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13 % MagickCore Methods to Reduce the Number of Unique Colors in an Image %
20 % Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
26 % http://www.imagemagick.org/script/license.php %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36 % Realism in computer graphics typically requires using 24 bits/pixel to
37 % generate an image. Yet many graphic display devices do not contain the
38 % amount of memory necessary to match the spatial and color resolution of
39 % the human eye. The Quantize methods takes a 24 bit image and reduces
40 % the number of colors so it can be displayed on raster device with less
41 % bits per pixel. In most instances, the quantized image closely
42 % resembles the original reference image.
44 % A reduction of colors in an image is also desirable for image
45 % transmission and real-time animation.
47 % QuantizeImage() takes a standard RGB or monochrome images and quantizes
48 % them down to some fixed number of colors.
50 % For purposes of color allocation, an image is a set of n pixels, where
51 % each pixel is a point in RGB space. RGB space is a 3-dimensional
52 % vector space, and each pixel, Pi, is defined by an ordered triple of
53 % red, green, and blue coordinates, (Ri, Gi, Bi).
55 % Each primary color component (red, green, or blue) represents an
56 % intensity which varies linearly from 0 to a maximum value, Cmax, which
57 % corresponds to full saturation of that color. Color allocation is
58 % defined over a domain consisting of the cube in RGB space with opposite
59 % vertices at (0,0,0) and (Cmax, Cmax, Cmax). QUANTIZE requires Cmax =
62 % The algorithm maps this domain onto a tree in which each node
63 % represents a cube within that domain. In the following discussion
64 % these cubes are defined by the coordinate of two opposite vertices:
65 % The vertex nearest the origin in RGB space and the vertex farthest from
68 % The tree's root node represents the entire domain, (0,0,0) through
69 % (Cmax,Cmax,Cmax). Each lower level in the tree is generated by
70 % subdividing one node's cube into eight smaller cubes of equal size.
71 % This corresponds to bisecting the parent cube with planes passing
72 % through the midpoints of each edge.
74 % The basic algorithm operates in three phases: Classification,
75 % Reduction, and Assignment. Classification builds a color description
76 % tree for the image. Reduction collapses the tree until the number it
77 % represents, at most, the number of colors desired in the output image.
78 % Assignment defines the output image's color map and sets each pixel's
79 % color by restorage_class in the reduced tree. Our goal is to minimize
80 % the numerical discrepancies between the original colors and quantized
81 % colors (quantization error).
83 % Classification begins by initializing a color description tree of
84 % sufficient depth to represent each possible input color in a leaf.
85 % However, it is impractical to generate a fully-formed color description
86 % tree in the storage_class phase for realistic values of Cmax. If
87 % colors components in the input image are quantized to k-bit precision,
88 % so that Cmax= 2k-1, the tree would need k levels below the root node to
89 % allow representing each possible input color in a leaf. This becomes
90 % prohibitive because the tree's total number of nodes is 1 +
93 % A complete tree would require 19,173,961 nodes for k = 8, Cmax = 255.
94 % Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
95 % Initializes data structures for nodes only as they are needed; (2)
96 % Chooses a maximum depth for the tree as a function of the desired
97 % number of colors in the output image (currently log2(colormap size)).
99 % For each pixel in the input image, storage_class scans downward from
100 % the root of the color description tree. At each level of the tree it
101 % identifies the single node which represents a cube in RGB space
102 % containing the pixel's color. It updates the following data for each
105 % n1: Number of pixels whose color is contained in the RGB cube which
106 % this node represents;
108 % n2: Number of pixels whose color is not represented in a node at
109 % lower depth in the tree; initially, n2 = 0 for all nodes except
110 % leaves of the tree.
112 % Sr, Sg, Sb: Sums of the red, green, and blue component values for all
113 % pixels not classified at a lower depth. The combination of these sums
114 % and n2 will ultimately characterize the mean color of a set of
115 % pixels represented by this node.
117 % E: the distance squared in RGB space between each pixel contained
118 % within a node and the nodes' center. This represents the
119 % quantization error for a node.
121 % Reduction repeatedly prunes the tree until the number of nodes with n2
122 % > 0 is less than or equal to the maximum number of colors allowed in
123 % the output image. On any given iteration over the tree, it selects
124 % those nodes whose E count is minimal for pruning and merges their color
125 % statistics upward. It uses a pruning threshold, Ep, to govern node
126 % selection as follows:
129 % while number of nodes with (n2 > 0) > required maximum number of colors
130 % prune all nodes such that E <= Ep
131 % Set Ep to minimum E in remaining nodes
133 % This has the effect of minimizing any quantization error when merging
134 % two nodes together.
136 % When a node to be pruned has offspring, the pruning procedure invokes
137 % itself recursively in order to prune the tree from the leaves upward.
138 % n2, Sr, Sg, and Sb in a node being pruned are always added to the
139 % corresponding data in that node's parent. This retains the pruned
140 % node's color characteristics for later averaging.
142 % For each node, n2 pixels exist for which that node represents the
143 % smallest volume in RGB space containing those pixel's colors. When n2
144 % > 0 the node will uniquely define a color in the output image. At the
145 % beginning of reduction, n2 = 0 for all nodes except a the leaves of
146 % the tree which represent colors present in the input image.
148 % The other pixel count, n1, indicates the total number of colors within
149 % the cubic volume which the node represents. This includes n1 - n2
150 % pixels whose colors should be defined by nodes at a lower level in the
153 % Assignment generates the output image from the pruned tree. The output
154 % image consists of two parts: (1) A color map, which is an array of
155 % color descriptions (RGB triples) for each color present in the output
156 % image; (2) A pixel array, which represents each pixel as an index
157 % into the color map array.
159 % First, the assignment phase makes one pass over the pruned color
160 % description tree to establish the image's color map. For each node
161 % with n2 > 0, it divides Sr, Sg, and Sb by n2 . This produces the mean
162 % color of all pixels that classify no lower than this node. Each of
163 % these colors becomes an entry in the color map.
165 % Finally, the assignment phase reclassifies each pixel in the pruned
166 % tree to identify the deepest node containing the pixel's color. The
167 % pixel's value in the pixel array becomes the index of this node's mean
168 % color in the color map.
170 % This method is based on a similar algorithm written by Paul Raveling.
175 Include declarations.
177 #include "MagickCore/studio.h"
178 #include "MagickCore/attribute.h"
179 #include "MagickCore/cache-view.h"
180 #include "MagickCore/color.h"
181 #include "MagickCore/color-private.h"
182 #include "MagickCore/colormap.h"
183 #include "MagickCore/colorspace.h"
184 #include "MagickCore/colorspace-private.h"
185 #include "MagickCore/enhance.h"
186 #include "MagickCore/exception.h"
187 #include "MagickCore/exception-private.h"
188 #include "MagickCore/histogram.h"
189 #include "MagickCore/image.h"
190 #include "MagickCore/image-private.h"
191 #include "MagickCore/list.h"
192 #include "MagickCore/memory_.h"
193 #include "MagickCore/monitor.h"
194 #include "MagickCore/monitor-private.h"
195 #include "MagickCore/option.h"
196 #include "MagickCore/pixel-accessor.h"
197 #include "MagickCore/quantize.h"
198 #include "MagickCore/quantum.h"
199 #include "MagickCore/quantum-private.h"
200 #include "MagickCore/resource_.h"
201 #include "MagickCore/string_.h"
202 #include "MagickCore/thread-private.h"
207 #if !defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
212 #define ErrorQueueLength 16
213 #define MaxNodes 266817
214 #define MaxTreeDepth 8
215 #define NodesInAList 1920
220 typedef struct _RealPixelInfo
229 typedef struct _NodeInfo
250 typedef struct _Nodes
259 typedef struct _CubeInfo
297 error[ErrorQueueLength];
300 weights[ErrorQueueLength];
326 *GetCubeInfo(const QuantizeInfo *,const size_t,const size_t);
329 *GetNodeInfo(CubeInfo *,const size_t,const size_t,NodeInfo *);
331 static MagickBooleanType
332 AssignImageColors(Image *,CubeInfo *,ExceptionInfo *),
333 ClassifyImageColors(CubeInfo *,const Image *,ExceptionInfo *),
334 DitherImage(Image *,CubeInfo *,ExceptionInfo *),
335 SetGrayscaleImage(Image *,ExceptionInfo *);
338 DefineImageColormap(Image *,CubeInfo *,NodeInfo *);
341 ClosestColor(const Image *,CubeInfo *,const NodeInfo *),
342 DestroyCubeInfo(CubeInfo *),
343 PruneLevel(const Image *,CubeInfo *,const NodeInfo *),
344 PruneToCubeDepth(const Image *,CubeInfo *,const NodeInfo *),
345 ReduceImageColors(const Image *,CubeInfo *);
348 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
352 % A c q u i r e Q u a n t i z e I n f o %
356 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
358 % AcquireQuantizeInfo() allocates the QuantizeInfo structure.
360 % The format of the AcquireQuantizeInfo method is:
362 % QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
364 % A description of each parameter follows:
366 % o image_info: the image info.
369 MagickExport QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
374 quantize_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*quantize_info));
375 if (quantize_info == (QuantizeInfo *) NULL)
376 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
377 GetQuantizeInfo(quantize_info);
378 if (image_info != (ImageInfo *) NULL)
383 quantize_info->dither_method=image_info->dither == MagickFalse ?
384 NoDitherMethod : RiemersmaDitherMethod;
385 option=GetImageOption(image_info,"dither");
386 if (option != (const char *) NULL)
387 quantize_info->dither_method=(DitherMethod) ParseCommandOption(
388 MagickDitherOptions,MagickFalse,option);
389 quantize_info->measure_error=image_info->verbose;
391 return(quantize_info);
395 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
399 + A s s i g n I m a g e C o l o r s %
403 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
405 % AssignImageColors() generates the output image from the pruned tree. The
406 % output image consists of two parts: (1) A color map, which is an array
407 % of color descriptions (RGB triples) for each color present in the
408 % output image; (2) A pixel array, which represents each pixel as an
409 % index into the color map array.
411 % First, the assignment phase makes one pass over the pruned color
412 % description tree to establish the image's color map. For each node
413 % with n2 > 0, it divides Sr, Sg, and Sb by n2 . This produces the mean
414 % color of all pixels that classify no lower than this node. Each of
415 % these colors becomes an entry in the color map.
417 % Finally, the assignment phase reclassifies each pixel in the pruned
418 % tree to identify the deepest node containing the pixel's color. The
419 % pixel's value in the pixel array becomes the index of this node's mean
420 % color in the color map.
422 % The format of the AssignImageColors() method is:
424 % MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
426 % A description of each parameter follows.
428 % o image: the image.
430 % o cube_info: A pointer to the Cube structure.
434 static inline void AssociateAlphaPixel(const Image *image,
435 const CubeInfo *cube_info,const Quantum *pixel,RealPixelInfo *alpha_pixel)
440 if ((cube_info->associate_alpha == MagickFalse) ||
441 (GetPixelAlpha(image,pixel)== OpaqueAlpha))
443 alpha_pixel->red=(MagickRealType) GetPixelRed(image,pixel);
444 alpha_pixel->green=(MagickRealType) GetPixelGreen(image,pixel);
445 alpha_pixel->blue=(MagickRealType) GetPixelBlue(image,pixel);
446 alpha_pixel->alpha=(MagickRealType) GetPixelAlpha(image,pixel);
449 alpha=(MagickRealType) (QuantumScale*GetPixelAlpha(image,pixel));
450 alpha_pixel->red=alpha*GetPixelRed(image,pixel);
451 alpha_pixel->green=alpha*GetPixelGreen(image,pixel);
452 alpha_pixel->blue=alpha*GetPixelBlue(image,pixel);
453 alpha_pixel->alpha=(MagickRealType) GetPixelAlpha(image,pixel);
456 static inline void AssociateAlphaPixelInfo(const Image *image,
457 const CubeInfo *cube_info,const PixelInfo *pixel,
458 RealPixelInfo *alpha_pixel)
463 if ((cube_info->associate_alpha == MagickFalse) ||
464 (pixel->alpha == OpaqueAlpha))
466 alpha_pixel->red=(MagickRealType) pixel->red;
467 alpha_pixel->green=(MagickRealType) pixel->green;
468 alpha_pixel->blue=(MagickRealType) pixel->blue;
469 alpha_pixel->alpha=(MagickRealType) pixel->alpha;
472 alpha=(MagickRealType) (QuantumScale*pixel->alpha);
473 alpha_pixel->red=alpha*pixel->red;
474 alpha_pixel->green=alpha*pixel->green;
475 alpha_pixel->blue=alpha*pixel->blue;
476 alpha_pixel->alpha=(MagickRealType) pixel->alpha;
479 static inline Quantum ClampToUnsignedQuantum(const MagickRealType value)
483 if (value >= QuantumRange)
484 return((Quantum) QuantumRange);
485 return((Quantum) (value+0.5));
488 static inline size_t ColorToNodeId(const CubeInfo *cube_info,
489 const RealPixelInfo *pixel,size_t index)
494 id=(size_t) (((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->red)) >> index) & 0x01) |
495 ((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->green)) >> index) & 0x01) << 1 |
496 ((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->blue)) >> index) & 0x01) << 2);
497 if (cube_info->associate_alpha != MagickFalse)
498 id|=((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->alpha)) >> index) & 0x1) << 3;
502 static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info,
503 ExceptionInfo *exception)
505 #define AssignImageTag "Assign/Image"
511 Allocate image colormap.
513 if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
514 (cube_info->quantize_info->colorspace != CMYKColorspace))
515 (void) TransformImageColorspace((Image *) image,
516 cube_info->quantize_info->colorspace,exception);
518 if ((image->colorspace != GRAYColorspace) &&
519 (IssRGBColorspace(image->colorspace) == MagickFalse) &&
520 (image->colorspace != CMYColorspace))
521 (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
522 if (AcquireImageColormap(image,cube_info->colors,exception) == MagickFalse)
523 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
526 cube_info->transparent_pixels=0;
527 cube_info->transparent_index=(-1);
528 (void) DefineImageColormap(image,cube_info,cube_info->root);
530 Create a reduced color image.
532 if ((cube_info->quantize_info->dither_method != NoDitherMethod) &&
533 (cube_info->quantize_info->dither_method != NoDitherMethod))
534 (void) DitherImage(image,cube_info,exception);
544 image_view=AcquireAuthenticCacheView(image,exception);
545 #if defined(MAGICKCORE_OPENMP_SUPPORT)
546 #pragma omp parallel for schedule(static,4) shared(status) \
547 dynamic_number_threads(image,image->columns,image->rows,1)
549 for (y=0; y < (ssize_t) image->rows; y++)
563 if (status == MagickFalse)
565 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
567 if (q == (Quantum *) NULL)
573 for (x=0; x < (ssize_t) image->columns; x+=count)
578 register const NodeInfo
589 Identify the deepest node containing the pixel's color.
591 for (count=1; (x+count) < (ssize_t) image->columns; count++)
596 GetPixelInfoPixel(image,q+count*GetPixelChannels(image),&packet);
597 if (IsPixelEquivalent(image,q,&packet) == MagickFalse)
600 AssociateAlphaPixel(image,&cube,q,&pixel);
602 for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--)
604 id=ColorToNodeId(&cube,&pixel,index);
605 if (node_info->child[id] == (NodeInfo *) NULL)
607 node_info=node_info->child[id];
610 Find closest color among siblings and their children.
613 cube.distance=(MagickRealType) (4.0*(QuantumRange+1.0)*
614 (QuantumRange+1.0)+1.0);
615 ClosestColor(image,&cube,node_info->parent);
616 index=cube.color_number;
617 for (i=0; i < (ssize_t) count; i++)
619 if (image->storage_class == PseudoClass)
620 SetPixelIndex(image,(Quantum) index,q);
621 if (cube.quantize_info->measure_error == MagickFalse)
623 SetPixelRed(image,ClampToQuantum(
624 image->colormap[index].red),q);
625 SetPixelGreen(image,ClampToQuantum(
626 image->colormap[index].green),q);
627 SetPixelBlue(image,ClampToQuantum(
628 image->colormap[index].blue),q);
629 if (cube.associate_alpha != MagickFalse)
630 SetPixelAlpha(image,ClampToQuantum(
631 image->colormap[index].alpha),q);
633 q+=GetPixelChannels(image);
636 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
638 if (image->progress_monitor != (MagickProgressMonitor) NULL)
643 #if defined(MAGICKCORE_OPENMP_SUPPORT)
644 #pragma omp critical (MagickCore_AssignImageColors)
646 proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) y,
648 if (proceed == MagickFalse)
652 image_view=DestroyCacheView(image_view);
654 if (cube_info->quantize_info->measure_error != MagickFalse)
655 (void) GetImageQuantizeError(image,exception);
656 if ((cube_info->quantize_info->number_colors == 2) &&
657 (cube_info->quantize_info->colorspace == GRAYColorspace))
672 for (i=0; i < (ssize_t) image->colors; i++)
674 intensity=(double) ((MagickRealType) GetPixelInfoIntensity(q) <
675 ((MagickRealType) QuantumRange/2.0) ? 0 : QuantumRange);
682 (void) SyncImage(image,exception);
683 if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
684 (cube_info->quantize_info->colorspace != CMYKColorspace))
685 (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
690 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
694 + C l a s s i f y I m a g e C o l o r s %
698 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
700 % ClassifyImageColors() begins by initializing a color description tree
701 % of sufficient depth to represent each possible input color in a leaf.
702 % However, it is impractical to generate a fully-formed color
703 % description tree in the storage_class phase for realistic values of
704 % Cmax. If colors components in the input image are quantized to k-bit
705 % precision, so that Cmax= 2k-1, the tree would need k levels below the
706 % root node to allow representing each possible input color in a leaf.
707 % This becomes prohibitive because the tree's total number of nodes is
710 % A complete tree would require 19,173,961 nodes for k = 8, Cmax = 255.
711 % Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
712 % Initializes data structures for nodes only as they are needed; (2)
713 % Chooses a maximum depth for the tree as a function of the desired
714 % number of colors in the output image (currently log2(colormap size)).
716 % For each pixel in the input image, storage_class scans downward from
717 % the root of the color description tree. At each level of the tree it
718 % identifies the single node which represents a cube in RGB space
719 % containing It updates the following data for each such node:
721 % n1 : Number of pixels whose color is contained in the RGB cube
722 % which this node represents;
724 % n2 : Number of pixels whose color is not represented in a node at
725 % lower depth in the tree; initially, n2 = 0 for all nodes except
726 % leaves of the tree.
728 % Sr, Sg, Sb : Sums of the red, green, and blue component values for
729 % all pixels not classified at a lower depth. The combination of
730 % these sums and n2 will ultimately characterize the mean color of a
731 % set of pixels represented by this node.
733 % E: the distance squared in RGB space between each pixel contained
734 % within a node and the nodes' center. This represents the quantization
737 % The format of the ClassifyImageColors() method is:
739 % MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
740 % const Image *image,ExceptionInfo *exception)
742 % A description of each parameter follows.
744 % o cube_info: A pointer to the Cube structure.
746 % o image: the image.
750 static inline void SetAssociatedAlpha(const Image *image,CubeInfo *cube_info)
755 associate_alpha=image->matte;
756 if (cube_info->quantize_info->colorspace == TransparentColorspace)
757 associate_alpha=MagickFalse;
758 if ((cube_info->quantize_info->number_colors == 2) &&
759 (cube_info->quantize_info->colorspace == GRAYColorspace))
760 associate_alpha=MagickFalse;
761 cube_info->associate_alpha=associate_alpha;
764 static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
765 const Image *image,ExceptionInfo *exception)
767 #define ClassifyImageTag "Classify/Image"
797 Classify the first cube_info->maximum_colors colors to a tree depth of 8.
799 SetAssociatedAlpha(image,cube_info);
800 if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
801 (cube_info->quantize_info->colorspace != CMYKColorspace))
802 (void) TransformImageColorspace((Image *) image,
803 cube_info->quantize_info->colorspace,exception);
805 if ((image->colorspace != GRAYColorspace) &&
806 (image->colorspace != CMYColorspace) &&
807 (IssRGBColorspace(image->colorspace) == MagickFalse))
808 (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
809 midpoint.red=(MagickRealType) QuantumRange/2.0;
810 midpoint.green=(MagickRealType) QuantumRange/2.0;
811 midpoint.blue=(MagickRealType) QuantumRange/2.0;
812 midpoint.alpha=(MagickRealType) QuantumRange/2.0;
814 image_view=AcquireVirtualCacheView(image,exception);
815 for (y=0; y < (ssize_t) image->rows; y++)
817 register const Quantum
823 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
824 if (p == (const Quantum *) NULL)
826 if (cube_info->nodes > MaxNodes)
829 Prune one level if the color tree is too large.
831 PruneLevel(image,cube_info,cube_info->root);
834 for (x=0; x < (ssize_t) image->columns; x+=(ssize_t) count)
837 Start at the root and descend the color cube tree.
839 for (count=1; (x+(ssize_t) count) < (ssize_t) image->columns; count++)
844 GetPixelInfoPixel(image,p+count*GetPixelChannels(image),&packet);
845 if (IsPixelEquivalent(image,p,&packet) == MagickFalse)
848 AssociateAlphaPixel(image,cube_info,p,&pixel);
849 index=MaxTreeDepth-1;
850 bisect=((MagickRealType) QuantumRange+1.0)/2.0;
852 node_info=cube_info->root;
853 for (level=1; level <= MaxTreeDepth; level++)
856 id=ColorToNodeId(cube_info,&pixel,index);
857 mid.red+=(id & 1) != 0 ? bisect : -bisect;
858 mid.green+=(id & 2) != 0 ? bisect : -bisect;
859 mid.blue+=(id & 4) != 0 ? bisect : -bisect;
860 mid.alpha+=(id & 8) != 0 ? bisect : -bisect;
861 if (node_info->child[id] == (NodeInfo *) NULL)
864 Set colors of new node to contain pixel.
866 node_info->child[id]=GetNodeInfo(cube_info,id,level,node_info);
867 if (node_info->child[id] == (NodeInfo *) NULL)
868 (void) ThrowMagickException(exception,GetMagickModule(),
869 ResourceLimitError,"MemoryAllocationFailed","'%s'",
871 if (level == MaxTreeDepth)
875 Approximate the quantization error represented by this node.
877 node_info=node_info->child[id];
878 error.red=QuantumScale*(pixel.red-mid.red);
879 error.green=QuantumScale*(pixel.green-mid.green);
880 error.blue=QuantumScale*(pixel.blue-mid.blue);
881 if (cube_info->associate_alpha != MagickFalse)
882 error.alpha=QuantumScale*(pixel.alpha-mid.alpha);
883 node_info->quantize_error+=sqrt((double) (count*error.red*error.red+
884 count*error.green*error.green+count*error.blue*error.blue+
885 count*error.alpha*error.alpha));
886 cube_info->root->quantize_error+=node_info->quantize_error;
890 Sum RGB for this leaf for later derivation of the mean cube color.
892 node_info->number_unique+=count;
893 node_info->total_color.red+=count*QuantumScale*pixel.red;
894 node_info->total_color.green+=count*QuantumScale*pixel.green;
895 node_info->total_color.blue+=count*QuantumScale*pixel.blue;
896 if (cube_info->associate_alpha != MagickFalse)
897 node_info->total_color.alpha+=count*QuantumScale*pixel.alpha;
898 p+=count*GetPixelChannels(image);
900 if (cube_info->colors > cube_info->maximum_colors)
902 PruneToCubeDepth(image,cube_info,cube_info->root);
905 proceed=SetImageProgress(image,ClassifyImageTag,(MagickOffsetType) y,
907 if (proceed == MagickFalse)
910 for (y++; y < (ssize_t) image->rows; y++)
912 register const Quantum
918 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
919 if (p == (const Quantum *) NULL)
921 if (cube_info->nodes > MaxNodes)
924 Prune one level if the color tree is too large.
926 PruneLevel(image,cube_info,cube_info->root);
929 for (x=0; x < (ssize_t) image->columns; x+=(ssize_t) count)
932 Start at the root and descend the color cube tree.
934 for (count=1; (x+(ssize_t) count) < (ssize_t) image->columns; count++)
939 GetPixelInfoPixel(image,p+count*GetPixelChannels(image),&packet);
940 if (IsPixelEquivalent(image,p,&packet) == MagickFalse)
943 AssociateAlphaPixel(image,cube_info,p,&pixel);
944 index=MaxTreeDepth-1;
945 bisect=((MagickRealType) QuantumRange+1.0)/2.0;
947 node_info=cube_info->root;
948 for (level=1; level <= cube_info->depth; level++)
951 id=ColorToNodeId(cube_info,&pixel,index);
952 mid.red+=(id & 1) != 0 ? bisect : -bisect;
953 mid.green+=(id & 2) != 0 ? bisect : -bisect;
954 mid.blue+=(id & 4) != 0 ? bisect : -bisect;
955 mid.alpha+=(id & 8) != 0 ? bisect : -bisect;
956 if (node_info->child[id] == (NodeInfo *) NULL)
959 Set colors of new node to contain pixel.
961 node_info->child[id]=GetNodeInfo(cube_info,id,level,node_info);
962 if (node_info->child[id] == (NodeInfo *) NULL)
963 (void) ThrowMagickException(exception,GetMagickModule(),
964 ResourceLimitError,"MemoryAllocationFailed","%s",
966 if (level == cube_info->depth)
970 Approximate the quantization error represented by this node.
972 node_info=node_info->child[id];
973 error.red=QuantumScale*(pixel.red-mid.red);
974 error.green=QuantumScale*(pixel.green-mid.green);
975 error.blue=QuantumScale*(pixel.blue-mid.blue);
976 if (cube_info->associate_alpha != MagickFalse)
977 error.alpha=QuantumScale*(pixel.alpha-mid.alpha);
978 node_info->quantize_error+=sqrt((double) (count*error.red*error.red+
979 count*error.green*error.green+count*error.blue*error.blue+
980 count*error.alpha*error.alpha));
981 cube_info->root->quantize_error+=node_info->quantize_error;
985 Sum RGB for this leaf for later derivation of the mean cube color.
987 node_info->number_unique+=count;
988 node_info->total_color.red+=count*QuantumScale*pixel.red;
989 node_info->total_color.green+=count*QuantumScale*pixel.green;
990 node_info->total_color.blue+=count*QuantumScale*pixel.blue;
991 if (cube_info->associate_alpha != MagickFalse)
992 node_info->total_color.alpha+=count*QuantumScale*pixel.alpha;
993 p+=count*GetPixelChannels(image);
995 proceed=SetImageProgress(image,ClassifyImageTag,(MagickOffsetType) y,
997 if (proceed == MagickFalse)
1000 image_view=DestroyCacheView(image_view);
1001 if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
1002 (cube_info->quantize_info->colorspace != CMYKColorspace))
1003 (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
1008 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1012 % C l o n e Q u a n t i z e I n f o %
1016 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1018 % CloneQuantizeInfo() makes a duplicate of the given quantize info structure,
1019 % or if quantize info is NULL, a new one.
1021 % The format of the CloneQuantizeInfo method is:
1023 % QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
1025 % A description of each parameter follows:
1027 % o clone_info: Method CloneQuantizeInfo returns a duplicate of the given
1028 % quantize info, or if image info is NULL a new one.
1030 % o quantize_info: a structure of type info.
1033 MagickExport QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
1038 clone_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*clone_info));
1039 if (clone_info == (QuantizeInfo *) NULL)
1040 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
1041 GetQuantizeInfo(clone_info);
1042 if (quantize_info == (QuantizeInfo *) NULL)
1044 clone_info->number_colors=quantize_info->number_colors;
1045 clone_info->tree_depth=quantize_info->tree_depth;
1046 clone_info->dither_method=quantize_info->dither_method;
1047 clone_info->colorspace=quantize_info->colorspace;
1048 clone_info->measure_error=quantize_info->measure_error;
1053 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1057 + C l o s e s t C o l o r %
1061 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1063 % ClosestColor() traverses the color cube tree at a particular node and
1064 % determines which colormap entry best represents the input color.
1066 % The format of the ClosestColor method is:
1068 % void ClosestColor(const Image *image,CubeInfo *cube_info,
1069 % const NodeInfo *node_info)
1071 % A description of each parameter follows.
1073 % o image: the image.
1075 % o cube_info: A pointer to the Cube structure.
1077 % o node_info: the address of a structure of type NodeInfo which points to a
1078 % node in the color cube tree that is to be pruned.
1081 static void ClosestColor(const Image *image,CubeInfo *cube_info,
1082 const NodeInfo *node_info)
1091 Traverse any children.
1093 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
1094 for (i=0; i < (ssize_t) number_children; i++)
1095 if (node_info->child[i] != (NodeInfo *) NULL)
1096 ClosestColor(image,cube_info,node_info->child[i]);
1097 if (node_info->number_unique != 0)
1102 register MagickRealType
1110 register RealPixelInfo
1114 Determine if this color is "closest".
1116 p=image->colormap+node_info->color_number;
1117 q=(&cube_info->target);
1120 if (cube_info->associate_alpha != MagickFalse)
1122 alpha=(MagickRealType) (QuantumScale*p->alpha);
1123 beta=(MagickRealType) (QuantumScale*q->alpha);
1125 pixel=alpha*p->red-beta*q->red;
1126 distance=pixel*pixel;
1127 if (distance <= cube_info->distance)
1129 pixel=alpha*p->green-beta*q->green;
1130 distance+=pixel*pixel;
1131 if (distance <= cube_info->distance)
1133 pixel=alpha*p->blue-beta*q->blue;
1134 distance+=pixel*pixel;
1135 if (distance <= cube_info->distance)
1138 distance+=pixel*pixel;
1139 if (distance <= cube_info->distance)
1141 cube_info->distance=distance;
1142 cube_info->color_number=node_info->color_number;
1151 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1155 % C o m p r e s s I m a g e C o l o r m a p %
1159 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1161 % CompressImageColormap() compresses an image colormap by removing any
1162 % duplicate or unused color entries.
1164 % The format of the CompressImageColormap method is:
1166 % MagickBooleanType CompressImageColormap(Image *image,
1167 % ExceptionInfo *exception)
1169 % A description of each parameter follows:
1171 % o image: the image.
1173 % o exception: return any errors or warnings in this structure.
1176 MagickExport MagickBooleanType CompressImageColormap(Image *image,
1177 ExceptionInfo *exception)
1182 assert(image != (Image *) NULL);
1183 assert(image->signature == MagickSignature);
1184 if (image->debug != MagickFalse)
1185 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1186 if (IsPaletteImage(image,exception) == MagickFalse)
1187 return(MagickFalse);
1188 GetQuantizeInfo(&quantize_info);
1189 quantize_info.number_colors=image->colors;
1190 quantize_info.tree_depth=MaxTreeDepth;
1191 return(QuantizeImage(&quantize_info,image,exception));
1195 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1199 + D e f i n e I m a g e C o l o r m a p %
1203 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1205 % DefineImageColormap() traverses the color cube tree and notes each colormap
1206 % entry. A colormap entry is any node in the color cube tree where the
1207 % of unique colors is not zero. DefineImageColormap() returns the number of
1208 % colors in the image colormap.
1210 % The format of the DefineImageColormap method is:
1212 % size_t DefineImageColormap(Image *image,CubeInfo *cube_info,
1213 % NodeInfo *node_info)
1215 % A description of each parameter follows.
1217 % o image: the image.
1219 % o cube_info: A pointer to the Cube structure.
1221 % o node_info: the address of a structure of type NodeInfo which points to a
1222 % node in the color cube tree that is to be pruned.
1225 static size_t DefineImageColormap(Image *image,CubeInfo *cube_info,
1226 NodeInfo *node_info)
1235 Traverse any children.
1237 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
1238 for (i=0; i < (ssize_t) number_children; i++)
1239 if (node_info->child[i] != (NodeInfo *) NULL)
1240 (void) DefineImageColormap(image,cube_info,node_info->child[i]);
1241 if (node_info->number_unique != 0)
1243 register MagickRealType
1250 Colormap entry is defined by the mean color in this cube.
1252 q=image->colormap+image->colors;
1253 alpha=(MagickRealType) ((MagickOffsetType) node_info->number_unique);
1254 alpha=1.0/(fabs((double) alpha) < MagickEpsilon ? MagickEpsilon : alpha);
1255 if (cube_info->associate_alpha == MagickFalse)
1257 q->red=(double) ClampToQuantum((MagickRealType)
1258 (alpha*QuantumRange*node_info->total_color.red));
1259 q->green=(double) ClampToQuantum((MagickRealType)
1260 (alpha*QuantumRange*node_info->total_color.green));
1261 q->blue=(double) ClampToQuantum((MagickRealType)
1262 (alpha*(double) QuantumRange*node_info->total_color.blue));
1263 q->alpha=OpaqueAlpha;
1270 opacity=(MagickRealType) (alpha*QuantumRange*
1271 node_info->total_color.alpha);
1272 q->alpha=(double) ClampToQuantum(opacity);
1273 if (q->alpha == OpaqueAlpha)
1275 q->red=(double) ClampToQuantum((MagickRealType)
1276 (alpha*QuantumRange*node_info->total_color.red));
1277 q->green=(double) ClampToQuantum((MagickRealType)
1278 (alpha*QuantumRange*node_info->total_color.green));
1279 q->blue=(double) ClampToQuantum((MagickRealType)
1280 (alpha*QuantumRange*node_info->total_color.blue));
1287 gamma=(MagickRealType) (QuantumScale*q->alpha);
1288 gamma=1.0/(fabs(gamma) < MagickEpsilon ? MagickEpsilon : gamma);
1289 q->red=(double) ClampToQuantum((MagickRealType)
1290 (alpha*gamma*QuantumRange*node_info->total_color.red));
1291 q->green=(double) ClampToQuantum((MagickRealType)
1292 (alpha*gamma*QuantumRange*node_info->total_color.green));
1293 q->blue=(double) ClampToQuantum((MagickRealType)
1294 (alpha*gamma*QuantumRange*node_info->total_color.blue));
1295 if (node_info->number_unique > cube_info->transparent_pixels)
1297 cube_info->transparent_pixels=node_info->number_unique;
1298 cube_info->transparent_index=(ssize_t) image->colors;
1302 node_info->color_number=image->colors++;
1304 return(image->colors);
1308 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1312 + D e s t r o y C u b e I n f o %
1316 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1318 % DestroyCubeInfo() deallocates memory associated with an image.
1320 % The format of the DestroyCubeInfo method is:
1322 % DestroyCubeInfo(CubeInfo *cube_info)
1324 % A description of each parameter follows:
1326 % o cube_info: the address of a structure of type CubeInfo.
1329 static void DestroyCubeInfo(CubeInfo *cube_info)
1335 Release color cube tree storage.
1339 nodes=cube_info->node_queue->next;
1340 cube_info->node_queue->nodes=(NodeInfo *) RelinquishMagickMemory(
1341 cube_info->node_queue->nodes);
1342 cube_info->node_queue=(Nodes *) RelinquishMagickMemory(
1343 cube_info->node_queue);
1344 cube_info->node_queue=nodes;
1345 } while (cube_info->node_queue != (Nodes *) NULL);
1346 if (cube_info->cache != (ssize_t *) NULL)
1347 cube_info->cache=(ssize_t *) RelinquishMagickMemory(cube_info->cache);
1348 cube_info->quantize_info=DestroyQuantizeInfo(cube_info->quantize_info);
1349 cube_info=(CubeInfo *) RelinquishMagickMemory(cube_info);
1353 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1357 % D e s t r o y Q u a n t i z e I n f o %
1361 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1363 % DestroyQuantizeInfo() deallocates memory associated with an QuantizeInfo
1366 % The format of the DestroyQuantizeInfo method is:
1368 % QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
1370 % A description of each parameter follows:
1372 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
1375 MagickExport QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
1377 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
1378 assert(quantize_info != (QuantizeInfo *) NULL);
1379 assert(quantize_info->signature == MagickSignature);
1380 quantize_info->signature=(~MagickSignature);
1381 quantize_info=(QuantizeInfo *) RelinquishMagickMemory(quantize_info);
1382 return(quantize_info);
1386 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1390 + D i t h e r I m a g e %
1394 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1396 % DitherImage() distributes the difference between an original image and
1397 % the corresponding color reduced algorithm to neighboring pixels using
1398 % serpentine-scan Floyd-Steinberg error diffusion. DitherImage returns
1399 % MagickTrue if the image is dithered otherwise MagickFalse.
1401 % The format of the DitherImage method is:
1403 % MagickBooleanType DitherImage(Image *image,CubeInfo *cube_info,
1404 % ExceptionInfo *exception)
1406 % A description of each parameter follows.
1408 % o image: the image.
1410 % o cube_info: A pointer to the Cube structure.
1412 % o exception: return any errors or warnings in this structure.
1416 static RealPixelInfo **DestroyPixelThreadSet(RealPixelInfo **pixels)
1421 assert(pixels != (RealPixelInfo **) NULL);
1422 for (i=0; i < (ssize_t) GetMagickResourceLimit(ThreadResource); i++)
1423 if (pixels[i] != (RealPixelInfo *) NULL)
1424 pixels[i]=(RealPixelInfo *) RelinquishMagickMemory(pixels[i]);
1425 pixels=(RealPixelInfo **) RelinquishMagickMemory(pixels);
1429 static RealPixelInfo **AcquirePixelThreadSet(const size_t count)
1440 number_threads=GetOpenMPMaximumThreads();
1441 pixels=(RealPixelInfo **) AcquireQuantumMemory(number_threads,
1443 if (pixels == (RealPixelInfo **) NULL)
1444 return((RealPixelInfo **) NULL);
1445 (void) ResetMagickMemory(pixels,0,number_threads*sizeof(*pixels));
1446 for (i=0; i < (ssize_t) number_threads; i++)
1448 pixels[i]=(RealPixelInfo *) AcquireQuantumMemory(count,
1449 2*sizeof(**pixels));
1450 if (pixels[i] == (RealPixelInfo *) NULL)
1451 return(DestroyPixelThreadSet(pixels));
1456 static inline ssize_t CacheOffset(CubeInfo *cube_info,
1457 const RealPixelInfo *pixel)
1459 #define RedShift(pixel) (((pixel) >> CacheShift) << (0*(8-CacheShift)))
1460 #define GreenShift(pixel) (((pixel) >> CacheShift) << (1*(8-CacheShift)))
1461 #define BlueShift(pixel) (((pixel) >> CacheShift) << (2*(8-CacheShift)))
1462 #define AlphaShift(pixel) (((pixel) >> CacheShift) << (3*(8-CacheShift)))
1468 (RedShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->red))) |
1469 GreenShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->green))) |
1470 BlueShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->blue))));
1471 if (cube_info->associate_alpha != MagickFalse)
1472 offset|=AlphaShift(ScaleQuantumToChar(ClampToUnsignedQuantum(
1477 static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info,
1478 ExceptionInfo *exception)
1480 #define DitherImageTag "Dither/Image"
1495 Distribute quantization error using Floyd-Steinberg.
1497 pixels=AcquirePixelThreadSet(image->columns);
1498 if (pixels == (RealPixelInfo **) NULL)
1499 return(MagickFalse);
1501 image_view=AcquireAuthenticCacheView(image,exception);
1502 for (y=0; y < (ssize_t) image->rows; y++)
1505 id = GetOpenMPThreadId();
1526 if (status == MagickFalse)
1528 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
1529 if (q == (Quantum *) NULL)
1534 q+=(y & 0x01)*image->columns*GetPixelChannels(image);
1536 current=pixels[id]+(y & 0x01)*image->columns;
1537 previous=pixels[id]+((y+1) & 0x01)*image->columns;
1538 v=(ssize_t) ((y & 0x01) != 0 ? -1 : 1);
1539 for (x=0; x < (ssize_t) image->columns; x++)
1551 q-=(y & 0x01)*GetPixelChannels(image);
1552 u=(y & 0x01) != 0 ? (ssize_t) image->columns-1-x : x;
1553 AssociateAlphaPixel(image,&cube,q,&pixel);
1556 pixel.red+=7*current[u-v].red/16;
1557 pixel.green+=7*current[u-v].green/16;
1558 pixel.blue+=7*current[u-v].blue/16;
1559 if (cube.associate_alpha != MagickFalse)
1560 pixel.alpha+=7*current[u-v].alpha/16;
1564 if (x < (ssize_t) (image->columns-1))
1566 pixel.red+=previous[u+v].red/16;
1567 pixel.green+=previous[u+v].green/16;
1568 pixel.blue+=previous[u+v].blue/16;
1569 if (cube.associate_alpha != MagickFalse)
1570 pixel.alpha+=previous[u+v].alpha/16;
1572 pixel.red+=5*previous[u].red/16;
1573 pixel.green+=5*previous[u].green/16;
1574 pixel.blue+=5*previous[u].blue/16;
1575 if (cube.associate_alpha != MagickFalse)
1576 pixel.alpha+=5*previous[u].alpha/16;
1579 pixel.red+=3*previous[u-v].red/16;
1580 pixel.green+=3*previous[u-v].green/16;
1581 pixel.blue+=3*previous[u-v].blue/16;
1582 if (cube.associate_alpha != MagickFalse)
1583 pixel.alpha+=3*previous[u-v].alpha/16;
1586 pixel.red=(MagickRealType) ClampToUnsignedQuantum(pixel.red);
1587 pixel.green=(MagickRealType) ClampToUnsignedQuantum(pixel.green);
1588 pixel.blue=(MagickRealType) ClampToUnsignedQuantum(pixel.blue);
1589 if (cube.associate_alpha != MagickFalse)
1590 pixel.alpha=(MagickRealType) ClampToUnsignedQuantum(pixel.alpha);
1591 i=CacheOffset(&cube,&pixel);
1592 if (cube.cache[i] < 0)
1601 Identify the deepest node containing the pixel's color.
1603 node_info=cube.root;
1604 for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--)
1606 id=ColorToNodeId(&cube,&pixel,index);
1607 if (node_info->child[id] == (NodeInfo *) NULL)
1609 node_info=node_info->child[id];
1612 Find closest color among siblings and their children.
1615 cube.distance=(MagickRealType) (4.0*(QuantumRange+1.0)*(QuantumRange+
1617 ClosestColor(image,&cube,node_info->parent);
1618 cube.cache[i]=(ssize_t) cube.color_number;
1621 Assign pixel to closest colormap entry.
1623 index=(size_t) cube.cache[i];
1624 if (image->storage_class == PseudoClass)
1625 SetPixelIndex(image,(Quantum) index,q);
1626 if (cube.quantize_info->measure_error == MagickFalse)
1628 SetPixelRed(image,ClampToQuantum(image->colormap[index].red),q);
1629 SetPixelGreen(image,ClampToQuantum(image->colormap[index].green),q);
1630 SetPixelBlue(image,ClampToQuantum(image->colormap[index].blue),q);
1631 if (cube.associate_alpha != MagickFalse)
1632 SetPixelAlpha(image,ClampToQuantum(image->colormap[index].alpha),q);
1634 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1639 AssociateAlphaPixelInfo(image,&cube,image->colormap+index,&color);
1640 current[u].red=pixel.red-color.red;
1641 current[u].green=pixel.green-color.green;
1642 current[u].blue=pixel.blue-color.blue;
1643 if (cube.associate_alpha != MagickFalse)
1644 current[u].alpha=pixel.alpha-color.alpha;
1645 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1650 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1651 #pragma omp critical (MagickCore_FloydSteinbergDither)
1653 proceed=SetImageProgress(image,DitherImageTag,(MagickOffsetType) y,
1655 if (proceed == MagickFalse)
1658 q+=((y+1) & 0x01)*GetPixelChannels(image);
1661 image_view=DestroyCacheView(image_view);
1662 pixels=DestroyPixelThreadSet(pixels);
1666 static MagickBooleanType
1667 RiemersmaDither(Image *,CacheView *,CubeInfo *,const unsigned int,
1668 ExceptionInfo *exception);
1670 static void Riemersma(Image *image,CacheView *image_view,CubeInfo *cube_info,
1671 const size_t level,const unsigned int direction,ExceptionInfo *exception)
1678 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1680 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1682 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1688 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1690 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1692 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1698 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1700 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1702 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1708 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1710 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1712 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1724 Riemersma(image,image_view,cube_info,level-1,NorthGravity,
1726 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1728 Riemersma(image,image_view,cube_info,level-1,WestGravity,
1730 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1732 Riemersma(image,image_view,cube_info,level-1,WestGravity,
1734 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1736 Riemersma(image,image_view,cube_info,level-1,SouthGravity,
1742 Riemersma(image,image_view,cube_info,level-1,SouthGravity,
1744 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1746 Riemersma(image,image_view,cube_info,level-1,EastGravity,
1748 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1750 Riemersma(image,image_view,cube_info,level-1,EastGravity,
1752 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1754 Riemersma(image,image_view,cube_info,level-1,NorthGravity,
1760 Riemersma(image,image_view,cube_info,level-1,WestGravity,
1762 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1764 Riemersma(image,image_view,cube_info,level-1,NorthGravity,
1766 (void) RiemersmaDither(image,image_view,cube_info,EastGravity,
1768 Riemersma(image,image_view,cube_info,level-1,NorthGravity,
1770 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1772 Riemersma(image,image_view,cube_info,level-1,EastGravity,
1778 Riemersma(image,image_view,cube_info,level-1,EastGravity,
1780 (void) RiemersmaDither(image,image_view,cube_info,NorthGravity,
1782 Riemersma(image,image_view,cube_info,level-1,SouthGravity,
1784 (void) RiemersmaDither(image,image_view,cube_info,WestGravity,
1786 Riemersma(image,image_view,cube_info,level-1,SouthGravity,
1788 (void) RiemersmaDither(image,image_view,cube_info,SouthGravity,
1790 Riemersma(image,image_view,cube_info,level-1,WestGravity,
1799 static MagickBooleanType RiemersmaDither(Image *image,CacheView *image_view,
1800 CubeInfo *cube_info,const unsigned int direction,ExceptionInfo *exception)
1802 #define DitherImageTag "Dither/Image"
1818 if ((p->x >= 0) && (p->x < (ssize_t) image->columns) &&
1819 (p->y >= 0) && (p->y < (ssize_t) image->rows))
1830 q=GetCacheViewAuthenticPixels(image_view,p->x,p->y,1,1,exception);
1831 if (q == (Quantum *) NULL)
1832 return(MagickFalse);
1833 AssociateAlphaPixel(image,cube_info,q,&pixel);
1834 for (i=0; i < ErrorQueueLength; i++)
1836 pixel.red+=p->weights[i]*p->error[i].red;
1837 pixel.green+=p->weights[i]*p->error[i].green;
1838 pixel.blue+=p->weights[i]*p->error[i].blue;
1839 if (cube_info->associate_alpha != MagickFalse)
1840 pixel.alpha+=p->weights[i]*p->error[i].alpha;
1842 pixel.red=(MagickRealType) ClampToUnsignedQuantum(pixel.red);
1843 pixel.green=(MagickRealType) ClampToUnsignedQuantum(pixel.green);
1844 pixel.blue=(MagickRealType) ClampToUnsignedQuantum(pixel.blue);
1845 if (cube_info->associate_alpha != MagickFalse)
1846 pixel.alpha=(MagickRealType) ClampToUnsignedQuantum(pixel.alpha);
1847 i=CacheOffset(cube_info,&pixel);
1848 if (p->cache[i] < 0)
1857 Identify the deepest node containing the pixel's color.
1860 for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--)
1862 id=ColorToNodeId(cube_info,&pixel,index);
1863 if (node_info->child[id] == (NodeInfo *) NULL)
1865 node_info=node_info->child[id];
1867 node_info=node_info->parent;
1869 Find closest color among siblings and their children.
1872 p->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*((MagickRealType)
1873 QuantumRange+1.0)+1.0);
1874 ClosestColor(image,p,node_info->parent);
1875 p->cache[i]=(ssize_t) p->color_number;
1878 Assign pixel to closest colormap entry.
1880 index=(size_t) p->cache[i];
1881 if (image->storage_class == PseudoClass)
1882 SetPixelIndex(image,(Quantum) index,q);
1883 if (cube_info->quantize_info->measure_error == MagickFalse)
1885 SetPixelRed(image,ClampToQuantum(image->colormap[index].red),q);
1886 SetPixelGreen(image,ClampToQuantum(image->colormap[index].green),q);
1887 SetPixelBlue(image,ClampToQuantum(image->colormap[index].blue),q);
1888 if (cube_info->associate_alpha != MagickFalse)
1889 SetPixelAlpha(image,ClampToQuantum(image->colormap[index].alpha),q);
1891 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1892 return(MagickFalse);
1894 Propagate the error as the last entry of the error queue.
1896 (void) CopyMagickMemory(p->error,p->error+1,(ErrorQueueLength-1)*
1897 sizeof(p->error[0]));
1898 AssociateAlphaPixelInfo(image,cube_info,image->colormap+index,&color);
1899 p->error[ErrorQueueLength-1].red=pixel.red-color.red;
1900 p->error[ErrorQueueLength-1].green=pixel.green-color.green;
1901 p->error[ErrorQueueLength-1].blue=pixel.blue-color.blue;
1902 if (cube_info->associate_alpha != MagickFalse)
1903 p->error[ErrorQueueLength-1].alpha=pixel.alpha-color.alpha;
1904 proceed=SetImageProgress(image,DitherImageTag,p->offset,p->span);
1905 if (proceed == MagickFalse)
1906 return(MagickFalse);
1911 case WestGravity: p->x--; break;
1912 case EastGravity: p->x++; break;
1913 case NorthGravity: p->y--; break;
1914 case SouthGravity: p->y++; break;
1919 static inline ssize_t MagickMax(const ssize_t x,const ssize_t y)
1926 static inline ssize_t MagickMin(const ssize_t x,const ssize_t y)
1933 static MagickBooleanType DitherImage(Image *image,CubeInfo *cube_info,
1934 ExceptionInfo *exception)
1948 if (cube_info->quantize_info->dither_method != RiemersmaDitherMethod)
1949 return(FloydSteinbergDither(image,cube_info,exception));
1951 Distribute quantization error along a Hilbert curve.
1953 (void) ResetMagickMemory(cube_info->error,0,ErrorQueueLength*
1954 sizeof(*cube_info->error));
1957 i=MagickMax((ssize_t) image->columns,(ssize_t) image->rows);
1958 for (depth=1; i != 0; depth++)
1960 if ((ssize_t) (1L << depth) < MagickMax((ssize_t) image->columns,(ssize_t) image->rows))
1962 cube_info->offset=0;
1963 cube_info->span=(MagickSizeType) image->columns*image->rows;
1964 image_view=AcquireAuthenticCacheView(image,exception);
1966 Riemersma(image,image_view,cube_info,depth-1,NorthGravity,exception);
1967 status=RiemersmaDither(image,image_view,cube_info,ForgetGravity,exception);
1968 image_view=DestroyCacheView(image_view);
1973 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1977 + G e t C u b e I n f o %
1981 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1983 % GetCubeInfo() initialize the Cube data structure.
1985 % The format of the GetCubeInfo method is:
1987 % CubeInfo GetCubeInfo(const QuantizeInfo *quantize_info,
1988 % const size_t depth,const size_t maximum_colors)
1990 % A description of each parameter follows.
1992 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
1994 % o depth: Normally, this integer value is zero or one. A zero or
1995 % one tells Quantize to choose a optimal tree depth of Log4(number_colors).
1996 % A tree of this depth generally allows the best representation of the
1997 % reference image with the least amount of memory and the fastest
1998 % computational speed. In some cases, such as an image with low color
1999 % dispersion (a few number of colors), a value other than
2000 % Log4(number_colors) is required. To expand the color tree completely,
2003 % o maximum_colors: maximum colors.
2006 static CubeInfo *GetCubeInfo(const QuantizeInfo *quantize_info,
2007 const size_t depth,const size_t maximum_colors)
2023 Initialize tree to describe color cube_info.
2025 cube_info=(CubeInfo *) AcquireMagickMemory(sizeof(*cube_info));
2026 if (cube_info == (CubeInfo *) NULL)
2027 return((CubeInfo *) NULL);
2028 (void) ResetMagickMemory(cube_info,0,sizeof(*cube_info));
2029 cube_info->depth=depth;
2030 if (cube_info->depth > MaxTreeDepth)
2031 cube_info->depth=MaxTreeDepth;
2032 if (cube_info->depth < 2)
2034 cube_info->maximum_colors=maximum_colors;
2036 Initialize root node.
2038 cube_info->root=GetNodeInfo(cube_info,0,0,(NodeInfo *) NULL);
2039 if (cube_info->root == (NodeInfo *) NULL)
2040 return((CubeInfo *) NULL);
2041 cube_info->root->parent=cube_info->root;
2042 cube_info->quantize_info=CloneQuantizeInfo(quantize_info);
2043 if (cube_info->quantize_info->dither_method == NoDitherMethod)
2046 Initialize dither resources.
2048 length=(size_t) (1UL << (4*(8-CacheShift)));
2049 cube_info->cache=(ssize_t *) AcquireQuantumMemory(length,
2050 sizeof(*cube_info->cache));
2051 if (cube_info->cache == (ssize_t *) NULL)
2052 return((CubeInfo *) NULL);
2054 Initialize color cache.
2056 for (i=0; i < (ssize_t) length; i++)
2057 cube_info->cache[i]=(-1);
2059 Distribute weights along a curve of exponential decay.
2062 for (i=0; i < ErrorQueueLength; i++)
2064 cube_info->weights[ErrorQueueLength-i-1]=1.0/weight;
2065 weight*=exp(log(((double) QuantumRange+1.0))/(ErrorQueueLength-1.0));
2068 Normalize the weighting factors.
2071 for (i=0; i < ErrorQueueLength; i++)
2072 weight+=cube_info->weights[i];
2074 for (i=0; i < ErrorQueueLength; i++)
2076 cube_info->weights[i]/=weight;
2077 sum+=cube_info->weights[i];
2079 cube_info->weights[0]+=1.0-sum;
2084 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2088 + G e t N o d e I n f o %
2092 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2094 % GetNodeInfo() allocates memory for a new node in the color cube tree and
2095 % presets all fields to zero.
2097 % The format of the GetNodeInfo method is:
2099 % NodeInfo *GetNodeInfo(CubeInfo *cube_info,const size_t id,
2100 % const size_t level,NodeInfo *parent)
2102 % A description of each parameter follows.
2104 % o node: The GetNodeInfo method returns a pointer to a queue of nodes.
2106 % o id: Specifies the child number of the node.
2108 % o level: Specifies the level in the storage_class the node resides.
2111 static NodeInfo *GetNodeInfo(CubeInfo *cube_info,const size_t id,
2112 const size_t level,NodeInfo *parent)
2117 if (cube_info->free_nodes == 0)
2123 Allocate a new queue of nodes.
2125 nodes=(Nodes *) AcquireMagickMemory(sizeof(*nodes));
2126 if (nodes == (Nodes *) NULL)
2127 return((NodeInfo *) NULL);
2128 nodes->nodes=(NodeInfo *) AcquireQuantumMemory(NodesInAList,
2129 sizeof(*nodes->nodes));
2130 if (nodes->nodes == (NodeInfo *) NULL)
2131 return((NodeInfo *) NULL);
2132 nodes->next=cube_info->node_queue;
2133 cube_info->node_queue=nodes;
2134 cube_info->next_node=nodes->nodes;
2135 cube_info->free_nodes=NodesInAList;
2138 cube_info->free_nodes--;
2139 node_info=cube_info->next_node++;
2140 (void) ResetMagickMemory(node_info,0,sizeof(*node_info));
2141 node_info->parent=parent;
2143 node_info->level=level;
2148 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2152 % G e t I m a g e Q u a n t i z e E r r o r %
2156 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2158 % GetImageQuantizeError() measures the difference between the original
2159 % and quantized images. This difference is the total quantization error.
2160 % The error is computed by summing over all pixels in an image the distance
2161 % squared in RGB space between each reference pixel value and its quantized
2162 % value. These values are computed:
2164 % o mean_error_per_pixel: This value is the mean error for any single
2165 % pixel in the image.
2167 % o normalized_mean_square_error: This value is the normalized mean
2168 % quantization error for any single pixel in the image. This distance
2169 % measure is normalized to a range between 0 and 1. It is independent
2170 % of the range of red, green, and blue values in the image.
2172 % o normalized_maximum_square_error: Thsi value is the normalized
2173 % maximum quantization error for any single pixel in the image. This
2174 % distance measure is normalized to a range between 0 and 1. It is
2175 % independent of the range of red, green, and blue values in your image.
2177 % The format of the GetImageQuantizeError method is:
2179 % MagickBooleanType GetImageQuantizeError(Image *image,
2180 % ExceptionInfo *exception)
2182 % A description of each parameter follows.
2184 % o image: the image.
2186 % o exception: return any errors or warnings in this structure.
2189 MagickExport MagickBooleanType GetImageQuantizeError(Image *image,
2190 ExceptionInfo *exception)
2202 mean_error_per_pixel;
2210 assert(image != (Image *) NULL);
2211 assert(image->signature == MagickSignature);
2212 if (image->debug != MagickFalse)
2213 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
2214 image->total_colors=GetNumberColors(image,(FILE *) NULL,exception);
2215 (void) ResetMagickMemory(&image->error,0,sizeof(image->error));
2216 if (image->storage_class == DirectClass)
2220 area=3.0*image->columns*image->rows;
2222 mean_error_per_pixel=0.0;
2224 image_view=AcquireVirtualCacheView(image,exception);
2225 for (y=0; y < (ssize_t) image->rows; y++)
2227 register const Quantum
2233 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
2234 if (p == (const Quantum *) NULL)
2236 for (x=0; x < (ssize_t) image->columns; x++)
2238 index=1UL*GetPixelIndex(image,p);
2239 if (image->matte != MagickFalse)
2241 alpha=(MagickRealType) (QuantumScale*GetPixelAlpha(image,p));
2242 beta=(MagickRealType) (QuantumScale*image->colormap[index].alpha);
2244 distance=fabs(alpha*GetPixelRed(image,p)-beta*
2245 image->colormap[index].red);
2246 mean_error_per_pixel+=distance;
2247 mean_error+=distance*distance;
2248 if (distance > maximum_error)
2249 maximum_error=distance;
2250 distance=fabs(alpha*GetPixelGreen(image,p)-beta*
2251 image->colormap[index].green);
2252 mean_error_per_pixel+=distance;
2253 mean_error+=distance*distance;
2254 if (distance > maximum_error)
2255 maximum_error=distance;
2256 distance=fabs(alpha*GetPixelBlue(image,p)-beta*
2257 image->colormap[index].blue);
2258 mean_error_per_pixel+=distance;
2259 mean_error+=distance*distance;
2260 if (distance > maximum_error)
2261 maximum_error=distance;
2262 p+=GetPixelChannels(image);
2265 image_view=DestroyCacheView(image_view);
2266 image->error.mean_error_per_pixel=(double) mean_error_per_pixel/area;
2267 image->error.normalized_mean_error=(double) QuantumScale*QuantumScale*
2269 image->error.normalized_maximum_error=(double) QuantumScale*maximum_error;
2274 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2278 % G e t Q u a n t i z e I n f o %
2282 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2284 % GetQuantizeInfo() initializes the QuantizeInfo structure.
2286 % The format of the GetQuantizeInfo method is:
2288 % GetQuantizeInfo(QuantizeInfo *quantize_info)
2290 % A description of each parameter follows:
2292 % o quantize_info: Specifies a pointer to a QuantizeInfo structure.
2295 MagickExport void GetQuantizeInfo(QuantizeInfo *quantize_info)
2297 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
2298 assert(quantize_info != (QuantizeInfo *) NULL);
2299 (void) ResetMagickMemory(quantize_info,0,sizeof(*quantize_info));
2300 quantize_info->number_colors=256;
2301 quantize_info->dither_method=RiemersmaDitherMethod;
2302 quantize_info->colorspace=UndefinedColorspace;
2303 quantize_info->measure_error=MagickFalse;
2304 quantize_info->signature=MagickSignature;
2308 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2312 % P o s t e r i z e I m a g e %
2316 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2318 % PosterizeImage() reduces the image to a limited number of colors for a
2321 % The format of the PosterizeImage method is:
2323 % MagickBooleanType PosterizeImage(Image *image,const size_t levels,
2324 % const DitherMethod dither_method,ExceptionInfo *exception)
2326 % A description of each parameter follows:
2328 % o image: Specifies a pointer to an Image structure.
2330 % o levels: Number of color levels allowed in each channel. Very low values
2331 % (2, 3, or 4) have the most visible effect.
2333 % o dither_method: choose from UndefinedDitherMethod, NoDitherMethod,
2334 % RiemersmaDitherMethod, FloydSteinbergDitherMethod.
2336 % o exception: return any errors or warnings in this structure.
2340 static inline ssize_t MagickRound(MagickRealType x)
2343 Round the fraction to nearest integer.
2346 return((ssize_t) (x+0.5));
2347 return((ssize_t) (x-0.5));
2350 MagickExport MagickBooleanType PosterizeImage(Image *image,const size_t levels,
2351 const DitherMethod dither_method,ExceptionInfo *exception)
2353 #define PosterizeImageTag "Posterize/Image"
2354 #define PosterizePixel(pixel) (Quantum) (QuantumRange*(MagickRound( \
2355 QuantumScale*pixel*(levels-1)))/MagickMax((ssize_t) levels-1,1))
2375 assert(image != (Image *) NULL);
2376 assert(image->signature == MagickSignature);
2377 if (image->debug != MagickFalse)
2378 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
2379 if (image->storage_class == PseudoClass)
2380 #if defined(MAGICKCORE_OPENMP_SUPPORT)
2381 #pragma omp parallel for schedule(static,4) shared(progress,status) \
2382 dynamic_number_threads(image,image->columns,1,1)
2384 for (i=0; i < (ssize_t) image->colors; i++)
2389 if ((GetPixelRedTraits(image) & UpdatePixelTrait) != 0)
2390 image->colormap[i].red=(double)
2391 PosterizePixel(image->colormap[i].red);
2392 if ((GetPixelGreenTraits(image) & UpdatePixelTrait) != 0)
2393 image->colormap[i].green=(double)
2394 PosterizePixel(image->colormap[i].green);
2395 if ((GetPixelBlueTraits(image) & UpdatePixelTrait) != 0)
2396 image->colormap[i].blue=(double)
2397 PosterizePixel(image->colormap[i].blue);
2398 if ((GetPixelAlphaTraits(image) & UpdatePixelTrait) != 0)
2399 image->colormap[i].alpha=(double)
2400 PosterizePixel(image->colormap[i].alpha);
2407 image_view=AcquireAuthenticCacheView(image,exception);
2408 #if defined(MAGICKCORE_OPENMP_SUPPORT)
2409 #pragma omp parallel for schedule(static,4) shared(progress,status) \
2410 dynamic_number_threads(image,image->columns,image->rows,1)
2412 for (y=0; y < (ssize_t) image->rows; y++)
2420 if (status == MagickFalse)
2422 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
2423 if (q == (Quantum *) NULL)
2428 for (x=0; x < (ssize_t) image->columns; x++)
2430 if ((GetPixelRedTraits(image) & UpdatePixelTrait) != 0)
2431 SetPixelRed(image,PosterizePixel(GetPixelRed(image,q)),q);
2432 if ((GetPixelGreenTraits(image) & UpdatePixelTrait) != 0)
2433 SetPixelGreen(image,PosterizePixel(GetPixelGreen(image,q)),q);
2434 if ((GetPixelBlueTraits(image) & UpdatePixelTrait) != 0)
2435 SetPixelBlue(image,PosterizePixel(GetPixelBlue(image,q)),q);
2436 if (((GetPixelBlackTraits(image) & UpdatePixelTrait) != 0) &&
2437 (image->colorspace == CMYKColorspace))
2438 SetPixelBlack(image,PosterizePixel(GetPixelBlack(image,q)),q);
2439 if (((GetPixelAlphaTraits(image) & UpdatePixelTrait) != 0) &&
2440 (image->matte == MagickTrue))
2441 SetPixelAlpha(image,PosterizePixel(GetPixelAlpha(image,q)),q);
2442 q+=GetPixelChannels(image);
2444 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
2446 if (image->progress_monitor != (MagickProgressMonitor) NULL)
2451 #if defined(MAGICKCORE_OPENMP_SUPPORT)
2452 #pragma omp critical (MagickCore_PosterizeImage)
2454 proceed=SetImageProgress(image,PosterizeImageTag,progress++,
2456 if (proceed == MagickFalse)
2460 image_view=DestroyCacheView(image_view);
2461 quantize_info=AcquireQuantizeInfo((ImageInfo *) NULL);
2462 quantize_info->number_colors=(size_t) MagickMin((ssize_t) levels*levels*
2463 levels,MaxColormapSize+1);
2464 quantize_info->dither_method=dither_method;
2465 quantize_info->tree_depth=MaxTreeDepth;
2466 status=QuantizeImage(quantize_info,image,exception);
2467 quantize_info=DestroyQuantizeInfo(quantize_info);
2472 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2476 + P r u n e C h i l d %
2480 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2482 % PruneChild() deletes the given node and merges its statistics into its
2485 % The format of the PruneSubtree method is:
2487 % PruneChild(const Image *image,CubeInfo *cube_info,
2488 % const NodeInfo *node_info)
2490 % A description of each parameter follows.
2492 % o image: the image.
2494 % o cube_info: A pointer to the Cube structure.
2496 % o node_info: pointer to node in color cube tree that is to be pruned.
2499 static void PruneChild(const Image *image,CubeInfo *cube_info,
2500 const NodeInfo *node_info)
2512 Traverse any children.
2514 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
2515 for (i=0; i < (ssize_t) number_children; i++)
2516 if (node_info->child[i] != (NodeInfo *) NULL)
2517 PruneChild(image,cube_info,node_info->child[i]);
2519 Merge color statistics into parent.
2521 parent=node_info->parent;
2522 parent->number_unique+=node_info->number_unique;
2523 parent->total_color.red+=node_info->total_color.red;
2524 parent->total_color.green+=node_info->total_color.green;
2525 parent->total_color.blue+=node_info->total_color.blue;
2526 parent->total_color.alpha+=node_info->total_color.alpha;
2527 parent->child[node_info->id]=(NodeInfo *) NULL;
2532 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2536 + P r u n e L e v e l %
2540 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2542 % PruneLevel() deletes all nodes at the bottom level of the color tree merging
2543 % their color statistics into their parent node.
2545 % The format of the PruneLevel method is:
2547 % PruneLevel(const Image *image,CubeInfo *cube_info,
2548 % const NodeInfo *node_info)
2550 % A description of each parameter follows.
2552 % o image: the image.
2554 % o cube_info: A pointer to the Cube structure.
2556 % o node_info: pointer to node in color cube tree that is to be pruned.
2559 static void PruneLevel(const Image *image,CubeInfo *cube_info,
2560 const NodeInfo *node_info)
2569 Traverse any children.
2571 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
2572 for (i=0; i < (ssize_t) number_children; i++)
2573 if (node_info->child[i] != (NodeInfo *) NULL)
2574 PruneLevel(image,cube_info,node_info->child[i]);
2575 if (node_info->level == cube_info->depth)
2576 PruneChild(image,cube_info,node_info);
2580 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2584 + P r u n e T o C u b e D e p t h %
2588 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2590 % PruneToCubeDepth() deletes any nodes at a depth greater than
2591 % cube_info->depth while merging their color statistics into their parent
2594 % The format of the PruneToCubeDepth method is:
2596 % PruneToCubeDepth(const Image *image,CubeInfo *cube_info,
2597 % const NodeInfo *node_info)
2599 % A description of each parameter follows.
2601 % o cube_info: A pointer to the Cube structure.
2603 % o node_info: pointer to node in color cube tree that is to be pruned.
2606 static void PruneToCubeDepth(const Image *image,CubeInfo *cube_info,
2607 const NodeInfo *node_info)
2616 Traverse any children.
2618 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
2619 for (i=0; i < (ssize_t) number_children; i++)
2620 if (node_info->child[i] != (NodeInfo *) NULL)
2621 PruneToCubeDepth(image,cube_info,node_info->child[i]);
2622 if (node_info->level > cube_info->depth)
2623 PruneChild(image,cube_info,node_info);
2627 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2631 % Q u a n t i z e I m a g e %
2635 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2637 % QuantizeImage() analyzes the colors within a reference image and chooses a
2638 % fixed number of colors to represent the image. The goal of the algorithm
2639 % is to minimize the color difference between the input and output image while
2640 % minimizing the processing time.
2642 % The format of the QuantizeImage method is:
2644 % MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
2645 % Image *image,ExceptionInfo *exception)
2647 % A description of each parameter follows:
2649 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
2651 % o image: the image.
2653 % o exception: return any errors or warnings in this structure.
2657 static MagickBooleanType DirectToColormapImage(Image *image,
2658 ExceptionInfo *exception)
2676 number_colors=(size_t) (image->columns*image->rows);
2677 if (AcquireImageColormap(image,number_colors,exception) == MagickFalse)
2678 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
2680 if (image->colors != number_colors)
2681 return(MagickFalse);
2683 image_view=AcquireAuthenticCacheView(image,exception);
2684 for (y=0; y < (ssize_t) image->rows; y++)
2695 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
2696 if (q == (Quantum *) NULL)
2698 for (x=0; x < (ssize_t) image->columns; x++)
2700 image->colormap[i].red=(double) GetPixelRed(image,q);
2701 image->colormap[i].green=(double) GetPixelGreen(image,q);
2702 image->colormap[i].blue=(double) GetPixelBlue(image,q);
2703 image->colormap[i].alpha=(double) GetPixelAlpha(image,q);
2704 SetPixelIndex(image,(Quantum) i,q);
2706 q+=GetPixelChannels(image);
2708 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
2710 proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) y,
2712 if (proceed == MagickFalse)
2715 image_view=DestroyCacheView(image_view);
2719 MagickExport MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
2720 Image *image,ExceptionInfo *exception)
2732 assert(quantize_info != (const QuantizeInfo *) NULL);
2733 assert(quantize_info->signature == MagickSignature);
2734 assert(image != (Image *) NULL);
2735 assert(image->signature == MagickSignature);
2736 if (image->debug != MagickFalse)
2737 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
2738 maximum_colors=quantize_info->number_colors;
2739 if (maximum_colors == 0)
2740 maximum_colors=MaxColormapSize;
2741 if (maximum_colors > MaxColormapSize)
2742 maximum_colors=MaxColormapSize;
2743 if ((image->columns*image->rows) <= maximum_colors)
2744 (void) DirectToColormapImage(image,exception);
2745 if ((IsImageGray(image,exception) != MagickFalse) &&
2746 (image->matte == MagickFalse))
2747 (void) SetGrayscaleImage(image,exception);
2748 if ((image->storage_class == PseudoClass) &&
2749 (image->colors <= maximum_colors))
2751 depth=quantize_info->tree_depth;
2758 Depth of color tree is: Log4(colormap size)+2.
2760 colors=maximum_colors;
2761 for (depth=1; colors != 0; depth++)
2763 if ((quantize_info->dither_method != NoDitherMethod) && (depth > 2))
2765 if ((image->matte != MagickFalse) && (depth > 5))
2769 Initialize color cube.
2771 cube_info=GetCubeInfo(quantize_info,depth,maximum_colors);
2772 if (cube_info == (CubeInfo *) NULL)
2773 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
2775 status=ClassifyImageColors(cube_info,image,exception);
2776 if (status != MagickFalse)
2779 Reduce the number of colors in the image.
2781 ReduceImageColors(image,cube_info);
2782 status=AssignImageColors(image,cube_info,exception);
2784 DestroyCubeInfo(cube_info);
2789 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2793 % Q u a n t i z e I m a g e s %
2797 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2799 % QuantizeImages() analyzes the colors within a set of reference images and
2800 % chooses a fixed number of colors to represent the set. The goal of the
2801 % algorithm is to minimize the color difference between the input and output
2802 % images while minimizing the processing time.
2804 % The format of the QuantizeImages method is:
2806 % MagickBooleanType QuantizeImages(const QuantizeInfo *quantize_info,
2807 % Image *images,ExceptionInfo *exception)
2809 % A description of each parameter follows:
2811 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
2813 % o images: Specifies a pointer to a list of Image structures.
2815 % o exception: return any errors or warnings in this structure.
2818 MagickExport MagickBooleanType QuantizeImages(const QuantizeInfo *quantize_info,
2819 Image *images,ExceptionInfo *exception)
2831 MagickProgressMonitor
2842 assert(quantize_info != (const QuantizeInfo *) NULL);
2843 assert(quantize_info->signature == MagickSignature);
2844 assert(images != (Image *) NULL);
2845 assert(images->signature == MagickSignature);
2846 if (images->debug != MagickFalse)
2847 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
2848 if (GetNextImageInList(images) == (Image *) NULL)
2851 Handle a single image with QuantizeImage.
2853 status=QuantizeImage(quantize_info,images,exception);
2857 maximum_colors=quantize_info->number_colors;
2858 if (maximum_colors == 0)
2859 maximum_colors=MaxColormapSize;
2860 if (maximum_colors > MaxColormapSize)
2861 maximum_colors=MaxColormapSize;
2862 depth=quantize_info->tree_depth;
2869 Depth of color tree is: Log4(colormap size)+2.
2871 colors=maximum_colors;
2872 for (depth=1; colors != 0; depth++)
2874 if (quantize_info->dither_method != NoDitherMethod)
2878 Initialize color cube.
2880 cube_info=GetCubeInfo(quantize_info,depth,maximum_colors);
2881 if (cube_info == (CubeInfo *) NULL)
2883 (void) ThrowMagickException(exception,GetMagickModule(),
2884 ResourceLimitError,"MemoryAllocationFailed","'%s'",images->filename);
2885 return(MagickFalse);
2887 number_images=GetImageListLength(images);
2889 for (i=0; image != (Image *) NULL; i++)
2891 progress_monitor=SetImageProgressMonitor(image,(MagickProgressMonitor) NULL,
2892 image->client_data);
2893 status=ClassifyImageColors(cube_info,image,exception);
2894 if (status == MagickFalse)
2896 (void) SetImageProgressMonitor(image,progress_monitor,image->client_data);
2897 proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) i,
2899 if (proceed == MagickFalse)
2901 image=GetNextImageInList(image);
2903 if (status != MagickFalse)
2906 Reduce the number of colors in an image sequence.
2908 ReduceImageColors(images,cube_info);
2910 for (i=0; image != (Image *) NULL; i++)
2912 progress_monitor=SetImageProgressMonitor(image,(MagickProgressMonitor)
2913 NULL,image->client_data);
2914 status=AssignImageColors(image,cube_info,exception);
2915 if (status == MagickFalse)
2917 (void) SetImageProgressMonitor(image,progress_monitor,
2918 image->client_data);
2919 proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) i,
2921 if (proceed == MagickFalse)
2923 image=GetNextImageInList(image);
2926 DestroyCubeInfo(cube_info);
2931 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2939 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2941 % Reduce() traverses the color cube tree and prunes any node whose
2942 % quantization error falls below a particular threshold.
2944 % The format of the Reduce method is:
2946 % Reduce(const Image *image,CubeInfo *cube_info,const NodeInfo *node_info)
2948 % A description of each parameter follows.
2950 % o image: the image.
2952 % o cube_info: A pointer to the Cube structure.
2954 % o node_info: pointer to node in color cube tree that is to be pruned.
2957 static void Reduce(const Image *image,CubeInfo *cube_info,
2958 const NodeInfo *node_info)
2967 Traverse any children.
2969 number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
2970 for (i=0; i < (ssize_t) number_children; i++)
2971 if (node_info->child[i] != (NodeInfo *) NULL)
2972 Reduce(image,cube_info,node_info->child[i]);
2973 if (node_info->quantize_error <= cube_info->pruning_threshold)
2974 PruneChild(image,cube_info,node_info);
2978 Find minimum pruning threshold.
2980 if (node_info->number_unique > 0)
2981 cube_info->colors++;
2982 if (node_info->quantize_error < cube_info->next_threshold)
2983 cube_info->next_threshold=node_info->quantize_error;
2988 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2992 + R e d u c e I m a g e C o l o r s %
2996 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2998 % ReduceImageColors() repeatedly prunes the tree until the number of nodes
2999 % with n2 > 0 is less than or equal to the maximum number of colors allowed
3000 % in the output image. On any given iteration over the tree, it selects
3001 % those nodes whose E value is minimal for pruning and merges their
3002 % color statistics upward. It uses a pruning threshold, Ep, to govern
3003 % node selection as follows:
3006 % while number of nodes with (n2 > 0) > required maximum number of colors
3007 % prune all nodes such that E <= Ep
3008 % Set Ep to minimum E in remaining nodes
3010 % This has the effect of minimizing any quantization error when merging
3011 % two nodes together.
3013 % When a node to be pruned has offspring, the pruning procedure invokes
3014 % itself recursively in order to prune the tree from the leaves upward.
3015 % n2, Sr, Sg, and Sb in a node being pruned are always added to the
3016 % corresponding data in that node's parent. This retains the pruned
3017 % node's color characteristics for later averaging.
3019 % For each node, n2 pixels exist for which that node represents the
3020 % smallest volume in RGB space containing those pixel's colors. When n2
3021 % > 0 the node will uniquely define a color in the output image. At the
3022 % beginning of reduction, n2 = 0 for all nodes except a the leaves of
3023 % the tree which represent colors present in the input image.
3025 % The other pixel count, n1, indicates the total number of colors
3026 % within the cubic volume which the node represents. This includes n1 -
3027 % n2 pixels whose colors should be defined by nodes at a lower level in
3030 % The format of the ReduceImageColors method is:
3032 % ReduceImageColors(const Image *image,CubeInfo *cube_info)
3034 % A description of each parameter follows.
3036 % o image: the image.
3038 % o cube_info: A pointer to the Cube structure.
3041 static void ReduceImageColors(const Image *image,CubeInfo *cube_info)
3043 #define ReduceImageTag "Reduce/Image"
3054 cube_info->next_threshold=0.0;
3055 for (span=cube_info->colors; cube_info->colors > cube_info->maximum_colors; )
3057 cube_info->pruning_threshold=cube_info->next_threshold;
3058 cube_info->next_threshold=cube_info->root->quantize_error-1;
3059 cube_info->colors=0;
3060 Reduce(image,cube_info,cube_info->root);
3061 offset=(MagickOffsetType) span-cube_info->colors;
3062 proceed=SetImageProgress(image,ReduceImageTag,offset,span-
3063 cube_info->maximum_colors+1);
3064 if (proceed == MagickFalse)
3070 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3074 % R e m a p I m a g e %
3078 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3080 % RemapImage() replaces the colors of an image with a dither of the colors
3083 % The format of the RemapImage method is:
3085 % MagickBooleanType RemapImage(const QuantizeInfo *quantize_info,
3086 % Image *image,const Image *remap_image,ExceptionInfo *exception)
3088 % A description of each parameter follows:
3090 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
3092 % o image: the image.
3094 % o remap_image: the reference image.
3096 % o exception: return any errors or warnings in this structure.
3099 MagickExport MagickBooleanType RemapImage(const QuantizeInfo *quantize_info,
3100 Image *image,const Image *remap_image,ExceptionInfo *exception)
3109 Initialize color cube.
3111 assert(image != (Image *) NULL);
3112 assert(image->signature == MagickSignature);
3113 if (image->debug != MagickFalse)
3114 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
3115 assert(remap_image != (Image *) NULL);
3116 assert(remap_image->signature == MagickSignature);
3117 cube_info=GetCubeInfo(quantize_info,MaxTreeDepth,
3118 quantize_info->number_colors);
3119 if (cube_info == (CubeInfo *) NULL)
3120 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
3122 status=ClassifyImageColors(cube_info,remap_image,exception);
3123 if (status != MagickFalse)
3126 Classify image colors from the reference image.
3128 cube_info->quantize_info->number_colors=cube_info->colors;
3129 status=AssignImageColors(image,cube_info,exception);
3131 DestroyCubeInfo(cube_info);
3136 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3140 % R e m a p I m a g e s %
3144 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3146 % RemapImages() replaces the colors of a sequence of images with the
3147 % closest color from a reference image.
3149 % The format of the RemapImage method is:
3151 % MagickBooleanType RemapImages(const QuantizeInfo *quantize_info,
3152 % Image *images,Image *remap_image,ExceptionInfo *exception)
3154 % A description of each parameter follows:
3156 % o quantize_info: Specifies a pointer to an QuantizeInfo structure.
3158 % o images: the image sequence.
3160 % o remap_image: the reference image.
3162 % o exception: return any errors or warnings in this structure.
3165 MagickExport MagickBooleanType RemapImages(const QuantizeInfo *quantize_info,
3166 Image *images,const Image *remap_image,ExceptionInfo *exception)
3177 assert(images != (Image *) NULL);
3178 assert(images->signature == MagickSignature);
3179 if (images->debug != MagickFalse)
3180 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
3182 if (remap_image == (Image *) NULL)
3185 Create a global colormap for an image sequence.
3187 status=QuantizeImages(quantize_info,images,exception);
3191 Classify image colors from the reference image.
3193 cube_info=GetCubeInfo(quantize_info,MaxTreeDepth,
3194 quantize_info->number_colors);
3195 if (cube_info == (CubeInfo *) NULL)
3196 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
3198 status=ClassifyImageColors(cube_info,remap_image,exception);
3199 if (status != MagickFalse)
3202 Classify image colors from the reference image.
3204 cube_info->quantize_info->number_colors=cube_info->colors;
3206 for ( ; image != (Image *) NULL; image=GetNextImageInList(image))
3208 status=AssignImageColors(image,cube_info,exception);
3209 if (status == MagickFalse)
3213 DestroyCubeInfo(cube_info);
3218 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3222 % S e t G r a y s c a l e I m a g e %
3226 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3228 % SetGrayscaleImage() converts an image to a PseudoClass grayscale image.
3230 % The format of the SetGrayscaleImage method is:
3232 % MagickBooleanType SetGrayscaleImage(Image *image,ExceptionInfo *exeption)
3234 % A description of each parameter follows:
3236 % o image: The image.
3238 % o exception: return any errors or warnings in this structure.
3242 #if defined(__cplusplus) || defined(c_plusplus)
3246 static int IntensityCompare(const void *x,const void *y)
3255 color_1=(PixelInfo *) x;
3256 color_2=(PixelInfo *) y;
3257 intensity=GetPixelInfoIntensity(color_1)-(ssize_t)
3258 GetPixelInfoIntensity(color_2);
3259 return((int) intensity);
3262 #if defined(__cplusplus) || defined(c_plusplus)
3266 static MagickBooleanType SetGrayscaleImage(Image *image,
3267 ExceptionInfo *exception)
3286 assert(image != (Image *) NULL);
3287 assert(image->signature == MagickSignature);
3288 if (image->type != GrayscaleType)
3289 (void) TransformImageColorspace(image,GRAYColorspace,exception);
3290 colormap_index=(ssize_t *) AcquireQuantumMemory(MaxMap+1,
3291 sizeof(*colormap_index));
3292 if (colormap_index == (ssize_t *) NULL)
3293 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
3295 if (image->storage_class != PseudoClass)
3297 for (i=0; i <= (ssize_t) MaxMap; i++)
3298 colormap_index[i]=(-1);
3299 if (AcquireImageColormap(image,MaxMap+1,exception) == MagickFalse)
3300 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
3304 image_view=AcquireAuthenticCacheView(image,exception);
3305 #if defined(MAGICKCORE_OPENMP_SUPPORT)
3306 #pragma omp parallel for schedule(static,4) shared(status) \
3307 dynamic_number_threads(image,image->columns,image->rows,1)
3309 for (y=0; y < (ssize_t) image->rows; y++)
3317 if (status == MagickFalse)
3319 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
3321 if (q == (Quantum *) NULL)
3326 for (x=0; x < (ssize_t) image->columns; x++)
3331 intensity=ScaleQuantumToMap(GetPixelRed(image,q));
3332 if (colormap_index[intensity] < 0)
3334 #if defined(MAGICKCORE_OPENMP_SUPPORT)
3335 #pragma omp critical (MagickCore_SetGrayscaleImage)
3337 if (colormap_index[intensity] < 0)
3339 colormap_index[intensity]=(ssize_t) image->colors;
3340 image->colormap[image->colors].red=(double)
3341 GetPixelRed(image,q);
3342 image->colormap[image->colors].green=(double)
3343 GetPixelGreen(image,q);
3344 image->colormap[image->colors].blue=(double)
3345 GetPixelBlue(image,q);
3349 SetPixelIndex(image,(Quantum)
3350 colormap_index[intensity],q);
3351 q+=GetPixelChannels(image);
3353 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
3356 image_view=DestroyCacheView(image_view);
3358 for (i=0; i < (ssize_t) image->colors; i++)
3359 image->colormap[i].alpha=(double) i;
3360 qsort((void *) image->colormap,image->colors,sizeof(PixelInfo),
3362 colormap=(PixelInfo *) AcquireQuantumMemory(image->colors,
3364 if (colormap == (PixelInfo *) NULL)
3365 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
3368 colormap[j]=image->colormap[0];
3369 for (i=0; i < (ssize_t) image->colors; i++)
3371 if (IsPixelInfoEquivalent(&colormap[j],&image->colormap[i]) == MagickFalse)
3374 colormap[j]=image->colormap[i];
3376 colormap_index[(ssize_t) image->colormap[i].alpha]=j;
3378 image->colors=(size_t) (j+1);
3379 image->colormap=(PixelInfo *) RelinquishMagickMemory(image->colormap);
3380 image->colormap=colormap;
3382 image_view=AcquireAuthenticCacheView(image,exception);
3383 #if defined(MAGICKCORE_OPENMP_SUPPORT)
3384 #pragma omp parallel for schedule(static,4) shared(status) \
3385 dynamic_number_threads(image,image->columns,image->rows,1)
3387 for (y=0; y < (ssize_t) image->rows; y++)
3395 if (status == MagickFalse)
3397 q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
3398 if (q == (Quantum *) NULL)
3403 for (x=0; x < (ssize_t) image->columns; x++)
3405 SetPixelIndex(image,(Quantum) colormap_index[ScaleQuantumToMap(
3406 GetPixelIndex(image,q))],q);
3407 q+=GetPixelChannels(image);
3409 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
3412 image_view=DestroyCacheView(image_view);
3413 colormap_index=(ssize_t *) RelinquishMagickMemory(colormap_index);
3414 image->type=GrayscaleType;
3415 if (IsImageMonochrome(image,exception) != MagickFalse)
3416 image->type=BilevelType;