1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
<!DOCTYPE html>
<html lang="en" data-bs-theme="dark">
<head>
<script src="assets/color-modes.js" ></script>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>ImageMagick – Parallel Execution with OpenCL</title>
<meta name="keywords" content="Parallel Execution with OpenCL, Image Processing, Digital Image Editing, Image Conversion, Open-Source Software, Image Manipulation, Command-Line Image Tools" />
<meta name="description" content="ImageMagick is a powerful, open-source software suite for creating, editing, converting, and manipulating images in over 200 formats. Ideal for web developers, graphic designers, and researchers, it offers versatile tools for image processing, including batch processing, format conversion, and complex image transformations." />
<meta name="application-name" content="ImageMagick" />
<meta name="application-url" content="https://imagemagick.org" />
<meta name="copyright" content="Copyright (c) 1999 ImageMagick Studio LLC" />
<meta itemprop='url' content='../' />
<meta itemprop='title' content='ImageMagick' />
<meta itemprop='description' content="ImageMagick is a powerful, open-source software suite for creating, editing, converting, and manipulating images in over 200 formats. Ideal for web developers, graphic designers, and researchers, it offers versatile tools for image processing, including batch processing, format conversion, and complex image transformations." />
<meta property='og:url' content='../' />
<meta property='og:name' content='ImageMagick' />
<meta property='og:image' content='../images/logo.png' />
<meta property='og:type' content='website' />
<meta property='og:site_name' content='ImageMagick' />
<meta property='og:description' content="ImageMagick is a powerful, open-source software suite for creating, editing, converting, and manipulating images in over 200 formats. Ideal for web developers, graphic designers, and researchers, it offers versatile tools for image processing, including batch processing, format conversion, and complex image transformations." />
<meta name="google-site-verification" content="_bMOCDpkx9ZAzBwb2kF3PRHbfUUdFj2uO8Jd1AXArz4" />
<link type="images/png" sizes="64x64" href="../images/wand.png" rel="icon" />
<link type="images/icon" sizes="16x16" href="../images/wand.ico" rel="shortcut icon" />
<link href="opencl.html" rel="canonical" />
<link href="assets/bootstrap.min.css" rel="stylesheet" />
</head>
<body>
<svg xmlns="http://www.w3.org/2000/svg" class="d-none">
<symbol id="check2" viewBox="0 0 16 16">
<path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z"/>
</symbol>
<symbol id="circle-half" viewBox="0 0 16 16">
<path d="M8 15A7 7 0 1 0 8 1v14zm0 1A8 8 0 1 1 8 0a8 8 0 0 1 0 16z"/>
</symbol>
<symbol id="moon-stars-fill" viewBox="0 0 16 16">
<path d="M6 .278a.768.768 0 0 1 .08.858 7.208 7.208 0 0 0-.878 3.46c0 4.021 3.278 7.277 7.318 7.277.527 0 1.04-.055 1.533-.16a.787.787 0 0 1 .81.316.733.733 0 0 1-.031.893A8.349 8.349 0 0 1 8.344 16C3.734 16 0 12.286 0 7.71 0 4.266 2.114 1.312 5.124.06A.752.752 0 0 1 6 .278z"/>
<path d="M10.794 3.148a.217.217 0 0 1 .412 0l.387 1.162c.173.518.579.924 1.097 1.097l1.162.387a.217.217 0 0 1 0 .412l-1.162.387a1.734 1.734 0 0 0-1.097 1.097l-.387 1.162a.217.217 0 0 1-.412 0l-.387-1.162A1.734 1.734 0 0 0 9.31 6.593l-1.162-.387a.217.217 0 0 1 0-.412l1.162-.387a1.734 1.734 0 0 0 1.097-1.097l.387-1.162zM13.863.099a.145.145 0 0 1 .274 0l.258.774c.115.346.386.617.732.732l.774.258a.145.145 0 0 1 0 .274l-.774.258a1.156 1.156 0 0 0-.732.732l-.258.774a.145.145 0 0 1-.274 0l-.258-.774a1.156 1.156 0 0 0-.732-.732l-.774-.258a.145.145 0 0 1 0-.274l.774-.258c.346-.115.617-.386.732-.732L13.863.1z"/>
</symbol>
<symbol id="sun-fill" viewBox="0 0 16 16">
<path d="M8 12a4 4 0 1 0 0-8 4 4 0 0 0 0 8zM8 0a.5.5 0 0 1 .5.5v2a.5.5 0 0 1-1 0v-2A.5.5 0 0 1 8 0zm0 13a.5.5 0 0 1 .5.5v2a.5.5 0 0 1-1 0v-2A.5.5 0 0 1 8 13zm8-5a.5.5 0 0 1-.5.5h-2a.5.5 0 0 1 0-1h2a.5.5 0 0 1 .5.5zM3 8a.5.5 0 0 1-.5.5h-2a.5.5 0 0 1 0-1h2A.5.5 0 0 1 3 8zm10.657-5.657a.5.5 0 0 1 0 .707l-1.414 1.415a.5.5 0 1 1-.707-.708l1.414-1.414a.5.5 0 0 1 .707 0zm-9.193 9.193a.5.5 0 0 1 0 .707L3.05 13.657a.5.5 0 0 1-.707-.707l1.414-1.414a.5.5 0 0 1 .707 0zm9.193 2.121a.5.5 0 0 1-.707 0l-1.414-1.414a.5.5 0 0 1 .707-.707l1.414 1.414a.5.5 0 0 1 0 .707zM4.464 4.465a.5.5 0 0 1-.707 0L2.343 3.05a.5.5 0 1 1 .707-.707l1.414 1.414a.5.5 0 0 1 0 .708z"/>
</symbol>
</svg>
<div class="dropdown position-fixed bottom-0 end-0 mb-3 me-3 bd-mode-toggle">
<button class="btn btn-bd-secondary py-2 dropdown-toggle d-flex align-items-center"
id="bd-theme"
type="button"
aria-expanded="false"
data-bs-toggle="dropdown"
aria-label="Toggle theme (auto)">
<svg class="bi my-1 theme-icon-active" width="1em" height="1em"><use href="#circle-half"></use></svg>
<span class="visually-hidden" id="bd-theme-text">Toggle theme</span>
</button>
<ul class="dropdown-menu dropdown-menu-end shadow" aria-labelledby="bd-theme-text">
<li>
<button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="light" aria-pressed="false">
<svg class="bi me-2 opacity-50" width="1em" height="1em"><use href="#sun-fill"></use></svg>
Light
<svg class="bi ms-auto d-none" width="1em" height="1em"><use href="#check2"></use></svg>
</button>
</li>
<li>
<button type="button" class="dropdown-item d-flex align-items-center active" data-bs-theme-value="dark" aria-pressed="false">
<svg class="bi me-2 opacity-50" width="1em" height="1em"><use href="#moon-stars-fill"></use></svg>
Dark
<svg class="bi ms-auto d-none" width="1em" height="1em"><use href="#check2"></use></svg>
</button>
</li>
<li>
<button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="auto" aria-pressed="true">
<svg class="bi me-2 opacity-50" width="1em" height="1em"><use href="#circle-half"></use></svg>
Auto
<svg class="bi ms-auto d-none" width="1em" height="1em"><use href="#check2"></use></svg>
</button>
</li>
</ul>
</div>
<svg xmlns="http://www.w3.org/2000/svg" class="d-none">
<symbol id="arrow-right-circle" viewBox="0 0 16 16">
<path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0zM4.5 7.5a.5.5 0 0 0 0 1h5.793l-2.147 2.146a.5.5 0 0 0 .708.708l3-3a.5.5 0 0 0 0-.708l-3-3a.5.5 0 1 0-.708.708L10.293 7.5H4.5z"/>
</symbol>
<symbol id="color-mode" viewBox="0 0 118 94">
<title>Color Modes</title>
<path fill-rule="evenodd" clip-rule="evenodd" d="M24.509 0c-6.733 0-11.715 5.893-11.492 12.284.214 6.14-.064 14.092-2.066 20.577C8.943 39.365 5.547 43.485 0 44.014v5.972c5.547.529 8.943 4.649 10.951 11.153 2.002 6.485 2.28 14.437 2.066 20.577C12.794 88.106 17.776 94 24.51 94H93.5c6.733 0 11.714-5.893 11.491-12.284-.214-6.14.064-14.092 2.066-20.577 2.009-6.504 5.396-10.624 10.943-11.153v-5.972c-5.547-.529-8.934-4.649-10.943-11.153-2.002-6.484-2.28-14.437-2.066-20.577C105.214 5.894 100.233 0 93.5 0H24.508zM80 57.863C80 66.663 73.436 72 62.543 72H44a2 2 0 01-2-2V24a2 2 0 012-2h18.437c9.083 0 15.044 4.92 15.044 12.474 0 5.302-4.01 10.049-9.119 10.88v.277C75.317 46.394 80 51.21 80 57.863zM60.521 28.34H49.948v14.934h8.905c6.884 0 10.68-2.772 10.68-7.727 0-4.643-3.264-7.207-9.012-7.207zM49.948 49.2v16.458H60.91c7.167 0 10.964-2.876 10.964-8.281 0-5.406-3.903-8.178-11.425-8.178H49.948z"></path>
</symbol>
</svg>
<nav class="navbar navbar-expand-md navbar-dark bg-dark fixed-top">
<div class="container-fluid">
<a class="navbar-brand" href="../index.html"><img class="d-block" id="icon" alt="ImageMagick" width="32" height="32" src="../images/wand.ico"/></a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#magick-navbars" aria-controls="magick-navbars" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="magick-navbars">
<ul class="navbar-nav me-auto mb-2 mb-md-0">
<li class="nav-item">
<a class="nav-link " href="download.html">Download</a>
</li>
<li class="nav-item">
<a class="nav-link " href="command-line-tools.html">Tools</a>
</li>
<li class="nav-item">
<a class="nav-link " href="command-line-processing.html">CLI</a>
</li>
<li class="nav-item">
<a class="nav-link " href="develop.html">Develop</a>
</li>
<li class="nav-item">
<a class="nav-link" rel="noopener" target="_blank" href="https://github.com/ImageMagick/ImageMagick/discussions">Community</a>
</li>
<li class="nav-item">
</li>
</ul>
</div>
</div>
</nav>
<div class="col-lg-8 mx-auto p-4 py-md-5 text-body-secondary">
<header class="d-flex align-items-center pb-3 mb-5 border-bottom">
<a href="../index.html" class="d-flex align-items-center text-decoration-none">
<h1 class="mt-5 fs-4">Parallel Execution with OpenCL</h1>
</a>
</header>
<main class="container">
<div>
<p class="lead">ImageMagick has built-in support for some <a href="http://en.wikipedia.org/wiki/OpenCL">OpenCL</a> accelerated operations. However, there are some conditions for its operation. These requirements are listed below.</p>
<ol>
<li><strong>GPU platform:</strong> AMD or Intel GPUs are supported. NVIDIA support is not enabled at the moment.</li>
<li><strong>OS and drivers:</strong>
<ul>
<li><strong>Mac OS X:</strong> has built-in support for OpenCL. No other actions required.</li>
<li><strong>Linux/Windows:</strong> on supported platforms, install required drivers to enable OpenCL.</li>
<li><strong>Mobile:</strong> ImageMagick's OpenCL support is not available on mobile OSes (IOS/Android).</li>
</ul>
</li>
<li><strong>Compile-time flag:</strong> ImageMagick's OpenCL must be explicitly enabled when compiling. This is done by running <samp>configure</samp> with <samp>--enable-opencl</samp> flag set.</li>
<li><strong>Check runtime support:</strong> to verify if OpenCL support is enabled, run <samp>magick --version</samp>. The command output should read <samp>Features: ... <strong>OpenCL</strong> ...</samp></li>
<li><strong>Runtime flag:</strong> OpenCL is disabled by default in runtime. To enable it use the environment variable <samp>MAGICK_OCL_DEVICE=true</samp>, e.g. <samp>MAGICK_OCL_DEVICE=true magick <options></samp>.</li>
<li><strong>Command line utility:</strong> for proper OpenCL support it's recommended to use <samp>magick</samp> utility over <samp>convert</samp>, <samp>mogrify</samp> and others.</li>
<li><strong>Image type:</strong> OpenCL acceleration only works on images without a color map. Use true color images instead.</li>
<li><strong>Operators:</strong> the following is a list of image operators that have been OpenCL accelerated.
<pre class="p-3 mb-2 text-body-secondary bg-body-tertiary"> blur
contrast
charcoal
function
grayscale
motion-blur
resize</pre>
The following operators are OpenCL accelerated as well, but they require alpha channel to be enabled, e.g. <samp>magick sample.jpg -alpha on -despeckle null:</samp>.
<pre class="p-3 mb-2 text-body-secondary bg-body-tertiary"> despeckle
equalize
modulate</pre>
</li>
</ol>
<h4>OpenCL Operation Notes</h4>
<p>When some of the OpenCL accelerated operators are invoked for the first time and all the conditions above are met, ImageMagick conducts a series of tests to configure the OpenCL environment according to the system hardware; therefore, it is normal to experience a higher latency the first time you use an accelerated option. The OpenCL kernels are embedded inside ImageMagick in source format. During the initial setup, ImageMagick discovers all the available OpenCL devices and compiles the kernels for each of these targets. ImageMagick also runs several performance tests internally to determine the preferred device to use. The compiled kernel code and the performance test results are stored into the cache directory so that the data can be reused by subsequent invocations of the OpenCL path. By default, the OpenCL cached data is stored in <samp>$HOME/.cache/ImageMagick</samp> on Linux and on MacOSX or in <samp>%LOCALAPPDATA%\ImageMagick</samp> on Windows. To run these tests for the first time, use the command below:</p>
<pre class="p-3 mb-2 text-body-secondary bg-body-tertiary cli"><samp>MAGICK_OCL_DEVICE=true magick sample.jpg -blur 0x5 null:</samp></pre>
<p>On Windows the <samp>MAGICK_OCL_DEVICE=true</samp> part should be removed and the command <samp>set MAGICK_OCL_DEVICE=true</samp> should be executed before executing the command above to enable OpenCL operations.</p>
<p>To change the cache directory, set the MAGICK_OPENCL_CACHE_DIR environment variable. ImageMagick is able to detect hardware changes, driver updates, and new kernel sources and re-run the setup and the calibration test. You can also force ImageMagick to re-run the process by removing the content from the cache directory.</p>
<p>In addition to the environment variables mentioned above, ImageMagick provides a set of APIs that allow developers to gain more fine-grained control of the OpenCL acceleration. For example, use the <samp>InitializeOpenCL()</samp> function to initialize the OpenCL environment:</p>
<pre class="p-3 mb-2 text-body-secondary bg-body-tertiary"><samp>clEnv=GetCurrentOpenCLEnv();
if (InitializeOpenCL(clEnv,exception) == MagickFalse)
{
/* looks like OpenCL is not supported */
}</samp></pre>
</div>
</main><!-- /.container -->
<footer class="text-center pt-5 my-5 text-body-secondary border-top">
<div class="container-fluid">
<a href="security-policy.html">Security</a> •
<a href="news.html">News</a>
<a href="#"><img class="d-inline" id="wand" alt="And Now a Touch of Magick" width="16" height="16" src="../images/wand.ico"/></a>
<a href="links.html">Related</a> •
<a href="sitemap.html">Sitemap</a>
<br/>
<a href="support.html">Sponsor</a> •
<a href="cite.html">Cite</a> •
<a href="http://pgp.mit.edu/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> •
<a href="../www/../www/../www/../www/https://imagemagick.org/script/contact.php">Contact Us</a>
<br/>
<a href="https://github.com/imagemagick/imagemagick" rel="noopener" target="_blank" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="navbar-nav-svg" viewBox="0 0 512 499.36" width="2%" height="2%" role="img" focusable="false"><title>GitHub</title><path fill="currentColor" fill-rule="evenodd" d="M256 0C114.64 0 0 114.61 0 256c0 113.09 73.34 209 175.08 242.9 12.8 2.35 17.47-5.56 17.47-12.34 0-6.08-.22-22.18-.35-43.54-71.2 15.49-86.2-34.34-86.2-34.34-11.64-29.57-28.42-37.45-28.42-37.45-23.27-15.84 1.73-15.55 1.73-15.55 25.69 1.81 39.21 26.38 39.21 26.38 22.84 39.12 59.92 27.82 74.5 21.27 2.33-16.54 8.94-27.82 16.25-34.22-56.84-6.43-116.6-28.43-116.6-126.49 0-27.95 10-50.8 26.35-68.69-2.63-6.48-11.42-32.5 2.51-67.75 0 0 21.49-6.88 70.4 26.24a242.65 242.65 0 0 1 128.18 0c48.87-33.13 70.33-26.24 70.33-26.24 14 35.25 5.18 61.27 2.55 67.75 16.41 17.9 26.31 40.75 26.31 68.69 0 98.35-59.85 120-116.88 126.32 9.19 7.9 17.38 23.53 17.38 47.41 0 34.22-.31 61.83-.31 70.23 0 6.85 4.61 14.81 17.6 12.31C438.72 464.97 512 369.08 512 256.02 512 114.62 397.37 0 256 0z"/></svg></a> •
<a href="https://twitter.com/imagemagick" rel="noopener" target="_blank" aria-label="Twitter"><svg xmlns="http://www.w3.org/2000/svg" class="navbar-nav-svg" viewBox="0 0 300 300" width="2%" height="2%" role="img" focusable="false"><title>Twitter</title><path d="M178.57 127.15 290.27 0h-26.46l-97.03 110.38L89.34 0H0l117.13 166.93L0 300.25h26.46l102.4-116.59 81.8 116.59h89.34M36.01 19.54H76.66l187.13 262.13h-40.66"/></svg></a>
<br/>
<small>Copyright © 1999 ImageMagick Studio LLC</small>
</div>
</footer>
</div>
<!-- Javascript assets -->
<script src="assets/bootstrap.bundle.min.js" ></script>
</body>
</html>
<!-- Magick Cache 1st March 2025 19:23 -->
|
