image.c

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/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                     IIIII  M   M   AAA    GGGG  EEEEE                       %
%                       I    MM MM  A   A  G      E                           %
%                       I    M M M  AAAAA  G  GG  EEE                         %
%                       I    M   M  A   A  G   G  E                           %
%                     IIIII  M   M  A   A   GGGG  EEEEE                       %
%                                                                             %
%                                                                             %
%                           MagickCore Image Methods                          %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                                 July 1992                                   %
%                                                                             %
%                                                                             %
%  Copyright 1999-2008 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.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%
*/

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/animate.h"
#include "magick/artifact.h"
#include "magick/blob.h"
#include "magick/blob-private.h"
#include "magick/cache.h"
#include "magick/cache-private.h"
#include "magick/cache-view.h"
#include "magick/client.h"
#include "magick/color.h"
#include "magick/color-private.h"
#include "magick/colorspace.h"
#include "magick/colorspace-private.h"
#include "magick/composite.h"
#include "magick/composite-private.h"
#include "magick/compress.h"
#include "magick/constitute.h"
#include "magick/deprecate.h"
#include "magick/display.h"
#include "magick/draw.h"
#include "magick/enhance.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/gem.h"
#include "magick/geometry.h"
#include "magick/list.h"
#include "magick/image-private.h"
#include "magick/magic.h"
#include "magick/magick.h"
#include "magick/memory_.h"
#include "magick/module.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/option.h"
#include "magick/paint.h"
#include "magick/pixel-private.h"
#include "magick/profile.h"
#include "magick/property.h"
#include "magick/quantize.h"
#include "magick/random_.h"
#include "magick/segment.h"
#include "magick/semaphore.h"
#include "magick/signature-private.h"
#include "magick/statistic.h"
#include "magick/string_.h"
#include "magick/threshold.h"
#include "magick/timer.h"
#include "magick/utility.h"
#include "magick/version.h"
#include "magick/xwindow-private.h"

/*
  Constant declaration.
*/
const char
  *BackgroundColor = "#ffffff",  /* white */
  *BorderColor = "#dfdfdf",  /* gray */
  *DefaultTileFrame = "15x15+3+3",
  *DefaultTileGeometry = "120x120+4+3>",
  *DefaultTileLabel = "%f\n%wx%h\n%b",
  *ForegroundColor = "#000",  /* black */
  *LoadImageTag = "Load/Image",
  *LoadImagesTag = "Load/Images",
  *MatteColor = "#bdbdbd",  /* gray */
  *PSDensityGeometry = "72.0x72.0",
  *PSPageGeometry = "612x792",
  *SaveImageTag = "Save/Image",
  *SaveImagesTag = "Save/Images",
  *TransparentColor = "#00000000";  /* transparent black */

const double
  DefaultResolution = 72.0;

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireImage() returns a pointer to an image structure initialized to
%  default values.
%
%  The format of the AcquireImage method is:
%
%      Image *AcquireImage(const ImageInfo *image_info)
%
%  A description of each parameter follows:
%
%    o image_info: Many of the image default values are set from this
%      structure.  For example, filename, compression, depth, background color,
%      and others.
%
*/
MagickExport Image *AcquireImage(const ImageInfo *image_info)
{
  const char
    *option;

  Image
    *image;

  MagickStatusType
    flags;

  /*
    Allocate image structure.
  */
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  image=(Image *) AcquireMagickMemory(sizeof(*image));
  if (image == (Image *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
  (void) ResetMagickMemory(image,0,sizeof(*image));
  /*
    Initialize Image structure.
  */
  (void) CopyMagickString(image->magick,"MIFF",MaxTextExtent);
  image->storage_class=DirectClass;
  image->depth=MAGICKCORE_QUANTUM_DEPTH;
  image->colorspace=RGBColorspace;
  image->interlace=NoInterlace;
  image->ticks_per_second=UndefinedTicksPerSecond;
  image->compose=OverCompositeOp;
  image->blur=1.0;
  GetExceptionInfo(&image->exception);
  (void) QueryColorDatabase(BackgroundColor,&image->background_color,
    &image->exception);
  (void) QueryColorDatabase(BorderColor,&image->border_color,&image->exception);
  (void) QueryColorDatabase(MatteColor,&image->matte_color,&image->exception);
  (void) QueryColorDatabase(TransparentColor,&image->transparent_color,
    &image->exception);
  image->x_resolution=DefaultResolution;
  image->y_resolution=DefaultResolution;
  image->units=PixelsPerInchResolution;
  GetTimerInfo(&image->timer);
  (void) GetCacheInfo(&image->cache);
  image->blob=CloneBlobInfo((BlobInfo *) NULL);
  image->debug=IsEventLogging();
  image->reference_count=1;
  image->semaphore=AllocateSemaphoreInfo();
  image->signature=MagickSignature;
  if (image_info == (ImageInfo *) NULL)
    return(image);
  /*
    Transfer image info.
  */
  SetBlobExempt(image,image_info->file != (FILE *) NULL ? MagickTrue :
    MagickFalse);
  (void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
  (void) CopyMagickString(image->magick_filename,image_info->filename,
    MaxTextExtent);
  (void) CopyMagickString(image->magick,image_info->magick,MaxTextExtent);
  if (image_info->size != (char *) NULL)
    {
      (void) ParseAbsoluteGeometry(image_info->size,&image->extract_info);
      image->columns=image->extract_info.width;
      image->rows=image->extract_info.height;
      image->offset=image->extract_info.x;
      image->extract_info.x=0;
      image->extract_info.y=0;
    }
  if (image_info->extract != (char *) NULL)
    {
      RectangleInfo
        geometry;

      flags=ParseAbsoluteGeometry(image_info->extract,&geometry);
      if (((flags & XValue) != 0) || ((flags & YValue) != 0))
        {
          image->extract_info=geometry;
          Swap(image->columns,image->extract_info.width);
          Swap(image->rows,image->extract_info.height);
        }
    }
  image->compression=image_info->compression;
  image->quality=image_info->quality;
  image->endian=image_info->endian;
  image->interlace=image_info->interlace;
  image->units=image_info->units;
  if (image_info->density != (char *) NULL)
    {
      GeometryInfo
        geometry_info;

      flags=ParseGeometry(image_info->density,&geometry_info);
      image->x_resolution=geometry_info.rho;
      image->y_resolution=geometry_info.sigma;
      if ((flags & SigmaValue) == 0)
        image->y_resolution=image->x_resolution;
    }
  if (image_info->page != (char *) NULL)
    {
      char
        *geometry;

      image->page=image->extract_info;
      geometry=GetPageGeometry(image_info->page);
      (void) ParseAbsoluteGeometry(geometry,&image->page);
      geometry=DestroyString(geometry);
    }
  if (image_info->depth != 0)
    image->depth=image_info->depth;
  image->dither=image_info->dither;
  image->background_color=image_info->background_color;
  image->border_color=image_info->border_color;
  image->matte_color=image_info->matte_color;
  image->transparent_color=image_info->transparent_color;
  option=GetImageOption(image_info,"tile-offset");
  if (option != (const char *) NULL)
    {
      char
        *geometry;

      geometry=GetPageGeometry(option);
      flags=ParseAbsoluteGeometry(geometry,&image->tile_offset);
      geometry=DestroyString(geometry);
    }
  image->progress_monitor=image_info->progress_monitor;
  image->client_data=image_info->client_data;
  if (image_info->cache != (void *) NULL)
    CloneCacheMethods(image->cache,image_info->cache);
  (void) SetImageVirtualPixelMethod(image,image_info->virtual_pixel_method);
  return(image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   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 unsigned long colors)
%
%  A description of each parameter follows:
%
%    o image: the image.
%
%    o colors: the number of colors in the image colormap.
%
*/

static inline unsigned long MagickMax(const unsigned long x,
  const unsigned long y)
{
  if (x > y)
    return(x);
  return(y);
}

static inline unsigned long MagickMin(const unsigned long x,
  const unsigned long y)
{
  if (x < y)
    return(x);
  return(y);
}

MagickExport MagickBooleanType AcquireImageColormap(Image *image,
  const unsigned long colors)
{
  register long
    i;

  size_t
    length;

  /*
    Allocate image colormap.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  image->colors=MagickMin(colors,MaxColormapSize);
  length=(size_t) colors;
  if (image->colormap == (PixelPacket *) NULL)
    image->colormap=(PixelPacket *) AcquireQuantumMemory(length,
      sizeof(*image->colormap));
  else
    image->colormap=(PixelPacket *) ResizeQuantumMemory(image->colormap,length,
      sizeof(*image->colormap));
  if (image->colormap == (PixelPacket *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  #pragma omp parallel for
#endif
  for (i=0; i < (long) image->colors; i++)
  {
    unsigned long
      pixel;

    pixel=(unsigned long) (i*(QuantumRange/MagickMax(colors-1,1)));
    image->colormap[i].red=(Quantum) pixel;
    image->colormap[i].green=(Quantum) pixel;
    image->colormap[i].blue=(Quantum) pixel;
    image->colormap[i].opacity=OpaqueOpacity;
  }
  return(SetImageStorageClass(image,PseudoClass));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e I m a g e I n f o                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireImageInfo() allocates the ImageInfo structure.
%
%  The format of the AcquireImageInfo method is:
%
%      ImageInfo *AcquireImageInfo(void)
%
*/
MagickExport ImageInfo *AcquireImageInfo(void)
{
  ImageInfo
    *image_info;

  image_info=(ImageInfo *) AcquireMagickMemory(sizeof(*image_info));
  if (image_info == (ImageInfo *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
  GetImageInfo(image_info);
  return(image_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e N e x t I m a g e                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireNextImage() initializes the next image in a sequence to
%  default values.  The next member of image points to the newly allocated
%  image.  If there is a memory shortage, next is assigned NULL.
%
%  The format of the AcquireNextImage method is:
%
%      void AcquireNextImage(const ImageInfo *image_info,Image *image)
%
%  A description of each parameter follows:
%
%    o image_info: Many of the image default values are set from this
%      structure.  For example, filename, compression, depth, background color,
%      and others.
%
%    o image: the image.
%
*/
MagickExport void AcquireNextImage(const ImageInfo *image_info,Image *image)
{
  /*
    Allocate image structure.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  image->next=AcquireImage(image_info);
  if (GetNextImageInList(image) == (Image *) NULL)
    return;
  (void) CopyMagickString(GetNextImageInList(image)->filename,image->filename,
    MaxTextExtent);
  if (image_info != (ImageInfo *) NULL)
    (void) CopyMagickString(GetNextImageInList(image)->filename,
      image_info->filename,MaxTextExtent);
  DestroyBlob(GetNextImageInList(image));
  image->next->blob=ReferenceBlob(image->blob);
  image->next->endian=image->endian;
  image->next->scene=image->scene+1;
  image->next->previous=image;
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%     A p p e n d I m a g e s                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AppendImages() takes all images from the current image pointer to the end
%  of the image list and appends them to each other top-to-bottom if the
%  stack parameter is true, otherwise left-to-right.
%
%  The format of the AppendImage method is:
%
%      Image *AppendImages(const Image *image,const MagickBooleanType stack,
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image: the image sequence.
%
%    o stack: A value other than 0 stacks the images top-to-bottom.
%
%    o exception: return any errors or warnings in this structure.
%
*/
MagickExport Image *AppendImages(const Image *image,
  const MagickBooleanType stack,ExceptionInfo *exception)
{
#define AppendImageTag  "Append/Image"

  Image
    *append_image;

  long
    n,
    y;

  MagickBooleanType
    matte,
    proceed,
    status;

  register const Image
    *next;

  register long
    i;

  unsigned long
    height,
    number_images,
    width;

  ViewInfo
    **append_view,
    **image_view;

  /*
    Ensure the image have the same column width.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  matte=image->matte;
  number_images=1;
  width=image->columns;
  height=image->rows;
  next=GetNextImageInList(image);
  for ( ; next != (Image *) NULL; next=GetNextImageInList(next))
  {
    if (next->matte != MagickFalse)
      matte=MagickTrue;
    number_images++;
    if (stack != MagickFalse)
      {
        if (next->columns > width)
          width=next->columns;
        height+=next->rows;
        continue;
      }
    width+=next->columns;
    if (next->rows > height)
      height=next->rows;
  }
  /*
    Initialize append next attributes.
  */
  append_image=CloneImage(image,width,height,MagickTrue,exception);
  if (append_image == (Image *) NULL)
    return((Image *) NULL);
  if (SetImageStorageClass(append_image,DirectClass) == MagickFalse)
    {
      InheritException(exception,&append_image->exception);
      append_image=DestroyImage(append_image);
      return((Image *) NULL);
    }
  append_image->matte=matte;
  (void) SetImageBackgroundColor(append_image);
  status=MagickTrue;
  i=0;
  append_view=AcquireCacheViewThreadSet(append_image);
  if (stack != MagickFalse)
    {
      /*
        Stack top-to-bottom.
      */
      for (n=0; n < (long) number_images; n++)
      {
        image_view=AcquireCacheViewThreadSet(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
        #pragma omp parallel for schedule(dynamic,8) shared(status)
#endif
        for (y=0; y < (long) image->rows; y++)
        {
          const IndexPacket
            *indexes;

          IndexPacket
            *append_indexes;

          MagickBooleanType
            sync;

          register const PixelPacket
            *p;

          register long
            id,
            x;

          register PixelPacket
            *q;

          if (status == MagickFalse)
            continue;
          id=GetCacheViewThreadId();
          p=GetCacheViewVirtualPixels(image_view[id],0,y,image->columns,1,
            exception);
          q=QueueCacheViewAuthenticPixels(append_view[id],0,i+y,
            append_image->columns,1,exception);
          if ((p == (const PixelPacket *) NULL) || (q == (PixelPacket *) NULL))
            {
              status=MagickFalse;
              continue;
            }
          indexes=GetCacheViewVirtualIndexes(image_view[id]);
          append_indexes=GetCacheViewAuthenticIndexes(append_view[id]);
          for (x=0; x < (long) image->columns; x++)
          {
            q->red=p->red;
            q->green=p->green;
            q->blue=p->blue;
            q->opacity=p->opacity;
            if (append_image->colorspace == CMYKColorspace)
              append_indexes[x]=indexes[x];
            p++;
            q++;
          }
          sync=SyncCacheViewAuthenticPixels(append_view[id],exception);
          if (sync == MagickFalse)
            continue;
        }
        image_view=DestroyCacheViewThreadSet(image_view);
        proceed=SetImageProgress(image,AppendImageTag,n,number_images);
        if (proceed == MagickFalse)
          break;
        i+=image->rows;
        image=GetNextImageInList(image);
      }
      append_view=DestroyCacheViewThreadSet(append_view);
      if (status == MagickFalse)
        append_image=DestroyImage(append_image);
      return(append_image);
    }
  /*
    Stack left-to-right.
  */
  for (n=0; n < (long) number_images; n++)
  {
    image_view=AcquireCacheViewThreadSet(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
    #pragma omp parallel for schedule(dynamic,8) shared(status)
#endif
    for (y=0; y < (long) image->rows; y++)
    {
      const IndexPacket
        *indexes;

      IndexPacket
        *append_indexes;

      MagickBooleanType
        sync;

      register const PixelPacket
        *p;

      register long
        id,
        x;

      register PixelPacket
        *q;

      if (status == MagickFalse)
        continue;
      id=GetCacheViewThreadId();
      p=GetCacheViewVirtualPixels(image_view[id],0,y,image->columns,1,
        exception);
      q=QueueCacheViewAuthenticPixels(append_view[id],i,y,image->columns,1,
        exception);
      if ((p == (const PixelPacket *) NULL) || (q == (PixelPacket *) NULL))
        {
          status=MagickFalse;
          continue;
        }
      indexes=GetCacheViewVirtualIndexes(image_view[id]);
      append_indexes=GetCacheViewAuthenticIndexes(append_view[id]);
      for (x=0; x < (long) image->columns; x++)
      {
        q->red=p->red;
        q->green=p->green;
        q->blue=p->blue;
        q->opacity=p->opacity;
        if (append_image->colorspace == CMYKColorspace)
          append_indexes[x]=indexes[x];
        p++;
        q++;
      }
      sync=SyncCacheViewAuthenticPixels(append_view[id],exception);
      if (sync == MagickFalse)
        continue;
    }
    image_view=DestroyCacheViewThreadSet(image_view);
    proceed=SetImageProgress(image,AppendImageTag,n,number_images);
    if (proceed == MagickFalse)
      break;
    i+=image->columns;
    image=GetNextImageInList(image);
  }
  append_view=DestroyCacheViewThreadSet(append_view);
  if (status == MagickFalse)
    append_image=DestroyImage(append_image);
  return(append_image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%     A v e r a g e I m a g e s                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AverageImages() takes a set of images and averages them together.  Each
%  image in the set must have the same width and height.  AverageImages()
%  returns a single image with each corresponding pixel component of each
%  image averaged.   On failure, a NULL image is returned and exception
%  describes the reason for the failure.
%
%  The format of the AverageImages method is:
%
%      Image *AverageImages(Image *image,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image: the image sequence.
%
%    o exception: return any errors or warnings in this structure.
%
*/

static MagickPixelPacket **DestroyPixelThreadSet(MagickPixelPacket **pixels)
{
  register long
    i;

  assert(pixels != (MagickPixelPacket **) NULL);
  for (i=0; i < (long) GetCacheViewMaximumThreads(); i++)
    if (pixels[i] != (MagickPixelPacket *) NULL)
      pixels[i]=(MagickPixelPacket *) RelinquishMagickMemory(pixels[i]);
  return((MagickPixelPacket **) RelinquishMagickMemory(pixels));
}

static MagickPixelPacket **AcquirePixelThreadSet(const Image *image)
{
  register long
    i,
    j;

  MagickPixelPacket
    **pixels;

  pixels=(MagickPixelPacket **) AcquireQuantumMemory(
    GetCacheViewMaximumThreads(),sizeof(*pixels));
  if (pixels == (MagickPixelPacket **) NULL)
    return((MagickPixelPacket **) NULL);
  (void) ResetMagickMemory(pixels,0,GetCacheViewMaximumThreads()*
    sizeof(*pixels));
  for (i=0; i < (long) GetCacheViewMaximumThreads(); i++)
  {
    pixels[i]=(MagickPixelPacket *) AcquireQuantumMemory(image->columns,
      sizeof(**pixels));
    if (pixels[i] == (MagickPixelPacket *) NULL)
      return(DestroyPixelThreadSet(pixels));
    for (j=0; j < (long) image->columns; j++)
      GetMagickPixelPacket(image,&pixels[i][j]);
  }
  return(pixels);
}

MagickExport Image *AverageImages(const Image *image,ExceptionInfo *exception)
{
#define AverageImageTag  "Average/Image"

  const Image
    *next;

  Image
    *average_image;

  long
    progress,
    y;

  MagickBooleanType
    status;

  MagickPixelPacket
    **average_pixel,
    zero;

  unsigned long
    number_images;

  ViewInfo
    **average_view;

  /*
    Ensure the image are the same size.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  for (next=image; next != (Image *) NULL; next=GetNextImageInList(next))
    if ((next->columns != image->columns) || (next->rows != image->rows))
      ThrowImageException(OptionError,"ImageWidthsOrHeightsDiffer");
  /*
    Initialize average next attributes.
  */
  average_image=CloneImage(image,image->columns,image->rows,MagickTrue,
    exception);
  if (average_image == (Image *) NULL)
    return((Image *) NULL);
  if (SetImageStorageClass(average_image,DirectClass) == MagickFalse)
    {
      InheritException(exception,&average_image->exception);
      average_image=DestroyImage(average_image);
      return((Image *) NULL);
    }
  average_pixel=AcquirePixelThreadSet(image);
  if (average_pixel == (MagickPixelPacket **) NULL)
    {
      average_image=DestroyImage(average_image);
      ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
    }
  /*
    Average image pixels.
  */
  status=MagickTrue;
  progress=0;
  GetMagickPixelPacket(image,&zero);
  number_images=GetImageListLength(image);
  average_view=AcquireCacheViewThreadSet(average_image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  #pragma omp parallel for schedule(dynamic,8) shared(progress,status)
#endif
  for (y=0; y < (long) average_image->rows; y++)
  {
    const Image
      *next;

    IndexPacket
      *average_indexes;

    MagickPixelPacket
      pixel;

    register long
      i,
      id,
      x;

    register PixelPacket
      *q;

    ViewInfo
      *image_view;

    if (status == MagickFalse)
      continue;
    id=GetCacheViewThreadId();
    q=QueueCacheViewAuthenticPixels(average_view[id],0,y,average_image->columns,
      1,exception);
    if (q == (PixelPacket *) NULL)
      {
        status=MagickFalse;
        continue;
      }
    pixel=zero;
    average_indexes=GetCacheViewAuthenticIndexes(average_view[id]);
    for (x=0; x < (long) average_image->columns; x++)
      average_pixel[id][x]=zero;
    next=image;
    for (i=0; i < (long) number_images; i++)
    {
      register const IndexPacket
        *indexes;

      register const PixelPacket
        *p;

      image_view=AcquireCacheView(next);
      p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
      if (p == (const PixelPacket *) NULL)
        {
          image_view=DestroyCacheView(image_view);
          break;
        }
      indexes=GetCacheViewVirtualIndexes(image_view);
      for (x=0; x < (long) next->columns; x++)
      {
        SetMagickPixelPacket(next,p,indexes+x,&pixel);
        average_pixel[id][x].red+=QuantumScale*pixel.red;
        average_pixel[id][x].green+=QuantumScale*pixel.green;
        average_pixel[id][x].blue+=QuantumScale*pixel.blue;
        average_pixel[id][x].opacity+=QuantumScale*pixel.opacity;
        if (average_image->colorspace == CMYKColorspace)
          average_pixel[id][x].index+=QuantumScale*pixel.index;
        p++;
      }
      image_view=DestroyCacheView(image_view);
      next=GetNextImageInList(next);
    }
    for (x=0; x < (long) average_image->columns; x++)
    {
      average_pixel[id][x].red=(MagickRealType) QuantumRange*
        average_pixel[id][x].red/number_images;
      average_pixel[id][x].green=(MagickRealType) QuantumRange*
        average_pixel[id][x].green/number_images;
      average_pixel[id][x].blue=(MagickRealType) QuantumRange*
        average_pixel[id][x].blue/number_images;
      average_pixel[id][x].opacity=(MagickRealType) QuantumRange*
        average_pixel[id][x].opacity/number_images;
      if (average_image->colorspace == CMYKColorspace)
        average_pixel[id][x].index=(MagickRealType) QuantumRange*
          average_pixel[id][x].index/number_images;
      SetPixelPacket(average_image,&average_pixel[id][x],q,average_indexes+x);
      q++;
    }
    if (SyncCacheViewAuthenticPixels(average_view[id],exception) == MagickFalse)
      status=MagickFalse;
    if (image->progress_monitor != (MagickProgressMonitor) NULL)
      {
        MagickBooleanType
          proceed;

#if defined(MAGICKCORE_OPENMP_SUPPORT)
        #pragma omp critical
#endif
        proceed=SetImageProgress(image,AverageImageTag,progress++,
          average_image->rows);
        if (proceed == MagickFalse)
          status=MagickFalse;
      }
  }
  average_view=DestroyCacheViewThreadSet(average_view);
  average_pixel=DestroyPixelThreadSet(average_pixel);
  if (status == MagickFalse)
    average_image=DestroyImage(average_image);
  return(average_image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C a t c h I m a g e E x c e p t i o n                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CatchImageException() returns if no exceptions are found in the image
%  sequence, otherwise it determines the most severe exception and reports
%  it as a warning or error depending on the severity.
%
%  The format of the CatchImageException method is:
%
%      ExceptionType CatchImageException(Image *image)
%
%  A description of each parameter follows:
%
%    o image: An image sequence.
%
*/
MagickExport ExceptionType CatchImageException(Image *image)
{
  ExceptionInfo
    *exception;

  ExceptionType
    severity;

  assert(image != (const Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->