MagickExport Image *SepiaToneImage(const Image *image,const double threshold,
  ExceptionInfo *exception)
{
#define SepiaToneImageTag  "SepiaTone/Image"

  CacheView
    *image_view,
    *sepia_view;

  Image
    *sepia_image;

  MagickBooleanType
    status;

  MagickOffsetType
    progress;

  ssize_t
    y;

  /*
    Initialize sepia-toned image attributes.
  */
  assert(image != (const Image *) NULL);
  assert(image->signature == MagickCoreSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  sepia_image=CloneImage(image,0,0,MagickTrue,exception);
  if (sepia_image == (Image *) NULL)
    return((Image *) NULL);
  if (SetImageStorageClass(sepia_image,DirectClass,exception) == MagickFalse)
    {
      sepia_image=DestroyImage(sepia_image);
      return((Image *) NULL);
    }
  /*
    Tone each row of the image.
  */
  status=MagickTrue;
  progress=0;
  image_view=AcquireVirtualCacheView(image,exception);
  sepia_view=AcquireAuthenticCacheView(sepia_image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  #pragma omp parallel for schedule(static,4) shared(progress,status) \
    magick_threads(image,sepia_image,image->rows,1)
#endif
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    register const Quantum
      *magick_restrict p;

    register ssize_t
      x;

    register Quantum
      *magick_restrict q;

    if (status == MagickFalse)
      continue;
    p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
    q=GetCacheViewAuthenticPixels(sepia_view,0,y,sepia_image->columns,1,
      exception);
    if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
      {
        status=MagickFalse;
        continue;
      }
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      double
        intensity,
        tone;

      intensity=GetPixelIntensity(image,p);
      tone=intensity > threshold ? (double) QuantumRange : intensity+
        (double) QuantumRange-threshold;
      SetPixelRed(sepia_image,ClampToQuantum(tone),q);
      tone=intensity > (7.0*threshold/6.0) ? (double) QuantumRange :
        intensity+(double) QuantumRange-7.0*threshold/6.0;
      SetPixelGreen(sepia_image,ClampToQuantum(tone),q);
      tone=intensity < (threshold/6.0) ? 0 : intensity-threshold/6.0;
      SetPixelBlue(sepia_image,ClampToQuantum(tone),q);
      tone=threshold/7.0;
      if ((double) GetPixelGreen(image,q) < tone)
        SetPixelGreen(sepia_image,ClampToQuantum(tone),q);
      if ((double) GetPixelBlue(image,q) < tone)
        SetPixelBlue(sepia_image,ClampToQuantum(tone),q);
      SetPixelAlpha(sepia_image,GetPixelAlpha(image,p),q);
      p+=GetPixelChannels(image);
      q+=GetPixelChannels(sepia_image);
    }
    if (SyncCacheViewAuthenticPixels(sepia_view,exception) == MagickFalse)
      status=MagickFalse;
    if (image->progress_monitor != (MagickProgressMonitor) NULL)
      {
        MagickBooleanType
          proceed;

#if defined(MAGICKCORE_OPENMP_SUPPORT)
        #pragma omp critical (MagickCore_SepiaToneImage)
#endif
        proceed=SetImageProgress(image,SepiaToneImageTag,progress++,
          image->rows);
        if (proceed == MagickFalse)
          status=MagickFalse;
      }
  }
  sepia_view=DestroyCacheView(sepia_view);
  image_view=DestroyCacheView(image_view);
  (void) NormalizeImage(sepia_image,exception);
  (void) ContrastImage(sepia_image,MagickTrue,exception);
  if (status == MagickFalse)
    sepia_image=DestroyImage(sepia_image);
  return(sepia_image);
}