuwahara <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004868</div>
4869
4870<p class="magick-description">edge preserving noise reduction filter.</p>
4871
Cristy594d2772015-11-15 10:47:42 -05004872<p>The <var >radius</var> is more important than the <var >sigma</var>. If <var >sigma</var> is left off, it will be computed automatically from the <var >radius</var> as <var >sigma</var>=<var >radius</var>-0.5. The <var >sigma</var> provides a bit of additional smoothing control.</p>
Cristy882d9f42015-10-29 16:48:39 -04004873
4874
4875<div style="margin: auto;">
4876 <h3 class="magick-header"><a id="label"></a>-label <var>name</var></h3>
4877</div>
4878
4879<p class="magick-description">assign a label to an image.</p>
4880
4881<p>Use this option to assign a specific label to the image, as it is read in
Cristy594d2772015-11-15 10:47:42 -05004882or created. You can use the <a href="command-line-options.html#set" >-set</a> operation to re-assign
Cristy882d9f42015-10-29 16:48:39 -04004883a the labels of images already read in. Image formats such as TIFF, PNG,
4884MIFF, supports saving the label information with the image.</p>
4885
4886<p>When saving an image to a <var>PostScript</var> file, any label
4887assigned to an image is used as a header string to print above the postscript
4888image. </p>
4889
4890<p>You can include the image filename, type, width, height, or other image
4891attribute by embedding special format character. See <a href="escape.html">Format and Print Image
4892Properties</a> for details of the percent escape codes.</p>
4893
4894<p>For example,</p>
4895
4896<pre>
4897-label "%m:%f %wx%h" bird.miff
4898</pre>
4899
4900<p>assigns an image label of <code>MIFF:bird.miff 512x480</code> to the
4901"<code>bird.miff</code>" image and whose width is 512 and height is 480, as it
4902is read in. If a <a href="command-line-options.html#label">+label</a> option was used instead, any
4903existing label present in the image would be used. You can remove all labels
4904from an image by assigning the empty string. </p>
4905
4906<p>A label is not drawn on the image, but is embedded in the image datastream
4907via <var>Label</var> tag or similar mechanism. If you want the label to be
4908visible on the image itself, use the <a href="command-line-options.html#draw">-draw</a> option, or
4909during the final processing in the creation of an image montage.</p>
4910
4911<p>If the first character of <var>string</var> is <var>@</var>, the image label is read from a file titled by the
4912remaining characters in the string. Labels in a file are literal, no embedded
4913formatting characters are recognized.</p>
4914
4915
4916<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05004917 <h3 class="magick-header"><a id="lat"></a>-lat <var>width</var><br />-lat <var>width</var>x<var>height</var>{<var>+-</var>}<var>offset</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04004918</div>
4919
4920<p class="magick-description">perform local adaptive threshold.</p>
4921
4922<p>Adaptively threshold each pixel based on the value of pixels in a
4923surrounding window. If the current pixel is lighter than this average plus
4924the optional <code>offset</code>, then it is made white, otherwise it is made
4925black. Small variations in pixel values such as found in scanned documents
4926can be ignored if offset is positive. A negative offset will make it more
4927sensitive to those small variations. </p>
4928
4929<p>This is commonly used to threshold images with an uneven background. It is
4930based on the assumption that average color of the small window is the
4931the local background color, from which to separate the foreground color. </p>
4932
4933
4934<div style="margin: auto;">
4935 <h3 class="magick-header"><a id="layers"></a>-layers <var>method</var></h3>
4936</div>
4937
4938<p class="magick-description">handle multiple images forming a set of image layers or animation frames.</p>
4939
4940<p>Perform various image operation methods to a ordered sequence of images
4941which may represent either a set of overlaid 'image layers', a GIF disposal
4942animation, or a fully-'coalesced' animation sequence. </p>
4943
4944<table class="table table-condensed table-striped">
4945 <tbody>
4946 <tr>
4947 <th style="width: 8%">Method</th>
4948 <th>Description</th>
4949 </tr>
4950
4951 <tr>
4952 <td>compare-any</td>
4953 <td>Crop the second and later frames to the smallest rectangle
Cristy594d2772015-11-15 10:47:42 -05004954 that contains all the differences between the two images. No GIF <a
4955 href="command-line-options.html#dispose" >-dispose</a> methods are taken into account. </td>
Cristy882d9f42015-10-29 16:48:39 -04004956 </tr>
4957
Cristy594d2772015-11-15 10:47:42 -05004958 <tr><td></td><td>This exactly the same as the <a href="command-line-options.html#deconstruct"
4959 >-deconstruct</a> operator, and does not preserve animations normal
Cristy882d9f42015-10-29 16:48:39 -04004960 working, especially when animation used layer disposal methods such as
4961 '<code>Previous</code>' or '<code>Background</code>'. </td>
4962 </tr>
4963
4964 <tr>
4965 <td>compare-clear</td>
4966 <td>As '<code>compare-any</code>' but crop to the bounds of any
4967 opaque pixels which become transparent in the second frame. That is the
4968 smallest image needed to mask or erase pixels for the next frame. </td>
4969 </tr>
4970
4971 <tr>
4972 <td>compare-overlay</td>
4973 <td>As '<code>compare-any</code>' but crop to pixels that add
4974 extra color to the next image, as a result of overlaying color pixels.
4975 That is the smallest single overlaid image to add or change colors. </td>
4976 </tr>
4977
Cristy594d2772015-11-15 10:47:42 -05004978 <tr><td></td><td>This can be used with the <a href="command-line-options.html#compose" >-compose</a> alpha
Cristy882d9f42015-10-29 16:48:39 -04004979 composition method '<code>change-mask</code>', to reduce the image to
4980 just the pixels that need to be overlaid. </td>
4981 </tr>
4982
4983 <tr>
4984 <td>coalesce</td>
Cristy594d2772015-11-15 10:47:42 -05004985 <td>Equivalent to a call to the <a href="command-line-options.html#coalesce"
4986 >-coalesce</a> operator. Apply the layer disposal methods set in the
Cristy882d9f42015-10-29 16:48:39 -04004987 current image sequence to form a fully defined animation sequence, as
4988 it should be displayed. Effectively converting a GIF animation into a
4989 'film strip'-like animation. </td>
4990 </tr>
4991
4992 <tr>
4993 <td>composite</td>
4994 <td>Alpha Composition of two image lists, separated by a
4995 "<code>null:</code>" image, with the destination image list first, and
4996 the source images last. An image from each list are composited
4997 together until one list is finished. The separator image and source
4998 image lists are removed. </td>
4999 </tr>
5000
5001
5002 <tr><td></td>
Cristy594d2772015-11-15 10:47:42 -05005003 <td>The <a href="command-line-options.html#geometry" >-geometry</a> offset is adjusted according
5004 to <a href="command-line-options.html#gravity" >-gravity</a> in accordance of the virtual
5005 canvas size of the first image in each list. Unlike a normal <a
5006 href="command-line-options.html#composite" >-composite</a> operation, the canvas offset is also
Cristy882d9f42015-10-29 16:48:39 -04005007 added to the final composite positioning of each image. </td> </tr>
5008
5009 <tr><td></td>
5010 <td>If one of the image lists only contains one image, that image is
5011 applied to all the images in the other image list, regardless of which
5012 list it is. In this case it is the image meta-data of the list which
5013 preserved. </td>
5014 </tr>
5015
5016
5017 <tr>
5018 <td>dispose</td>
5019 <td>This like '<code>coalesce</code>' but shows the look of
5020 the animation after the layer disposal method has been applied, before
5021 the next sub-frame image is overlaid. That is the 'dispose' image that
Cristy594d2772015-11-15 10:47:42 -05005022 results from the application of the GIF <a href="command-line-options.html#dispose"
5023 >-dispose</a> method. This allows you to check what
Cristy882d9f42015-10-29 16:48:39 -04005024 is going wrong with a particular animation you may be developing.
5025 </td>
5026 </tr>
5027
5028 <tr>
5029 <td>flatten</td>
5030 <td>Create a canvas the size of the first images virtual
Cristy594d2772015-11-15 10:47:42 -05005031 canvas using the current <a href="command-line-options.html#background" >-background</a> color,
5032 and <a href="command-line-options.html#compose" >-compose</a> each image in turn onto that
Cristy882d9f42015-10-29 16:48:39 -04005033 canvas. Images falling outside that canvas is clipped. Final
5034 image will have a zero virtual canvas offset. </td>
5035 </tr>
5036
5037 <tr><td></td>
5038 <td>This usually used as one of the final 'image layering' operations
5039 overlaying all the prepared image layers into a final image. </td>
5040 </tr>
5041
5042 <tr><td></td>
5043 <td>For a single image this method can also be used to fillout a virtual
5044 canvas with real pixels, or to underlay an opaque color to remove
5045 transparency from an image.</td>
5046 </tr>
5047
5048
5049 <tr>
5050 <td>merge</td>
5051 <td>As 'flatten' method but merging all the given image
5052 layers to create a new layer image just large enough to hold all the
5053 image without clipping or extra space. The new images virtual offset
5054 will preserve the position of the new layer, even if this offset is
5055 negative. The virtual canvas size of the first image is preserved.
5056 </td>
5057 </tr>
5058
5059 <tr><td></td><td>Caution is advised when handling image layers with
5060 negative offsets as few image file formats handle them correctly.
Cristy594d2772015-11-15 10:47:42 -05005061 Following this operation method with <a href="command-line-options.html#repage" >+repage</a>
Cristy882d9f42015-10-29 16:48:39 -04005062 will remove the layer offset, and create an image in which all the
5063 overlaid image positions relative to each other is preserved, though
5064 not necessarily exactly where you specified them.
5065 </td>
5066 </tr>
5067
5068 <tr><td></td><td>See also 'trim-bounds' below which is closely related but
5069 without doing the'flatten' to merge the images together. </td>
5070 </tr>
5071
5072 <tr>
5073 <td>mosaic</td>
5074 <td>As 'flatten' method but expanding the initial canvas size
5075 of the first image in a positive direction only so as to hold all the
5076 image layers. However as a virtual canvas is 'locked' to the origin,
5077 by its own definition, image layers with a negative offsets will still
5078 become clipped by the top and left edges. See 'merge' or 'trim-bounds'
5079 if this could be a problem. </td>
5080
5081 </tr>
5082
5083 <tr><td></td><td>This method is commonly used to layout individual image
5084 using various offset but without knowing the final canvas size. The
5085 resulting image will, like 'flatten' not have any virtual offset, so
5086 can be saved to any image file format. </td>
5087 </tr>
5088
5089
5090 <tr>
5091 <td>optimize</td>
5092 <td>Optimize a coalesced animation, into GIF animation using
5093 a number of general techniques. This currently a short cut to
5094 apply both the '<code>optimize-frame</code>', and
5095 '<code>optimize-transparency</code>' methods but may be expanded to
5096 include other optimization methods as they are developed. </td>
5097 </tr>
5098
5099 <tr>
5100 <td>optimize-frame</td>
5101 <td>Optimize a coalesced animation, into GIF animation by
5102 reducing the number of pixels per frame as much as possible by
5103 attempting to pick the best layer disposal method to use, while ensuring
5104 the result will continue to animate properly. </td>
5105 </tr>
5106
5107 <tr><td></td><td> There is no guarantee that the best optimization is found.
5108 But then no reasonably fast GIF optimization algorithm can do this.
5109 However this does seem to do better than most other GIF frame
5110 optimizers seen. </td>
5111 </tr>
5112
5113 <tr>
5114 <td>optimize-plus</td>
5115 <td>As '<code>optimize-frame</code>' but attempt to improve the
5116 overall optimization by adding extra frames to the animation, without
5117 changing the final look or timing of the animation. The frames are
5118 added to attempt to separate the clearing of pixels from the
5119 overlaying of new additional pixels from one animation frame to the
5120 next. If this does not improve the optimization (for the next frame
5121 only), it will fall back to the results of the previous normal
5122 '<code>optimize-frame</code>' technique. </td>
5123 </tr>
5124
5125 <tr><td></td><td>There is the possibility that the change in the disposal
5126 style will result in a worsening in the optimization of later frames,
5127 though this is unlikely. In other words there no guarantee that it is
5128 better than the normal '<code>optimize-frame</code>' technique. For some
5129 animations however you can get a vast improvement in the final
5130 animation size. </td>
5131 </tr>
5132
5133 <tr>
5134 <td>optimize-transparency</td>
5135 <td>Given a GIF animation, replace any pixel in the sub-frame
5136 overlay images with transparency, if it does not change the resulting
Cristy594d2772015-11-15 10:47:42 -05005137 animation by more than the current <a href="command-line-options.html#fuzz" >-fuzz</a> factor.
Cristy882d9f42015-10-29 16:48:39 -04005138 </td>
5139 </tr>
5140
5141 <tr><td></td><td>This should allow a existing frame optimized GIF animation
5142 to compress into a smaller file size due to larger areas of one
5143 (transparent) color rather than a pattern of multiple colors repeating
5144 the current disposed image of the last frame. </td>
5145 </tr>
5146
5147 <tr>
5148 <td>remove-dups</td>
5149 <td>Remove (and merge time delays) of duplicate consecutive
5150 images, so as to simplify layer overlays of coalesced animations.
5151 </td>
5152 </tr>
5153
5154 <tr><td></td><td>Usually this a result of using a constant time delay
5155 across the whole animation, or after a larger animation was split into
5156 smaller sub-animations. The duplicate frames could also have been
5157 used as part of some frame optimization methods. </td>
5158 </tr>
5159
5160 <tr>
5161 <td>remove-zero</td>
5162 <td>Remove any image with a zero time delay, unless ALL the
5163 images have a zero time delay (and is not a proper timed animation, a
5164 warning is then issued). </td>
5165 </tr>
5166
5167 <tr><td></td><td>In a GIF animation, such images are usually frames which
5168 provide partial intermediary updates between the frames that are
5169 actually displayed to users. These frames are usually added for
5170 improved frame optimization in GIF animations. </td>
5171 </tr>
5172
5173 <tr>
5174 <td>trim-bounds</td>
5175 <td>Find the bounds of all the images in the current
5176 image sequence, then adjust the offsets so all images are contained on
5177 a minimal positive canvas. None of the image data is modified or
5178 merged, only the individual image virtual canvas size and offset.
5179 All the images is given the same canvas size, and and will have
5180 a positive offset, but will remain in the same position relative to
5181 each other. As a result of the minimal canvas size at least one image
5182 will touch every edge of that canvas. The image data touching those
5183 edges however may be transparent. </td>
5184 </tr>
5185
5186 <tr><td></td><td>The result is much like if you used 'merge' followed by a
Cristy594d2772015-11-15 10:47:42 -05005187 <a href="command-line-options.html#repage" >+repage</a> option, except that all the images
Cristy882d9f42015-10-29 16:48:39 -04005188 have been kept separate. If 'flatten' is used after using
5189 'trim-bounds' you will get the same result. </td>
5190 </tr>
5191
5192 </tbody>
5193</table>
5194
5195<p>To print a complete list of layer types, use <a href="command-line-options.html#list">-list layers</a>.</p>
5196
Cristy594d2772015-11-15 10:47:42 -05005197<p>The operators <a href="command-line-options.html#coalesce" >-coalesce</a>, <a href="command-line-options.html#deconstruct"
5198>-deconstruct</a>, <a href="command-line-options.html#flatten" >-flatten</a>, and <a href="command-line-options.html#mosaic"
5199>-mosaic</a> are only aliases for the above methods and may be depreciated in
5200the future. Also see <a href="command-line-options.html#page" >-page</a>, <a href="command-line-options.html#repage"
5201>-repage</a> operators, the <a href="command-line-options.html#compose" >-compose</a> setting, and the
5202GIF <a href="command-line-options.html#dispose" >-dispose</a> and <a href="command-line-options.html#delay" >-delay</a>
Cristy882d9f42015-10-29 16:48:39 -04005203settings. </p>
5204
5205
5206<div style="margin: auto;">
5207 <h3 class="magick-header"><a id="level"></a>-level <var>black_point</var>{,<var>white_point</var>}{<var>%</var>}{,<var>gamma</var>}</h3>
5208</div>
5209
5210<p class="magick-description">adjust the level of image channels.</p>
5211
5212<p>Given one, two or three values delimited with commas: black-point,
5213white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
5214white points range from 0 to <var>QuantumRange</var>, or from 0 to
5215100%; if the white point is omitted it is set to (<var>QuantumRange</var> - black_point), so as to center contrast changes.
5216If a <code>%</code> sign is present anywhere in the string, both black and white
Cristy594d2772015-11-15 10:47:42 -05005217points are percentages of the full color range. Gamma will do a <a
5218href="command-line-options.html#gamma">-gamma</a> adjustment of the values. If it is omitted, the
Cristy882d9f42015-10-29 16:48:39 -04005219default of 1.0 (no gamma correction) is assumed.</p>
5220
5221<p>In normal usage (<code>-level</code>) the image values are stretched so that
5222the given '<code>black_point</code>' value in the original image is set to zero
5223(or black), while the given '<code>white_point</code>' value is set to <var>QuantumRange</var> (or white). This provides you with direct
5224contrast adjustments to the image. The '<code>gamma</code>' of the resulting
5225image will then be adjusted. </p>
5226
5227<p>From ImageMagick v6.4.1-9 using the plus form of the operator
5228(<code>+level</code>) or adding the special '!' flag anywhere in the argument
5229list, will cause the operator to do the reverse of the level adjustment. That
5230is a zero, or <var>QuantumRange</var> value (black, and white, resp.)
5231in the original image, is adjusted to the given level values, allowing you to
5232de-contrast, or compress the channel values within the image. The
5233'<code>gamma</code>' is adjusted before the level adjustment to de-contrast the
5234image is made. </p>
5235
5236<p>Only the channels defined by the current <a href="command-line-options.html#channel">-channel</a>
5237setting are adjusted (defaults to RGB color channels only), allowing you to
5238limit the effect of this operator. </p>
5239
5240<p>Please note that the transparency channel is treated as 'matte'
5241values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
5242
5243
5244<div style="margin: auto;">
5245 <h3 class="magick-header"><a id="level-colors"></a>-level-colors {<var>black_color</var>}{,}{<var>white_color</var>}</h3>
5246</div>
5247
5248<p class="magick-description">adjust the level of an image using the provided dash separated colors.</p>
5249
5250<p>This function is exactly like <a href="command-line-options.html#level">-level</a>, except that the
5251value value for each color channel is determined by the
5252'<code>black_color</code>' and '<code>white_color</code>' colors given (as
5253described under the <a href="command-line-options.html#fill">-fill</a> option). </p>
5254
5255<p>This effectually means the colors provided to <code>-level-colors</code>
5256is mapped to become 'black' and 'white' respectively, with all the other
5257colors linearly adjusted (or clipped) to match that change. Each channel is
5258adjusted separately using the channel values of the colors specified. </p>
5259
5260<p>On the other hand the plus form of the operator (<code>+level-colors</code>)
5261will map the image color 'black' and 'white' to the given colors
5262respectively, resulting in a gradient (de-contrasting) tint of the image to
Cristy769d8892016-01-19 18:11:14 -05005263those colors. This can also be used to convert a plain grayscale image into a
Cristy882d9f42015-10-29 16:48:39 -04005264one using the gradient of colors specified. </p>
5265
5266<p>By supplying a single color with a comma separator either before or after
5267that color, will just replace the respective 'black' or 'white' point
5268respectively. But if no comma separator is provided, the given color is
5269used for both the black and white color points, making the operator either
5270threshold the images around that color (- form) or set all colors to that
5271color (+ form). </p>
5272
5273
5274<div style="margin: auto;">
5275 <h3 class="magick-header"><a id="limit"></a>-limit <var>type value</var></h3>
5276</div>
5277
5278<p class="magick-description">Set the pixel cache resource limit.</p>
5279
Cristye09ed312016-03-06 08:07:39 -05005280<p>Choose from: <code>width</code>, <code>height</code>, <code>area</code>, <code>memory</code>, <code>map</code>, <code>disk</code>, <code>file</code>, <code>thread</code>, <code>throttle</code>, or <code>time</code>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005281
5282<p>The value for <code>file</code> is in number of files. The other limits are
5283in bytes. Define arguments for the memory, map, area, and disk resource limits
5284with SI prefixes (.e.g 100MB).</p>
5285
5286<p>By default the limits are 768 files, 3GB of image area, 1.5GiB memory, 3GiB
5287memory map, and 18.45EB of disk. These limits are adjusted relative to the
5288available resources on your computer if this information is available. When
5289any limit is reached, ImageMagick fails in some fashion but attempts to take
5290compensating actions, if possible. For example, the following limits
5291memory:</p>
5292
5293<pre>
5294-limit memory 32MiB -limit map 64MiB
5295</pre>
5296
5297<p>Use <a href="command-line-options.html#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p>
5298
5299<pre>
Cristy594d2772015-11-15 10:47:42 -05005300-> identify -list resource
Cristy882d9f42015-10-29 16:48:39 -04005301Resource limits:
5302 Width: 100MP
5303 Height: 100MP
5304 Area: 25.181GB
5305 Memory: 11.726GiB
5306 Map: 23.452GiB
5307 Disk: unlimited
5308 File: 768
5309 Thread: 12
5310 Throttle: 0
5311 Time: unlimited
5312</pre>
5313
5314<p>Requests for pixel storage to keep intermediate images are satisfied by one
5315of three resource categories: in-memory pool, memory-mapped files pool, and
Cristy594d2772015-11-15 10:47:42 -05005316disk pool (in that order) depending on the <a href="command-line-options.html#limit">&#x2011;limit</a> settings
Cristy882d9f42015-10-29 16:48:39 -04005317and whether the system honors a resource request. If the total size of
5318allocated pixel storage in the given pool reaches the corresponding limit, the
5319request is passed to the next pool. Additionally, requests that exceed the
5320<code>area</code> limit automagically are allocated on disk.</p>
5321
5322<p>To illustrate how ImageMagick utilizes resource limits, consider a typical
5323image resource request. First, ImageMagick tries to allocate the pixels in
5324memory. The request might be denied if the resource request exceeds the
5325<code>memory</code> limit or if the system does not honor the request. If
5326a memory request is not honored, the pixels are allocated to disk and the file
5327is memory-mapped. However, if the allocation request exceeds the
5328<code>map</code> limit, the resource allocation goes to disk. In all cases, if
5329the resource request exceeds the <code>area</code> limit, the pixels are
5330automagically cached to disk. If the disk has a hard limit, the program
5331fails.</p>
5332
5333<p>In most cases you simply do not need to concern yourself with resource
5334limits. ImageMagick chooses reasonable defaults and most images do not tax
5335your computer resources. Where limits do come in handy is when you process
5336images that are large or on shared systems where ImageMagick can consume all
5337or most of the available memory. In this case, the ImageMagick workflow slows
5338other processes or, in extreme cases, brings the system to a halt. Under
5339these circumstances, setting limits give some assurances that the ImageMagick
5340workflow will not interfere with other concurrent uses of the computer. For
5341example, assume you have a web interface that processes images uploaded from
5342the Internet. To assure ImageMagick does not exceed 10MiB of memory you can
5343simply set the area limit to 10MiB:</p>
5344
5345<pre>
5346-limit area 10MB
5347</pre>
5348
5349<p>Now whenever a large image is processed, the pixels are automagically
5350cached to disk instead of memory. This of course implies that large images
5351typically process very slowly, simply because pixel processing in memory can
5352be an order of magnitude faster than on disk. Because your web site users
5353might inadvertently upload a huge image to process, you should set a disk
5354limit as well:</p>
5355
5356<pre>
5357-limit area 10MB -limit disk 500MB
5358</pre>
5359
5360<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
5361
5362<p>In addition to command-line resource limit option, resources can be set
Cristy594d2772015-11-15 10:47:42 -05005363with <a href="resources.html#environment" >environment variables</a>. Set the
Cristy882d9f42015-10-29 16:48:39 -04005364environment variables <code>MAGICK_AREA_LIMIT</code>,
5365<code>MAGICK_DISK_LIMIT</code>, <code>MAGICK_FILE_LIMIT</code>,
5366<code>MAGICK_MEMORY_LIMIT</code>, <code>MAGICK_MAP_LIMIT</code>,
5367<code>MAGICK_THREAD_LIMIT</code>, <code>MAGICK_TIME_LIMIT</code> for limits of
5368image area, disk space, open files, heap memory, memory map, number of threads
5369of execution, and maximum elapsed time in seconds respectively.</p>
5370
5371<p> Inquisitive users can try adding <a href="command-line-options.html#debug">-debug cache</a> to
5372their commands and then scouring the generated output for references to the
5373pixel cache, in order to determine how the pixel cache was allocated and how
5374resources were consumed. Advanced Unix/Linux users can pipe that output
5375through <code>grep memory|open|destroy|disk</code> for more readable sifting.
5376</p>
5377
5378<p>For more about ImageMagick's use of resources, see the section <b>Cache
Cristy594d2772015-11-15 10:47:42 -05005379Storage and Resource Requirements</b> on the <a href="architecture.html#cache
5380">Architecture</a> page. </p>
Cristy882d9f42015-10-29 16:48:39 -04005381
5382<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05005383 <h3 class="magick-header"><a id="linear-stretch"></a>-linear-stretch <var>black-point</var><br />-linear-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005384</div>
5385
5386<p class="magick-description">Linear with saturation stretch.</p>
5387
Cristy594d2772015-11-15 10:47:42 -05005388<p>This is very similar to <a href="command-line-options.html#contrast-stretch" >-contrast-stretch</a>,
Cristy882d9f42015-10-29 16:48:39 -04005389and uses a 'histogram bin' to determine the range of color values that needs to
Cristy594d2772015-11-15 10:47:42 -05005390be stretched. However it then stretches those colors using the <a
5391href="command-line-options.html#level" >-level</a> operator.</p>
Cristy882d9f42015-10-29 16:48:39 -04005392
5393<p>As such while the initial determination may have 'binning' round off
5394effects, the image colors are stretched mathematically, rather than using the
5395histogram bins. This makes the operator more accurate. </p>
5396
Cristy594d2772015-11-15 10:47:42 -05005397<p>note however that a <a href="command-line-options.html#linear-stretch" >-linear-stretch</a> of
Cristy882d9f42015-10-29 16:48:39 -04005398'<code>0</code>' does nothing, while a value of '<code>1</code>' does a near
5399perfect stretch of the color range. </p>
5400
Cristy594d2772015-11-15 10:47:42 -05005401<p>See also <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect'
Cristy882d9f42015-10-29 16:48:39 -04005402normalization of mathematical images. </p>
5403
5404<p>This operator is under review for re-development. </p>
5405
5406
5407<div style="margin: auto;">
5408 <h3 class="magick-header"><a id="linewidth"></a>-linewidth</h3>
5409</div>
5410
5411<p class="magick-description">the line width for subsequent draw operations.</p>
5412
5413<div style="margin: auto;">
5414 <h3 class="magick-header"><a id="liquid-rescale"></a>-liquid-rescale <var>geometry</var></h3>
5415</div>
5416
5417<p class="magick-description">rescale image with seam-carving.</p>
5418
5419<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5420
5421<div style="margin: auto;">
5422 <h3 class="magick-header"><a id="list"></a>-list <var>type</var></h3>
5423</div>
5424
5425<p class="magick-description">Print a list of supported arguments for various options or settings. Choose from these list types:</p>
5426
5427<pre class="pre-scrollable">
5428Align
5429Alpha
5430Boolean
5431Cache
5432Channel
5433Class
5434ClipPath
5435Coder
5436Color
5437Colorspace
5438Command
5439Complex
5440Compose
5441Compress
5442Configure
5443DataType
5444Debug
5445Decoration
5446Delegate
5447Direction
5448Dispose
5449Distort
5450Dither
5451Endian
5452Evaluate
5453FillRule
5454Filter
5455Font
5456Format
5457Function
5458Gravity
5459Intensity
5460Intent
5461Interlace
5462Interpolate
5463Kernel
5464Layers
5465LineCap
5466LineJoin
5467List
5468Locale
5469LogEvent
5470Log
5471Magic
5472Method
5473Metric
5474Mime
5475Mode
5476Morphology
5477Module
5478Noise
5479Orientation
5480PixelIntensity
5481Policy
5482PolicyDomain
5483PolicyRights
5484Preview
5485Primitive
5486QuantumFormat
5487Resource
5488SparseColor
5489Statistic
5490Storage
5491Stretch
5492Style
5493Threshold
5494Type
5495Units
5496Validate
5497VirtualPixel
5498</pre>
5499
5500<p>These lists vary depending on your version of ImageMagick. Use "<code>-list
5501list</code>" to get a complete listing of all the "<code>-list</code>" arguments
5502available:</p>
5503
5504<pre>
5505identify -list list
5506</pre>
5507
5508<div style="margin: auto;">
5509 <h3 class="magick-header"><a id="log"></a>-log <var>string</var></h3>
5510</div>
5511
5512<p class="magick-description">Specify format for debug log.</p>
5513
Cristy594d2772015-11-15 10:47:42 -05005514<p>This option specifies the format for the log printed when the <a
5515href="command-line-options.html#debug">-debug</a> option is active.</p>
Cristy882d9f42015-10-29 16:48:39 -04005516
5517<p>You can display the following components by embedding special format
5518characters:</p>
5519
5520<dl class="dl-horizontal">
5521<dt>%d</dt><dd>domain</dd>
5522<dt>%e</dt><dd>event</dd>
5523<dt>%f</dt><dd>function</dd>
5524<dt>%l</dt><dd>line</dd>
5525<dt>%m</dt><dd>module</dd>
5526<dt>%p</dt><dd>process ID</dd>
5527<dt>%r</dt><dd>real CPU time</dd>
5528<dt>%t</dt><dd>wall clock time</dd>
5529<dt>%u</dt><dd>user CPU time</dd>
5530<dt>%%</dt><dd>percent sign</dd>
5531<dt>\n</dt><dd>newline</dd>
5532<dt>\r</dt><dd>carriage return</dd>
5533</dl>
5534
5535<p>For example:</p>
5536
5537<pre>
5538convert -debug coders -log "%u %m:%l %e" in.gif out.png
5539</pre>
5540
5541<p>The default behavior is to print all of the components.</p>
5542
5543<div style="margin: auto;">
5544 <h3 class="magick-header"><a id="loop"></a>-loop <var>iterations</var></h3>
5545</div>
5546
5547<p class="magick-description">add Netscape loop extension to your GIF animation.</p>
5548
5549<p>Set iterations to zero to repeat the animation an infinite number of times,
5550otherwise the animation repeats itself up to <var>iterations</var>
5551times.</p>
5552
5553<div style="margin: auto;">
5554 <h3 class="magick-header"><a id="lowlight-color"></a>-lowlight-color <var>color</var></h3>
5555</div>
5556
5557<p class="magick-description">when comparing images, de-emphasize pixel differences with this color.</p>
5558
5559<div style="margin: auto;">
5560 <h3 class="magick-header"><a id="magnify"></a>-magnify</h3>
5561</div>
5562
5563<p class="magick-description">double the size of the image with pixel art scaling.</p>
5564
5565
5566<div style="margin: auto;">
5567 <h3 class="magick-header"><a id="map"></a>-map <var>type</var></h3>
5568</div>
5569
5570<p class="magick-description">Display image using this <var>type</var>.</p>
5571
5572<p>Choose from these <var>Standard Colormap</var> types:</p>
5573
5574<pre>
5575best
5576default
5577gray
5578red
5579green
5580blue
5581</pre>
5582
5583<p>The <var>X server</var> must support the <var>Standard
5584Colormap</var> you choose, otherwise an error occurs. Use <code>list</code> as
5585the type and <code>display</code> searches the list of colormap types in
5586<code>top-to-bottom</code> order until one is located. See <var>xstdcmap(1)</var> for one way of creating Standard Colormaps.</p>
5587
5588
5589<div style="margin: auto;">
5590 <h3 class="magick-header"><a id="map_stream_"></a>-map <var>components</var></h3>
5591</div>
5592
5593<p class="magick-description">pixel map.</p>
5594
5595<p>Here are the valid components of a map:</p>
5596
5597<dl class="dl-horizontal">
5598<dt>r</dt><dd> red pixel component</dd>
5599<dt>g</dt><dd> green pixel component</dd>
5600<dt>b</dt><dd> blue pixel component</dd>
5601<dt>a</dt><dd> alpha pixel component (0 is transparent)</dd>
5602<dt>o</dt><dd> opacity pixel component (0 is opaque)</dd>
5603<dt>i</dt><dd> grayscale intensity pixel component</dd>
5604<dt>c</dt><dd> cyan pixel component</dd>
5605<dt>m</dt><dd> magenta pixel component</dd>
5606<dt>y</dt><dd> yellow pixel component</dd>
5607<dt>k</dt><dd> black pixel component</dd>
5608<dt>p</dt><dd> pad component (always 0)</dd>
5609</dl>
5610
5611<p>You can specify as many of these components as needed in any order (e.g.
5612bgr). The components can repeat as well (e.g. rgbr).</p>
5613
5614
5615<div style="margin: auto;">
Cristy882d9f42015-10-29 16:48:39 -04005616 <h3 class="magick-header"><a id="mattecolor"></a>-mattecolor <var>color</var></h3>
5617</div>
5618
5619<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p>
5620
5621<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
5622
Cristy594d2772015-11-15 10:47:42 -05005623<p>The default matte color is <code>#BDBDBD</code>, <span
5624style="background-color: #bdbdbd;">this shade of gray</span>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005625
Cristyf650f4f2016-04-01 10:53:07 -04005626<p>This is an IMv6 option, use <a href="command-line-options.html#alpha-color">-alpha-color</a> with IMv7.</p>
5627
Cristy882d9f42015-10-29 16:48:39 -04005628<div style="margin: auto;">
5629 <h3 class="magick-header"><a id="maximum"></a>-maximum</h3>
5630</div>
5631
5632<p class="magick-description">return the maximum intensity of an image sequence.</p>
5633
5634<p>Select the 'maximum' value from all the surrounding pixels. </p>
5635
Cristy594d2772015-11-15 10:47:42 -05005636<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005637name. </p>
5638
5639<div style="margin: auto;">
5640 <h3 class="magick-header"><a id="median"></a>-median <var>geometry</var></h3>
5641</div>
5642
5643<p class="magick-description">apply a median filter to the image.</p>
5644
5645<p>Select the 'middle' value from all the surrounding pixels. </p>
5646
Cristy594d2772015-11-15 10:47:42 -05005647<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005648name. </p>
5649
5650<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05005651 <h3 class="magick-header"><a id="mean-shift"></a>-mean-shift <var>width</var>x<var>height</var>{<var>+distance</var>{%}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005652</div>
5653
5654<p class="magick-description">image noise removal and color reduction/segmentation (e.g. -mean-shift 7x7+10%).</p>
5655
5656<p><var>width</var>x<var>height</var> is the window size and <var>distance</var> is the color distance measured in the range 0 to 1 or 0 to 100%</p>
5657
5658<p>The mean shift algorithm is iterative and thus slower the larger the window size. For each pixel, it gets all the pixels in the window centered at the pixel and excludes those that are outside the <var>radius=sqrt((width-1)(height-1)/4)</var> surrounding the pixel. From those pixels, it finds which of them are within the specified squared color distance from the current mean. It then computes a new x,y centroid from those coordinates and a new mean. This new x,y centroid is used as the center for a new window. This process is iterated until it converges and the final mean is then used to replace the original pixel value. It repeats this process for the next pixel, etc, until it processes all pixels in the image. Results are better when using other colorspaces rather than RGB. Recommend YIQ, YUV or YCbCr, which seem to give equivalent results.</p>
5659
5660<div style="margin: auto;">
5661 <h3 class="magick-header"><a id="metric"></a>-metric <var>type</var></h3>
5662</div>
5663
5664<p class="magick-description">Output to STDERR a measure of the differences between images according to the <var>type</var> given metric.</p>
5665
5666<p>Choose from:</p>
5667
5668<dl class="dl-horizontal">
5669<dt>AE</dt><dd> absolute error count, number of different pixels (-fuzz effected)</dd>
5670<dt>FUZZ</dt><dd> mean color distance</dd>
5671<dt>MAE</dt><dd> mean absolute error (normalized), average channel error distance</dd>
5672<dt>MEPP</dt><dd> mean error per pixel (normalized mean error, normalized peak error)</dd>
5673<dt>MSE</dt><dd> mean error squared, average of the channel error squared</dd>
5674<dt>NCC</dt><dd> normalized cross correlation</dd>
5675<dt>PAE</dt><dd> peak absolute (normalized peak absolute)</dd>
5676<dt>PHASH</dt><dd> perceptual hash</dd>
5677<dt>PSNR</dt><dd> peak signal to noise ratio</dd>
5678<dt>RMSE</dt><dd> root mean squared (normalized root mean squared)</dd>
5679</dl>
5680
5681<p>Control the '<code>AE</code>', or absolute count of pixels that are different,
Cristy594d2772015-11-15 10:47:42 -05005682with the <a href="command-line-options.html#fuzz" >-fuzz</a> factor (ignore pixels which
Cristy882d9f42015-10-29 16:48:39 -04005683only changed by a small amount). Use '<code>PAE</code>' to find the
Cristy594d2772015-11-15 10:47:42 -05005684size of the <a href="command-line-options.html#fuzz" >-fuzz</a> factor needed to make all pixels
Cristy882d9f42015-10-29 16:48:39 -04005685'similar', while '<code>MAE</code>' determines the factor needed
5686for about half the pixels to be similar. </p>
5687
5688<p>The '<code>MEPP</code>' metric returns three different metrics
5689('<code>MAE</code>', '<code>MAE</code>' normalized, and '<code>PAE</code>'
5690normalized) from a single comparison run. </p>
5691
5692<p>To print a complete list of metrics, use the <a href="command-line-options.html#list">-list
5693metric</a> option.</p>
5694
5695
5696<div style="margin: auto;">
5697 <h3 class="magick-header"><a id="minimum"></a>-minimum</h3>
5698</div>
5699
5700<p class="magick-description">return the minimum intensity of an image sequence.</p>
5701
5702<p>Select the 'minimal' value from all the surrounding pixels. </p>
5703
Cristy594d2772015-11-15 10:47:42 -05005704<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005705name. </p>
5706
5707
5708
5709<div style="margin: auto;">
5710 <h3 class="magick-header"><a id="mode"></a>-mode <var>geometry</var></h3>
5711</div>
5712
5713<p class="magick-description">make each pixel the \'predominant color\' of the neighborhood.'</p>
5714
5715<div style="margin: auto;">
5716 <h3 class="magick-header">-mode <var>value</var></h3>
5717</div>
5718
5719<p class="magick-description">Mode of operation.</p>
5720
5721<p>Choose the <var>value</var> from these styles: <code>Frame,
5722Unframe, or Concatenate</code></p>
5723
Cristy594d2772015-11-15 10:47:42 -05005724<p>Use the <a href="command-line-options.html#list" >-list</a> option with a '<code>Mode</code>' argument
5725for a list of <a href="command-line-options.html#mode" >-mode</a> arguments available in your
Cristy882d9f42015-10-29 16:48:39 -04005726ImageMagick installation.</p>
5727
5728
5729<div style="margin: auto;">
5730 <h3 class="magick-header"><a id="modulate"></a>-modulate <var>brightness</var>[,<var>saturation</var>,<var>hue</var>]</h3>
5731</div>
5732
5733<p class="magick-description">Vary the <var>brightness</var>, <var>saturation</var>, and <var>hue</var> of an image.</p>
5734
5735<p>The arguments are given as a percentages of variation. A value of 100 means
5736no change, and any missing values are taken to mean 100.</p>
5737
5738<p>The <var>brightness</var> is a multiplier of the overall
5739brightness of the image, so 0 means pure black, 50 is half as bright, 200 is
5740twice as bright. To invert its meaning <a href="command-line-options.html#negate">-negate</a> the image
5741before and after. </p>
5742
5743<p>The <var>saturation</var> controls the amount of color in an
5744image. For example, 0 produce a grayscale image, while a large value such as
5745200 produce a very colorful, 'cartoonish' color.</p>
5746
5747<p>The <var>hue</var> argument causes a "rotation" of the colors
5748within the image by the amount specified. For example, 50 results in
5749a counter-clockwise rotation of 90, mapping red shades to purple, and so on.
5750A value of either 0 or 200 results in a complete 180 degree rotation of the
5751image. Using a value of 300 is a 360 degree rotation resulting in no change to
5752the original image. </p>
5753
5754<p>For example, to increase the color brightness by 20% and decrease the color
Cristy594d2772015-11-15 10:47:42 -05005755saturation by 10% and leave the hue unchanged, use <a
5756href="command-line-options.html#modulate">-modulate 120,90</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005757
Cristy594d2772015-11-15 10:47:42 -05005758<p>Use <a href="command-line-options.html#set">-set</a> attribute of '<code
5759>option:modulate:colorspace</code>' to specify which colorspace to
Cristy882d9f42015-10-29 16:48:39 -04005760modulate. Choose from <code>HCL</code>, <code>HCLp</code>, <code>HSB</code>, <code>HSI</code>, <code>HSL</code> (the default), <code>HSV</code>, <code>HWB</code>, or <code>LCH</code> (LCHuv). For example,</p>
5761
5762<pre>
5763convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png
5764</pre>
5765
5766<div style="margin: auto;">
5767 <h3 class="magick-header"><a id="moments"></a>-moments</h3>
5768</div>
5769
5770<p class="magick-description">report image moments and perceptual hash.</p>
5771
5772
5773<div style="margin: auto;">
5774 <h3 class="magick-header"><a id="monitor"></a>-monitor</h3>
5775</div>
5776
5777<p class="magick-description">monitor progress.</p>
5778
5779
5780<div style="margin: auto;">
5781 <h3 class="magick-header"><a id="monochrome"></a>-monochrome</h3>
5782</div>
5783
5784<p class="magick-description">transform the image to black and white.</p>
5785
5786<div style="margin: auto;">
5787 <h3 class="magick-header"><a id="morph"></a>-morph <var>frames</var></h3>
5788</div>
5789
5790<p class="magick-description">morphs an image sequence.</p>
5791
5792<p>Both the image pixels and size are linearly interpolated to give the
5793appearance of a metamorphosis from one image to the next, over all the images
Cristy594d2772015-11-15 10:47:42 -05005794in the current image list. The added images are the equivalent of a <a
5795href="command-line-options.html#blend">-blend</a> composition. The <var>frames</var>
Cristy882d9f42015-10-29 16:48:39 -04005796argument determine how many images to interpolate between each image. </p>
5797
5798
5799<div style="margin: auto;">
5800 <h3 class="magick-header"><a id="morphology"></a>-morphology</h3>
5801 <h3 class="magick-header">-morphology <var>method</var> <var>kernel</var></h3>
5802</div>
5803
5804<p class="magick-description">apply a morphology method to the image.</p>
5805
Cristy594d2772015-11-15 10:47:42 -05005806<p>Until I get around to writing an option summary for this, see <a
5807href="http://www.imagemagick.org/Usage/morphology/" >IM Usage Examples,
Cristy882d9f42015-10-29 16:48:39 -04005808Morphology</a>. </p>
5809
5810
5811<div style="margin: auto;">
5812 <h3 class="magick-header"><a id="mosaic"></a>-mosaic</h3>
5813</div>
5814
Cristy594d2772015-11-15 10:47:42 -05005815<p class="magick-description">an simple alias for the <a href="command-line-options.html#layers" >-layers</a> method "mosaic"</p>
Cristy882d9f42015-10-29 16:48:39 -04005816
5817
5818<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05005819 <h3 class="magick-header"><a id="motion-blur"></a>-motion-blur <var>radius</var><br />-motion-blur <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005820</div>
5821
5822<p class="magick-description">simulate motion blur.</p>
5823
5824<p>Blur with the given radius, standard deviation (sigma), and angle. The
5825angle given is the angle toward which the image is blurred. That is the
5826direction people would consider the object is coming from. </p>
5827
5828<p>Note that the blur is not uniform distribution, giving the motion a
5829definite sense of direction of movement. </p>
5830
5831<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
5832pixels which are outside the image proper are blurred into the final result.
5833</p>
5834
5835<div style="margin: auto;">
5836 <h3 class="magick-header"><a id="name"></a>-name</h3>
5837</div>
5838
5839<p class="magick-description">name an image.</p>
5840<div style="margin: auto;">
5841 <h3 class="magick-header"><a id="negate"></a>-negate</h3>
5842</div>
5843
5844<p class="magick-description">replace each pixel with its complementary color.</p>
5845
5846<p>The red, green, and blue intensities of an image are negated. White becomes
5847black, yellow becomes blue, etc. Use <a href="command-line-options.html#negate">+negate</a> to only
5848negate the grayscale pixels of the image.</p>
5849
5850<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05005851 <h3 class="magick-header"><a id="noise"></a>-noise <var>geometry</var><br/>
Cristy882d9f42015-10-29 16:48:39 -04005852 +noise <var>type</var></h3>
5853</div>
5854
5855<p class="magick-description">Add or reduce noise in an image.</p>
5856
5857<p>The principal function of noise peak elimination filter is to smooth the
5858objects within an image without losing edge information and without creating
5859undesired structures. The central idea of the algorithm is to replace a pixel
5860with its next neighbor in value within a pixel window, if this pixel has been
5861found to be noise. A pixel is defined as noise if and only if this pixel is
5862a maximum or minimum within the pixel window.</p>
5863
5864<p>Use <code><a href="command-line-options.html#noise">-noise</a> <var>radius</var></code> to
5865specify the width of the neighborhood when reducing noise. This is equivalent
Cristy594d2772015-11-15 10:47:42 -05005866to using a <code><a href="command-line-options.html#statistic" >-statistic</a> NonPeak</code> operation,
Cristy882d9f42015-10-29 16:48:39 -04005867which should be used in preference.</p>
5868
5869<p>Use <a href="command-line-options.html#noise">+noise</a> followed by a noise <var>type</var> to add noise to an image. Choose from these noise
5870types:</p>
5871
5872<pre>
5873Gaussian
5874Impulse
5875Laplacian
5876Multiplicative
5877Poisson
5878Random
5879Uniform
5880</pre>
5881
Cristy594d2772015-11-15 10:47:42 -05005882<p>The amount of noise added can be controlled by the <code><a
5883href="command-line-options.html#attenuate" >-attenuate</a></code> setting. If unset the value is
Cristy882d9f42015-10-29 16:48:39 -04005884equivalent to 1.0, or a maximum noise addition.</p>
5885
5886<p>Note that Random will replace the image with noise rather than add noise to the image. Use Uniform, if you wish to add random noise to the image.</p>
5887
5888<p>To print a complete list of noises, use the <a href="command-line-options.html#list">-list noise</a> option.</p>
5889
5890<p>Also see the <a href="command-line-options.html#evaluate">-evaluate</a> noise functions that allows
5891the use of a controlling value to specify the amount of noise that should be
5892added to an image. </p>
5893
5894
5895<div style="margin: auto;">
5896 <h3 class="magick-header"><a id="normalize"></a>-normalize</h3>
5897</div>
5898
5899<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
5900
5901<p>The intensity values are stretched to cover the entire range of possible
5902values. While doing so, black-out at most <var>2%</var> of the pixels and
5903white-out at most <var>1%</var> of the pixels.</p>
5904
Cristy594d2772015-11-15 10:47:42 -05005905<p>Note that as of ImageMagick 6.4.7-0, <a href="command-line-options.html#normalize" >-normalize</a>
5906is equivalent to <a href="command-line-options.html#contrast-stretch" >-contrast-stretch 2%x1%</a>.
5907(Before this version, it was equivalent to <a href="command-line-options.html#contrast-stretch"
5908>-contrast-stretch 2%x99%</a>).</p>
Cristy882d9f42015-10-29 16:48:39 -04005909
Cristy769d8892016-01-19 18:11:14 -05005910<p>All the channels are normalized in concert by the same amount so as to
Cristy594d2772015-11-15 10:47:42 -05005911preserve color integrity, when the default <a href="command-line-options.html#channel" >+channel</a>
5912setting is in use. Specifying any other <a href="command-line-options.html#channel" >-channel</a>
Cristy882d9f42015-10-29 16:48:39 -04005913setting will normalize the RGB channels independently.</p>
5914
Cristy594d2772015-11-15 10:47:42 -05005915<p>See <a href="command-line-options.html#contrast-stretch" >-contrast-stretch</a> for more details.
5916Also see <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect' normalization
Cristy882d9f42015-10-29 16:48:39 -04005917that is better suited to mathematically generated images. </p>
5918
5919<p>This operator is under review for re-development. </p>
5920
5921
5922<div style="margin: auto;">
5923 <h3 class="magick-header"><a id="opaque"></a>-opaque <var>color</var></h3>
5924</div>
5925
5926<p class="magick-description">change this color to the fill color within the image.</p>
5927
5928<p>The <var>color</var> argument is defined using the format
Cristy594d2772015-11-15 10:47:42 -05005929described under the <a href="command-line-options.html#fill" >-fill</a> option. The <a href="command-line-options.html#fuzz"
5930>-fuzz</a> setting can be used to match and replace colors similar to the one
Cristy882d9f42015-10-29 16:48:39 -04005931given.</p>
5932
5933<p>Use <a href="command-line-options.html#opaque">+opaque</a> to paint any pixel that does not match
5934the target color. </p>
5935
5936<p>The <a href="command-line-options.html#transparent">-transparent</a> operator is exactly the same
Cristy594d2772015-11-15 10:47:42 -05005937as <a href="command-line-options.html#opaque" >-opaque</a> but replaces the matching color with
Cristy882d9f42015-10-29 16:48:39 -04005938transparency rather than the current <a href="command-line-options.html#fill">-fill</a> color setting.
5939To ensure that it can do this it also ensures that the image has an alpha
Cristy594d2772015-11-15 10:47:42 -05005940channel enabled, as per "<code><a href="command-line-options.html#alpha" >-alpha</a> set</code>", for
5941the new transparent colors, and does not require you to modify the <a
5942href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
Cristy882d9f42015-10-29 16:48:39 -04005943
5944
5945<div style="margin: auto;">
5946 <h3 class="magick-header"><a id="ordered-dither"></a>-ordered-dither <var>threshold_map</var>{,<var>level</var>...}</h3>
5947</div>
5948
5949<p class="magick-description">dither the image using a pre-defined ordered dither <var>threshold map</var> specified, and a uniform color map with the
5950given number of <var>levels</var> per color channel.</p>
5951
5952<p>You can choose from these standard threshold maps:</p>
5953
5954<pre class="pre-scrollable">
5955threshold 1x1 Threshold 1x1 (non-dither)
5956checks 2x1 Checkerboard 2x1 (dither)
5957o2x2 2x2 Ordered 2x2 (dispersed)
5958o3x3 3x3 Ordered 3x3 (dispersed)
5959o4x4 4x4 Ordered 4x4 (dispersed)
5960o8x8 8x8 Ordered 8x8 (dispersed)
5961h3x4a 4x1 Halftone 4x4 (angled)
5962h6x6a 6x1 Halftone 6x6 (angled)
5963h8x8a 8x1 Halftone 8x8 (angled)
5964h3x4o Halftone 4x4 (orthogonal)
5965h6x6o Halftone 6x6 (orthogonal)
5966h8x8o Halftone 8x8 (orthogonal)
5967h36x16o Halftone 16x16 (orthogonal)
5968c5x5b c5x5 Circles 5x5 (black)
5969c5x5w Circles 5x5 (white)
5970c6x6b c6x6 Circles 6x6 (black)
5971c6x6w Circles 6x6 (white)
5972c7x7b c7x7 Circles 7x7 (black)
5973c7x7w Circles 7x7 (white)
5974</pre>
5975
5976<p> The <code>threshold</code> generated a simple 50% threshold of the image.
Cristy594d2772015-11-15 10:47:42 -05005977This could be used with <var >level</var> to do the equivalent of <a
5978href="command-line-options.html#posterize" >-posterize</a> to reduce an image to basic primary colors.
Cristy882d9f42015-10-29 16:48:39 -04005979</p>
5980
5981<p>The <code>checks</code> pattern produces a 3 level checkerboard dither
5982pattern. That is a grayscale will become a pattern of solid black, solid
5983white, and mid-tone colors into a checkerboard pattern of black and white.
5984</p>
5985
Cristy594d2772015-11-15 10:47:42 -05005986<p>You can define your own <var >threshold map</var> for ordered
Cristy882d9f42015-10-29 16:48:39 -04005987dithering and halftoning your images, in either personal or system
Cristy594d2772015-11-15 10:47:42 -05005988<code>thresholds.xml</code> XML file. See <a href="resources.html" >Resources</a>
Cristy882d9f42015-10-29 16:48:39 -04005989for more details of configuration files. </p>
5990
5991<p>To print a complete list of the thresholds that have been defined, use the
Cristy594d2772015-11-15 10:47:42 -05005992<a href="command-line-options.html#list" >-list threshold</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04005993
5994<p>Note that at this time the same threshold dithering map is used for all
5995color channels, no attempt is made to offset or rotate the map for different
5996channels is made, to create an offset printing effect. Also as the maps are
5997simple threshold levels, the halftone and circle maps will create incomplete
5998circles along the edges of a colored area. Also all the effects are purely
5999on/off boolean effects, without anti-aliasing to make the circles smooth
6000looking. Large dots can be made to look better with a small amount of blurring
6001after being created. </p>
6002
6003
6004<div style="margin: auto;">
6005 <h3 class="magick-header"><a id="orient"></a>-orient <var>image orientation</var></h3>
6006</div>
6007
6008<p class="magick-description">specify orientation of a digital camera image.</p>
6009
6010<p>Choose from these orientations:</p>
6011
6012<pre>
6013bottom-left right-top
6014bottom-right top-left
6015left-bottom top-right
6016left-top undefined
6017right-bottom
6018</pre>
6019
Cristy594d2772015-11-15 10:47:42 -05006020<p>To print a complete list of orientations, use the <a href="command-line-options.html#list" >-list
Cristy882d9f42015-10-29 16:48:39 -04006021orientation</a> option.</p>
6022
6023
6024<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05006025 <h3 class="magick-header"><a id="page"></a>-page <var>geometry</var><br/>
6026 -page <var>media</var>[<var>offset</var>][{<var>^!&lt;&gt;</var>}]<br/>
Cristy882d9f42015-10-29 16:48:39 -04006027 +page
6028 </h3>
6029</div>
6030
6031<p class="magick-description">Set the size and location of an image on the larger virtual canvas.</p>
6032
6033<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6034
6035<p>For convenience you can specify the page size using <var>media</var> (see below). Offsets can then be added as with other
Cristy594d2772015-11-15 10:47:42 -05006036<var>geometry</var> arguments (e.g. <a
6037href="command-line-options.html#page">-page</a> <code>Letter+43+43</code>).</p>
Cristy882d9f42015-10-29 16:48:39 -04006038
6039<p>Use <var>media</var> as shorthand to specify the dimensions (<var>width</var>x<var>height</var>) of the <var>PostScript</var> page in dots per inch or a TEXT page in pixels.
6040The choices for a PostScript page are:</p>
6041
6042<dl class="dl-horizontal">
6043<dt> 11x17 </dt> <dd> 792 x 1224</dd>
6044<dt> Ledger </dt> <dd> 1224 x 792</dd>
6045<dt> Legal </dt> <dd> 612 x 1008</dd>
6046<dt> Letter </dt> <dd> 612 x 792</dd>
6047<dt> LetterSmall</dt> <dd> 612 x 792</dd>
6048<dt> ArchE </dt> <dd> 2592 x 3456</dd>
6049<dt> ArchD </dt> <dd> 1728 x 2592</dd>
6050<dt> ArchC </dt> <dd> 1296 x 1728</dd>
6051<dt> ArchB </dt> <dd> 864 x 1296</dd>
6052<dt> ArchA </dt> <dd> 648 x 864</dd>
6053<dt> A0 </dt> <dd> 2380 x 3368</dd>
6054<dt> A1 </dt> <dd> 1684 x 2380</dd>
6055<dt> A2 </dt> <dd> 1190 x 1684</dd>
6056<dt> A3 </dt> <dd> 842 x 1190</dd>
6057<dt> A4 </dt> <dd> 595 x 842</dd>
6058<dt> A4Small </dt> <dd> 595 x 842</dd>
6059<dt> A5 </dt> <dd> 421 x 595</dd>
6060<dt> A6 </dt> <dd> 297 x 421</dd>
6061<dt> A7 </dt> <dd> 210 x 297</dd>
6062<dt> A8 </dt> <dd> 148 x 210</dd>
6063<dt> A9 </dt> <dd> 105 x 148</dd>
6064<dt> A10 </dt> <dd> 74 x 105</dd>
6065<dt> B0 </dt> <dd> 2836 x 4008</dd>
6066<dt> B1 </dt> <dd> 2004 x 2836</dd>
6067<dt> B2 </dt> <dd> 1418 x 2004</dd>
6068<dt> B3 </dt> <dd> 1002 x 1418</dd>
6069<dt> B4 </dt> <dd> 709 x 1002</dd>
6070<dt> B5 </dt> <dd> 501 x 709</dd>
6071<dt> C0 </dt> <dd> 2600 x 3677</dd>
6072<dt> C1 </dt> <dd> 1837 x 2600</dd>
6073<dt> C2 </dt> <dd> 1298 x 1837</dd>
6074<dt> C3 </dt> <dd> 918 x 1298</dd>
6075<dt> C4 </dt> <dd> 649 x 918</dd>
6076<dt> C5 </dt> <dd> 459 x 649</dd>
6077<dt> C6 </dt> <dd> 323 x 459</dd>
6078<dt> Flsa </dt> <dd> 612 x 936</dd>
6079<dt> Flse </dt> <dd> 612 x 936</dd>
6080<dt> HalfLetter </dt> <dd> 396 x 612</dd>
6081</dl>
6082
6083<p>This option is also used to place subimages when writing to a multi-image
6084format that supports offsets, such as GIF89 and MNG. When used for this
6085purpose the offsets are always measured from the top left corner of the canvas
6086and are not affected by the <a href="command-line-options.html#gravity">-gravity</a> option. To
6087position a GIF or MNG image, use <a href="command-line-options.html#page">-page</a><var>{+-}x{+-}y</var> (e.g. -page +100+200). When writing to a MNG
6088file, a <a href="command-line-options.html#page">-page</a> option appearing ahead of the first image in
6089the sequence with nonzero width and height defines the width and height values
6090that are written in the <code>MHDR</code> chunk. Otherwise, the MNG width and
6091height are computed from the bounding box that contains all images in the
6092sequence. When writing a GIF89 file, only the bounding box method is used to
6093determine its dimensions.</p>
6094
Cristy594d2772015-11-15 10:47:42 -05006095<p>For a PostScript page, the image is sized as in <a
6096href="command-line-options.html#geometry">-geometry</a> but positioned relative to the <var>lower
6097left-hand corner</var> of the page by {+-}<code>x</code><var>offset</var>{+-}<code>y</code> <var>offset</var>. Use <a
6098href="command-line-options.html#page">-page 612x792</a>, for example, to center the image within the
Cristy882d9f42015-10-29 16:48:39 -04006099page. If the image size exceeds the PostScript page, it is reduced to fit the
6100page. The default gravity for the <a href="command-line-options.html#page">-page</a> option is <var>NorthWest</var>, i.e., positive <code>x</code> and <code>y</code> <var>offset</var> are measured rightward and downward from the top left
6101corner of the page, unless the <a href="command-line-options.html#gravity">-gravity</a> option is
6102present with a value other than <var>NorthWest</var>.</p>
6103
6104<p>The default page dimensions for a TEXT image is 612x792.</p>
6105
6106<p>This option is used in concert with <a href="command-line-options.html#density">-density</a>.</p>
6107
6108<p>Use <a href="command-line-options.html#page">+page</a> to remove the page settings for an image.</p>
6109
6110<div style="margin: auto;">
6111 <h3 class="magick-header"><a id="paint"></a>-paint <var>radius</var></h3>
6112</div>
6113
6114<p class="magick-description">simulate an oil painting.</p>
6115
6116<p>Each pixel is replaced by the most frequent color in a circular
6117neighborhood whose width is specified with <var>radius</var>.</p>
6118
6119<div style="margin: auto;">
6120 <h3 class="magick-header"><a id="path"></a>-path <var>path</var></h3></div>
6121
6122<p class="magick-description">write images to this path on disk.</p>
6123
6124<div style="margin: auto;">
6125 <h3 class="magick-header"><a id="pause_animate_"></a>-pause <var>seconds</var></h3>
6126</div>
6127
6128<p class="magick-description">Pause between animation loops</p>
6129
6130<p>Pause for the specified number of seconds before repeating the animation.</p>
6131
6132<div style="margin: auto;">
6133 <h3 class="magick-header"><a id="pause_import_"></a>-pause <var>seconds</var></h3>
6134</div>
6135
6136<p class="magick-description">Pause between snapshots.</p>
6137
6138<p>Pause for the specified number of seconds before taking the next snapshot.</p>
6139
6140<div style="margin: auto;">
6141 <h3 class="magick-header"><a id="perceptible"></a>-perceptible <var>epsilon</var></h3>
6142</div>
6143
6144<p class="magick-description">set each pixel whose value is less than |<var>epsilon</var>| to <var>-epsilon</var> or <var>epsilon</var> (whichever is closer) otherwise the pixel value remains unchanged.</p>
6145
6146<div style="margin: auto;">
6147 <h3 class="magick-header"><a id="ping"></a>-ping</h3>
6148</div>
6149
6150<p class="magick-description">efficiently determine image characteristics.</p>
6151
6152<div style="margin: auto;">
6153 <h3 class="magick-header"><a id="pointsize"></a>-pointsize <var>value</var></h3>
6154</div>
6155
6156<p class="magick-description">pointsize of the PostScript, OPTION1, or TrueType font.</p>
6157
6158<div style="margin: auto;">
6159 <h3 class="magick-header"><a id="polaroid"></a>-polaroid <var>angle</var></h3>
6160</div>
6161
6162<p class="magick-description">simulate a Polaroid picture.</p>
6163
6164<p>Use <code>+polaroid</code> to rotate the image at a random angle between -15 and +15 degrees.</p>
6165
6166<div style="margin: auto;">
6167 <h3 class="magick-header"><a id="poly"></a>-poly <var>"wt,exp ..."</var></h3>
6168</div>
6169
6170<p class="magick-description">combines multiple images according to a weighted sum of polynomials; one floating point weight (coefficient) and one floating point polynomial exponent (power) for each image expressed as comma separated pairs.</p>
6171
6172<p> The weights should typically be fractions between -1 and 1. But the sum of weights should be 1 or at least between 0 and 1 to avoid clamping in non-hdri mode at black and white.</p>
6173
6174<p>The exponents may be positive, negative or zero. A negative exponent is equivalent to 1 divided by the image raised to the corresponding positive exponent. A zero exponent always produces 1 scaled by quantumrange to white, i.e. wt*white, no matter what the image.</p>
6175
6176<p>The format is: <var>output = wt1*image1^exp1 + wt2*image2^exp2 </var>...</p>
6177
6178<p>Some simple uses are:</p>
6179<ul>
6180<li>A weighted sum of each image provided all weights add to unity and all exponents=1. If the the weights are all equal to 1/(number of images), then this is equivalent to <a href="command-line-options.html#profile">-evaluate-sequence</a> <var>mean</var>.</li>
6181<li>The sum of squares of two or more images, provided the weights are equal (and sum to 1 to avoid clamping) and the exponents equal 2.</li>
6182</ul>
6183
6184<p>Note that one may add a constant color to the expression simply by using xc:somecolor for one of the images and specifying the desired weight and exponent equal to 0.</p>
6185
6186<p>Similarly one may add white to the expression by simply using null: (or xc:white) for one of the images with the appropriate weight and exponent equal to 0.</p>
6187
6188
6189<div style="margin: auto;">
6190 <h3 class="magick-header"><a id="posterize"></a>-posterize <var>levels</var></h3>
6191</div>
6192
6193<p class="magick-description">reduce the image to a limited number of color levels per channel.</p>
6194
6195<p>Very low values of <var>levels</var>, e.g., 2, 3, 4, have the most
6196visible effect.</p>
6197
6198<div style="margin: auto;">
6199 <h3 class="magick-header"><a id="precision"></a>-precision <var>value</var></h3>
6200</div>
6201
6202<p class="magick-description">set the maximum number of significant digits to be printed.</p>
6203
6204<div style="margin: auto;">
6205 <h3 class="magick-header"><a id="preview"></a>-preview <var>type</var></h3>
6206</div>
6207
6208<p class="magick-description">image preview type.</p>
6209
6210<p>Use this option to affect the preview operation of an image (e.g.
6211<code>convert file.png -preview Gamma Preview:gamma.png</code>). Choose from
6212these previews:</p>
6213
6214<pre class="pre-scrollable">
6215AddNoise
6216Blur
6217Brightness
6218Charcoal
6219Despeckle
6220Dull
6221EdgeDetect
6222Gamma
6223Grayscale
6224Hue
6225Implode
6226JPEG
6227OilPaint
6228Quantize
6229Raise
6230ReduceNoise
6231Roll
6232Rotate
6233Saturation
6234Segment
6235Shade
6236Sharpen
6237Shear
6238Solarize
6239Spiff
6240Spread
6241Swirl
6242Threshold
6243Wave
6244</pre>
6245
6246<p>To print a complete list of previews, use the <a href="command-line-options.html#list">-list preview</a> option.</p>
6247
6248<p>The default preview is <code>JPEG</code>.</p>
6249
6250<div style="margin: auto;">
6251 <h3 class="magick-header"><a id="print"></a>-print <var>string</var></h3>
6252</div>
6253
6254<p class="magick-description">interpret string and print to console.</p>
6255
6256<div style="margin: auto;">
6257 <h3 class="magick-header"><a id="process"></a>-process <var>command</var></h3>
6258</div>
6259
6260<p class="magick-description">process the image with a custom image filter.</p>
6261
6262<p>The command arguments has the form <code>"module arg1 arg2 arg3 ...
6263argN"</code> where <code>module</code> is the name of the module to invoke (e.g.
6264"Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to
6265pass to the process module.</p>
6266
6267<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05006268 <h3 class="magick-header"><a id="profile"></a>-profile <var>filename</var><br/>
Cristy882d9f42015-10-29 16:48:39 -04006269 +profile <var>profile_name</var></h3>
6270</div>
6271
6272<p class="magick-description">Manage ICM, IPTC, or generic profiles in an image.</p>
6273
6274<p>Using <a href="command-line-options.html#profile">-profile</a> <var>filename</var> adds an
6275ICM (ICC color management), IPTC (newswire information), or a generic profile
6276to the image.</p>
6277
6278<p>Use <a href="command-line-options.html#profile">+profile <var>profile_name</var></a> to
6279remove the indicated profile. ImageMagick uses standard filename globbing, so
6280wildcard expressions may be used to remove more than one profile. Here we
6281remove all profiles from the image except for the XMP profile: <code>+profile
6282"!xmp,*"</code>. </p>
6283
6284<p>Use <code>identify -verbose</code> to find out which profiles are in the
6285image file. Use <a href="command-line-options.html#strip">-strip</a> to remove all profiles (and
6286comments).</p>
6287
6288<p>To extract a profile, the <a href="command-line-options.html#profile">-profile</a> option is not
6289used. Instead, simply write the file to an image format such as <var>APP1, 8BIM, ICM,</var> or <var>IPTC</var>.</p>
6290
6291<p>For example, to extract the Exif data (which is stored in JPEG files in the
6292<var>APP1</var> profile), use.</p>
6293
6294<pre>
6295convert cockatoo.jpg profile.exif
6296</pre>
6297
6298<p>It is important to note that results may depend on whether or not the
Cristy594d2772015-11-15 10:47:42 -05006299original image already has an included profile. Also, keep in mind that <a
6300href="command-line-options.html#profile">-profile</a> is an "operator" (as opposed to a "setting") and
Cristy882d9f42015-10-29 16:48:39 -04006301therefore a conversion is made each time it is encountered, in order, in the
6302command-line. For instance, in the following example, if the original image is
6303CMYK with profile, a CMYK-CMYK-RGB conversion results.</p>
6304
6305<pre>
6306convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff
6307</pre>
6308
6309<p>Furthermore, since ICC profiles are not necessarily symmetric, extra
6310conversion steps can yield unwanted results. CMYK profiles are often very
6311asymmetric since they involve 3−&gt;4 and 4−&gt;3 channel mapping.
6312</p>
6313
6314<div style="margin: auto;">
6315 <h3 class="magick-header"><a id="quality"></a>-quality <var>value</var></h3>
6316</div>
6317
6318<p class="magick-description">JPEG/MIFF/PNG compression level.</p>
6319
6320<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and
6321highest compression) to 100 (best quality but least effective compression).
6322The default is to use the estimated quality of your input image if it can
6323be determined, otherwise 92. When the quality is greater than 90, then the
6324chroma channels are not downsampled.
6325Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to specify the
6326factors for chroma downsampling.</p>
6327
6328<p>For the JPEG-2000 image format, quality is mapped using a non-linear
6329equation to the compression ratio required by the Jasper library. This
6330non-linear equation is intended to loosely approximate the quality provided by
6331the JPEG v1 format. The default quality value 100, a request for non-lossy
6332compression. A quality of 75 results in a request for 16:1 compression.</p>
6333
6334<p>For the MNG and PNG image formats, the quality value sets the zlib
6335compression level (quality / 10) and filter-type (quality % 10). The default
6336PNG "quality" is 75, which means compression level 7 with adaptive PNG
6337filtering, unless the image has a color map, in which case it means
6338compression level 7 with no PNG filtering.</p>
6339
6340<p>For compression level 0 (quality value less than 10), the Huffman-only
6341strategy is used, which is fastest but not necessarily the worst
6342compression.</p>
6343
6344<p>If filter-type is 4 or less, the specified PNG filter-type is used for
6345all scanlines:</p>
6346
6347<dl class="dl-horizontal">
6348<dt>0</dt><dd>none</dd>
6349<dt>1</dt><dd>sub</dd>
6350<dt>2</dt><dd>up</dd>
6351<dt>3</dt><dd>average</dd>
6352<dt>4</dt><dd>Paeth</dd>
6353</dl>
6354
6355<p>If filter-type is 5, adaptive filtering is used when quality is greater
6356than 50 and the image does not have a color map, otherwise no filtering is
6357used.</p>
6358
6359<p>If filter-type is 6, adaptive filtering
6360with <var>minimum-sum-of-absolute-values</var> is used.</p>
6361
6362<p>Only if the output is MNG, if filter-type is 7, the LOCO color
6363transformation (intrapixel differencing) and adaptive filtering
6364with <var>minimum-sum-of-absolute-values</var> are used.</p>
6365
6366<p>If the filter-type is 8 the zlib Z_RLE compression strategy (or the
6367Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6368adaptive PNG filtering.</p>
6369
6370<p>If the filter-type is 9 the zlib Z_RLE compression strategy (or the
6371Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6372no PNG filtering.</p>
6373
6374<p>The quality setting has no effect on the appearance or signature of PNG
6375and MNG images, since the compression is always lossless.</p>
6376
6377<p>Not all combinations of compression level, strategy, and PNG filter type
6378can be obtained using the -quality option. For more precise control,
6379you can use the PNG:compression-level=N, PNG:compression-strategy=N, and
6380PNG:compression-filter=N defines, respectively, instead.
6381See <a href="command-line-options.html#define">-define</a>. Values from the defines take precedence
6382over values from the -quality option.</p>
6383
6384<p>For further information, see
6385the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
6386
6387<p>For the MIFF and TIFF image formats, quality/10 is the <a href="command-line-options.html#compress">Zip/BZip</a> 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>
6388
6389<p>For the BPG image format, quality/2 is the actual BPG compression level (range from 0 to 51).</p>
6390
6391<div style="margin: auto;">
6392 <h3 class="magick-header"><a id="quantize"></a>-quantize <var>colorspace</var></h3>
6393</div>
6394
6395<p class="magick-description">reduce colors using this colorspace.</p>
6396
6397<p>This setting defines the colorspace used to sort out and reduce the number
Cristy594d2772015-11-15 10:47:42 -05006398of colors needed by an image (for later dithering) by operators such as <a
6399href="command-line-options.html#colors" >-colors</a>, Note that color reduction also happens
Cristy882d9f42015-10-29 16:48:39 -04006400automatically when saving images to color-limited image file formats, such as
6401GIF, and PNG8.</p>
6402
6403
6404<div style="margin: auto;">
6405 <h3 class="magick-header"><a id="quiet"></a>-quiet</h3>
6406</div>
6407
6408<p class="magick-description">suppress all warning messages. Error messages are still reported.</p>
6409
6410<div style="margin: auto;">
6411 <h3 class="magick-header"><a id="radial-blur"></a>-radial-blur <var>angle</var></h3>
6412</div>
6413
6414<p class="magick-description">Blur around the center of the image.</p>
6415
6416<p>Note that this is actually a rotational blur rather than a radial and as
6417such actually mis-named. </p>
6418
6419<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
6420pixels which are outside the image proper are blurred into the final result.
6421</p>
6422
6423
6424<div style="margin: auto;">
6425 <h3 class="magick-header"><a id="raise"></a>-raise <var>thickness</var></h3>
6426</div>
6427
6428<p class="magick-description">Lighten or darken image edges.</p>
6429
6430<p>This will create a 3-D effect. Use <a href="command-line-options.html#raise">-raise</a> to create
6431a raised effect, otherwise use <a href="command-line-options.html#raise">+raise</a>. </p>
6432
Cristy594d2772015-11-15 10:47:42 -05006433<p>Unlike the similar <a href="command-line-options.html#frame">-frame</a> option, <a
6434href="command-line-options.html#raise">-raise</a> does not alter the dimensions of the image.</p>
Cristy882d9f42015-10-29 16:48:39 -04006435
6436<div style="margin: auto;">
6437 <h3 class="magick-header"><a id="random-threshold"></a>-random-threshold <var>low</var>x<var>high</var></h3>
6438</div>
6439
6440<p class="magick-description">Apply a random threshold to the image.</p>
6441
6442<div style="margin: auto;">
Cristye0779712016-07-30 17:25:22 -04006443 <h3 class="magick-header"><a id="read-mask"></a>-read-mask
6444<var>filename</var></h3>
6445</div>
6446
6447<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
6448
6449<p>This the same as using a mask used for composite masking operations, with
6450grayscale values causing blended updates of the image the mask is attached to.
6451</p>
6452
6453<p>Use <a href="command-line-options.html#read-mask">+read-mask</a> to remove the mask from images.</p>
6454
6455<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
6456but with strict boolean masking. </p>
6457
6458<div style="margin: auto;">
Cristy882d9f42015-10-29 16:48:39 -04006459 <h3 class="magick-header"><a id="red-primary"></a>-red-primary <var>x,y</var></h3>
6460</div>
6461
6462<p class="magick-description">Set the red chromaticity primary point.</p>
6463
6464<div style="margin: auto;">
6465 <h3 class="magick-header"><a id="regard-warnings"></a>-regard-warnings</h3>
6466</div>
6467
6468<p class="magick-description">Pay attention to warning messages.</p>
6469
6470<p>This option causes some warnings in some image formats to be treated
6471as errors. </p>
6472
6473<div style="margin: auto;">
6474 <h3 class="magick-header"><a id="remap"></a>-remap <var>filename</var></h3>
6475</div>
6476
6477<p class="magick-description">Reduce the number of colors in an image to the colors used by this image.</p>
6478
6479<p>If the <a href="command-line-options.html#dither">-dither</a> setting is enabled (the default) then
6480the given colors are dithered over the image as necessary, otherwise the closest
6481color (in RGB colorspace) is selected to replace that pixel in the image. </p>
6482
6483<p>As a side effect of applying a <a href="command-line-options.html#remap">-remap</a> of colors across all
6484images in the current image sequence, all the images will have the same color
6485table. That means that when saved to a file format such as GIF, it will use
6486that color table as a single common or global color table, for all the images,
6487without requiring extra local color tables. </p>
6488
6489<p>Use <a href="command-line-options.html#remap">+remap</a> to reduce all images in the current image
6490sequence to use a common color map over all the images. This equivalent to
6491appending all the images together (without extra background colors) and color
6492reducing those images using <a href="command-line-options.html#colors">-colors</a> with a 256 color
6493limit, then <a href="command-line-options.html#remap">-remap</a> those colors over the original list of
6494images. This ensures all the images follow a single color map. </p>
6495
Cristy594d2772015-11-15 10:47:42 -05006496<p>If the number of colors over all the images is less than 256, then <a
6497href="command-line-options.html#remap">+remap</a> should not perform any color reduction or dithering, as
Cristy882d9f42015-10-29 16:48:39 -04006498no color changes are needed. In that case, its only effect is to force the use
Cristy594d2772015-11-15 10:47:42 -05006499of a global color table. This recommended after using either <a
6500href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to
Cristy882d9f42015-10-29 16:48:39 -04006501reduce the number of colors in an animated image sequence. </p>
6502
6503<p>Note, the remap image colormap has at most 8-bits of precision. Deeper color maps are automagically coalesced with other colors to meet this requirement.</p>
6504
6505<div style="margin: auto;">
6506 <h3 class="magick-header"><a id="region"></a>-region <var>geometry</var></h3>
6507</div>
6508
6509<p class="magick-description">Set a region in which subsequent operations apply.</p>
6510
6511<p>The <var>x</var> and <var>y</var> offsets are treated
6512in the same manner as in <a href="command-line-options.html#crop">-crop</a>.</p>
6513
6514<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6515
6516<p>Use <code>+region</code> to remove any previously set regions.</p>
6517
Cristy882d9f42015-10-29 16:48:39 -04006518<div style="margin: auto;">
6519 <h3 class="magick-header"><a id="remote"></a>-remote</h3>
6520</div>
6521
6522<p class="magick-description">perform a remote operation.</p>
6523
6524<p>The only command recognized is the name of an image file to load.</p>
6525
6526<p>If you have more than one <a href="display.html">display</a> application
6527running simultaneously, use the <a href="command-line-options.html#window"> window</a> option to
6528specify which application to control.</p>
6529
6530<div style="margin: auto;">
6531 <h3 class="magick-header"><a id="render"></a>-render</h3>
6532</div>
6533
6534<p class="magick-description">render vector operations.</p>
6535
6536<p>Use <a href="command-line-options.html#render">+render</a> to turn off rendering vector operations.
6537This useful when saving the result to vector formats such as MVG or SVG.</p>
6538
6539<div style="margin: auto;">
6540<h3 class="magick-header"><a id="repage"></a>-repage <var>geometry</var></h3>
6541</div>
6542
6543<p class="magick-description">Adjust the canvas and offset information of the image.</p>
6544
6545<p>This option is like <a href="command-line-options.html#page">-page</a> but acts as an image operator
6546rather than a setting. You can separately set the canvas size or the offset
6547of the image on that canvas by only providing those components. </p>
6548
6549<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6550
6551<p>If a <code>!</code> flag is given the offset given is added to the existing
6552offset to move the image relative to its previous position. This useful for
6553animation sequences. </p>
6554
6555<p>A given a canvas size of zero such as '<code>0x0</code>' forces it to
6556recalculate the canvas size so the image (at its current offset) will appear
6557completely on that canvas (unless it has a negative offset).</p>
6558
6559<p>Use <a href="command-line-options.html#repage">+repage</a> to completely remove/reset the virtual
6560canvas meta-data from the images. </p>
6561
6562<p>The <a href="command-line-options.html#set">-set</a> '<code>page</code>' option can be used to
6563directly assign virtual canvas meta-data. </p>
6564
6565
6566<div style="margin: auto;">
6567 <h3 class="magick-header"><a id="resample"></a>-resample <var>horizontal</var>x<var>vertical</var></h3>
6568</div>
6569
6570<p class="magick-description">Resample image to specified horizontal and vertical resolution.</p>
6571
6572<p>Resize the image so that its rendered size remains the same as the original
6573at the specified target resolution. For example, if a 300 DPI image renders at
65743 inches by 2 inches on a 300 DPI device, when the image has been resampled to
657572 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that
6576only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of
6577storing the image resolution. For formats which do not support an image
Cristy594d2772015-11-15 10:47:42 -05006578resolution, the original resolution of the image must be specified via <a
6579href="command-line-options.html#density">-density</a> on the command line prior to specifying the
Cristy882d9f42015-10-29 16:48:39 -04006580resample resolution.</p>
6581
6582<p>Note that Photoshop stores and obtains image resolution from a proprietary
6583embedded profile. If this profile exists in the image, then Photoshop will
6584continue to treat the image using its former resolution, ignoring the image
6585resolution specified in the standard file header.</p>
6586
6587<div style="margin: auto;">
6588 <h3 class="magick-header"><a id="resize"></a>-resize <var>geometry</var></h3>
6589</div>
6590
6591<p class="magick-description">Resize an image.</p>
6592
6593<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are
6594ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
6595
6596<p>If the <a href="command-line-options.html#filter">-filter</a> option
Cristy594d2772015-11-15 10:47:42 -05006597or <code>-define filter:option=value</code> precedes the <a
6598href="command-line-options.html#resize">-resize</a> option, the image is resized with the specified
Cristy882d9f42015-10-29 16:48:39 -04006599filter.</p>
6600
6601<p>Many image processing algorithms assume your image is in a linear-light
6602coding. If your image is gamma-corrected, you can remove the nonlinear gamma
6603correction, apply the transform, then restore it like this:</p>
6604
6605<pre>
6606convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \
6607 -quality 92 passport.jpg
6608</pre>
6609
6610<div style="margin: auto;">
6611 <h3 class="magick-header"><a id="respect-parentheses"></a>-respect-parentheses</h3>
6612</div>
6613
6614<p class="magick-description">settings remain in effect until parenthesis boundary.</p>
6615
6616<div style="margin: auto;">
6617 <h3 class="magick-header"><a id="reverse"></a>-reverse</h3>
6618</div>
6619
6620<p class="magick-description">Reverse the order of images in the current image list.</p>
6621
6622
6623<div style="margin: auto;">
6624 <h3 class="magick-header"><a id="roll"></a>-roll {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
6625</div>
6626
6627<p class="magick-description">roll an image vertically or horizontally by the amount given.</p>
6628
6629<p>A negative <var>x</var> offset rolls the image right-to-left.
6630A negative <var>y</var> offset rolls the image bottom-to-top.</p>
6631
6632
6633<div style="margin: auto;">
6634 <h3 class="magick-header"><a id="rotate"></a>-rotate <var>degrees</var>{<var>&lt;</var>}{<var>&gt;</var>}</h3>
6635</div>
6636
6637<p class="magick-description">Apply Paeth image rotation (using shear operations) to the image.</p>
6638
6639<p>Use <code>&gt;</code> to rotate the image only if its width exceeds the
6640height. <code>&lt;</code> rotates the image <var>only</var> if its width is less
6641than the height. For example, if you specify <code>-rotate "-90&gt;"</code> and
6642the image size is 480x640, the image is not rotated. However, if the image is
6643640x480, it is rotated by -90 degrees. If you use <code>&gt;</code> or
6644<code>&lt;</code>, enclose it in quotation marks to prevent it from being
6645misinterpreted as a file redirection.</p>
6646
6647<p>Empty triangles in the corners, left over from rotating the image, are
6648filled with the <code>background</code> color. </p>
6649
6650<p>See also the <a href="command-line-options.html#distort">-distort</a> operator and specifically the
6651'<code>ScaleRotateTranslate</code>' distort method. </p>
6652
6653
6654<div style="margin: auto;">
6655 <h3 class="magick-header"><a id="sample"></a>-sample <var>geometry</var></h3>
6656</div>
6657
6658<p class="magick-description">minify / magnify the image with pixel subsampling and pixel replication, respectively.</p>
6659
6660<p>Change the image size simply by directly sampling the pixels original
6661from the image. When magnifying, pixels are replicated in blocks. When
6662minifying, pixels are sub-sampled (i.e., some rows and columns are skipped
6663over). </p>
6664
6665<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6666a <a href="command-line-options.html#filter">-filter</a> setting of <code>point</code> (nearest
6667neighbor), though <a href="command-line-options.html#sample">-sample</a> is a lot faster, as it
6668avoids all the filter processing of the image. As such it completely ignores
6669the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6670
6671<p>The key feature of the <a href="command-line-options.html#sample">-sample</a> is that no new colors
6672will be added to the resulting image, though some colors may disappear. </p>
6673
6674<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are
6675ignored, unlike <a href="command-line-options.html#resize">-resize</a>. </p>
6676
6677
6678<p>The actual sampling point is the middle of the sub-region being sampled.
6679As such a single pixel sampling of an image will take the middle pixel, (or
Cristy594d2772015-11-15 10:47:42 -05006680top-left-middle if image has even dimensions). However the <a
6681href="command-line-options.html#define">-define</a> '<code>sample:offset</code>' can be set to modify
Cristy882d9f42015-10-29 16:48:39 -04006682this position some other location within each sub-region being sampled, as
6683a percentage offset.</p>
6684
6685<p>By default this value is '<code>50</code>' for the midpoint, but could be set
6686to '<code>0</code>' for top-left, '<code>100</code>' for bottom-right, or with
6687separate X and Y offsets such as '<code>0x50</code>' for left-middle edge of
6688sampling sub-region.</p>
6689
6690
6691<div style="margin: auto;">
6692 <h3 class="magick-header"><a id="sampling-factor"></a>-sampling-factor <var>horizontal-factor</var>x<var>vertical-factor</var></h3>
6693</div>
6694
6695<p class="magick-description">sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</p>
6696
6697<p>This option specifies the sampling factors to be used by the JPEG encoder
6698for chroma downsampling. If this option is omitted, the JPEG library will use
6699its own default values. When reading or writing the YUV format and when
Cristy594d2772015-11-15 10:47:42 -05006700writing the M2V (MPEG-2) format, use <a
6701href="command-line-options.html#sampling-factor">-sampling-factor 2x1</a> or <a
6702href="command-line-options.html#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2
Cristy882d9f42015-10-29 16:48:39 -04006703downsampling method.</p>
6704
6705<div style="margin: auto;">
6706 <h3 class="magick-header"><a id="scale"></a>-scale <var>geometry</var></h3>
6707</div>
6708
6709<p class="magick-description">minify / magnify the image with pixel block averaging and pixel replication, respectively.</p>
6710
6711<p>Change the image size simply by replacing pixels by averaging pixels
6712together when minifying, or replacing pixels when magnifying. </p>
6713
6714<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6715a <a href="command-line-options.html#filter">-filter</a> setting of <code>box</code>. Though it is a lot
6716faster, as it avoids all the filter processing of the image. As such it
6717completely ignores the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6718
6719<p>If when shrinking (minifying) images the original image is some integer
6720multiple of the new image size, the number of pixels averaged together to
6721produce the new pixel color is the same across the whole image. This is
6722a special case known as 'binning' and is often used as a method of reducing
6723noise in image such as those generated by digital cameras, especially in low
6724light conditions. </p>
6725
6726
6727<div style="margin: auto;">
6728 <h3 class="magick-header"><a id="scene"></a>-scene <var>value</var></h3>
6729</div>
6730
6731<p class="magick-description">set scene number.</p>
6732
6733<p>This option sets the scene number of an image or the first image in an image sequence.</p>
6734
6735<div style="margin: auto;">
6736 <h3 class="magick-header"><a id="screen"></a>-screen</h3>
6737</div>
6738
6739<p class="magick-description">specify the screen to capture.</p>
6740
6741<p>This option indicates that the GetImage request used to obtain the image
6742should be done on the root window, rather than directly on the specified
6743window. In this way, you can obtain pieces of other windows that overlap the
6744specified window, and more importantly, you can capture menus or other popups
6745that are independent windows but appear over the specified window.</p>
6746
6747<div style="margin: auto;">
6748 <h3 class="magick-header"><a id="seed"></a>-seed</h3>
6749</div>
6750
6751<p class="magick-description">seed a new sequence of pseudo-random numbers</p>
6752
6753<div style="margin: auto;">
6754 <h3 class="magick-header"><a id="segment"></a>-segment <var>cluster-threshold</var>x<var>smoothing-threshold</var></h3>
6755</div>
6756
6757<p class="magick-description">segment the colors of an image.</p>
6758
6759<p>Segment an image by analyzing the histograms of the color components and
6760identifying units that are homogeneous with the fuzzy c-means technique. This
6761is part of the ImageMagick color quantization routines. </p>
6762
6763<p>Specify <var>cluster threshold</var> as the number of pixels in
6764each cluster that must exceed the cluster threshold to be considered valid.
6765<var>Smoothing threshold</var> eliminates noise in the second
6766derivative of the histogram. As the value is increased, you can expect
6767a smoother second derivative. The default is 1.5.</p>
6768
6769<p>If the <a href="command-line-options.html#verbose">-verbose</a> setting is defined, a detailed report
6770of the color clusters is returned.</p>
6771
6772
6773<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05006774 <h3 class="magick-header"><a id="selective-blur"></a>-selective-blur <var>radius</var><br />-selective-blur <var>radius</var>x<var>sigma</var>{<var>+threshold</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04006775</div>
6776
6777<p class="magick-description">Selectively blur pixels within a contrast threshold.</p>
6778
6779<p>Blurs those pixels that are less than or equal to the threshold in
6780contrast. The threshold may be expressed as a fraction of <var>QuantumRange</var> or as a percentage.</p>
6781
6782<div style="margin: auto;">
6783 <h3 class="magick-header"><a id="separate"></a>-separate</h3>
6784</div>
6785
6786<p class="magick-description">separate an image channel into a grayscale image. Specify the channel with <a href="command-line-options.html#channel">-channel</a>.</p>
6787
6788<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05006789 <h3 class="magick-header"><a id="sepia-tone"></a>-sepia-tone <var>percent-threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006790</div>
6791
6792<p class="magick-description">simulate a sepia-toned photo.</p>
6793
6794<p>Specify <var>threshold</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6795
6796<p>This option applies a special effect to the image, similar to the effect
6797achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to <var>QuantumRange</var> and is a measure of the extent of the sepia
6798toning. A threshold of 80% is a good starting point for a reasonable
6799tone.</p>
6800
6801
6802
6803<div style="margin: auto;">
6804 <h3 class="magick-header"><a id="set"></a>-set <var>key value</var></h3>
6805 <h3 class="magick-header">+set <var>key</var></h3>
6806</div>
6807
6808<p class="magick-description">sets image attributes and properties for images in the current image sequence.</p>
6809
6810<p>This will assign (or modify) specific settings attached to all the images
6811in the current image sequence. Using the <a href="command-line-options.html#set">+set</a> form of the
6812option will either remove, or reset that setting to a default state, as
6813appropriate. </p>
6814
6815<p>For example, it will modify specific well known image meta-data
Cristy594d2772015-11-15 10:47:42 -05006816'attributes' such as those normally overridden by: the options <a
6817href="command-line-options.html#delay" >-delay</a>, <a href="command-line-options.html#dispose" >-dispose</a>, and <a
6818href="command-line-options.html#page" >-page</a>, <a href="command-line-options.html#colorspace" >-colorspace</a>; generally
Cristy882d9f42015-10-29 16:48:39 -04006819assigned before the image is read in, by using a <var>key</var> of
6820the same name. </p>
6821
6822<p>If the given <var>key</var> does not match a specific known
6823'attribute ', such as shown above, the setting is stored as a a free form
Cristy594d2772015-11-15 10:47:42 -05006824'property' string. Such settings are listed in <a href="command-line-options.html#verbose"
6825>-verbose</a> information ("<code>info:</code>" output format) as "Properties".
Cristy882d9f42015-10-29 16:48:39 -04006826</p>
6827
6828<p>This includes string 'properties' that are set by and assigned to images
Cristy594d2772015-11-15 10:47:42 -05006829using the options <a href="command-line-options.html#comment" >-comment</a>, <a href="command-line-options.html#label"
6830>-label</a>, <a href="command-line-options.html#caption" >-caption</a>. These options actually assign
6831a global 'artifact' which are automatically assigned (and any <a href="escape.html" >Format Percent
Cristy882d9f42015-10-29 16:48:39 -04006832Escapes</a> expanded) to images as they are read in. For example:</p>
6833
6834<pre>
Cristy594d2772015-11-15 10:47:42 -05006835-> convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png
Cristy882d9f42015-10-29 16:48:39 -04006836identify -format %c rose.png
6837Rose is a rose is a rose is a rose
6838</pre>
6839
Cristy594d2772015-11-15 10:47:42 -05006840<p>The set value can also make use of <a href="escape.html" >Format and Print Image
Cristy882d9f42015-10-29 16:48:39 -04006841Properties</a> in the defined value. For example:</p>
6842
6843<pre>
Cristy594d2772015-11-15 10:47:42 -05006844-> convert rose: -set origsize '%wx%h' -resize 50% \
Cristy882d9f42015-10-29 16:48:39 -04006845 -format 'Old size = %[origsize] New size = %wx%h' info:
6846Old size = 70x46 New size = 35x23
6847</pre>
6848
6849<p>Other well known 'properties' that are available include:
6850'<code>date:create</code>' and '<code>date:modify</code>' and
6851'<code>signature</code>'. </p>
6852
6853<p>The <a href="command-line-options.html#repage">-repage</a> operator will also allow you to modify
6854the '<code>page</code>' attribute of an image for images already in memory (also
6855see <a href="command-line-options.html#repage">-page</a>). However it is designed to provide a finer
6856control of the sub-parts of this 'attribute'. The <a href="command-line-options.html#set">-set page</a>
6857option will only provide a direct, unmodified assignment of '<code>page</code>'
6858attribute. </p>
6859
6860<p>This option can also associate a colorspace or profile with your image.
6861For example,</p>
6862
6863<pre>
6864convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd
6865</pre>
6866
6867<p>Some 'properties' must be defined in a specific way to be used. For
6868example only 'properties' prefixed with "<code>filename:</code>" can be used to
6869modify the output filename of an image. For example</p>
6870
6871<pre>
6872convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'
6873</pre>
6874
6875<p>If the setting value is prefixed with "<code>option:</code>" the setting will
Cristy594d2772015-11-15 10:47:42 -05006876be saved as a global "Artifact" exactly as if it was set using the <a
6877href="command-line-options.html#define" >-define</a> option. As such settings are global in scope, they
Cristy882d9f42015-10-29 16:48:39 -04006878can be used to pass 'attributes' and 'properties' of one specific image,
6879in a way that allows you to use them in a completely different image, even if
6880the original image has long since been modified or destroyed. For example: </p>
6881
6882<pre>
6883convert rose: -set option:rosesize '%wx%h' -delete 0 \
6884 label:'%[rosesize]' label_size_of_rose.gif"
6885</pre>
6886
Cristy594d2772015-11-15 10:47:42 -05006887<p>Note that <a href="escape.html" >Format Percent Escapes</a> will only match
Cristy882d9f42015-10-29 16:48:39 -04006888a 'artifact' if the given <var>key</var> does not match an existing
6889'attribute' or 'property'. </p>
6890
6891<p>You can set the attributes of the image registry by prefixing the value
6892with <code>registry:</code>.</p>
6893
6894<p>The <a href="command-line-options.html#set">-set profile</a> option can also be used to inject
6895previously-formatted ancillary chunks into the output PNG file, using
6896the commandline option as shown below or by setting the profile via a
6897programming interface:</p>
6898
6899<pre>
6900convert in.png -set profile PNG-chunk-x:&lt;filename&gt; out.png
6901</pre>
6902
6903<p>where <var>x</var> is a location flag and
6904<var>filename</var> is a file containing the chunk
6905name in the first 4 bytes, then a colon (":"), followed by the chunk data.
6906This encoder will compute the chunk length and CRC, so those must not
6907be included in the file.</p>
6908
6909<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT),
6910or "e" (end, i.e., after IDAT). If you want to write multiple chunks
6911of the same type, then add a short unique string after the "x" to prevent
6912subsequent profiles from overwriting the preceding ones, e.g.,</p>
6913
6914
6915<pre>
6916convert in.png -set profile PNG-chunk-b01:file01 \
6917 -profile PNG-chunk-b02:file02 out.png
6918</pre>
6919
6920<div style="margin: auto;">
6921 <h3 class="magick-header"><a id="shade"></a>-shade <var>azimuth</var>x<var>elevation</var></h3>
6922</div>
6923
6924<p class="magick-description">shade the image using a distant light source.</p>
6925
6926<p>Specify <var>azimuth</var> and <var>elevation</var> as
6927the position of the light source. Use <a href="command-line-options.html#shade">+shade</a> to return
6928the shading results as a grayscale image.</p>
6929
6930<div style="margin: auto;">
6931 <h3 class="magick-header"><a id="shadow"></a>-shadow <var>percent-opacity</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3>
6932</div>
6933
6934<p class="magick-description">simulate an image shadow.</p>
6935
6936<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05006937 <h3 class="magick-header"><a
6938id="shared-memory"></a>-shared-memory</h3>
Cristy882d9f42015-10-29 16:48:39 -04006939</div>
6940
6941<p class="magick-description">use shared memory.</p>
6942
6943<p>This option specifies whether the utility should attempt to use shared
6944memory for pixmaps. ImageMagick must be compiled with shared memory support,
6945and the display must support the <var>MIT-SHM</var> extension.
6946Otherwise, this option is ignored. The default is <code>True</code>.</p>
6947
6948<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05006949 <h3 class="magick-header"><a id="sharpen"></a>-sharpen <var>radius</var><br />-sharpen <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006950</div>
6951
6952<p class="magick-description">sharpen the image.</p>
6953
6954<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
6955
6956<div style="margin: auto;">
6957 <h3 class="magick-header"><a id="shave"></a>-shave <var>geometry</var></h3>
6958</div>
6959
6960<p class="magick-description">Shave pixels from the image edges.</p>
6961
6962<p>The <var>size</var> portion of the <var>geometry</var>
6963argument specifies the width of the region to be removed from both sides of
6964the image and the height of the regions to be removed from top and bottom.
6965Offsets are ignored.</p>
6966
6967<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6968
6969<div style="margin: auto;">
6970 <h3 class="magick-header"><a id="shear"></a>-shear <var>Xdegrees</var>[x<var>Ydegrees</var>]</h3>
6971</div>
6972
6973<p class="magick-description">Shear the image along the x-axis and/or y-axis.</p>
6974
6975<p>The shear angles may be positive, negative, or zero. When <var>Ydegrees</var> is omitted it defaults to 0. When both angles are
6976given, the horizontal component of the shear is performed before the vertical
6977component.</p>
6978
6979<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e.,
6980horizontally or vertically, respectively),creating a parallelogram. The amount
6981of each is controlled by the respective shear angle. For horizontal shears,
6982<var>Xdegrees</var> is measured clockwise relative to "up" (the
6983negative y-axis), sliding the top edge to the right when 0°&lt;<var>Xdegrees</var>&lt;90° and to the left when 90°&lt;<var>Xdegrees</var>&lt;180°. For vertical shears <var>Ydegrees</var> is measured clockwise relative to "right" (the
6984positive x-axis), sliding the right edge down when 0°&lt;<var>Ydegrees</var>&lt;90° and up when 90°&lt;<var>Ydegrees</var>&lt;180°.</p>
6985
6986<p>Empty triangles left over from shearing the image are filled with the color
6987defined by the <a href="command-line-options.html#fill">-background</a> option. The color is specified
6988using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
6989
6990<p>The horizontal shear is performed before the vertical part. This is
6991important to note, since horizontal and vertical shears do not
6992<var>commute</var>, i.e., the order matters in a sequence of shears. For
6993example, the following two commands are not equivalent.</p>
6994
6995<pre>
6996convert logo: -shear 20x0 -shear 0x60 logo-sheared.png
6997convert logo: -shear 0x60 -shear 20x0 logo-sheared.png
6998</pre>
6999
7000<p>The first of the two commands above is equivalent to the following, except
7001for the amount of empty space created; the command that follows generates
7002a smaller image, and so is a better choice in terms of time and space.</p>
7003
7004<pre>
7005convert logo: -shear 20x60 logo-sheared.png
7006</pre>
7007
7008<div style="margin: auto;">
7009 <h3 class="magick-header"><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <var>contrast</var>x<var>mid-point</var></h3>
7010</div>
7011
7012<p class="magick-description">increase the contrast without saturating highlights or shadows.</p>
7013
7014<p>Increase the contrast of the image using a sigmoidal transfer function
7015without saturating highlights or shadows. <var>Contrast</var>
7016indicates how much to increase the contrast. For example, 0 is none, 3 is
7017typical and 20 is a lot.
7018</p>
7019
7020<p>The <var>mid-point</var> indicates where the maximum change
7021'slope' in contrast should fall in the resultant image (0 is white; 50% is
7022middle-gray; 100% is black). </p>
7023
7024<p>By default the image contrast is increased, use <var>+sigmoidal-contrast</var> to decrease the contrast.</p>
7025
7026<p>To achieve the equivalent of a sigmoidal brightness change (similar to
7027a gamma adjustment), you would use <var>-sigmoidal-contrast
7028{brightness}x0%</var> to increase brightness and <var>+sigmoidal-contrast {brightness}x0%</var> to decrease brightness.
7029Note the use of '0' fo rthe mid-point of the sigmoidal curve. </p>
7030
7031<p>Using a very high <var>contrast</var> will produce a sort of
7032'smoothed thresholding' of the image. Not as sharp (with high aliasing
7033effects) of a true threshold, but with tapered gray-levels around the threshold
7034<var>mid-point</var>. </p>
7035
7036<div style="margin: auto;">
7037 <h3 class="magick-header"><a id="silent"></a>-silent</h3>
Cristyf650f4f2016-04-01 10:53:07 -04007038
7039
Cristy882d9f42015-10-29 16:48:39 -04007040</div>
7041
Cristyf650f4f2016-04-01 10:53:07 -04007042<p class="magick-description">operate silently. This option is only used
7043by the <a href="import.html">import</a> tool.</p>
Cristy882d9f42015-10-29 16:48:39 -04007044
7045<div style="margin: auto;">
7046 <h3 class="magick-header"><a id="similarity-threshold"></a>-similarity-threshold <var>value</var></h3>
7047</div>
7048
7049<p class="magick-description">minimum RMSE for subimage match.</p>
7050
7051<p>If this setting is used, then the search will stop as soon as it finds a match whose metric is less than or equal to the value. A partially filled second output image will result. Using a value of zero, will cause the search to stop at the first perfect match it finds. If this setting is left off, then the search will proceed to completion or as limited by <var>-dissimilarity-threshold</var>.</p>
7052
7053<div style="margin: auto;">
7054 <h3 class="magick-header"><a id="size"></a>-size <var>width</var>[x<var>height</var>][<var>+offset</var>]</h3>
7055</div>
7056
7057<p class="magick-description">set the width and height of the image.</p>
7058
7059<p>Use this option to specify the width and height of raw images whose
7060dimensions are unknown such as <code>GRAY</code>, <code>RGB</code>, or
Cristy594d2772015-11-15 10:47:42 -05007061<code>CMYK</code>. In addition to width and height, use <a
7062href="command-line-options.html#size">-size</a> with an offset to skip any header information in the
Cristy882d9f42015-10-29 16:48:39 -04007063image or tell the number of colors in a <code>MAP</code> image file, (e.g. -size
7064640x512+256).</p>
7065
7066<p>For Photo CD images, choose from these sizes:</p>
7067
7068<pre>
7069192x128
7070384x256
7071768x512
70721536x1024
70733072x2048
7074</pre>
7075
7076<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05007077 <h3 class="magick-header"><a id="sketch"></a>-sketch <var>radius</var><br />-sketch <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007078</div>
7079
7080<p class="magick-description">simulate a pencil sketch.</p>
7081
7082<p>Sketch with the given radius, standard deviation (sigma), and angle. The
7083angle given is the angle toward which the image is sketched. That is the
7084direction people would consider the object is coming from. </p>
7085
7086<div style="margin: auto;">
7087 <h3 class="magick-header"><a id="smush"></a>-smush <var>offset</var></h3>
7088</div>
7089
7090<p class="magick-description">smush an image sequence together.</p>
7091
7092<div style="margin: auto;">
7093 <h3 class="magick-header"><a id="snaps"></a>-snaps <var>value</var></h3>
7094</div>
7095
7096<p class="magick-description">Set the number of screen snapshots.</p>
7097
7098<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
7099
7100<div style="margin: auto;">
Cristy769d8892016-01-19 18:11:14 -05007101 <h3 class="magick-header"><a id="solarize"></a>-solarize <var>percent-threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007102</div>
7103
7104<p class="magick-description">negate all pixels above the threshold level.</p>
7105
7106<p>Specify <var>factor</var> as the percent threshold of the intensity (0 - 99.9%).</p>
7107
7108<p>This option produces a <var>solarization</var> effect seen when
7109exposing a photographic film to light during the development process.</p>
7110
7111<div style="margin: auto;">
7112 <h3 class="magick-header"><a id="sparse-color"></a>-sparse-color <var>method</var> '<var>x</var>,<var>y</var> <var>color</var> ...'</h3>
7113</div>
7114
7115<p class="magick-description"> color the given image using the specified points of color, and filling the other intervening colors using the given methods. </p>
7116
7117
7118<dl class="dl-horizontal">
7119 <dt>barycentric</dt>
7120 <dd>three point triangle of color given 3 points.
7121 Giving only 2 points will form a linear gradient between those points.
7122 The gradient generated extends beyond the triangle created by those
7123 3 points. </dd>
7124 <dt>bilinear</dt>
7125 <dd>Like barycentric but for 4 points. Less than 4 points
7126 fall back to barycentric. </dd>
7127 <dt>voronoi</dt>
7128 <dd>Simply map each pixel to the to nearest color point
7129 given. The result are polygonal 'cells' of solid color. </dd>
7130 <dt>manhatten</dt>
7131 <dd>Like voronoi, but resulting polygonal 'cells' are mapped to a fixed coordinate system.</dd>
7132 <dt>shepards</dt>
7133 <dd>Colors points biased on the ratio of inverse distance
7134 squared. Generating spots of color in a sea of the average of
7135 colors. </dd>
7136 <dt>inverse</dt>
7137 <dd>Colors points biased on the ratio of inverse distance.
7138 This generates sharper points of color rather than rounded spots of
7139 '<code>shepards</code>' Generating spots of color in a sea of the
7140 average of colors. </dd>
7141</dl>
7142
7143<p>The points are placed according to the images location on the virtual
Cristy594d2772015-11-15 10:47:42 -05007144canvas (<a href="command-line-options.html#page" >-page</a> or <a href="command-line-options.html#repage" >-repage</a>
Cristy882d9f42015-10-29 16:48:39 -04007145offset), and do not actually have to exist on the given image, but may be
7146some point beyond the edge of the image. All points are floating point values.
7147</p>
7148
Cristy594d2772015-11-15 10:47:42 -05007149<p>Only the color channels defined by the <a href="command-line-options.html#channel" >-channel</a> are
Cristy882d9f42015-10-29 16:48:39 -04007150modified, which means that by default matte/alpha transparency channel is not
7151effected. Typically transparency channel is turned off either before or after
7152the operation. </p>
7153
7154<p>Of course if some color points are transparent to generate a transparent
7155gradient, then the image also requires transparency enabled to store the
7156values. </p>
7157
7158<p>All the above methods when given a single point of color will replace all
7159the colors in the image with the color given, regardless of the point. This is
7160logical, and provides an alternative technique to recolor an image to some
7161default value. </p>
7162
7163
7164<div style="margin: auto;">
7165 <h3 class="magick-header"><a id="splice"></a>-splice <var>geometry</var></h3>
7166</div>
7167
7168<p class="magick-description">Splice the current background color into the image.</p>
7169
Cristy594d2772015-11-15 10:47:42 -05007170<p>This will add rows and columns of the current <a
7171href="command-line-options.html#background">-background</a> color into the given image according to the
Cristy882d9f42015-10-29 16:48:39 -04007172given <a href="command-line-options.html#gravity">-gravity</a> geometry setting. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Essentially <a href="command-line-options.html#splice">-splice</a> will divide the
7173image into four quadrants, separating them by the inserted rows and columns.
7174</p>
7175
7176<p>If a dimension of geometry is zero no rows or columns will be added for that
Cristy594d2772015-11-15 10:47:42 -05007177dimension. Similarly using a zero offset with the appropriate <a
7178href="command-line-options.html#gravity">-gravity</a> setting will add rows and columns to the edges of
7179the image, padding the image only along that one edge. Edge padding is what <a
7180href="command-line-options.html#splice">-splice</a> is most commonly used for. </p>
Cristy882d9f42015-10-29 16:48:39 -04007181
Cristy594d2772015-11-15 10:47:42 -05007182<p>If the exact same <var>geometry</var> and <a
7183href="command-line-options.html#gravity">-gravity</a> is later used with <a href="command-line-options.html#chop">-chop</a> the
Cristy882d9f42015-10-29 16:48:39 -04007184added added all splices removed. </p>
7185
7186<div style="margin: auto;">
7187 <h3 class="magick-header"><a id="spread"></a>-spread <var>amount</var></h3>
7188</div>
7189
7190<p class="magick-description">displace image pixels by a random amount.</p>
7191
7192<p>The argument <var>amount</var> defines the size of the
7193neighborhood around each pixel from which to choose a candidate pixel to
7194blend.</p>
7195
7196<p>The lookup is controlled by the <a href="command-line-options.html#interpolate">-interpolate</a> setting.</p>
7197
7198<div style="margin: auto;">
7199 <h3 class="magick-header"><a id="statistic"></a>-statistic <var>type</var> <var>geometry</var></h3>
7200</div>
7201
7202<p class="magick-description">replace each pixel with corresponding statistic from the neighborhood.</p>
7203
7204<p>Choose from these statistic types:</p>
7205<dl class="dl-horizontal">
7206<dt>Gradient</dt><dd>maximum difference (max - min) value in neighborhood</dd>
7207<dt>Maximum</dt><dd>maximum value per channel in neighborhood</dd>
7208<dt>Minimum</dt><dd>minimum value per channel in neighborhood</dd>
7209<dt>Mean</dt><dd>average value per channel in neighborhood</dd>
7210<dt>Median</dt><dd>median value per channel in neighborhood</dd>
7211<dt>Mode</dt><dd>mode (most frequent) value per channel in neighborhood</dd>
7212<dt>Nonpeak</dt><dd>value just before or after the median value per channel in neighborhood</dd>
7213<dt>RMS</dt><dd>root mean square value per channel in neighborhood</dd>
7214<dt>StandardDeviation</dt><dd> standard deviation value per channel in neighborhood</dd>
7215</dl>
7216
7217<div style="margin: auto;">
7218 <h3 class="magick-header"><a id="stegano"></a>-stegano <var>offset</var></h3>
7219</div>
7220
7221<p class="magick-description">hide watermark within an image.</p>
7222
7223<p>Use an offset to start the image hiding some number of pixels from the
7224beginning of the image. Note this offset and the image size. You will need
7225this information to recover the steganographic image (e.g. display -size
7226320x256+35 stegano:image.png).</p>
7227
7228<div style="margin: auto;">
7229 <h3 class="magick-header"><a id="stereo"></a>-stereo <var>+x</var>{<var>+y</var>}</h3>
7230</div>
7231
7232<p class="magick-description">composite two images to create a red / cyan stereo anaglyph.</p>
7233
7234<p>The left side of the stereo pair (second image) is saved as the red channel of the output image. The right side (first image) is saved as the green and blue channels. Red-green stereo glasses are required to properly view the stereo image.</p>
7235
7236<div style="margin: auto;">
7237 <h3 class="magick-header"><a id="storage-type"></a>-storage-type <var>type</var></h3>
7238</div>
7239
7240<p class="magick-description">pixel storage type. Here are the valid types:</p>
7241
7242<dl class="dl-horizontal">
7243<dt>char</dt><dd>unsigned characters</dd>
7244<dt>double</dt><dd>doubles</dd>
7245<dt>float</dt><dd>floats</dd>
7246<dt>integer</dt><dd>integers</dd>
7247<dt>long</dt><dd>longs</dd>
7248<dt>quantum</dt><dd>pixels in the native depth of your ImageMagick distribution</dd>
7249<dt>short</dt><dd>unsigned shorts</dd>
7250</dl>
7251
7252<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
7253values range from 0 to the maximum value the storage type can support.</p>
7254
7255<div style="margin: auto;">
7256 <h3 class="magick-header"><a id="stretch"></a>-stretch <var>fontStretch</var></h3>
7257</div>
7258
7259<p class="magick-description">Set a type of stretch style for fonts.</p>
7260
7261<p>This setting suggests a type of stretch that ImageMagick should try to
7262apply to the currently selected font family. Select <var>fontStretch</var> from the following.</p>
7263
7264<pre>
7265Any
7266Condensed
7267Expanded
7268ExtraCondensed
7269ExtraExpanded
7270Normal
7271SemiCondensed
7272SemiExpanded
7273UltraCondensed
7274UltraExpanded
7275</pre>
7276
7277<p>To print a complete list of stretch types, use <a href="command-line-options.html#list">-list
7278stretch</a>.</p>
7279
Cristy594d2772015-11-15 10:47:42 -05007280<p>For other settings that affect fonts, see the options <a
7281href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
7282href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007283
7284<div style="margin: auto;">
7285 <h3 class="magick-header"><a id="strip"></a>-strip</h3>
7286</div>
7287
Cristy776113a2016-04-29 12:01:19 -04007288<p class="magick-description">strip the image of any profiles, comments or these PNG chunks: bKGD,cHRM,EXIF,gAMA,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date.</p>
Cristy882d9f42015-10-29 16:48:39 -04007289
7290<div style="margin: auto;">
7291 <h3 class="magick-header"><a id="stroke"></a>-stroke <var>color</var></h3>
7292</div>
7293
7294<p class="magick-description">color to use when stroking a graphic primitive.</p>
7295
7296<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7297
7298<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7299
7300<div style="margin: auto;">
7301 <h3 class="magick-header"><a id="strokewidth"></a>-strokewidth <var>value</var></h3>
7302</div>
7303
7304<p class="magick-description">set the stroke width.</p>
7305
7306<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7307
7308<div style="margin: auto;">
7309 <h3 class="magick-header"><a id="style"></a>-style <var>fontStyle</var></h3>
7310</div>
7311
7312<p class="magick-description">Set a font style for text.</p>
7313
7314<p>This setting suggests a font style that ImageMagick should try to apply to
7315the currently selected font family. Select <var>fontStyle</var> from
7316the following.</p>
7317
7318<pre>
7319Any
7320Italic
7321Normal
7322Oblique
7323</pre>
7324
Cristy594d2772015-11-15 10:47:42 -05007325<p>For other settings that affect fonts, see the options <a
7326href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
7327href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007328
7329<div style="margin: auto;">
7330 <h3 class="magick-header"><a id="subimage-search"></a>-subimage-search</h3>
7331</div>
7332
7333<p class="magick-description">search for subimage.</p>
7334
7335<p>This option is required to have compare search for the best match location
7336of a small image within a larger image. This search will produce two images
7337(or two frames). The first is the "difference" image and the second will
7338be the "match score" image.</p>
7339
7340<p>The "match-score" image is smaller containing a pixel for ever possible
7341position of the top-left corner of the given sub-image. that is its size will
7342be the size of the larger_image - sub_image + 1. The brightest location in
7343this image is the location s the locate on the best match that is also
7344reported. Note that this may or may not be a perfect match, and the actual
7345brightness will reflect this. Other bright 'peaks' can be used to locate other
7346possible matching locations. </p>
7347
7348<p>Note that the search will try to compare the sub-image at every possible
7349location in the larger image, as such it can be very slow. The smaller the
7350sub-image the faster this search is. </p>
7351
7352
7353<div style="margin: auto;">
7354 <h3 class="magick-header"><a id="swap"></a>-swap <var>index,index</var></h3>
7355</div>
7356
7357<p class="magick-description">Swap the positions of two images in the image sequence.</p>
7358
7359<p>For example, <a href="command-line-options.html#swap">-swap 0,2</a> swaps the first and the third
7360images in the current image sequence. Use <a href="command-line-options.html#swap">+swap</a> to switch
7361the last two images in the sequence.</p>
7362
7363<div style="margin: auto;">
7364 <h3 class="magick-header"><a id="swirl"></a>-swirl <var>degrees</var></h3>
7365</div>
7366
7367<p class="magick-description">swirl image pixels about the center.</p>
7368
7369<p><var>Degrees</var> defines the tightness of the swirl.</p>
7370
7371<div style="margin: auto;">
7372 <h3 class="magick-header"><a id="synchronize"></a>-synchronize</h3>
7373</div>
7374
7375<p class="magick-description">synchronize image to storage device.</p>
7376
7377<p>Set to "true" to ensure all image data is fully flushed and synchronized
7378to disk. There is a performance penalty, but the benefits include ensuring a
7379valid image file in the event of a system crash and early reporting if there
7380is not enough disk space for the image pixel cache.</p>
7381
7382<div style="margin: auto;">
7383 <h3 class="magick-header"><a id="taint"></a>-taint</h3>
7384</div>
7385
7386<p class="magick-description">Mark the image as modified.</p>
7387
7388<div style="margin: auto;">
7389 <h3 class="magick-header"><a id="text-font"></a>-text-font <var>name</var></h3>
7390</div>
7391
7392<p class="magick-description">font for writing fixed-width text.</p>
7393
7394<p>Specifies the name of the preferred font to use in fixed (typewriter style)
7395formatted text. The default is 14 point <var>Courier</var>.</p>
7396
7397<p>You can tag a font to specify whether it is a PostScript, TrueType, or
7398OPTION1 font. For example, <code>Courier.ttf</code> is a TrueType font and
7399<code>x:fixed</code> is OPTION1.</p>
7400
7401<div style="margin: auto;">
7402 <h3 class="magick-header"><a id="texture"></a>-texture <var>filename</var></h3>
7403</div>
7404
7405<p class="magick-description">name of texture to tile onto the image background.</p>
7406
7407<div style="margin: auto;">
7408 <h3 class="magick-header"><a id="threshold"></a>-threshold <var>value</var>{<var>%</var>}</h3>
7409</div>
7410
7411<!-- {<var>green,blue,opacity</var>}
7412<p>If the green or blue value is omitted, these channels use the same value as
7413the first one provided. If all three color values are the same, the result is
7414a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used
7415and any partially transparent pixel becomes fully transparent.</p>
7416-->
7417
7418<p class="magick-description">Apply simultaneous black/white threshold to the image.</p>
7419
Cristy594d2772015-11-15 10:47:42 -05007420<p>Any pixel values (more specifically, those channels set using <a href="command-line-options.html#channel">&#x2011;channel</a>) that exceed the specified threshold are reassigned the
Cristy882d9f42015-10-29 16:48:39 -04007421maximum channel value, while all other values are assigned the minimum.</p>
7422
7423<p> The threshold value can be given as a percentage or as an absolute integer
7424value corresponding to the desired channel value. When given as an integer,
7425the minimum attainable value is 0 (corresponding to black when all channels
7426are affected), but the maximum value (corresponding to white) is that of the
7427<code>quantum depth</code> of the particular build of ImageMagick, and is
7428therefore dependent on the installation. For that reason, a reasonable
7429recommendation for most applications is to specify the threshold values as
7430a percentage. </p>
7431
7432<p> The following would force pixels with red values above 50% to have 100%
7433red values, while those at or below 50% red would be set to 0 in the red
7434channel. The green, blue, and alpha channels (if present) would be unchanged.
7435</p>
7436
7437<pre>
7438convert in.png -channel red -threshold 50% out.png
7439</pre>
7440
7441<p>As (possibly) impractical but instructive examples, the following would
7442generate an all-black and an all-white image with the same dimensions as the
7443input image.</p>
7444
7445
7446<pre>
7447convert in.png -threshold 100% black.png
7448convert in.png -threshold -1 white.png
7449</pre>
7450
7451<p>Note that the values of the transparency channel is treated as 'matte'
7452values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
7453
Cristy594d2772015-11-15 10:47:42 -05007454<p> See also <a href="command-line-options.html#black-threshold">&#x2011;black&#x2011;threshold</a> and <a href="command-line-options.html#white-threshold">&#x2011;white&#x2011;threshold</a>.
Cristy882d9f42015-10-29 16:48:39 -04007455</p>
7456
7457<div style="margin: auto;">
7458 <h3 class="magick-header"><a id="thumbnail"></a>-thumbnail <var>geometry</var></h3>
7459</div>
7460
7461<p class="magick-description">Create a thumbnail of the image.</p>
7462
7463<p>This is similar to <a href="command-line-options.html#resize">-resize</a>, except it is optimized
7464for speed and any image profile, other than a color profile, is removed to
Cristy594d2772015-11-15 10:47:42 -05007465reduce the thumbnail size. To strip the color profiles as well, add <a
7466href="command-line-options.html#strip">-strip</a> just before of after this option.</p>
Cristy882d9f42015-10-29 16:48:39 -04007467
7468<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7469
7470<div style="margin: auto;">
7471 <h3 class="magick-header"><a id="tile"></a>-tile <var>filename</var></h3>
7472</div>
7473
7474<p class="magick-description">Set the tile image used for filling a subsequent graphic primitive.</p>
7475
7476<div style="margin: auto;">
7477 <h3 class="magick-header">-tile <var>geometry</var></h3>
7478</div>
7479
7480<p class="magick-description">Specify the layout of images.</p>
7481
7482<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7483
7484<div style="margin: auto;">
7485 <h3 class="magick-header">-tile</h3>
7486</div>
7487
7488<p class="magick-description">Specifies that a subsequent composite operation is repeated across and down image.</p>
7489
7490<div style="margin: auto;">
7491 <h3 class="magick-header"><a id="tile-offset"></a>-tile-offset {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
7492</div>
7493
7494<p class="magick-description">Specify the offset for tile images, relative to the background image it is tiled on.</p>
7495
Cristy594d2772015-11-15 10:47:42 -05007496<p>This should be set before the tiling image is set by <a href="command-line-options.html#tile"
7497>-tile</a> or <a href="command-line-options.html#texture" >-texture</a>, or directly applied for
Cristy882d9f42015-10-29 16:48:39 -04007498creating a tiled canvas using <code>TILE:</code> or <code>PATTERN:</code> input
7499formats. </p>
7500
Cristy594d2772015-11-15 10:47:42 -05007501<p>Internally ImageMagick does a <a href="command-line-options.html#roll" >-roll</a> of the tile image
Cristy882d9f42015-10-29 16:48:39 -04007502by the arguments given when the tile image is set. </p>
7503
7504<div style="margin: auto;">
7505 <h3 class="magick-header"><a id="tint"></a>-tint <var>value</var></h3>
7506</div>
7507
7508<p class="magick-description">Tint the image with the fill color.</p>
7509
7510<p>Tint the image with the fill color.</p>
7511
7512<p>Specify the amount of tinting as a percentage. Pure colors like black,
7513white red, yellow, will not be affected by -tint. Only mid-range colors such
7514as the various shades of grey.</p>
7515
7516<div style="margin: auto;">
7517 <h3 class="magick-header"><a id="title"></a>-title <var>string</var></h3>
7518</div>
7519
7520<p class="magick-description">Assign a title to displayed image.", "animate", "display", "montage</p>
7521
7522<p>Use this option to assign a specific title to the image. This assigned to
7523the image window and is typically displayed in the window title bar.
7524Optionally you can include the image filename, type, width, height, Exif data,
7525or other image attribute by embedding special format characters described
7526under the <a href="command-line-options.html#format">-format</a> option.</p>
7527
7528<p>For example,</p>
7529
7530<pre>
7531-title "%m:%f %wx%h"
7532</pre>
7533
7534<p>produces an image title of <code>MIFF:bird.miff 512x480</code> for an image
7535titled <code>bird.miff</code> and whose width is 512 and height is 480.</p>
7536
7537
7538<div style="margin: auto;">
7539 <h3 class="magick-header"><a id="transform"></a>-transform</h3>
7540</div>
7541
7542<p class="magick-description">transform the image.</p>
7543
7544<p>This option applies the transformation matrix from a previous <a href="command-line-options.html#affine">-affine</a> option.</p>
7545
7546<pre>
7547convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
7548</pre>
7549
7550
Cristy594d2772015-11-15 10:47:42 -05007551<p>This operator has been now been superseded by the <a
7552href="command-line-options.html#distort">-distort</a> '<code>AffineProjection</code>' method. </p>
Cristy882d9f42015-10-29 16:48:39 -04007553
7554
7555<div style="margin: auto;">
7556 <h3 class="magick-header"><a id="transparent"></a>-transparent <var>color</var></h3>
7557</div>
7558
7559<p class="magick-description">Make this color transparent within the image.</p>
7560
7561<p>The <var>color</var> argument is defined using the format
Cristy594d2772015-11-15 10:47:42 -05007562described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz"
7563>-fuzz</a> setting can be used to match and replace colors similar to the one
Cristy882d9f42015-10-29 16:48:39 -04007564given. </p>
7565
Cristy594d2772015-11-15 10:47:42 -05007566<p>Use <a href="command-line-options.html#transparent" >+transparent</a> to invert the pixels matched.
Cristy882d9f42015-10-29 16:48:39 -04007567that is make all non-matching colors transparent. </p>
7568
Cristy594d2772015-11-15 10:47:42 -05007569<p>The <a href="command-line-options.html#opaque">-opaque</a> operator is exactly the same as <a
7570href="command-line-options.html#transparent" >-transparent</a> but replaces the matching color with the
Cristy882d9f42015-10-29 16:48:39 -04007571current <a href="command-line-options.html#fill">-fill</a> color setting, rather than transparent.
Cristy594d2772015-11-15 10:47:42 -05007572However the <a href="command-line-options.html#transparent" >-transparent</a> operator also ensures
7573that the image has an alpha channel enabled, as per "<code><a href="command-line-options.html#alpha"
7574>-alpha</a> set</code>", and does not require you to modify the <a
7575href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
Cristy882d9f42015-10-29 16:48:39 -04007576
7577<p>Note that this does not define the color as being the 'transparency color'
Cristy594d2772015-11-15 10:47:42 -05007578used for color-mapped image formats, such as GIF. For that use <a
7579href="command-line-options.html#transparent-color" >-transparent-color</a> </p>
Cristy882d9f42015-10-29 16:48:39 -04007580
7581
7582<div style="margin: auto;">
7583 <h3 class="magick-header"><a id="transparent-color"></a>-transparent-color <var>color</var></h3>
7584</div>
7585
7586<p class="magick-description">Set the transparent color.</p>
7587
7588<p>Sometimes this is used for saving to image formats such as
7589GIF and PNG8 which uses this color to represent boolean transparency. This
7590does not make a color transparent, it only defines what color the transparent
Cristy594d2772015-11-15 10:47:42 -05007591color is in the color palette of the saved image. Use <a
7592href="command-line-options.html#transparent">-transparent</a> to make an opaque color transparent.</p>
Cristy882d9f42015-10-29 16:48:39 -04007593
7594<p>This option allows you to have both an opaque visible color, as well as a
7595transparent color of the same color value without conflict. That is, you can
7596use the same color for both the transparent and opaque color areas within an
7597image. This, in turn, frees to you to select a transparent color that is
7598appropriate when an image is displayed by an application that does not handle a
7599transparent color index, while allowing ImageMagick to correctly handle images of this
7600type. </p>
7601
7602<p>The default transparent color is <code>#00000000</code>, which is fully transparent black.</p>
7603
7604<div style="margin: auto;">
7605 <h3 class="magick-header"><a id="transpose"></a>-transpose</h3>
7606</div>
7607
7608<p class="magick-description">Mirror the image along the top-left to bottom-right diagonal.</p>
7609
7610<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <code>-flip -rotate 90</code>.
7611</p>
7612
7613<div style="margin: auto;">
7614 <h3 class="magick-header"><a id="transverse"></a>-transverse</h3>
7615</div>
7616
7617<p class="magick-description">Mirror the image along the images bottom-left top-right diagonal. Equivalent to the operations <code>-flop -rotate 90</code>.</p>
7618
7619
7620<div style="margin: auto;">
7621 <h3 class="magick-header"><a id="treedepth"></a>-treedepth <var>value</var></h3>
7622</div>
7623
7624<p class="magick-description">tree depth for the color reduction algorithm.</p>
7625
7626<p>Normally, this integer value is zero or one. A value of zero or one causes
7627the use of an optimal tree depth for the color reduction algorithm.</p>
7628
7629<p>An optimal depth generally allows the best representation of the source
7630image with the fastest computational speed and the least amount of memory.
7631However, the default depth is inappropriate for some images. To assure the
7632best representation, try values between 2 and 8 for this parameter. Refer to
Cristy594d2772015-11-15 10:47:42 -05007633the <a href="quantize.html"
7634>color reduction algorithm</a> for more details.</p>
Cristy882d9f42015-10-29 16:48:39 -04007635
7636<p>The <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#monochrome">-monochrome</a>
7637option, or writing to an image format which requires color reduction, is
7638required for this option to take effect.</p>
7639
7640<div style="margin: auto;">
7641 <h3 class="magick-header"><a id="trim"></a>-trim</h3>
7642</div>
7643
7644<p class="magick-description">trim an image.</p>
7645
7646<p>This option removes any edges that are exactly the same color as the corner
7647pixels. Use <a href="command-line-options.html#fuzz">-fuzz</a> to make <a href="command-line-options.html#trim">-trim</a> remove
7648edges that are nearly the same color as the corner pixels.</p>
7649
7650<p>The page or virtual canvas information of the image is preserved allowing
7651you to extract the result of the <a href="command-line-options.html#trim">-trim</a> operation from the
7652image. Use a <a href="command-line-options.html#repage">+repage</a> to remove the virtual canvas page
7653information if it is unwanted.</p>
7654
7655<p>If the trimmed image 'disappears' an warning is produced, and a special
7656single pixel transparent 'missed' image is returned, in the same way as when a
7657<a href="command-line-options.html#crop">-crop</a> operation 'misses' the image proper. </p>
7658
7659
7660<div style="margin: auto;">
7661 <h3 class="magick-header"><a id="type"></a>-type <var>type</var></h3>
7662</div>
7663
7664<p class="magick-description">the image type.</p> <p>Choose from: <code>Bilevel</code>,
7665<code>Grayscale</code>, <code>GrayscaleMatte</code>, <code>Palette</code>,
7666<code>PaletteMatte</code>, <code>TrueColor</code>, <code>TrueColorMatte</code>,
7667<code>ColorSeparation</code>, or <code>ColorSeparationMatte</code>.</p>
7668
7669<p>Normally, when a format supports different subformats such as grayscale and
Cristy594d2772015-11-15 10:47:42 -05007670truecolor, the encoder will try to choose an efficient subformat. The <a
7671href="command-line-options.html#type">-type</a> option can be used to override this behavior. For
Cristy882d9f42015-10-29 16:48:39 -04007672example, to prevent a JPEG from being written in grayscale format even though
7673only gray pixels are present, use.</p>
7674
7675<pre>
7676convert bird.png -type TrueColor bird.jpg
7677</pre>
7678
7679<p>Similarly, use <a href="command-line-options.html#type">-type TrueColorMatte</a> to force the
7680encoder to write an alpha channel even though the image is opaque, if the
7681output format supports transparency.</p>
7682
7683<p>Use <a href="command-line-options.html#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p>
7684
7685<div style="margin: auto;">
7686 <h3 class="magick-header"><a id="undercolor"></a>-undercolor <var>color</var></h3>
7687</div>
7688
7689<p class="magick-description">set the color of the annotation bounding box.</p>
7690
7691<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7692
7693<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7694
7695
7696<div style="margin: auto;">
7697 <h3 class="magick-header"><a id="update"></a>-update <var>seconds</var></h3>
7698</div>
7699
7700<p class="magick-description">detect when image file is modified and redisplay.</p>
7701
7702<p>Suppose that while you are displaying an image the file that is currently
7703displayed is over-written. <code>display</code> will automagically detect that
7704the input file has been changed and update the displayed image
7705accordingly.</p>
7706
7707
7708<div style="margin: auto;">
7709 <h3 class="magick-header"><a id="unique-colors"></a>-unique-colors</h3>
7710</div>
7711
7712<p class="magick-description">discard all but one of any pixel color.</p>
7713
7714
7715<div style="margin: auto;">
7716 <h3 class="magick-header"><a id="units"></a>-units <var>type</var></h3>
7717</div>
7718
7719<p class="magick-description">the units of image resolution.</p>
7720
7721<p>Choose from: <code>Undefined</code>, <code>PixelsPerInch</code>, or
7722<code>PixelsPerCentimeter</code>. This option is normally used in conjunction
7723with the <a href="command-line-options.html#density">-density</a> option.</p>
7724
7725
7726<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05007727 <h3 class="magick-header"><a id="unsharp"></a>-unsharp <var>radius</var><br />-unsharp <var>radius</var>x<var>sigma</var>{<var>+gain</var>}{<var>+threshold</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007728</div>
7729
7730<p class="magick-description">sharpen the image with an unsharp mask operator.</p>
7731
7732<p>The <a href="command-line-options.html#unsharp">-unsharp</a> option sharpens an image. The image is
7733convolved with a Gaussian operator of the given radius and standard deviation
7734(sigma). For reasonable results, radius should be larger than sigma. Use
7735a radius of 0 to have the method select a suitable radius.</p>
7736
7737<p>The parameters are:</p>
7738
7739<dl class="dl-horizontal">
7740<dt>radius</dt>
7741<dd>The radius of the Gaussian, in pixels, not counting the center pixel (default 0).</dd>
7742<dt>sigma</dt>
7743<dd>The standard deviation of the Gaussian, in pixels (default 1.0).</dd>
7744<dt>gain</dt>
7745<dd>The fraction of the difference between the original and the blur image that is added back into the original (default 1.0).</dd>
7746<dt>threshold</dt>
7747<dd>The threshold, as a fraction of <var>QuantumRange</var>, needed to apply the difference amount (default 0.05).</dd>
7748</dl>
7749
7750<div style="margin: auto;">
7751 <h3 class="magick-header"><a id="verbose"></a>-verbose</h3>
7752</div>
7753
7754<p class="magick-description">print detailed information about the image when this option precedes the <a href="command-line-options.html#identify">-identify</a> option or <code>info:</code>.</p>
7755
7756
7757<div style="margin: auto;">
7758 <h3 class="magick-header"><a id="version"></a>-version</h3>
7759</div>
7760
7761<p class="magick-description">print ImageMagick version string and exit.</p>
7762
7763
7764<div style="margin: auto;">
7765 <h3 class="magick-header"><a id="view"></a>-view <var>string</var></h3>
7766</div>
7767
7768<p class="magick-description">FlashPix viewing parameters.</p>
7769
7770
7771<div style="margin: auto;">
7772 <h3 class="magick-header"><a id="vignette"></a>-vignette <var>radius</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3>
7773</div>
7774
7775<p class="magick-description">soften the edges of the image in vignette style.</p>
7776
7777<p>The vignette effect rolloff is controlled by radiusxsigma. For nominal rolloff, this would be set to 0xsigma. A value of 0x0 will produce a circle/ellipse with no rolloff. The arguments x and y control the size of the circle. Larger values decrease the radii and smaller values increase the radii. Values of +0+0 will generate a circle/ellipse the same size as the image. The default values for x and y are 10% of the corresponding image dimension. Thus, the radii will be decreased by 10%, i.e., the diameters of the circle/ellipse will be 80% of the corresponding image dimension.</p>
7778
7779<div style="margin: auto;">
7780 <h3 class="magick-header"><a id="virtual-pixel"></a>-virtual-pixel <var>method</var></h3>
7781</div>
7782
7783<p class="magick-description">Specify contents of <var>virtual pixels</var>.</p>
7784
7785<p>This option defines what color source should be used if and when a color
7786lookup completely 'misses' the source image. The color(s) that appear to
7787surround the source image. Generally this color is derived from the source
7788image, but could also be set to a specify background color. </p>
7789
7790<p>Choose from these methods:</p>
7791
7792<dl class="dl-horizontal">
7793<dt>background</dt><dd>the area surrounding the image is the background color</dd>
7794<dt>black</dt><dd>the area surrounding the image is black</dd>
7795<dt>checker-tile</dt><dd>alternate squares with image and background color</dd>
7796<dt>dither</dt><dd>non-random 32x32 dithered pattern</dd>
7797<dt>edge</dt><dd>extend the edge pixel toward infinity</dd>
7798<dt>gray</dt><dd>the area surrounding the image is gray</dd>
7799<dt>horizontal-tile</dt><dd>horizontally tile the image, background color above/below</dd>
7800<dt>horizontal-tile-edge</dt><dd>horizontally tile the image and replicate the side edge pixels</dd>
7801<dt>mirror</dt><dd>mirror tile the image</dd>
7802<dt>random</dt><dd>choose a random pixel from the image</dd>
7803<dt>tile</dt><dd>tile the image (default)</dd>
7804<dt>transparent</dt><dd>the area surrounding the image is transparent blackness</dd>
7805<dt>vertical-tile</dt><dd>vertically tile the image, sides are background color</dd>
7806<dt>vertical-tile-edge</dt><dd>vertically tile the image and replicate the side edge pixels</dd>
7807<dt>white</dt><dd>the area surrounding the image is white</dd>
7808</dl>
7809
7810<p>The default value is "edge".</p>
7811
Cristy594d2772015-11-15 10:47:42 -05007812<p>This most important for distortion operators such as <a href="command-line-options.html#distort"
7813>-distort</a>, <a href="command-line-options.html#implode" >-implode</a>, and <a href="command-line-options.html#fx" >-fx</a>.
Cristy882d9f42015-10-29 16:48:39 -04007814However it also effects operations that may access pixels just outside the
Cristy594d2772015-11-15 10:47:42 -05007815image proper, such as <a href="command-line-options.html#convolve">-convolve</a>, <a
7816href="command-line-options.html#blur">-blur</a>, and <a href="command-line-options.html#sharpen">-sharpen</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007817
Cristy594d2772015-11-15 10:47:42 -05007818<p>To print a complete list of virtual pixel types, use the <a
7819href="command-line-options.html#list">-list virtual-pixel</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04007820
7821
7822<div style="margin: auto;">
7823 <h3 class="magick-header"><a id="visual"></a>-visual <var>type</var></h3>
7824</div>
7825
7826<p class="magick-description">Animate images using this X visual type.", 'animate', 'display'</p>
7827
7828<p>Choose from these visual classes:</p>
7829
7830<pre>
7831StaticGray TrueColor
7832GrayScale DirectColor
7833StaticColor default
7834PseudoColor visual id
7835</pre>
7836
7837<p>The X server must support the visual you choose, otherwise an error occurs.
7838If a visual is not specified, the visual class that can display the most
7839simultaneous colors on the default screen is chosen.</p>
7840
7841
7842<div style="margin: auto;">
7843 <h3 class="magick-header"><a id="watermark"></a>-watermark <var>brightness</var>x<var>saturation</var></h3>
7844</div>
7845
7846<p class="magick-description">Watermark an image using the given percentages of brightness and saturation.</p>
7847
7848<p>Take a grayscale image (with alpha mask) and modify the destination image's
7849brightness according to watermark image's grayscale value and the
7850<var>brightness</var> percentage. The destinations color saturation
7851attribute is just direct modified by the <var>saturation</var>
7852percentage, which defaults to 100 percent (no color change). </p>
7853
7854
7855<div style="margin: auto;">
Cristy594d2772015-11-15 10:47:42 -05007856 <h3 class="magick-header"><a id="wave"></a>-wave <var>amplitude</var><br />-wave <var>amplitude</var>x<var>wavelength</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007857</div>
7858
7859<p class="magick-description">Shear the columns of an image into a sine wave.</p>
7860
Cristye09ed312016-03-06 08:07:39 -05007861<div style="margin: auto;">
7862 <h3 class="magick-header"><a id="wavelet-denoise"></a>-wavelet-denoise <var>threshold</var><br />-wavelet-denoise <var>threshold</var>x<var>softness</var></h3>
7863</div>
7864
7865<p class="magick-description">removes noise from the image using a wavelet transform. The threshold is the value below which everything is considered noise and ranges from 0.0 (none) to QuantumRange or use percent (e.g. 5%). Softness attenuates the threshold and typically ranges from 0.0 (none) to 1.0. The higher the value the more noise that remains in the image.</p>
Cristy882d9f42015-10-29 16:48:39 -04007866
7867<div style="margin: auto;">
7868 <h3 class="magick-header"><a id="weight"></a>-weight <var>fontWeight</var></h3>
7869</div>
7870
7871<p class="magick-description">Set a font weight for text.</p>
7872
7873<p>This setting suggests a font weight that ImageMagick should try to apply to
7874the currently selected font family. Use a positive integer for
7875<var>fontWeight</var> or select from the following.</p>
7876
7877<dl class="dl-horizontal">
7878<dt>Thin </dt>
7879<dd>Same as <var>fontWeight</var> = 100.</dd>
7880<dt>ExtraLight </dt>
7881<dd>Same as <var>fontWeight</var> = 200.</dd>
7882<dt>Light </dt>
7883<dd>Same as <var>fontWeight</var> = 300.</dd>
7884<dt>Normal </dt>
7885<dd>Same as <var>fontWeight</var> = 400.</dd>
7886<dt>Medium </dt>
7887<dd>Same as <var>fontWeight</var> = 500.</dd>
7888<dt>DemiBold </dt>
7889<dd>Same as <var>fontWeight</var> = 600.</dd>
7890<dt>Bold </dt>
7891<dd>Same as <var>fontWeight</var> = 700.</dd>
7892<dt>ExtraBold </dt>
7893<dd>Same as <var>fontWeight</var> = 800.</dd>
7894<dt>Heavy </dt>
7895<dd>Same as <var>fontWeight</var> = 900.</dd>
7896</dl>
Cristy594d2772015-11-15 10:47:42 -05007897<br/>
Cristy882d9f42015-10-29 16:48:39 -04007898
7899<p>To print a complete list of weight types, use <a href="command-line-options.html#list">-list weight</a>.</p>
7900
Cristy594d2772015-11-15 10:47:42 -05007901<p>For other settings that affect fonts, see the options <a
7902href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
7903href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#style">-style</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007904
7905<div style="margin: auto;">
7906 <h3 class="magick-header"><a id="white-point"></a>-white-point <var>x,y</var></h3>
7907</div>
7908
7909<p class="magick-description">chromaticity white point.</p>
7910
7911<div style="margin: auto;">
7912 <h3 class="magick-header"><a id="white-threshold"></a>-white-threshold <var>value</var>{<var>%</var>}</h3>
7913</div>
7914
7915<p class="magick-description">Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</p>
7916
7917<p> The threshold value can be given as a percentage or as an absolute integer
7918value within [0, <var>QuantumRange</var>] corresponding to the
Cristy594d2772015-11-15 10:47:42 -05007919desired <a href="command-line-options.html#channel">&#x2011;channel</a> value. See <a href="command-line-options.html#threshold">&#x2011;threshold</a>for more details on thresholds and resulting values. </p>
Cristy882d9f42015-10-29 16:48:39 -04007920
7921<div style="margin: auto;">
7922 <h3 class="magick-header"><a id="window"></a>-window <var>id</var></h3>
7923</div>
7924
7925<p class="magick-description">Make the image the background of a window.", 'animate', 'display'</p>
7926
7927<p><var>id</var> can be a window id or name. Specify <code>root</code>
7928to select X's root window as the target window.</p>
7929
7930<p>By default the image is tiled onto the background of the target window. If
7931<code>backdrop</code> or <a href="command-line-options.html#geometry">-resize</a> are specified, the
7932image is surrounded by the background color. Refer to <code>X RESOURCES</code>
7933for details.</p>
7934
7935<p>The image will not display on the root window if the image has more unique
Cristy594d2772015-11-15 10:47:42 -05007936colors than the target window colormap allows. Use <a
7937href="command-line-options.html#colors">-colors</a> to reduce the number of colors.</p>
Cristy882d9f42015-10-29 16:48:39 -04007938
7939<div style="margin: auto;">
7940 <h3 class="magick-header"><a id="window-group"></a>-window-group</h3>
7941</div>
7942
7943<p class="magick-description">specify the window group.</p>
7944
7945<div style="margin: auto;">
7946 <h3 class="magick-header"><a id="write"></a>-write <var>filename</var></h3>
7947</div>
7948
7949<p class="magick-description">write an image sequence.</p>
7950
7951<p>The image sequence preceding the <a href="command-line-options.html#write">-write</a> <var>filename</var> option is written out, and processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the <a href="command-line-options.html#write">+write</a> <var>filename</var> option.</p>
7952
7953<p>Use <a href="command-line-options.html#compress">-compress</a> to specify the type of image compression.</p>
Cristye0779712016-07-30 17:25:22 -04007954
7955<div style="margin: auto;">
7956 <h3 class="magick-header"><a id="write-mask"></a>-write-mask <var>filename</var></h3>
7957</div>
7958
7959<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
7960
7961<p>This the same as using a mask used for composite masking operations, with
7962grayscale values causing blended updates of the image the mask is attached to.
7963</p>
7964
7965<p>Use <a href="command-line-options.html#write-mask">+write-mask</a> to remove the mask from images.</p>
7966
7967<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
7968but with strict boolean masking. </p>
Cristy882d9f42015-10-29 16:48:39 -04007969</div>
7970</div>
7971
7972
Cristye93be682015-11-26 09:07:51 -05007973
Cristy882d9f42015-10-29 16:48:39 -04007974 <footer class="magick-footer">
cristy29f2c972015-07-28 13:37:46 +00007975 <p><a href="support.html">Donate</a>
7976 <a href="sitemap.html">Sitemap</a>
cristyd2432012015-05-04 23:15:15 +00007977 <a href="links.html">Related</a>
Cristye0779712016-07-30 17:25:22 -04007978 <a href="security-policy.html">Security</a>
cristy29f2c972015-07-28 13:37:46 +00007979 <a href="architecture.html">Architecture</a>
cristyd2432012015-05-04 23:15:15 +00007980</p>
7981 <p><a href="command-line-options.html#">Back to top</a>
cristyea2793e2015-05-31 16:52:26 +00007982 <a href="http://pgp.mit.edu:11371/pks/lookup?op=get&amp;search=0x89AB63D48277377A">Public Key</a>
Cristy1f1f3a02016-06-01 07:25:42 -04007983 <a href="http://www.imagemagick.org/script/contact.php">Contact Us</a></p>
Cristyde27d762016-01-02 12:56:44 -05007984 <p><small>© 1999-2016 ImageMagick Studio LLC</small></p>
cristyd2432012015-05-04 23:15:15 +00007985 </footer>
7986</div><!-- /.container -->
7987
Cristy542697a2015-10-12 20:10:32 -04007988 <script src="https://localhost/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
Cristy1f1f3a02016-06-01 07:25:42 -04007989 <script src="../js/magick.html"></script>
cristyd2432012015-05-04 23:15:15 +00007990</div>
cristyad41c0c2012-10-31 00:49:28 +00007991</body>
cristy5a367e42015-05-05 12:39:18 +00007992</html>
Cristye0779712016-07-30 17:25:22 -04007993<!-- Magick Cache 30th July 2016 09:49 -->