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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
|
<!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 – MagickCore, C API: Image Histograms</title>
<meta name="keywords" content="MagickCore, C API: Image Histograms, 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="histogram.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="../www/download.html">Download</a>
</li>
<li class="nav-item">
<a class="nav-link " href="../www/command-line-tools.html">Tools</a>
</li>
<li class="nav-item">
<a class="nav-link " href="../www/command-line-processing.html">CLI</a>
</li>
<li class="nav-item">
<a class="nav-link " href="../www/develop.html">Develop</a>
</li>
<li class="nav-item">
<a class="nav-link" target="_blank" href="https://github.com/ImageMagick/ImageMagick/discussions">Community</a>
</li>
<li class="nav-item">
</li>
</ul>
<form class="d-flex form-inline" action="../../https://imagemagick.org/script/search.php">
<input class="form-control me-2" type="text" name="q" placeholder="Search" aria-label="Search" />
<button class="btn btn-outline-success" type="submit" name="sa">Search</button>
</form>
</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-3">MagickCore, C API: Image Histograms</h1>
</a>
</header>
<main class="container">
<h1 class="text-center">Histogram</h1>
<div class="btn-group">
<button class="btn btn-secondary dropdown-toggle" type="button" id="defaultDropdown" data-bs-toggle="dropdown" data-bs-auto-close="true" aria-expanded="false">
Select API Method
</button>
<ul class="dropdown-menu pre-scrollable" aria-labelledby="defaultDropdown">
<li><a href="#GetImageHistogram">GetImageHistogram</a></li>
<li><a href="#IdentifyPaletteImage">IdentifyPaletteImage</a></li>
<li><a href="#IsHistogramImage">IsHistogramImage</a></li>
<li><a href="#IsPaletteImage">IsPaletteImage</a></li>
<li><a href="#MinMaxStretchImage">MinMaxStretchImage</a></li>
<li><a href="#GetNumberColors">GetNumberColors</a></li>
</ul>
</div>
<br/>
<br/>
<div class="magick-header">
<h2><a href="../../api/MagickCore/histogram_8c.html" id="GetImageHistogram">GetImageHistogram</a></h2>
<p>GetImageHistogram() returns the unique colors in an image.</p>
<p>The format of the GetImageHistogram method is:</p>
<pre class="bg-light text-dark mx-4"><samp>size_t GetImageHistogram(const Image *image,
size_t *number_colors,ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<dt>file</dt>
<p>Write a histogram of the color distribution to this file handle.</p>
<dt>exception</dt>
<p>return any errors or warnings in this structure.</p>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="IdentifyPaletteImage">IdentifyPaletteImage</a></h2>
<p>IdentifyPaletteImage() returns MagickTrue if the image does not have more unique colors than specified in max_colors.</p>
<p>The format of the IdentifyPaletteImage method is:</p>
<pre class="bg-light text-dark mx-4"><samp>MagickBooleanType IdentifyPaletteImage(const Image *image,
ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<dt>max_colors</dt>
<p>the maximum unique colors.</p>
<dt>exception</dt>
<p>return any errors or warnings in this structure.</p>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="IsHistogramImage">IsHistogramImage</a></h2>
<p>IsHistogramImage() returns MagickTrue if the image has 1024 unique colors or less.</p>
<p>The format of the IsHistogramImage method is:</p>
<pre class="bg-light text-dark mx-4"><samp>MagickBooleanType IsHistogramImage(const Image *image,
ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<dt>exception</dt>
<p>return any errors or warnings in this structure.</p>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="IsPaletteImage">IsPaletteImage</a></h2>
<p>IsPaletteImage() returns MagickTrue if the image is PseudoClass and has 256 unique colors or less.</p>
<p>The format of the IsPaletteImage method is:</p>
<pre class="bg-light text-dark mx-4"><samp>MagickBooleanType IsPaletteImage(const Image *image)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="MinMaxStretchImage">MinMaxStretchImage</a></h2>
<p>MinMaxStretchImage() uses the exact minimum and maximum values found in each of the channels given, as the BlackPoint and WhitePoint to linearly stretch the colors (and histogram) of the image. The stretch points are also moved further inward by the adjustment values given.</p>
<p>If the adjustment values are both zero this function is equivalent to a perfect normalization (or autolevel) of the image.</p>
<p>Each channel is stretched independently of each other (producing color distortion) unless the special 'SyncChannels' flag is also provided in the channels setting. If this flag is present the minimum and maximum point will be extracted from all the given channels, and those channels will be stretched by exactly the same amount (preventing color distortion).</p>
<p>In the special case that only ONE value is found in a channel of the image that value is not stretched, that value is left as is.</p>
<p>The 'SyncChannels' is turned on in the 'DefaultChannels' setting by default.</p>
<p>The format of the MinMaxStretchImage method is:</p>
<pre class="bg-light text-dark mx-4"><samp>MagickBooleanType MinMaxStretchImage(Image *image,const double black,
const double white,const double gamma,ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows:</p>
<dd>
</dd>
<dd> </dd>
<dl class="dl-horizontal">
<dt>image</dt>
<dd>The image to auto-level </dd>
<dd> </dd>
<dt>black, white</dt>
<dd> move the black / white point inward from the minimum and maximum points by this color value. </dd>
<dd> </dd>
<dt>gamma</dt>
<dd>the gamma. </dd>
<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>
<dd> </dd>
</dl>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="GetNumberColors">GetNumberColors</a></h2>
<p>GetNumberColors() returns the number of unique colors in an image.</p>
<p>The format of the GetNumberColors method is:</p>
<pre class="bg-light text-dark mx-4"><samp>size_t GetNumberColors(const Image *image,FILE *file,
ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<dt>file</dt>
<p>Write a histogram of the color distribution to this file handle.</p>
<dt>exception</dt>
<p>return any errors or warnings in this structure.</p>
<h2><a href="../../api/MagickCore/histogram_8c.html" id="UniqueImageColors">UniqueImageColors</a></h2>
<p>UniqueImageColors() returns the unique colors of an image.</p>
<p>The format of the UniqueImageColors method is:</p>
<pre class="bg-light text-dark mx-4"><samp>Image *UniqueImageColors(const Image *image,ExceptionInfo *exception)
</samp></pre>
<p>A description of each parameter follows.</p>
<dt>image</dt>
<p>the image.</p>
<dt>exception</dt>
<p>return any errors or warnings in this structure.</p>
</div>
</main><!-- /.container -->
<footer class="py-5 text-center text-body-secondary bg-body-tertiary">
<div class="container-fluid">
<a href="../www/security-policy.html">Security</a> •
<a href="../www/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="../www/links.html">Related</a> •
<a href="../www/sitemap.html">Sitemap</a>
<br/>
<a href="../www/support.html">Sponsor</a> •
<a href="../www/cite.html">Cite</a> •
<a href="http://pgp.mit.edu/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> •
<a href="../www/contact.html">Contact Us</a>
<br/>
<a href="https://github.com/imagemagick/imagemagick" target="_blank" rel="noopener" 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" target="_blank" rel="noopener" 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>
|
