MagickCore/colormap.c - platform/external/ImageMagick - Git at Google

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %            CCCC   OOO   L       OOO   RRRR   M   M   AAA   PPPP             %
 %           C      O   O  L      O   O  R   R  MM MM  A   A  P   P            %
 %           C      O   O  L      O   O  RRRR   M M M  AAAAA  PPPP             %
 %           C      O   O  L      O   O  R R    M   M  A   A  P                %
 %            CCCC   OOO   LLLLL   OOO   R  R   M   M  A   A  P                %
 %                                                                             %
 %                                                                             %
 %                        MagickCore Colormap Methods                          %
 %                                                                             %
 %                              Software Design                                %
 %                                   Cristy                                    %
 %                                 July 1992                                   %
 %                                                                             %
 %                                                                             %
 %  Copyright 1999-2016 ImageMagick Studio LLC, a non-profit organization      %
 %  dedicated to making software imaging solutions freely available.           %
 %                                                                             %
 %  You may not use this file except in compliance with the License.  You may  %
 %  obtain a copy of the License at                                            %
 %                                                                             %
 %    http://www.imagemagick.org/script/license.php                            %
 %                                                                             %
 %  Unless required by applicable law or agreed to in writing, software        %
 %  distributed under the License is distributed on an "AS IS" BASIS,          %
 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
 %  See the License for the specific language governing permissions and        %
 %  limitations under the License.                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  We use linked-lists because splay-trees do not currently support duplicate
 %  key / value pairs (.e.g X11 green compliance and SVG green compliance).
 %
 */

 /*
   Include declarations.
 */
 #include "MagickCore/studio.h"
 #include "MagickCore/attribute.h"
 #include "MagickCore/blob.h"
 #include "MagickCore/cache-view.h"
 #include "MagickCore/cache.h"
 #include "MagickCore/color.h"
 #include "MagickCore/color-private.h"
 #include "MagickCore/colormap.h"
 #include "MagickCore/client.h"
 #include "MagickCore/configure.h"
 #include "MagickCore/exception.h"
 #include "MagickCore/exception-private.h"
 #include "MagickCore/gem.h"
 #include "MagickCore/geometry.h"
 #include "MagickCore/image-private.h"
 #include "MagickCore/memory_.h"
 #include "MagickCore/monitor.h"
 #include "MagickCore/monitor-private.h"
 #include "MagickCore/option.h"
 #include "MagickCore/pixel-accessor.h"
 #include "MagickCore/quantize.h"
 #include "MagickCore/quantum.h"
 #include "MagickCore/resource_.h"
 #include "MagickCore/semaphore.h"
 #include "MagickCore/string_.h"
 #include "MagickCore/thread-private.h"
 #include "MagickCore/token.h"
 #include "MagickCore/utility.h"
 #include "MagickCore/xml-tree.h"

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %   A c q u i r e I m a g e C o l o r m a p                                   %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  AcquireImageColormap() allocates an image colormap and initializes
 %  it to a linear gray colorspace.  If the image already has a colormap,
 %  it is replaced.  AcquireImageColormap() returns MagickTrue if successful,
 %  otherwise MagickFalse if there is not enough memory.
 %
 %  The format of the AcquireImageColormap method is:
 %
 %      MagickBooleanType AcquireImageColormap(Image *image,const size_t colors,
 %        ExceptionInfo *exception)
 %
 %  A description of each parameter follows:
 %
 %    o image: the image.
 %
 %    o colors: the number of colors in the image colormap.
 %
 %    o exception: return any errors or warnings in this structure.
 %
 */
 MagickExport MagickBooleanType AcquireImageColormap(Image *image,
   const size_t colors,ExceptionInfo *exception)
 {
   register ssize_t
     i;

   /*
     Allocate image colormap.
   */
   assert(image != (Image *) NULL);
   assert(image->signature == MagickCoreSignature);
   if (image->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
   image->colors=MagickMax(colors,1);
   if (image->colormap == (PixelInfo *) NULL)
     image->colormap=(PixelInfo *) AcquireQuantumMemory(image->colors,
       sizeof(*image->colormap));
   else
     image->colormap=(PixelInfo *) ResizeQuantumMemory(image->colormap,
       image->colors,sizeof(*image->colormap));
   if (image->colormap == (PixelInfo *) NULL)
     {
       image->colors=0;
       image->storage_class=DirectClass;
       ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
         image->filename);
     }
   for (i=0; i < (ssize_t) image->colors; i++)
   {
     double
       pixel;

     pixel=(double) (i*(QuantumRange/MagickMax(colors-1,1)));
     GetPixelInfo(image,image->colormap+i);
     image->colormap[i].alpha_trait=BlendPixelTrait;
     image->colormap[i].red=pixel;
     image->colormap[i].green=pixel;
     image->colormap[i].blue=pixel;
     image->colormap[i].alpha=OpaqueAlpha;
   }
   return(SetImageStorageClass(image,PseudoClass,exception));
 }

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %     C y c l e C o l o r m a p I m a g e                                     %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  CycleColormap() displaces an image's colormap by a given number of
 %  positions.  If you cycle the colormap a number of times you can produce
 %  a psychodelic effect.
 %
 %  WARNING: this assumes an images colormap is in a well know and defined
 %  order. Currently Imagemagick has no way of setting that order.
 %
 %  The format of the CycleColormapImage method is:
 %
 %      MagickBooleanType CycleColormapImage(Image *image,const ssize_t displace,
 %        ExceptionInfo *exception)
 %
 %  A description of each parameter follows:
 %
 %    o image: the image.
 %
 %    o displace:  displace the colormap this amount.
 %
 %    o exception: return any errors or warnings in this structure.
 %
 */
 MagickExport MagickBooleanType CycleColormapImage(Image *image,
   const ssize_t displace,ExceptionInfo *exception)
 {
   CacheView
     *image_view;

   MagickBooleanType
     status;

   ssize_t
     y;

   assert(image != (Image *) NULL);
   assert(image->signature == MagickCoreSignature);
   if (image->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
   if (image->storage_class == DirectClass)
     (void) SetImageType(image,PaletteType,exception);
   status=MagickTrue;
   image_view=AcquireAuthenticCacheView(image,exception);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static,4) \
     magick_threads(image,image,1,1)
 #endif
   for (y=0; y < (ssize_t) image->rows; y++)
   {
     register ssize_t
       x;

     register Quantum
       *magick_restrict q;

     ssize_t
       index;

     if (status == MagickFalse)
       continue;
     q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
     if (q == (Quantum *) NULL)
       {
         status=MagickFalse;
         continue;
       }
     for (x=0; x < (ssize_t) image->columns; x++)
     {
       index=(ssize_t) (GetPixelIndex(image,q)+displace) % image->colors;
       if (index < 0)
         index+=(ssize_t) image->colors;
       SetPixelIndex(image,(Quantum) index,q);
       SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
       q+=GetPixelChannels(image);
     }
     if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
       status=MagickFalse;
   }
   image_view=DestroyCacheView(image_view);
   return(status);
 }

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 +   S o r t C o l o r m a p B y I n t e n s i t y                             %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  SortColormapByIntensity() sorts the colormap of a PseudoClass image by
 %  decreasing color intensity.
 %
 %  The format of the SortColormapByIntensity method is:
 %
 %      MagickBooleanType SortColormapByIntensity(Image *image,
 %        ExceptionInfo *exception)
 %
 %  A description of each parameter follows:
 %
 %    o image: A pointer to an Image structure.
 %
 %    o exception: return any errors or warnings in this structure.
 %
 */

 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif

 static int IntensityCompare(const void *x,const void *y)
 {
   const PixelInfo
     *color_1,
     *color_2;

   int
     intensity;

   color_1=(const PixelInfo *) x;
   color_2=(const PixelInfo *) y;
   intensity=(int) GetPixelInfoIntensity((const Image *) NULL,color_2)-(int)
     GetPixelInfoIntensity((const Image *) NULL,color_1);
   return(intensity);
 }

 #if defined(__cplusplus) || defined(c_plusplus)
 }
 #endif

 MagickExport MagickBooleanType SortColormapByIntensity(Image *image,
   ExceptionInfo *exception)
 {
   CacheView
     *image_view;

   MagickBooleanType
     status;

   register ssize_t
     i;

   ssize_t
     y;

   unsigned short
     *pixels;

   assert(image != (Image *) NULL);
   if (image->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
   assert(image->signature == MagickCoreSignature);
   if (image->storage_class != PseudoClass)
     return(MagickTrue);
   /*
     Allocate memory for pixel indexes.
   */
   pixels=(unsigned short *) AcquireQuantumMemory((size_t) image->colors,
     sizeof(*pixels));
   if (pixels == (unsigned short *) NULL)
     ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
       image->filename);
   /*
     Assign index values to colormap entries.
   */
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static,4) shared(status) \
     magick_threads(image,image,1,1)
 #endif
   for (i=0; i < (ssize_t) image->colors; i++)
     image->colormap[i].alpha=(double) i;
   /*
     Sort image colormap by decreasing color popularity.
   */
   qsort((void *) image->colormap,(size_t) image->colors,
     sizeof(*image->colormap),IntensityCompare);
   /*
     Update image colormap indexes to sorted colormap order.
   */
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static,4) shared(status)
 #endif
   for (i=0; i < (ssize_t) image->colors; i++)
     pixels[(ssize_t) image->colormap[i].alpha]=(unsigned short) i;
   status=MagickTrue;
   image_view=AcquireAuthenticCacheView(image,exception);
   for (y=0; y < (ssize_t) image->rows; y++)
   {
     Quantum
       index;

     register ssize_t
       x;

     register Quantum
       *magick_restrict q;

     q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
     if (q == (Quantum *) NULL)
       {
         status=MagickFalse;
         break;
       }
     for (x=0; x < (ssize_t) image->columns; x++)
     {
       index=(Quantum) pixels[(ssize_t) GetPixelIndex(image,q)];
       SetPixelIndex(image,index,q);
       SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
       q+=GetPixelChannels(image);
     }
     if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
       status=MagickFalse;
     if (status == MagickFalse)
       break;
   }
   image_view=DestroyCacheView(image_view);
   pixels=(unsigned short *) RelinquishMagickMemory(pixels);
   return(status);
 }
	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% CCCC OOO L OOO RRRR M M AAA PPPP %
	% C O O L O O R R MM MM A A P P %
	% C O O L O O RRRR M M M AAAAA PPPP %
	% C O O L O O R R M M A A P %
	% CCCC OOO LLLLL OOO R R M M A A P %
	% %
	% %
	% MagickCore Colormap Methods %
	% %
	% Software Design %
	% Cristy %
	% July 1992 %
	% %
	% %
	% Copyright 1999-2016 ImageMagick Studio LLC, a non-profit organization %
	% dedicated to making software imaging solutions freely available. %
	% %
	% You may not use this file except in compliance with the License. You may %
	% obtain a copy of the License at %
	% %
	% http://www.imagemagick.org/script/license.php %
	% %
	% Unless required by applicable law or agreed to in writing, software %
	% distributed under the License is distributed on an "AS IS" BASIS, %
	% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
	% See the License for the specific language governing permissions and %
	% limitations under the License. %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% We use linked-lists because splay-trees do not currently support duplicate
	% key / value pairs (.e.g X11 green compliance and SVG green compliance).
	%
	*/

	/*
	Include declarations.
	*/
	#include "MagickCore/studio.h"
	#include "MagickCore/attribute.h"
	#include "MagickCore/blob.h"
	#include "MagickCore/cache-view.h"
	#include "MagickCore/cache.h"
	#include "MagickCore/color.h"
	#include "MagickCore/color-private.h"
	#include "MagickCore/colormap.h"
	#include "MagickCore/client.h"
	#include "MagickCore/configure.h"
	#include "MagickCore/exception.h"
	#include "MagickCore/exception-private.h"
	#include "MagickCore/gem.h"
	#include "MagickCore/geometry.h"
	#include "MagickCore/image-private.h"
	#include "MagickCore/memory_.h"
	#include "MagickCore/monitor.h"
	#include "MagickCore/monitor-private.h"
	#include "MagickCore/option.h"
	#include "MagickCore/pixel-accessor.h"
	#include "MagickCore/quantize.h"
	#include "MagickCore/quantum.h"
	#include "MagickCore/resource_.h"
	#include "MagickCore/semaphore.h"
	#include "MagickCore/string_.h"
	#include "MagickCore/thread-private.h"
	#include "MagickCore/token.h"
	#include "MagickCore/utility.h"
	#include "MagickCore/xml-tree.h"

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% A c q u i r e I m a g e C o l o r m a p %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% AcquireImageColormap() allocates an image colormap and initializes
	% it to a linear gray colorspace. If the image already has a colormap,
	% it is replaced. AcquireImageColormap() returns MagickTrue if successful,
	% otherwise MagickFalse if there is not enough memory.
	%
	% The format of the AcquireImageColormap method is:
	%
	% MagickBooleanType AcquireImageColormap(Image *image,const size_t colors,
	% ExceptionInfo *exception)
	%
	% A description of each parameter follows:
	%
	% o image: the image.
	%
	% o colors: the number of colors in the image colormap.
	%
	% o exception: return any errors or warnings in this structure.
	%
	*/
	MagickExport MagickBooleanType AcquireImageColormap(Image *image,
	const size_t colors,ExceptionInfo *exception)
	{
	register ssize_t
	i;

	/*
	Allocate image colormap.
	*/
	assert(image != (Image *) NULL);
	assert(image->signature == MagickCoreSignature);
	if (image->debug != MagickFalse)
	(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
	image->colors=MagickMax(colors,1);
	if (image->colormap == (PixelInfo *) NULL)
	image->colormap=(PixelInfo *) AcquireQuantumMemory(image->colors,
	sizeof(*image->colormap));
	else
	image->colormap=(PixelInfo *) ResizeQuantumMemory(image->colormap,
	image->colors,sizeof(*image->colormap));
	if (image->colormap == (PixelInfo *) NULL)
	{
	image->colors=0;
	image->storage_class=DirectClass;
	ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
	image->filename);
	}
	for (i=0; i < (ssize_t) image->colors; i++)
	{
	double
	pixel;

	pixel=(double) (i*(QuantumRange/MagickMax(colors-1,1)));
	GetPixelInfo(image,image->colormap+i);
	image->colormap[i].alpha_trait=BlendPixelTrait;
	image->colormap[i].red=pixel;
	image->colormap[i].green=pixel;
	image->colormap[i].blue=pixel;
	image->colormap[i].alpha=OpaqueAlpha;
	}
	return(SetImageStorageClass(image,PseudoClass,exception));
	}

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% C y c l e C o l o r m a p I m a g e %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% CycleColormap() displaces an image's colormap by a given number of
	% positions. If you cycle the colormap a number of times you can produce
	% a psychodelic effect.
	%
	% WARNING: this assumes an images colormap is in a well know and defined
	% order. Currently Imagemagick has no way of setting that order.
	%
	% The format of the CycleColormapImage method is:
	%
	% MagickBooleanType CycleColormapImage(Image *image,const ssize_t displace,
	% ExceptionInfo *exception)
	%
	% A description of each parameter follows:
	%
	% o image: the image.
	%
	% o displace: displace the colormap this amount.
	%
	% o exception: return any errors or warnings in this structure.
	%
	*/
	MagickExport MagickBooleanType CycleColormapImage(Image *image,
	const ssize_t displace,ExceptionInfo *exception)
	{
	CacheView
	*image_view;

	MagickBooleanType
	status;

	ssize_t
	y;

	assert(image != (Image *) NULL);
	assert(image->signature == MagickCoreSignature);
	if (image->debug != MagickFalse)
	(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
	if (image->storage_class == DirectClass)
	(void) SetImageType(image,PaletteType,exception);
	status=MagickTrue;
	image_view=AcquireAuthenticCacheView(image,exception);
	#if defined(MAGICKCORE_OPENMP_SUPPORT)
	#pragma omp parallel for schedule(static,4) \
	magick_threads(image,image,1,1)
	#endif
	for (y=0; y < (ssize_t) image->rows; y++)
	{
	register ssize_t
	x;

	register Quantum
	*magick_restrict q;

	ssize_t
	index;

	if (status == MagickFalse)
	continue;
	q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
	if (q == (Quantum *) NULL)
	{
	status=MagickFalse;
	continue;
	}
	for (x=0; x < (ssize_t) image->columns; x++)
	{
	index=(ssize_t) (GetPixelIndex(image,q)+displace) % image->colors;
	if (index < 0)
	index+=(ssize_t) image->colors;
	SetPixelIndex(image,(Quantum) index,q);
	SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
	q+=GetPixelChannels(image);
	}
	if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
	status=MagickFalse;
	}
	image_view=DestroyCacheView(image_view);
	return(status);
	}

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	+ S o r t C o l o r m a p B y I n t e n s i t y %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% SortColormapByIntensity() sorts the colormap of a PseudoClass image by
	% decreasing color intensity.
	%
	% The format of the SortColormapByIntensity method is:
	%
	% MagickBooleanType SortColormapByIntensity(Image *image,
	% ExceptionInfo *exception)
	%
	% A description of each parameter follows:
	%
	% o image: A pointer to an Image structure.
	%
	% o exception: return any errors or warnings in this structure.
	%
	*/

	#if defined(__cplusplus) \|\| defined(c_plusplus)
	extern "C" {
	#endif

	static int IntensityCompare(const void x,const void y)
	{
	const PixelInfo
	*color_1,
	*color_2;

	int
	intensity;

	color_1=(const PixelInfo *) x;
	color_2=(const PixelInfo *) y;
	intensity=(int) GetPixelInfoIntensity((const Image *) NULL,color_2)-(int)
	GetPixelInfoIntensity((const Image *) NULL,color_1);
	return(intensity);
	}

	#if defined(__cplusplus) \|\| defined(c_plusplus)
	}
	#endif

	MagickExport MagickBooleanType SortColormapByIntensity(Image *image,
	ExceptionInfo *exception)
	{
	CacheView
	*image_view;

	MagickBooleanType
	status;

	register ssize_t
	i;

	ssize_t
	y;

	unsigned short
	*pixels;

	assert(image != (Image *) NULL);
	if (image->debug != MagickFalse)
	(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
	assert(image->signature == MagickCoreSignature);
	if (image->storage_class != PseudoClass)
	return(MagickTrue);
	/*
	Allocate memory for pixel indexes.
	*/
	pixels=(unsigned short *) AcquireQuantumMemory((size_t) image->colors,
	sizeof(*pixels));
	if (pixels == (unsigned short *) NULL)
	ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
	image->filename);
	/*
	Assign index values to colormap entries.
	*/
	#if defined(MAGICKCORE_OPENMP_SUPPORT)
	#pragma omp parallel for schedule(static,4) shared(status) \
	magick_threads(image,image,1,1)
	#endif
	for (i=0; i < (ssize_t) image->colors; i++)
	image->colormap[i].alpha=(double) i;
	/*
	Sort image colormap by decreasing color popularity.
	*/
	qsort((void *) image->colormap,(size_t) image->colors,
	sizeof(*image->colormap),IntensityCompare);
	/*
	Update image colormap indexes to sorted colormap order.
	*/
	#if defined(MAGICKCORE_OPENMP_SUPPORT)
	#pragma omp parallel for schedule(static,4) shared(status)
	#endif
	for (i=0; i < (ssize_t) image->colors; i++)
	pixels[(ssize_t) image->colormap[i].alpha]=(unsigned short) i;
	status=MagickTrue;
	image_view=AcquireAuthenticCacheView(image,exception);
	for (y=0; y < (ssize_t) image->rows; y++)
	{
	Quantum
	index;

	register ssize_t
	x;

	register Quantum
	*magick_restrict q;

	q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
	if (q == (Quantum *) NULL)
	{
	status=MagickFalse;
	break;
	}
	for (x=0; x < (ssize_t) image->columns; x++)
	{
	index=(Quantum) pixels[(ssize_t) GetPixelIndex(image,q)];
	SetPixelIndex(image,index,q);
	SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
	q+=GetPixelChannels(image);
	}
	if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
	status=MagickFalse;
	if (status == MagickFalse)
	break;
	}
	image_view=DestroyCacheView(image_view);
	pixels=(unsigned short *) RelinquishMagickMemory(pixels);
	return(status);
	}