MagickExport Image *EvaluateImages(const Image *images,
  const MagickEvaluateOperator op,ExceptionInfo *exception)
{
#define EvaluateImageTag  "Evaluate/Image"

  CacheView
    *evaluate_view;

  Image
    *image;

  MagickBooleanType
    status;

  MagickOffsetType
    progress;

  MagickPixelPacket
    **magick_restrict evaluate_pixels,
    zero;

  RandomInfo
    **magick_restrict random_info;

  size_t
    number_images;

  ssize_t
    y;

#if defined(MAGICKCORE_OPENMP_SUPPORT)
  unsigned long
    key;
#endif

  assert(images != (Image *) NULL);
  assert(images->signature == MagickCoreSignature);
  if (images->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  image=AcquireImageCanvas(images,exception);
  if (image == (Image *) NULL)
    return((Image *) NULL);
  if (SetImageStorageClass(image,DirectClass) == MagickFalse)
    {
      InheritException(exception,&image->exception);
      image=DestroyImage(image);
      return((Image *) NULL);
    }
  evaluate_pixels=AcquirePixelThreadSet(images);
  if (evaluate_pixels == (MagickPixelPacket **) NULL)
    {
      image=DestroyImage(image);
      (void) ThrowMagickException(exception,GetMagickModule(),
        ResourceLimitError,"MemoryAllocationFailed","`%s'",images->filename);
      return((Image *) NULL);
    }
  /*
    Evaluate image pixels.
  */
  status=MagickTrue;
  progress=0;
  number_images=GetImageListLength(images);
  GetMagickPixelPacket(images,&zero);
  random_info=AcquireRandomInfoThreadSet();
  evaluate_view=AcquireAuthenticCacheView(image,exception);
  if (op == MedianEvaluateOperator)
    {
#if defined(MAGICKCORE_OPENMP_SUPPORT)
      key=GetRandomSecretKey(random_info[0]);
      #pragma omp parallel for schedule(static) shared(progress,status) \
        magick_number_threads(image,images,image->rows,key == ~0UL)
#endif
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        CacheView
          *image_view;

        const Image
          *next;

        const int
          id = GetOpenMPThreadId();

        register IndexPacket
          *magick_restrict evaluate_indexes;

        register MagickPixelPacket
          *evaluate_pixel;

        register PixelPacket
          *magick_restrict q;

        register ssize_t
          x;

        if (status == MagickFalse)
          continue;
        q=QueueCacheViewAuthenticPixels(evaluate_view,0,y,image->columns,1,
          exception);
        if (q == (PixelPacket *) NULL)
          {
            status=MagickFalse;
            continue;
          }
        evaluate_indexes=GetCacheViewAuthenticIndexQueue(evaluate_view);
        evaluate_pixel=evaluate_pixels[id];
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          register ssize_t
            i;

          for (i=0; i < (ssize_t) number_images; i++)
            evaluate_pixel[i]=zero;
          next=images;
          for (i=0; i < (ssize_t) number_images; i++)
          {
            register const IndexPacket
              *indexes;

            register const PixelPacket
              *p;

            image_view=AcquireVirtualCacheView(next,exception);
            p=GetCacheViewVirtualPixels(image_view,x,y,1,1,exception);
            if (p == (const PixelPacket *) NULL)
              {
                image_view=DestroyCacheView(image_view);
                break;
              }
            indexes=GetCacheViewVirtualIndexQueue(image_view);
            evaluate_pixel[i].red=ApplyEvaluateOperator(random_info[id],
              GetPixelRed(p),op,evaluate_pixel[i].red);
            evaluate_pixel[i].green=ApplyEvaluateOperator(random_info[id],
              GetPixelGreen(p),op,evaluate_pixel[i].green);
            evaluate_pixel[i].blue=ApplyEvaluateOperator(random_info[id],
              GetPixelBlue(p),op,evaluate_pixel[i].blue);
            evaluate_pixel[i].opacity=ApplyEvaluateOperator(random_info[id],
              GetPixelAlpha(p),op,evaluate_pixel[i].opacity);
            if (image->colorspace == CMYKColorspace)
              evaluate_pixel[i].index=ApplyEvaluateOperator(random_info[id],
                *indexes,op,evaluate_pixel[i].index);
            image_view=DestroyCacheView(image_view);
            next=GetNextImageInList(next);
          }
          qsort((void *) evaluate_pixel,number_images,sizeof(*evaluate_pixel),
            IntensityCompare);
          SetPixelRed(q,ClampToQuantum(evaluate_pixel[i/2].red));
          SetPixelGreen(q,ClampToQuantum(evaluate_pixel[i/2].green));
          SetPixelBlue(q,ClampToQuantum(evaluate_pixel[i/2].blue));
          SetPixelAlpha(q,ClampToQuantum(evaluate_pixel[i/2].opacity));
          if (image->colorspace == CMYKColorspace)
            SetPixelIndex(evaluate_indexes+i,ClampToQuantum(
              evaluate_pixel[i/2].index));
          q++;
        }
        if (SyncCacheViewAuthenticPixels(evaluate_view,exception) == MagickFalse)
          status=MagickFalse;
        if (images->progress_monitor != (MagickProgressMonitor) NULL)
          {
            MagickBooleanType
              proceed;

#if defined(MAGICKCORE_OPENMP_SUPPORT)
            #pragma omp atomic
#endif
            progress++;
            proceed=SetImageProgress(images,EvaluateImageTag,progress,
              image->rows);
            if (proceed == MagickFalse)
              status=MagickFalse;
          }
      }
    }
  else
    {
#if defined(MAGICKCORE_OPENMP_SUPPORT)
      key=GetRandomSecretKey(random_info[0]);
      #pragma omp parallel for schedule(static) shared(progress,status) \
        magick_number_threads(image,images,image->rows,key == ~0UL)
#endif
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        CacheView
          *image_view;

        const Image
          *next;

        const int
          id = GetOpenMPThreadId();

        register IndexPacket
          *magick_restrict evaluate_indexes;

        register ssize_t
          i,
          x;

        register MagickPixelPacket
          *evaluate_pixel;

        register PixelPacket
          *magick_restrict q;

        if (status == MagickFalse)
          continue;
        q=QueueCacheViewAuthenticPixels(evaluate_view,0,y,image->columns,1,
          exception);
        if (q == (PixelPacket *) NULL)
          {
            status=MagickFalse;
            continue;
          }
        evaluate_indexes=GetCacheViewAuthenticIndexQueue(evaluate_view);
        evaluate_pixel=evaluate_pixels[id];
        for (x=0; x < (ssize_t) image->columns; x++)
          evaluate_pixel[x]=zero;
        next=images;
        for (i=0; i < (ssize_t) number_images; i++)
        {
          register const IndexPacket
            *indexes;

          register const PixelPacket
            *p;

          image_view=AcquireVirtualCacheView(next,exception);
          p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,
            exception);
          if (p == (const PixelPacket *) NULL)
            {
              image_view=DestroyCacheView(image_view);
              break;
            }
          indexes=GetCacheViewVirtualIndexQueue(image_view);
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            evaluate_pixel[x].red=ApplyEvaluateOperator(random_info[id],
              GetPixelRed(p),i == 0 ? AddEvaluateOperator : op,
              evaluate_pixel[x].red);
            evaluate_pixel[x].green=ApplyEvaluateOperator(random_info[id],
              GetPixelGreen(p),i == 0 ? AddEvaluateOperator : op,
              evaluate_pixel[x].green);
            evaluate_pixel[x].blue=ApplyEvaluateOperator(random_info[id],
              GetPixelBlue(p),i == 0 ? AddEvaluateOperator : op,
              evaluate_pixel[x].blue);
            evaluate_pixel[x].opacity=ApplyEvaluateOperator(random_info[id],
              GetPixelAlpha(p),i == 0 ? AddEvaluateOperator : op,
              evaluate_pixel[x].opacity);
            if (image->colorspace == CMYKColorspace)
              evaluate_pixel[x].index=ApplyEvaluateOperator(random_info[id],
                GetPixelIndex(indexes+x),i == 0 ? AddEvaluateOperator : op,
                evaluate_pixel[x].index);
            p++;
          }
          image_view=DestroyCacheView(image_view);
          next=GetNextImageInList(next);
        }
        if (op == MeanEvaluateOperator)
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            evaluate_pixel[x].red/=number_images;
            evaluate_pixel[x].green/=number_images;
            evaluate_pixel[x].blue/=number_images;
            evaluate_pixel[x].opacity/=number_images;
            evaluate_pixel[x].index/=number_images;
          }
        if (op == RootMeanSquareEvaluateOperator)
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            evaluate_pixel[x].red=sqrt((double) evaluate_pixel[x].red/
              number_images);
            evaluate_pixel[x].green=sqrt((double) evaluate_pixel[x].green/
              number_images);
            evaluate_pixel[x].blue=sqrt((double) evaluate_pixel[x].blue/
              number_images);
            evaluate_pixel[x].opacity=sqrt((double) evaluate_pixel[x].opacity/
              number_images);
            evaluate_pixel[x].index=sqrt((double) evaluate_pixel[x].index/
              number_images);
          }
        if (op == MultiplyEvaluateOperator)
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            register ssize_t
              j;

            for (j=0; j < (ssize_t) (number_images-1); j++)
            {
              evaluate_pixel[x].red*=(MagickRealType) QuantumScale;
              evaluate_pixel[x].green*=(MagickRealType) QuantumScale;
              evaluate_pixel[x].blue*=(MagickRealType) QuantumScale;
              evaluate_pixel[x].opacity*=(MagickRealType) QuantumScale;
              evaluate_pixel[x].index*=(MagickRealType) QuantumScale;
            }
          }
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          SetPixelRed(q,ClampToQuantum(evaluate_pixel[x].red));
          SetPixelGreen(q,ClampToQuantum(evaluate_pixel[x].green));
          SetPixelBlue(q,ClampToQuantum(evaluate_pixel[x].blue));
          SetPixelAlpha(q,ClampToQuantum(evaluate_pixel[x].opacity));
          if (image->colorspace == CMYKColorspace)
            SetPixelIndex(evaluate_indexes+x,ClampToQuantum(
              evaluate_pixel[x].index));
          q++;
        }
        if (SyncCacheViewAuthenticPixels(evaluate_view,exception) == MagickFalse)
          status=MagickFalse;
        if (images->progress_monitor != (MagickProgressMonitor) NULL)
          {
            MagickBooleanType
              proceed;

            proceed=SetImageProgress(images,EvaluateImageTag,progress++,
              image->rows);
            if (proceed == MagickFalse)
              status=MagickFalse;
          }
      }
    }
  evaluate_view=DestroyCacheView(evaluate_view);
  evaluate_pixels=DestroyPixelThreadSet(evaluate_pixels);
  random_info=DestroyRandomInfoThreadSet(random_info);
  if (status == MagickFalse)
    image=DestroyImage(image);
  return(image);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.