summaryrefslogtreecommitdiff
path: root/www/api/quantize.html
blob: 735e875c82536a2b1b9d002ac7c41e8843ab7ada (plain)
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
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567




<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8"  />
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"  />
  <title>ImageMagick - MagickCore, C API: Reduce the Number of Unique Colors in an Image</title>
  <meta name="application-name" content="ImageMagick" />
  <meta name="description" content="Use ImageMagick® to create, edit, compose, and convert bitmap images. Resize an image, crop it, change its shades and colors, add captions, and more." />
  <meta name="application-url" content="https://imagemagick.org" />
  <meta name="generator" content="PHP" />
  <meta name="keywords" content="magickcore, c, api:, reduce, the, number, of, unique, colors, in, an, image, image converter, image resizer, image editor, photo editor, jpg converter, png converter, tiff converter, vector images, online, free, swiss army" />
  <meta name="rating" content="GENERAL" />
  <meta name="robots" content="INDEX, FOLLOW" />
  <meta name="generator" content="ImageMagick Studio LLC" />
  <meta name="author" content="ImageMagick Studio LLC" />
  <meta name="revisit-after" content="2 DAYS" />
  <meta name="resource-type" content="document" />
  <meta name="copyright" content="Copyright (c) 1999-2020 ImageMagick Studio LLC" />
  <meta name="distribution" content="Global" />
  <meta name="magick-serial" content="P131-S030410-R485315270133-P82224-A6668-G1245-1" />
  <meta property='og:url' content='../../' />
  <meta property='og:title' 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="Create, Edit, Compose, or Convert Bitmap Images" />
  <meta name="google-site-verification" content="_bMOCDpkx9ZAzBwb2kF3PRHbfUUdFj2uO8Jd1AXArz4" />
  <link href="quantize.html" rel="canonical" />
  <link href="../../images/wand.png" rel="icon" />
  <link href="../../images/wand.ico" rel="shortcut icon" />
  <link href="../assets/magick.css" rel="stylesheet" />
</head>
<body>
  <nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
    <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-toggle="collapse" data-target="#navbarsMagick" aria-controls="navbarsMagick" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div class="navbar-collapse collapse" id="navbarsMagick" style="">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item ">
        <a class="nav-link" href="../index.html">Home <span class="sr-only">(current)</span></a>
      </li>
      <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">Command-line</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>
      <li class="nav-item">
        <iframe src="https://github.com/sponsors/ImageMagick/button" title="Sponsor ImageMagick" height="35" width="107" style="border: 0;"></iframe>
      </li>
    </ul>
    </div>
    <form class="form-inline my-2 my-md-0" action="https://imagemagick.org/script/search.php">
      <input class="form-control mr-sm-2" type="text" name="q" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit" name="sa">Search</button>
    </form>
  </nav>
  <div class="container">
   <script async="async" src="https://localhost/pagead/js/adsbygoogle.js"></script>    <ins class="adsbygoogle"
         style="display:block"
         data-ad-client="ca-pub-3129977114552745"
         data-ad-slot="6345125851"
         data-full-width-responsive="true"
         data-ad-format="horizontal"></ins>
    <script>
      (adsbygoogle = window.adsbygoogle || []).push({});
    </script>

  </div>

  <main role="main" class="container">
    <div class="magick-template">
<div class="magick-header">
<p class="text-center"><a href="quantize.html#QuantizeImage">QuantizeImage</a> &#8226; <a href="quantize.html#AcquireQuantizeInfo">AcquireQuantizeInfo</a> &#8226; <a href="quantize.html#CloneQuantizeInfo">CloneQuantizeInfo</a> &#8226; <a href="quantize.html#CompressImageColormap">CompressImageColormap</a> &#8226; <a href="quantize.html#DestroyQuantizeInfo">DestroyQuantizeInfo</a> &#8226; <a href="quantize.html#GetImageQuantizeError">GetImageQuantizeError</a> &#8226; <a href="quantize.html#GetQuantizeInfo">GetQuantizeInfo</a> &#8226; <a href="quantize.html#KmeansImage">KmeansImage</a> &#8226; <a href="quantize.html#PosterizeImage">PosterizeImage</a> &#8226; <a href="quantize.html#QuantizeImage">QuantizeImage</a> &#8226; <a href="quantize.html#QuantizeImages">QuantizeImages</a> &#8226; <a href="quantize.html#RemapImage">RemapImage</a> &#8226; <a href="quantize.html#RemapImages">RemapImages</a> &#8226; <a href="quantize.html#SetGrayscaleImage">SetGrayscaleImage</a></p>

<h2><a href="../../api/MagickCore/quantize_8c.html" id="QuantizeImage">QuantizeImage</a></h2>

<p>QuantizeImage() takes a standard RGB or monochrome images and quantizes them down to some fixed number of colors.</p>

<p>For purposes of color allocation, an image is a set of n pixels, where each pixel is a point in RGB space.  RGB space is a 3-dimensional vector space, and each pixel, Pi,  is defined by an ordered triple of red, green, and blue coordinates, (Ri, Gi, Bi).</p>

<p>Each primary color component (red, green, or blue) represents an intensity which varies linearly from 0 to a maximum value, Cmax, which corresponds to full saturation of that color.  Color allocation is defined over a domain consisting of the cube in RGB space with opposite vertices at (0,0,0) and (Cmax, Cmax, Cmax).  QUANTIZE requires Cmax = 255.</p>

<p>The algorithm maps this domain onto a tree in which each node represents a cube within that domain.  In the following discussion these cubes are defined by the coordinate of two opposite vertices (vertex nearest the origin in RGB space and the vertex farthest from the origin).</p>

<p>The tree's root node represents the entire domain, (0,0,0) through (Cmax,Cmax,Cmax).  Each lower level in the tree is generated by subdividing one node's cube into eight smaller cubes of equal size. This corresponds to bisecting the parent cube with planes passing through the midpoints of each edge.</p>

<p>The basic algorithm operates in three phases: Classification, Reduction, and Assignment.  Classification builds a color description tree for the image.  Reduction collapses the tree until the number it represents, at most, the number of colors desired in the output image. Assignment defines the output image's color map and sets each pixel's color by restorage_class in the reduced tree.  Our goal is to minimize the numerical discrepancies between the original colors and quantized colors (quantization error).</p>

<p>Classification begins by initializing a color description tree of sufficient depth to represent each possible input color in a leaf. However, it is impractical to generate a fully-formed color description tree in the storage_class phase for realistic values of Cmax.  If colors components in the input image are quantized to k-bit precision, so that Cmax= 2k-1, the tree would need k levels below the root node to allow representing each possible input color in a leaf.  This becomes prohibitive because the tree's total number of nodes is 1 + sum(i=1, k, 8k).</p>

<p>A complete tree would require 19,173,961 nodes for k = 8, Cmax = 255.</p>
<dt>avoid building a fully populated tree, QUANTIZE</dt>
<p>(1) Initializes data structures for nodes only as they are needed;  (2) Chooses a maximum depth for the tree as a function of the desired number of colors in the output image (currently log2(colormap size)).</p>

<p>For each pixel in the input image, storage_class scans downward from the root of the color description tree.  At each level of the tree it identifies the single node which represents a cube in RGB space containing the pixel's color.  It updates the following data for each such node:</p>

<pre class="text">
    n1: Number of pixels whose color is contained in the RGB cube which
    this node represents;
</pre>

<p>n2: Number of pixels whose color is not represented in a node at lower depth in the tree;  initially,  n2 = 0 for all nodes except leaves of the tree.</p>

<p>Sr, Sg, Sb: Sums of the red, green, and blue component values for all pixels not classified at a lower depth. The combination of these sums and n2 will ultimately characterize the mean color of a set of pixels represented by this node.</p>

<p>E: the distance squared in RGB space between each pixel contained within a node and the nodes' center.  This represents the quantization error for a node.</p>

<p>Reduction repeatedly prunes the tree until the number of nodes with n2 &gt; 0 is less than or equal to the maximum number of colors allowed in the output image.  On any given iteration over the tree, it selects those nodes whose E count is minimal for pruning and merges their color statistics upward. It uses a pruning threshold, Ep, to govern node selection as follows:</p>

<dd>
</dd>

<dd> Ep = 0 while number of nodes with (n2 &gt; 0) &gt; required maximum number of colors prune all nodes such that E &lt;= Ep Set Ep to minimum E in remaining nodes </dd>

<dd> This has the effect of minimizing any quantization error when merging two nodes together. </dd>

<dd> When a node to be pruned has offspring, the pruning procedure invokes itself recursively in order to prune the tree from the leaves upward. n2,  Sr, Sg,  and  Sb in a node being pruned are always added to the corresponding data in that node's parent.  This retains the pruned node's color characteristics for later averaging. </dd>

<dd> For each node, n2 pixels exist for which that node represents the smallest volume in RGB space containing those pixel's colors.  When n2 &gt; 0 the node will uniquely define a color in the output image. At the beginning of reduction,  n2 = 0  for all nodes except a the leaves of the tree which represent colors present in the input image. </dd>

<dd> The other pixel count, n1, indicates the total number of colors within the cubic volume which the node represents.  This includes n1 - n2 pixels whose colors should be defined by nodes at a lower level in the tree. </dd>

<dd> Assignment generates the output image from the pruned tree.  The output </dd>
<dl class="dl-horizontal">
<dt>parts</dt>
<dd>(1)  A color map, which is an array of color descriptions (RGB triples) for each color present in the output image;  (2)  A pixel array, which represents each pixel as an index into the color map array. </dd>

<dd> First, the assignment phase makes one pass over the pruned color description tree to establish the image's color map.  For each node with n2  &gt; 0, it divides Sr, Sg, and Sb by n2 .  This produces the mean color of all pixels that classify no lower than this node.  Each of these colors becomes an entry in the color map. </dd>

<dd> Finally,  the assignment phase reclassifies each pixel in the pruned tree to identify the deepest node containing the pixel's color.  The pixel's value in the pixel array becomes the index of this node's mean color in the color map. </dd>

<dd> This method is based on a similar algorithm written by Paul Raveling. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="AcquireQuantizeInfo">AcquireQuantizeInfo</a></h2>

<p>AcquireQuantizeInfo() allocates the QuantizeInfo structure.</p>

<p>The format of the AcquireQuantizeInfo method is:</p>

<pre class="text">
QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>image_info</dt>
<dd>the image info. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="CloneQuantizeInfo">CloneQuantizeInfo</a></h2>

<p>CloneQuantizeInfo() makes a duplicate of the given quantize info structure, or if quantize info is NULL, a new one.</p>

<p>The format of the CloneQuantizeInfo method is:</p>

<pre class="text">
QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>clone_info</dt>
<dd>Method CloneQuantizeInfo returns a duplicate of the given quantize info, or if image info is NULL a new one. </dd>

<dd> </dd>
<dt>quantize_info</dt>
<dd>a structure of type info. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="CompressImageColormap">CompressImageColormap</a></h2>

<p>CompressImageColormap() compresses an image colormap by removing any duplicate or unused color entries.</p>

<p>The format of the CompressImageColormap method is:</p>

<pre class="text">
MagickBooleanType CompressImageColormap(Image *image,
  ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>image</dt>
<dd>the image. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="DestroyQuantizeInfo">DestroyQuantizeInfo</a></h2>

<p>DestroyQuantizeInfo() deallocates memory associated with an QuantizeInfo structure.</p>

<p>The format of the DestroyQuantizeInfo method is:</p>

<pre class="text">
QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to an QuantizeInfo structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="GetImageQuantizeError">GetImageQuantizeError</a></h2>

<p>GetImageQuantizeError() measures the difference between the original and quantized images.  This difference is the total quantization error. The error is computed by summing over all pixels in an image the distance squared in RGB space between each reference pixel value and its quantized value.  These values are computed:</p>

<pre class="text">
    o mean_error_per_pixel:  This value is the mean error for any single
pixel in the image.
</pre>

<dt>normalized_mean_square_error</dt>
<p>This value is the normalized mean quantization error for any single pixel in the image.  This distance measure is normalized to a range between 0 and 1.  It is independent of the range of red, green, and blue values in the image.</p>

<dt>normalized_maximum_square_error</dt>
<p>Thsi value is the normalized maximum quantization error for any single pixel in the image.  This distance measure is normalized to a range between 0 and 1.  It is independent of the range of red, green, and blue values in your image.</p>

<p>The format of the GetImageQuantizeError method is:</p>

<pre class="text">
MagickBooleanType GetImageQuantizeError(Image *image,
  ExceptionInfo *exception)
</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/quantize_8c.html" id="GetQuantizeInfo">GetQuantizeInfo</a></h2>

<p>GetQuantizeInfo() initializes the QuantizeInfo structure.</p>

<p>The format of the GetQuantizeInfo method is:</p>

<pre class="text">
GetQuantizeInfo(QuantizeInfo *quantize_info)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to a QuantizeInfo structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="KmeansImage">KmeansImage</a></h2>

<p>KmeansImage() applies k-means color reduction to an image. This is a colorspace clustering or segmentation technique.</p>

<p>The format of the KmeansImage method is:</p>

<pre class="text">
MagickBooleanType KmeansImage(Image *image,const size_t number_colors,
  const size_t max_iterations,const double tolerance,
  ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>image</dt>
<dd>the image. </dd>

<dd> </dd>
<dt>number_colors</dt>
<dd>number of colors to use as seeds. </dd>

<dd> </dd>
<dt>max_iterations</dt>
<dd>maximum number of iterations while converging. </dd>

<dd> </dd>
<dt>tolerance</dt>
<dd>the maximum tolerance. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="PosterizeImage">PosterizeImage</a></h2>

<p>PosterizeImage() reduces the image to a limited number of colors for a "poster" effect.</p>

<p>The format of the PosterizeImage method is:</p>

<pre class="text">
MagickBooleanType PosterizeImage(Image *image,const size_t levels,
  const DitherMethod dither_method,ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>image</dt>
<dd>Specifies a pointer to an Image structure. </dd>

<dd> </dd>
<dt>levels</dt>
<dd>Number of color levels allowed in each channel.  Very low values (2, 3, or 4) have the most visible effect. </dd>

<dd> </dd>
<dt>dither_method</dt>
<dd>choose from UndefinedDitherMethod, NoDitherMethod, RiemersmaDitherMethod, FloydSteinbergDitherMethod. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="QuantizeImage">QuantizeImage</a></h2>

<p>QuantizeImage() analyzes the colors within a reference image and chooses a fixed number of colors to represent the image.  The goal of the algorithm is to minimize the color difference between the input and output image while minimizing the processing time.</p>

<p>The format of the QuantizeImage method is:</p>

<pre class="text">
MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
  Image *image,ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to an QuantizeInfo structure. </dd>

<dd> </dd>
<dt>image</dt>
<dd>the image. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="QuantizeImages">QuantizeImages</a></h2>

<p>QuantizeImages() analyzes the colors within a set of reference images and chooses a fixed number of colors to represent the set.  The goal of the algorithm is to minimize the color difference between the input and output images while minimizing the processing time.</p>

<p>The format of the QuantizeImages method is:</p>

<pre class="text">
MagickBooleanType QuantizeImages(const QuantizeInfo *quantize_info,
  Image *images,ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to an QuantizeInfo structure. </dd>

<dd> </dd>
<dt>images</dt>
<dd>Specifies a pointer to a list of Image structures. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="RemapImage">RemapImage</a></h2>

<p>RemapImage() replaces the colors of an image with the closest of the colors from the reference image.</p>

<p>The format of the RemapImage method is:</p>

<pre class="text">
MagickBooleanType RemapImage(const QuantizeInfo *quantize_info,
  Image *image,const Image *remap_image,ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to an QuantizeInfo structure. </dd>

<dd> </dd>
<dt>image</dt>
<dd>the image. </dd>

<dd> </dd>
<dt>remap_image</dt>
<dd>the reference image. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="RemapImages">RemapImages</a></h2>

<p>RemapImages() replaces the colors of a sequence of images with the closest color from a reference image.</p>

<p>The format of the RemapImage method is:</p>

<pre class="text">
MagickBooleanType RemapImages(const QuantizeInfo *quantize_info,
  Image *images,Image *remap_image,ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>quantize_info</dt>
<dd>Specifies a pointer to an QuantizeInfo structure. </dd>

<dd> </dd>
<dt>images</dt>
<dd>the image sequence. </dd>

<dd> </dd>
<dt>remap_image</dt>
<dd>the reference image. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
<h2><a href="../../api/MagickCore/quantize_8c.html" id="SetGrayscaleImage">SetGrayscaleImage</a></h2>

<p>SetGrayscaleImage() converts an image to a PseudoClass grayscale image.</p>

<p>The format of the SetGrayscaleImage method is:</p>

<pre class="text">
MagickBooleanType SetGrayscaleImage(Image *image,
  ExceptionInfo *exception)
</pre>

<p>A description of each parameter follows:</p>

<dd>
</dd>

<dd> </dd>
<dl class="dl-horizontal">
<dt>image</dt>
<dd>The image. </dd>

<dd> </dd>
<dt>exception</dt>
<dd>return any errors or warnings in this structure. </dd>

<dd>  </dd>
</dl>
</div>
    </div>
  </main><!-- /.container -->
  <footer class="magick-footer">
    <div class="container">
    <p><a href="../www/security-policy.html">Security</a> •
    <a href="../www/news.html">News</a>
     
    <a href="quantize.html#"><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&amp;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 0 512 416.32" width="2%" height="2%" role="img" focusable="false"><title>Twitter</title><path fill="currentColor" d="M160.83 416.32c193.2 0 298.92-160.22 298.92-298.92 0-4.51 0-9-.2-13.52A214 214 0 0 0 512 49.38a212.93 212.93 0 0 1-60.44 16.6 105.7 105.7 0 0 0 46.3-58.19 209 209 0 0 1-66.79 25.37 105.09 105.09 0 0 0-181.73 71.91 116.12 116.12 0 0 0 2.66 24c-87.28-4.3-164.73-46.3-216.56-109.82A105.48 105.48 0 0 0 68 159.6a106.27 106.27 0 0 1-47.53-13.11v1.43a105.28 105.28 0 0 0 84.21 103.06 105.67 105.67 0 0 1-47.33 1.84 105.06 105.06 0 0 0 98.14 72.94A210.72 210.72 0 0 1 25 370.84a202.17 202.17 0 0 1-25-1.43 298.85 298.85 0 0 0 160.83 46.92"/></svg></a>
    <br/>
    <small>© 1999-2021 ImageMagick Studio LLC</small></p>
    <div>
  </footer>

  <!-- Javascript assets -->
  <script>window.jQuery || document.write('<script src="../assets/jquery.slim.min.js"><\/script>')</script><script src="../assets/bootstrap.bundle.min.js" integrity="sha384-LtrjvnR4Twt/qOuYxE721u19sVFLVSA4hf/rRt6PrZTmiPltdZcI7q7PXQBYTKyf" crossorigin="anonymous">
</body>
</html>