Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / ImageMagick / 1efc1ab178a608af159af3038281939c727a11d2 / . / www / porting.html
blob: 7167648ace293ee88dd081e46f886b205fc46b25 [file] [log] [blame]
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]1
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
3 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
4<html version="-//W3C//DTD XHTML 1.1//EN"
5 xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"
6 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
7 xsi:schemaLocation="http://www.w3.org/1999/xhtml
8 http://www.w3.org/MarkUp/SCHEMA/xhtml11.xsd">
9<head>
10 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]11 <meta name="google-site-verification" content="MxsMq6bdLOx0KSuz1MY6yG9ZTIJ7_7DVRfl5NCAT5Yg"/>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]12 <title>ImageMagick: Porting to ImageMagick Version 7</title>
13 <meta http-equiv="Content-Language" content="en-US"/>
14 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
15 <meta http-equiv="Reply-to" content="magick-users@imagemagick.org"/>
16 <meta name="Application-name" content="ImageMagick"/>
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]17 <meta name="Description" content="Use ImageMagick to convert, edit, or compose bitmap images in a variety of formats. In addition resize, rotate, shear, distort and transform images automagically."/>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]18 <meta name="Application-url" content="http://www.imagemagick.org"/>
19 <meta name="Generator" content="PHP"/>
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]20 <meta name="Keywords" content="porting, to, imagemagick, version, 7, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand, ImageMagickObject, Image, Processing, Automagically"/>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]21 <meta name="Rating" content="GENERAL"/>
22 <meta name="Robots" content="INDEX, FOLLOW"/>
23 <meta name="Generator" content="ImageMagick Studio LLC"/>
24 <meta name="Author" content="ImageMagick Studio LLC"/>
25 <meta name="Revisit-after" content="2 DAYS"/>
26 <meta name="Resource-type" content="document"/>
27 <meta name="Copyright" content="Copyright (c) 1999-2011 ImageMagick Studio LLC"/>
28 <meta name="Distribution" content="Global"/>
29 <link rel="icon" href="../images/wand.png"/>
30 <link rel="shortcut icon" href="../images/wand.ico" type="images/x-icon"/>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]31 <link rel="canonical" href="http://www.imagemagick.org" />
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]32 <link rel="meta" type="application/rdf+xml" title="ICI" href="http://imagemagick.org/ici.rdf"/>
33 <link rel="stylesheet" href="http://www.google.com/cse/style/look/default.css" type="text/css" />
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]34 <link rel="stylesheet" type="text/css" href="http://www.imagemagick.org/fancybox/jquery.fancybox-1.3.4.css" media="screen" />
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]35 <style type="text/css" media="all">
36 @import url("../www/magick.css");
37 </style>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]38 <script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]39 <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"></script>
40 <script type="text/javascript" src="http://www.imagemagick.org/fancybox/jquery.fancybox-1.3.4.pack.js"></script>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]41 <script type="text/javascript">
42 $(document).ready(function() {
43 $("a[href$=.jpg],a[href$=.png],a[href$=.gif]").fancybox({
44 'transitionIn' : 'elastic',
45 'transitionOut' : 'elastic',
46 'overlayShow' : false,
47 'opacity' : true
48 });
49 });
50 </script>
51</head>
52
53<body id="www-imagemagick-org">
54<div class="titlebar">
55<div style="margin: 17px auto; float: left;">
56 <script type="text/javascript">
57 <!--
58 google_ad_client = "pub-3129977114552745";
59 google_ad_slot = "5439289906";
60 google_ad_width = 728;
61 google_ad_height = 90;
62 //-->
63 </script>
64 <script type="text/javascript"
65 src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
66 </script>
67</div>
68<a href="http://www.imagemagick.org/discourse-server/">
69 <img src="../images/logo.jpg"
70 alt="ImageMagick Logo"
71 style="width: 123px; height: 118px; border: 0px; float: right;" /></a>
72<a href="../index.html">
73 <img src="../images/sprite.jpg"
74 alt="ImageMagick Sprite"
75 style="width: 114px; height: 118px; border: 0px; float: right;" /></a>
76</div>
77
78<div class="westbar">
79
80<div class="menu">
81 <a title="About ImageMagick" href="../index.html">About ImageMagick</a>
82</div>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]83<div class="menu">
84 <a title="Binary Releases" href="../www/binary-releases.html">Binary Releases</a>
85</div>
86<div class="sub">
87 <a title="Binary Release: Unix" href="../www/binary-releases.html#unix">Unix</a>
88</div>
89<div class="sub">
90 <a title="Binary Release: MacOS X" href="../www/binary-releases.html#macosx">Mac OS X</a>
91</div>
92<div class="sub">
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]93 <a title="Binary Release: iOS" href="../www/binary-releases.html#iOS">iOS</a>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]94</div>
95<div class="sub">
96 <a title="Binary Release: Windows" href="../www/binary-releases.html#windows">Windows</a>
97</div>
98<div class="sep"></div>
99<div class="menu">
100 <a title="Command-line Tools" href="../www/command-line-tools.html">Command-line Tools</a>
101</div>
102<div class="sub">
103 <a title="Command-line Tools: Processing" href="../www/command-line-processing.html">Processing</a>
104</div>
105<div class="sub">
106 <a title="Command-line Tools: Options" href="../www/command-line-options.html">Options</a>
107</div>
108<div class="sub">
109 <a title="Command-line Tools: Usage" href="http://www.imagemagick.org/Usage/">Usage</a>
110</div>
111<div class="menu">
112 <a title="Program Interfaces" href="../www/api.html">Program Interfaces</a>
113</div>
114<div class="sub">
115 <a title="Program Interface: MagickWand" href="../www/magick-wand.html">MagickWand</a>
116</div>
117<div class="sub">
118 <a title="Program Interface: MagickCore" href="../www/magick-core.html">MagickCore</a>
119</div>
120<div class="sub">
121 <a title="Program Interface: PerlMagick" href="../www/perl-magick.html">PerlMagick</a>
122</div>
123<div class="sub">
124 <a title="Program Interface: Magick++" href="../www/magick++.html">Magick++</a>
125</div>
126<div class="sep"></div>
127<div class="menu">
128 <a title="Install from Source" href="../www/install-source.html">Install from Source</a>
129</div>
130<div class="sub">
131 <a title="Install from Source: Unix" href="../www/install-source.html#unix">Unix</a>
132</div>
133<div class="sub">
134 <a title="Install from Source: Windows" href="../www/install-source.html#windows">Windows</a>
135 </div>
136<div class="menu">
137 <a title="Resources" href="../www/resources.html">Resources</a>
138</div>
139<div class="menu">
140 <a title="Architecture" href="../www/architecture.html">Architecture</a>
141</div>
142<div class="menu">
143 <a title="Download" href="../www/download.html">Download</a>
144</div>
145<div class="sep"></div>
146<div class="menu">
147 <a title="Search" href="../www/search.html">Search</a>
148</div>
149<div class="sep"></div>
150<div class="menu">
151 <a title="Site Map" href="../www/sitemap.html">Site Map</a>
152</div>
153<div class="sub">
154 <a title="Site Map: Links" href="../www/links.html">Links</a>
155</div>
156<div class="sep"></div>
157<div class="menu">
158 <a rel="follow" title="Sponsors" href="../www/sponsors.html">Sponsors:</a>
159
160<a href="http://www.networkredux.com">
161 <img src="../images/networkredux.png" alt="[sponsor]"
162 style="margin-top: 4px; margin-left: 4px; border: 0px; float: left;" /></a>
163<div class="sponsbox">
164<div class="sponsor">
cristy81492d62011-06-07 16:41:42 +0000[diff] [blame]165 <a rel="follow" title="Sponsor: Web Hosting" href="http://www.micfo.com">Web Hosting</a><!-- 209901010090s golestan -->
166</div>
167<div class="sponsor">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]168 <a rel="follow" title="Sponsor: Autos part" href="http://www.pkwteile.de/autoteile">Autos part</a><!-- 201112010090s jr@pkwte... -->
169</div>
170<div class="sponsor">
cristy84134182011-06-15 22:59:00 +0000[diff] [blame]171 <a rel="follow" title="Sponsor: Search engine optimisation" href="http://www.seomoves.com.au">Search engine optimisation</a><!-- 201110010090s jen@seo lowprofilelinks -->
172</div>
173<div class="sponsor">
cristy81492d62011-06-07 16:41:42 +0000[diff] [blame]174 <a rel="follow" title="Sponsor: Druckerei" href="http://print24.com/de/">Druckerei</a><!-- 201110010720 -->
175</div>
176<div class="sponsor">
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]177 <a rel="follow" title="Sponsor: Web Hosting Deals" href="http://www.webhostingdeals.org">Web Hosting Deals</a><!-- 201111010270 chee.hoa darin -->
178</div>
179<div class="sponsor">
180 <a rel="follow" title="Sponsor: Web Hosting Reviews" href="http://www.webhostingsecretrevealed.com">Web Hosting Secret Revealed</a><!-- 201204010540 iamchee jerry -->
181</div>
182<div class="sponsor">
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]183 <a rel="follow" title="Sponsor: Web Hosting Break" href="http://www.webhostingbreak.com">Web Hosting Break</a><!-- 201109010090 ian@ian-m... -->
184</div>
185<div class="sponsor">
186 <a rel="follow" title="Sponsor: Druckerei" href="http://www.allesdruck.de">Druckerei</a><!-- 201303011500 r.leo -->
187</div>
188<div class="sponsor">
189 <a rel="follow" title="Sponsor: Website Hosting" href="http://www.hostreviewgeeks.com">Website Hosting</a><!-- 201110010090 alexanian media -->
190</div>
191<div class="sponsor">
192 <a rel="follow" title="Sponsor: Hotel München" href="http://www.messehotel-erb-muenchen.de">Hotel München</a><!-- 201111010450 cerb -->
193</div>
194<div class="sponsor">
195 <a rel="follow" title="Sponsor: Best Web Hosting" href="http://webhostinggeeks.com">Best Web Hosting</a><!-- 201110010720 -->
196</div>
197<div class="sponsor">
198 <a rel="follow" title="Sponsor: Flyer drucken" href="http://www.online-druck.biz">Flyer drucken</a><!-- 201109010900 Floeter-->
199</div>
200<div class="sponsor">
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]201 <a rel="follow" title="Sponsor: Web Hosting Ratings" href="http://webhostingrating.com">Web Hosting Ratings</a><!-- 201110010720 -->
202</div>
203<div class="sponsor">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]204 <a rel="follow" title="Sponsor: Fernsehdienst Berlin" href="http://www.atlas-multimedia.de">Fernsehdienst Berlin</a><!-- 2011090100025 atlas.multimedia-->
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]205</div>
206</div>
207</div>
208</div>
209
210<div class="eastbar">
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]211 <div class="g-plusone" data-size="standard" data-count="false"></div>
212</div>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]213
214<div class="main">
215
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]216<h1>ImageMagick Version 7 Porting Guide</h1>
217
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]218<p class="navigation-index">[<a href="#headers">Header Files</a> &bull; <a href="#channels">Pixel Channels</a> &bull; <a href="#alpha">Alpha</a> &bull; <a href="#grayscale">Grayscale</a> &bull; <a href="#core">MagickCore API Changes</a> &bull; <a href="#depecate">Deprecated Features Removed</a> &bull; <a href="#cli">Command-line Interface</a> &bull; <a href="#summary">Version 7 Change Summary</a> ]</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]219
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]220<p>The design of ImageMagick is an evolutionary process, with the design and implementation efforts serving to influence and guide further progress in the other. With ImageMagick version 7 we aim to improve the design based on lessons learned from the version 6 implementation. ImageMagick was originally designed to display RGB images to an X Windows server. Over time we extended support to RGBA images and then to the CMYK and CMYKA image format. With ImageMagick version 7, we extend support to arbitrary colorspaces with an arbitrary number of pixel channels. Other design changes are in the works and we will document them here so be sure to revisit periodically.</p>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]221
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]222<p>To support variable pixel channels in the MagickCore API, pixel handling has changed when getting or setting the pixel channels. You can access channels as an array, pixel[i], or use an accessor such as GetPixelRed() or SetPixelRed(). There are some modest changes to the MagickWand API. Magick++ and PerlMagick should behave exactly as it does for ImageMagick version 6.</p>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]223
224<p>We intend to make ImageMagick version 7 available as an Alpha release by the end-of-year 2011. Look for a Beta release sometime in 2012. An official ImageMagick version 7 release will depend on how smoothly the Beta cycle progresses. During the Beta cycle, version 6 developers can attempt to port their software to version 7.<p>
225
226<p>During the ImageMagick version 7 development cycle and release, we will continue to support and enhance version 6 for a minimum of 10 years.</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]227<h2><a id="headers"></a>Header Files</h2>
228<div class="doc-section">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]229<p>Prior versions of ImageMagick (4-6) reference the ImageMagick header files as <kbd>magick/</kbd> and <kbd>wand/</kbd>. ImageMagick 7 instead uses <kbd>MagickCore/</kbd> and <kbd>MagickWand/</kbd> respectively. For example,</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]230<pre class="code">
231#include &lt;MagickCore/MagickCore.h>
232#include &lt;MagickWand/MagickWand.h>
233</pre>
234</div>
235
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]236<h2><a id="channels"></a>Pixel Channels</h2>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]237<div class="doc-section">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]238<p>A pixel is comprised of one or more color values, or <em>channels</em> (e.g. red pixel channel).</p>
239<p>Prior versions of ImageMagick (4-6), support 4 to 5 pixel channels (RGBA or CMYKA). The first 4 channels are accessed with the PixelPacket data structure. The structure includes 4 members of type Quantum (typically 16-bits) of red, green, blue, and opacity. The black channel or colormap indexes are supported by a separate method and structure, IndexPacket. As an example, here is a code snippet from ImageMagick version 6 that negates the color components (but not the alpha component) of the image pixels:</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]240
241<pre class="code">
242 for (y=0; y &lt; (ssize_t) image->rows; y++)
243 {
244 register IndexPacket
245 *indexes;
246
247 register PixelPacket
248 *q;
249
250 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
251 if (q == (PixelPacket *) NULL)
252 {
253 status=MagickFalse;
254 continue;
255 }
256 indexes=GetCacheViewAuthenticIndexQueue(image_view);
257 for (x=0; x &lt; (ssize_t) image->columns; x++)
258 {
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]259 if ((channel & RedChannel) != 0)
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]260 q->red=(Quantum) QuantumRange-q->red;
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]261 if ((channel & GreenChannel) != 0)
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]262 q->green=(Quantum) QuantumRange-q->green;
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]263 if ((channel & BlueChannel) != 0)
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]264 q->blue=(Quantum) QuantumRange-q->blue;
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]265 if (((channel & IndexChannel) != 0) &&
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]266 (image->colorspace == CMYKColorspace))
267 indexes[x]=(IndexPacket) QuantumRange-indexes[x];
268 q++;
269 }
270 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
271 status=MagickFalse;
272 }
273</pre>
274
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]275<p>ImageMagick version 7 supports any number of channels from 1 to 100 (and beyond) and simplifies access with a single method that returns an array of pixel channels of type Quantum. Source code that compiles against prior versions of ImageMagick will require refactoring to work with ImageMagick version 7. We illustrate with an example. Let's naively refactor the version 6 code snippet from above so it works with the ImageMagick version 7 API:</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]276
277<pre class="code">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]278 SetPixelAlphaTraits(CopyPixelTrait);
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]279 for (y=0; y &lt; (ssize_t) image->rows; y++)
280 {
281 register Quantum
282 *q;
283
284 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
285 if (q == (Quantum *) NULL)
286 {
287 status=MagickFalse;
288 continue;
289 }
290 for (x=0; x &lt; (ssize_t) image->columns; x++)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]291 {
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]292 if ((GetPixelRedTraits(image) & UpdatePixelTrait) != 0)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]293 SetPixelRed(image,QuantumRange-GetPixelRed(image,q),q);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]294 if ((GetPixelGreenTraits(image) & UpdatePixelTrait) != 0)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]295 SetPixelGreen(image,QuantumRange-GetPixelGreen(image,q),q);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]296 if ((GetPixelBlueTraits(image) & UpdatePixelTrait) != 0)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]297 SetPixelBlue(image,QuantumRange-GetPixelBlue(image,q),q);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]298 if ((GetPixelBlackTraits(image) & UpdatePixelTrait) != 0)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]299 SetPixelBlack(image,QuantumRange-GetPixelBlack(image,q),q);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]300 if ((GetPixelAlphaTraits(image) & UpdatePixelTrait) != 0)
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]301 SetPixelAlpha(image,QuantumRange-GetPixelAlpha(image,q),q);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]302 q+=GetPixelChannels(image);
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]303 }
304 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
305 status=MagickFalse;
306 }
307</pre>
308
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]309<p>Let's do that again but take full advantage of the new variable pixel channel support:</p>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]310<pre class="code">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]311 SetPixelAlphaTraits(CopyPixelTrait);
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]312 for (y=0; y &lt; (ssize_t) image->rows; y++)
313 {
314 register Quantum
315 *q;
316
317 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
318 if (q == (Quantum *) NULL)
319 {
320 status=MagickFalse;
321 continue;
322 }
323 for (x=0; x &lt; (ssize_t) image->columns; x++)
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]324 {
325 register ssize_t
326 i;
327
328 for (i=0; i &lt; (ssize_t) GetPixelChannels(image); i++)
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]329 {
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]330 PixelTrait
331 traits;
332
333 traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
334 if ((traits &amp; UpdatePixelTrait) != 0)
335 q[i]=QuantumRange-q[i];
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]336 }
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]337 q+=GetPixelChannels(image);
338 }
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]339 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
340 status=MagickFalse;
341 }
342</pre>
343
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]344<p>Use GetPixelChannels() to advance to the next set of pixel channels.</p>
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]345
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]346<p>The colormap indexes and black pixel channel (for the CMYK colorspace) are no longer stored in the index channel, previously accessed with GetAuthenticIndexQueue() and GetCacheViewAuthenticIndexQueue((). Instead they are now a pixel channel and accessed with the convenience pixel macros GetPixelIndex(), SetPixelIndex(), GetPixelBlack(), and SetPixelBlack().</p>
cristy29c5c992011-06-25 13:58:49 +0000[diff] [blame]347
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]348<h4></a>Pixel Accessors</h4>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]349<p>Use accessors to get or set pixel channels:</p>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]350
351<pre class="text">
352 GetPixelAlpha()
353 GetPixelBlack()
354 GetPixelBlue()
355 GetPixelCb()
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]356 GetPixelChannels()
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]357 GetPixelCr()
358 GetPixelCyan()
359 GetPixelGray()
360 GetPixelGreen()
361 GetPixelIndex()
362 GetPixelInfoIntensity()
363 GetPixelInfoLuminance()
364 GetPixelMagenta()
365 GetPixelRed()
366 GetPixelPacket()
367 GetPixelPacketIntensity()
368 GetPixelY()
369 GetPixelYellow()
370 GetPixelIntensity()
371 SetPixelAlpha()
372 SetPixelBlack()
373 SetPixelBlue()
374 SetPixelCb()
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]375 SetPixelChannels()
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]376 SetPixelCr()
377 SetPixelCyan()
378 SetPixelGray()
379 SetPixelGreen()
380 SetPixelIndex()
381 SetPixelInfo()
382 SetPixelInfoBias()
383 SetPixelInfoPacket()
384 SetPixelMagenta()
385 SetPixelRed()
386 SetPixelPacket()
387 SetPixelPixelInfo()
388 SetPixelYellow()
389 SetPixelY()
390</pre>
391
392<p>You can find these accessors defined in the header file, <kbd>MagickCore/pixel-accessor.h</kbd></p>
393
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]394<h4></a>Pixel Traits</h4>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]395<p>Each pixel channel includes one or more of these traits:</p>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]396<dl>
397<dt>Undefined</dt>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]398<dd>no traits associated with this pixel channel<dd>
399<dt>Copy</dt>
400<dd>do not update this pixel channel, just copy it<dd>
401<dt>Update</dt>
402<dd>update this pixel channel<dd>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]403<dt>Blend</dt>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]404<dd>blend this pixel channel with the alpha mask if it's enabled<dd>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]405</dl>
406<p>We provide these methods to set and get pixel traits:</p>
407<pre class="text">
408 GetPixelAlphaTraits()
409 GetPixelBlackTraits()
410 GetPixelBlueTraits()
411 GetPixelCbTraits()
412 GetPixelCrTraits()
413 GetPixelCyanTraits()
414 GetPixelGrayTraits()
415 GetPixelGreenTraits()
416 GetPixelIndexTraits()
417 GetPixelMagentaTraits()
418 GetPixelRedTraits()
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]419 GetPixelChannelTraits()
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]420 GetPixelYTraits()
421 GetPixelYellowTraits()
422 SetPixelAlphaTraits()
423 SetPixelBlackTraits()
424 SetPixelBlueTraits()
425 SetPixelCbTraits()
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]426 SetPixelChannelTraits()
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]427 SetPixelCrTraits()
428 SetPixelGrayTraits()
429 SetPixelGreenTraits()
430 SetPixelIndexTraits()
431 SetPixelMagentaTraits()
432 SetPixelRedTraits()
433 SetPixelYellowTraits()
434 SetPixelYTraits()
435</pre>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]436<p>For convenience you can set the active trait for a set of pixel channels with a channel mask and these methods:</p>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]437<pre class="text">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]438 PopPixelChannelMap()
439 PushPixelChannelMap()
440 SetPixelChannelMap()
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]441</pre>
442
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]443<p>Previously MagickCore methods had channel analogs, for example, NegateImage() and NegateImageChannels(). The channel analog methods are no longer necessary because the pixel channel traits specify whether to act on a particular pixel channel and whether to blend with the alpha mask. For example, instead of</p>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]444<pre class="text">
445 NegateImageChannel(image,channel);
446</pre>
447<p>we use:</p>
448<pre class="text">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]449 PushPixelChannelMap(image,channel);
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]450 NegateImage(image);
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]451 PopPixelChannelMap(image);
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]452</pre>
453
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]454<h4></a>Pixel Meta Channels</h4>
455<p>In version 7, we introduce pixel meta channels. Traditionally we utilize 4 channels, red, green, blue, and alpha. For CMYK we also have a black channel. Meta channels are designed to contain whatever additional channel information that makes sense. Some examples include extra channels in TIFF or PSD images or perhaps you require a channel with infrared information for the pixel. You can associate traits with the meta channels so that they when they are acted upon by an image processing algorithm (e.g. blur) the pixels are copied, acted upon by the algorithm, or even blended with the alpha channel if that makes sense.</p>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]456<h4></a>Pixel Metacontent</h4>
457<p>In version 7, we introduce pixel metacontent. Metacontent is content about content. So rather than being the content itself, it's something that describes or amplifies the content. Here the content is a pixel. The pixel metacontent is for your exclusive use and is accessed with these MagickCore API methods:</p>
458<pre class="text">
459 SetImageMetacontentExtent()
460 GetImageMetacontentExtent()
461 GetVirtualMetacontent()
462 GetAuthenticMetacontent()
463 GetCacheViewAuthenticMetacontent()
464 GetCacheViewVirtualMetacontent()
465</pre>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]466</div>
467
468<h2><a id="alpha"></a>Alpha</h2>
469<div class="doc-section">
cristy2dcd6822011-06-13 16:21:20 +0000[diff] [blame]470<p>We support alpha now, previously opacity. With alpha, a value of 0 means that the pixel does not have any coverage information and is transparent; i.e. there was no color contribution from any geometry because the geometry did not overlap this pixel. A value of QuantumRange means that the pixel is opaque because the geometry completely overlapped the pixel. As a consequence, in version 7, the PixelPacket structure member alpha has replaced the previous opacity member.</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]471</div>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]472<h2><a id="grayscale"></a>Grayscale</h2>
473<div class="doc-section">
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]474<p>Previously, grayscale images consumed 4 channels: red, green, blue, and alpha. With version 7, grayscale consumes only 1 channel consuming far less resources as a result. However, there may be unintended consequences. With 1 channel, all image processing algorithms write to this one channel. Drawing yellow text on a grayscale image will produce gray lettering. To get the expected results, simply modify the colorspace to RGB (e.g. -colorspace rgb).</p>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]475</div>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]476
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]477<h2><a id="core"></a>MagickCore API Changes</h2>
478<div class="doc-section">
479<p>MagickCore, version 7, adds an ExceptionInfo argument to those methods that lacked it in version 6, e.g. NegateImage(image,MagickTrue,exception);</p>
480<p>All method channel analogs have been removed (e.g. BlurImageChannel()), they are no longer necessary, use pixel traits instead.</p>
481</div>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]482<h2><a id="deprecate"></a>Deprecated Features Removed</h2>
483<div class="doc-section">
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]484<p>All deprecated features from ImageMagick version 6 are removed in version 7. These include the <kbd>Magick-config</kbd> and <kbd>Wand-config</kbd> configuration utilities. Instead use:</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]485
486<pre class="code">
487 MagickCore-config
488 MagickWand-config
489</pre>
490
491<p>In addition, all deprecated <a href="http://magick.imagemagick.org/api/deprecate.html">MagickCore</a> and <a href="http://magick.imagemagick.org/api/magick-deprecate.html">MagickWand</a> methods are no longer available in version 7.</p>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]492<li>The FilterImage() method has been removed. Use ConvolveImage() instead.</li>
493</div>
494<h2><a id="cli"></a>Command-line Interface</h2>
495<div class="doc-section">
496<p>By default, most algorithms update the red, green, blue, black (for CMYK), and alpha channels. If appropriate, alpha is blended with red, green, blue, and black. For some algorithms, it only makes sense to copy alpha. For these cases, use the -channel option (e.g. convert castle.gif -channel RGB -negate castle.png).</p>
497<p>The <kbd>-convolve</kbd> option no longer normalizes the kernel argument and accepts non-square <a href="http://www.imagemagick.org/Usage/morphology/#user">user defined kernels</a>.</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]498</div>
499<h2><a id="summary"></a>Version 7 Change Summary</h2>
500<div class="doc-section">
cristye6e84152011-06-06 14:16:49 +0000[diff] [blame]501<p>Changes from ImageMagick version 6 to version 7 are summarized here:</p>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]502<h5>Pixels</h5>
503<dl>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]504<li>Pixels are no longer addressed with PixelPacket structure members (e.g. red, green, blue, opacity) but as an array of channels (e.g. pixel[PixelRedChannel]).</li>
505<li>Use convenience macros to access pixel channels (e.g. GetPixelRed(), SetPixelRed()).</li>
506<li>The black channel for the CMYK colorspace is no longer stored in the index channel, previously accessed with GetAuthenticIndexQueue() and GetCacheViewAuthenticIndexQueue((). Instead it is now a pixel channel and accessed with the convenience pixel macros GetPixelBlack() and SetPixelBlack().</li>
507<li>The index channel for colormapped images is no longer stored in the index channel, previously accessed with GetAuthenticIndexQueue() and GetCacheViewAuthenticIndexQueue((). Instead it is now a pixel channel and accessed with the convenience pixel macros GetPixelIndex() and SetPixelIndex().</li>
508<li>Use GetPixelChannels() to advance to the next set of pixel channels.</li>
509<li>Use the <em>metacontent</em> channel to associate metacontent with each pixel.</li>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]510</dl>
511<h5>Alpha</h5>
512<dl>
513<li>We support alpha rather than opacity (0 transparent; QuantumRange opaque).</li>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]514<li>Use GetPixelAlpha() or SetPixelAlpha() to get or set the alpha pixel channel value.</li>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]515</dl>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]516<h5>Grayscale</h5>
517<dl>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]518<li>Grayscale images consume one pixel channel in ImageMagick version 7. To process RGB, set the colorspace to RGB (e.g. -colorspace rgb).</li>
519</dl>
520<h5>MagickCore API Changes</h5>
521<dl>
522<li>MagickCore, version 7, adds an ExceptionInfo argument to those methods that lacked it in version 6, e.g. NegateImage(image,MagickTrue,exception);</li>
523<li>All method channel analogs have been removed (e.g. BlurImageChannel()), they are no longer necessary, use pixel traits instead.</li>
cristy87a7f072011-07-01 00:08:52 +0000[diff] [blame]524</dl>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]525<h5>Deprecated Methods</h5>
526<dl>
cristy2dcd6822011-06-13 16:21:20 +0000[diff] [blame]527<li>All ImageMagick version 6 MagickCore and MagickWand deprecated methods are removed and no longer available in ImageMagick version 7.</li>
cristya4dfb122011-07-07 19:01:57 +0000[diff] [blame]528<li>All MagickCore channel method analogs are removed (e.g. NegateImageChannels()). For version 7, use pixel traits instead.</li>
cristy1efc1ab2011-08-01 14:47:02 +0000[diff] [blame^]529<li>The FilterImage() method has been removed. Use ConvolveImage() instead.</li>
530<h5>Command-line Interface</h5>
531<dl>
532<li>If you don't want alpha negated, use the -channel option, e.g. convert castle.gif -channel RGB -negate castle.png.</li>
533<li>The <kbd>-convolve</kbd> option no longer normalizes the kernel argument and accepts non-square <a href="http://www.imagemagick.org/Usage/morphology/#user">user defined kernels</a>.</li>
534</dl>
cristyba1758d2011-06-03 01:29:12 +0000[diff] [blame]535</dl>
536</div>
537
538</div>
539
540<div id="linkbar">
541 <span id="linkbar-west">&nbsp;</span>
542 <span id="linkbar-center">
543 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> &bull;
544 <a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi">Studio</a>
545 </span>
546 <span id="linkbar-east">&nbsp;</span>
547 </div>
548 <div class="footer">
549 <span id="footer-west">&copy; 1999-2011 ImageMagick Studio LLC</span>
550 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span>
551 </div>
552 <div style="clear: both; margin: 0; width: 100%; "></div>
553 <script type="text/javascript">
554 var _gaq = _gaq || [];
555 _gaq.push(['_setAccount', 'UA-17690367-1']);
556 _gaq.push(['_trackPageview']);
557
558 (function() {
559 var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
560 ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
561 var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
562 })();
563 </script>
564</body>
565</html>