Commit message: Different fix for #869.
CVE: CVE-2017-17681
CWE: CWE-835
Vulnerability description: In ImageMagick 7.0.7-12 Q16, an infinite loop vulnerability was found in the function ReadPSDChannelZip in coders/psd.c, which allows attackers to cause a denial of service (CPU exhaustion) via a crafted psd image file.

Project: ImageMagick
File: psd.c

static Image *ReadPSDImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *image;

  MagickBooleanType
    has_merged_image,
    skip_layers;

  MagickOffsetType
    offset;

  MagickSizeType
    length;

  MagickBooleanType
    status;

  PSDInfo
    psd_info;

  register ssize_t
    i;

  ssize_t
    count;

  unsigned char
    *data;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);

  image=AcquireImage(image_info,exception);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  /*
    Read image header.
  */
  image->endian=MSBEndian;
  count=ReadBlob(image,4,(unsigned char *) psd_info.signature);
  psd_info.version=ReadBlobMSBShort(image);
  if ((count == 0) || (LocaleNCompare(psd_info.signature,"8BPS",4) != 0) ||
      ((psd_info.version != 1) && (psd_info.version != 2)))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  (void) ReadBlob(image,6,psd_info.reserved);
  psd_info.channels=ReadBlobMSBShort(image);
  if (psd_info.channels > MaxPSDChannels)
    ThrowReaderException(CorruptImageError,"MaximumChannelsExceeded");
  psd_info.rows=ReadBlobMSBLong(image);
  psd_info.columns=ReadBlobMSBLong(image);
  if ((psd_info.version == 1) && ((psd_info.rows > 30000) ||
      (psd_info.columns > 30000)))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  psd_info.depth=ReadBlobMSBShort(image);
  if ((psd_info.depth != 1) && (psd_info.depth != 8) && (psd_info.depth != 16))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  psd_info.mode=ReadBlobMSBShort(image);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Image is %.20g x %.20g with channels=%.20g, depth=%.20g, mode=%s",
      (double) psd_info.columns,(double) psd_info.rows,(double)
      psd_info.channels,(double) psd_info.depth,ModeToString((PSDImageType)
      psd_info.mode));
  if (EOFBlob(image) != MagickFalse)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  /*
    Initialize image.
  */
  image->depth=psd_info.depth;
  image->columns=psd_info.columns;
  image->rows=psd_info.rows;
  status=SetImageExtent(image,image->columns,image->rows,exception);
  if (status == MagickFalse)
    return(DestroyImageList(image));
  if (SetImageBackgroundColor(image,exception) == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  if (psd_info.mode == LabMode)
    SetImageColorspace(image,LabColorspace,exception);
  if (psd_info.mode == CMYKMode)
    {
      SetImageColorspace(image,CMYKColorspace,exception);
      if (psd_info.channels > 4)
        SetImageAlphaChannel(image,ActivateAlphaChannel,exception);
    }
  else if ((psd_info.mode == BitmapMode) || (psd_info.mode == GrayscaleMode) ||
           (psd_info.mode == DuotoneMode))
    {
      status=AcquireImageColormap(image,psd_info.depth != 16 ? 256 : 65536,
        exception);
      if (status == MagickFalse)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      if (image->debug != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Image colormap allocated");
      SetImageColorspace(image,GRAYColorspace,exception);
      if (psd_info.channels > 1)
        SetImageAlphaChannel(image,ActivateAlphaChannel,exception);
    }
  else
    if (psd_info.channels > 3)
      SetImageAlphaChannel(image,ActivateAlphaChannel,exception);
  /*
    Read PSD raster colormap only present for indexed and duotone images.
  */
  length=ReadBlobMSBLong(image);
  if (length != 0)
    {
      if (image->debug != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  reading colormap");
      if (psd_info.mode == DuotoneMode)
        {
          /*
            Duotone image data;  the format of this data is undocumented.
          */
          data=(unsigned char *) AcquireQuantumMemory((size_t) length,
            sizeof(*data));
          if (data == (unsigned char *) NULL)
            ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
          (void) ReadBlob(image,(size_t) length,data);
          data=(unsigned char *) RelinquishMagickMemory(data);
        }
      else
        {
          size_t
            number_colors;

          /*
            Read PSD raster colormap.
          */
          number_colors=length/3;
          if (number_colors > 65536)
            ThrowReaderException(CorruptImageError,"ImproperImageHeader");
          if (AcquireImageColormap(image,number_colors,exception) == MagickFalse)
            ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
          for (i=0; i < (ssize_t) image->colors; i++)
            image->colormap[i].red=ScaleCharToQuantum((unsigned char)
              ReadBlobByte(image));
          for (i=0; i < (ssize_t) image->colors; i++)
            image->colormap[i].green=ScaleCharToQuantum((unsigned char)
              ReadBlobByte(image));
          for (i=0; i < (ssize_t) image->colors; i++)
            image->colormap[i].blue=ScaleCharToQuantum((unsigned char)
              ReadBlobByte(image));
          image->alpha_trait=UndefinedPixelTrait;
        }
    }
  if ((image->depth == 1) && (image->storage_class != PseudoClass))
    ThrowReaderException(CorruptImageError, "ImproperImageHeader");
  has_merged_image=MagickTrue;
  length=ReadBlobMSBLong(image);
  if (length != 0)
    {
      unsigned char
        *blocks;

      /*
        Image resources block.
      */
      if (image->debug != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  reading image resource blocks - %.20g bytes",(double)
          ((MagickOffsetType) length));
      if (length > GetBlobSize(image))
        ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
      blocks=(unsigned char *) AcquireQuantumMemory((size_t) length,
        sizeof(*blocks));
      if (blocks == (unsigned char *) NULL)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      count=ReadBlob(image,(size_t) length,blocks);
      if ((count != (ssize_t) length) || (length < 4) ||
          (LocaleNCompare((char *) blocks,"8BIM",4) != 0))
        {
          blocks=(unsigned char *) RelinquishMagickMemory(blocks);
          ThrowReaderException(CorruptImageError,"ImproperImageHeader");
        }
      ParseImageResourceBlocks(image,blocks,(size_t) length,&has_merged_image,
        exception);
      blocks=(unsigned char *) RelinquishMagickMemory(blocks);
    }
  /*
    Layer and mask block.
  */
  length=GetPSDSize(&psd_info,image);
  if (length == 8)
    {
      length=ReadBlobMSBLong(image);
      length=ReadBlobMSBLong(image);
    }
  offset=TellBlob(image);
  skip_layers=MagickFalse;
  if ((image_info->number_scenes == 1) && (image_info->scene == 0) &&
      (has_merged_image != MagickFalse))
    {
      if (image->debug != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  read composite only");
      skip_layers=MagickTrue;
    }
  if (length == 0)
    {
      if (image->debug != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  image has no layers");
    }
  else
    {
      if (ReadPSDLayersInternal(image,image_info,&psd_info,skip_layers,
            exception) != MagickTrue)
        {
          (void) CloseBlob(image);
          image=DestroyImageList(image);
          return((Image *) NULL);
        }

      /*
         Skip the rest of the layer and mask information.
      */
      SeekBlob(image,offset+length,SEEK_SET);
    }
  /*
    If we are only "pinging" the image, then we're done - so return.
  */
  if (EOFBlob(image) != MagickFalse)
    ThrowReaderException(CorruptImageError,"UnexpectedEndOfFile");
  if (image_info->ping != MagickFalse)
    {
      (void) CloseBlob(image);
      return(GetFirstImageInList(image));
    }
  /*
    Read the precombined layer, present for PSD < 4 compatibility.
  */
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  reading the precombined layer");
  if ((has_merged_image != MagickFalse) || (GetImageListLength(image) == 1))
    has_merged_image=(MagickBooleanType) ReadPSDMergedImage(image_info,image,
      &psd_info,exception);
  if ((has_merged_image == MagickFalse) && (GetImageListLength(image) == 1) &&
      (length != 0))
    {
      SeekBlob(image,offset,SEEK_SET);
      status=ReadPSDLayersInternal(image,image_info,&psd_info,MagickFalse,
        exception);
      if (status != MagickTrue)
        {
          (void) CloseBlob(image);
          image=DestroyImageList(image);
          return((Image *) NULL);
        }
    }
  if (has_merged_image == MagickFalse)
    {
      Image
        *merged;

      if (GetImageListLength(image) == 1)
        ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
      SetImageAlphaChannel(image,TransparentAlphaChannel,exception);
      image->background_color.alpha=TransparentAlpha;
      image->background_color.alpha_trait=BlendPixelTrait;
      merged=MergeImageLayers(image,FlattenLayer,exception);
      ReplaceImageInList(&image,merged);
    }
  (void) CloseBlob(image);
  return(GetFirstImageInList(image));
}

Project: ImageMagick
File: psd.c

static MagickBooleanType ReadPSDChannelRLE(Image *image,const PSDInfo *psd_info,
  const ssize_t type,MagickOffsetType *sizes,ExceptionInfo *exception)
{
  MagickBooleanType
    status;

  size_t
    length,
    row_size;

  ssize_t
    count,
    y;

  unsigned char
    *compact_pixels,
    *pixels;

  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
       "      layer data is RLE compressed");

  row_size=GetPSDRowSize(image);
  pixels=(unsigned char *) AcquireQuantumMemory(row_size,sizeof(*pixels));
  if (pixels == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);

  length=0;
  for (y=0; y < (ssize_t) image->rows; y++)
    if ((MagickOffsetType) length < sizes[y])
      length=(size_t) sizes[y];

  if (length > (row_size+512)) // arbitrary number
    {
      pixels=(unsigned char *) RelinquishMagickMemory(pixels);
      ThrowBinaryException(ResourceLimitError,"InvalidLength",image->filename);
    }

  compact_pixels=(unsigned char *) AcquireQuantumMemory(length,sizeof(*pixels));
  if (compact_pixels == (unsigned char *) NULL)
    {
      pixels=(unsigned char *) RelinquishMagickMemory(pixels);
      ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
        image->filename);
    }

  (void) ResetMagickMemory(compact_pixels,0,length*sizeof(*compact_pixels));

  status=MagickTrue;
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    status=MagickFalse;

    count=ReadBlob(image,(size_t) sizes[y],compact_pixels);
    if (count != (ssize_t) sizes[y])
      break;

    count=DecodePSDPixels((size_t) sizes[y],compact_pixels,
      (ssize_t) (image->depth == 1 ? 123456 : image->depth),row_size,pixels);
    if (count != (ssize_t) row_size)
      break;

    status=ReadPSDChannelPixels(image,psd_info->channels,y,type,pixels,
      exception);
    if (status == MagickFalse)
      break;
  }

  compact_pixels=(unsigned char *) RelinquishMagickMemory(compact_pixels);
  pixels=(unsigned char *) RelinquishMagickMemory(pixels);
  return(status);
}

Project: ImageMagick
File: psd.c

static MagickBooleanType ApplyPSDLayerOpacity(Image *image,Quantum opacity,
  MagickBooleanType revert,ExceptionInfo *exception)
{
  MagickBooleanType
    status;

  ssize_t
    y;

  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  applying layer opacity %.20g", (double) opacity);
  if (opacity == OpaqueAlpha)
    return(MagickTrue);
  image->alpha_trait=BlendPixelTrait;
  status=MagickTrue;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(status) \
  magick_number_threads(image,image,image->rows,1)
#endif
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    register Quantum
      *magick_restrict q;

    register ssize_t
      x;

    if (status == MagickFalse)
      continue;
    q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
    if (q == (Quantum *) NULL)
      {
        status=MagickFalse;
        continue;
      }
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      if (revert == MagickFalse)
        SetPixelAlpha(image,(Quantum) (QuantumScale*(GetPixelAlpha(image,q))*
          opacity),q);
      else if (opacity > 0)
        SetPixelAlpha(image,(Quantum) (QuantumRange*(GetPixelAlpha(image,q)/
          (MagickRealType) opacity)),q);
      q+=GetPixelChannels(image);
    }
    if (SyncAuthenticPixels(image,exception) == MagickFalse)
      status=MagickFalse;
  }

  return(status);
}

Project: ImageMagick
File: psd.c

static MagickBooleanType ApplyPSDOpacityMask(Image *image,const Image *mask,
  Quantum background,MagickBooleanType revert,ExceptionInfo *exception)
{
  Image
    *complete_mask;

  MagickBooleanType
    status;

  PixelInfo
    color;

  ssize_t
    y;

  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  applying opacity mask");
  complete_mask=CloneImage(image,image->columns,image->rows,MagickTrue,
    exception);
  if (complete_mask == (Image *) NULL)
    return(MagickFalse);
  complete_mask->alpha_trait=BlendPixelTrait;
  GetPixelInfo(complete_mask,&color);
  color.red=background;
  SetImageColor(complete_mask,&color,exception);
  status=CompositeImage(complete_mask,mask,OverCompositeOp,MagickTrue,
    mask->page.x-image->page.x,mask->page.y-image->page.y,exception);
  if (status == MagickFalse)
    {
      complete_mask=DestroyImage(complete_mask);
      return(status);
    }
  image->alpha_trait=BlendPixelTrait;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(status) \
  magick_number_threads(image,image,image->rows,1)
#endif
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    register Quantum
      *magick_restrict q;

    register Quantum
      *p;

    register ssize_t
      x;

    if (status == MagickFalse)
      continue;
    q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
    p=GetAuthenticPixels(complete_mask,0,y,complete_mask->columns,1,exception);
    if ((q == (Quantum *) NULL) || (p == (Quantum *) NULL))
      {
        status=MagickFalse;
        continue;
      }
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      MagickRealType
        alpha,
        intensity;

      alpha=GetPixelAlpha(image,q);
      intensity=GetPixelIntensity(complete_mask,p);
      if (revert == MagickFalse)
        SetPixelAlpha(image,ClampToQuantum(intensity*(QuantumScale*alpha)),q);
      else if (intensity > 0)
        SetPixelAlpha(image,ClampToQuantum((alpha/intensity)*QuantumRange),q);
      q+=GetPixelChannels(image);
      p+=GetPixelChannels(complete_mask);
    }
    if (SyncAuthenticPixels(image,exception) == MagickFalse)
      status=MagickFalse;
  }
  complete_mask=DestroyImage(complete_mask);
  return(status);
}

Project: ImageMagick
File: psd.c

static MagickBooleanType ReadPSDChannelZip(Image *image,const size_t channels,
  const ssize_t type,const PSDCompressionType compression,
  const size_t compact_size,ExceptionInfo *exception)
{
  MagickBooleanType
    status;

  register unsigned char
    *p;

  size_t
    count,
    length,
    packet_size,
    row_size;

  ssize_t
    y;

  unsigned char
    *compact_pixels,
    *pixels;

  z_stream
    stream;

  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
       "      layer data is ZIP compressed");

  compact_pixels=(unsigned char *) AcquireQuantumMemory(compact_size,
    sizeof(*compact_pixels));
  if (compact_pixels == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);

  packet_size=GetPSDPacketSize(image);
  row_size=image->columns*packet_size;
  count=image->rows*row_size;

  pixels=(unsigned char *) AcquireQuantumMemory(count,sizeof(*pixels));
  if (pixels == (unsigned char *) NULL)
    {
      compact_pixels=(unsigned char *) RelinquishMagickMemory(compact_pixels);
      ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
        image->filename);
    }
  if (ReadBlob(image,compact_size,compact_pixels) != (ssize_t) compact_size)
    {
      pixels=(unsigned char *) RelinquishMagickMemory(pixels);
      compact_pixels=(unsigned char *) RelinquishMagickMemory(compact_pixels);
      ThrowBinaryException(CorruptImageError,"UnexpectedEndOfFile",
        image->filename);
    }

  ResetMagickMemory(&stream,0,sizeof(stream));
  stream.data_type=Z_BINARY;
  stream.next_in=(Bytef *)compact_pixels;
  stream.avail_in=(uInt) compact_size;
  stream.next_out=(Bytef *)pixels;
  stream.avail_out=(uInt) count;

  if (inflateInit(&stream) == Z_OK)
    {
      int
        ret;

      while (stream.avail_out > 0)
      {
        ret=inflate(&stream,Z_SYNC_FLUSH);
        if ((ret != Z_OK) && (ret != Z_STREAM_END))
          {
            (void) inflateEnd(&stream);
            compact_pixels=(unsigned char *) RelinquishMagickMemory(
              compact_pixels);
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            return(MagickFalse);
          }
        if (ret == Z_STREAM_END)
          break;
      }
      (void) inflateEnd(&stream);
    }

  if (compression == ZipWithPrediction)
  {
     p=pixels;
     while (count > 0)
     {
       length=image->columns;
       while (--length)
       {
         if (packet_size == 2)
           {
             p[2]+=p[0]+((p[1]+p[3]) >> 8);
             p[3]+=p[1];
           }
         else
          *(p+1)+=*p;
         p+=packet_size;
       }
       p+=packet_size;
       count-=row_size;
     }
  }

  status=MagickTrue;
  p=pixels;
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    status=ReadPSDChannelPixels(image,channels,y,type,p,exception);
    if (status == MagickFalse)
      break;

    p+=row_size;
  }

  compact_pixels=(unsigned char *) RelinquishMagickMemory(compact_pixels);
  pixels=(unsigned char *) RelinquishMagickMemory(pixels);
  return(status);
}

Project: ImageMagick
File: psd.c

static MagickBooleanType CorrectPSDAlphaBlend(const ImageInfo *image_info,
  Image *image,ExceptionInfo* exception)
{
  const char
    *option;

  MagickBooleanType
    status;

  ssize_t
    y;

  if (image->alpha_trait != BlendPixelTrait || image->colorspace != sRGBColorspace)
    return(MagickTrue);
  option=GetImageOption(image_info,"psd:alpha-unblend");
  if (IsStringFalse(option) != MagickFalse)
    return(MagickTrue);
  status=MagickTrue;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(status) \
  magick_number_threads(image,image,image->rows,1)
#endif
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    register Quantum
      *magick_restrict q;

    register ssize_t
      x;

    if (status == MagickFalse)
      continue;
    q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
    if (q == (Quantum *) NULL)
    {
      status=MagickFalse;
      continue;
    }
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      double
        gamma;

      register ssize_t
        i;

      gamma=QuantumScale*GetPixelAlpha(image, q);
      if (gamma != 0.0 && gamma != 1.0)
        {
          for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
          {
            PixelChannel channel = GetPixelChannelChannel(image,i);
            if (channel != AlphaPixelChannel)
              q[i]=ClampToQuantum((q[i]-((1.0-gamma)*QuantumRange))/gamma);
          }
        }
      q+=GetPixelChannels(image);
    }
    if (SyncAuthenticPixels(image,exception) == MagickFalse)
      status=MagickFalse;
  }

  return(status);
}

Project: ImageMagick
File: psd.c

static MagickBooleanType WritePSDImage(const ImageInfo *image_info,
  Image *image,ExceptionInfo *exception)
{
  const StringInfo
    *icc_profile;

  MagickBooleanType
    status;

  PSDInfo
    psd_info;

  register ssize_t
    i;

  size_t
    length,
    num_channels,
    packet_size;

  StringInfo
    *bim_profile;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(image != (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);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
  if (status == MagickFalse)
    return(status);
  packet_size=(size_t) (image->depth > 8 ? 6 : 3);
  if (image->alpha_trait != UndefinedPixelTrait)
    packet_size+=image->depth > 8 ? 2 : 1;
  psd_info.version=1;
  if ((LocaleCompare(image_info->magick,"PSB") == 0) ||
      (image->columns > 30000) || (image->rows > 30000))
    psd_info.version=2;
  (void) WriteBlob(image,4,(const unsigned char *) "8BPS");
  (void) WriteBlobMSBShort(image,psd_info.version);  /* version */
  for (i=1; i <= 6; i++)
    (void) WriteBlobByte(image, 0);  /* 6 bytes of reserved */
  /* When the image has a color profile it won't be converted to gray scale */
  if ((GetImageProfile(image,"icc") == (StringInfo *) NULL) &&
      (SetImageGray(image,exception) != MagickFalse))
    num_channels=(image->alpha_trait != UndefinedPixelTrait ? 2UL : 1UL);
  else
    if ((image_info->type != TrueColorType) && (image_info->type !=
         TrueColorAlphaType) && (image->storage_class == PseudoClass))
      num_channels=(image->alpha_trait != UndefinedPixelTrait ? 2UL : 1UL);
    else
      {
        if (image->storage_class == PseudoClass)
          (void) SetImageStorageClass(image,DirectClass,exception);
        if (image->colorspace != CMYKColorspace)
          num_channels=(image->alpha_trait != UndefinedPixelTrait ? 4UL : 3UL);
        else
          num_channels=(image->alpha_trait != UndefinedPixelTrait ? 5UL : 4UL);
      }
  (void) WriteBlobMSBShort(image,(unsigned short) num_channels);
  (void) WriteBlobMSBLong(image,(unsigned int) image->rows);
  (void) WriteBlobMSBLong(image,(unsigned int) image->columns);
  if (IsImageGray(image) != MagickFalse)
    {
      MagickBooleanType
        monochrome;

      /*
        Write depth & mode.
      */
      monochrome=IsImageMonochrome(image) && (image->depth == 1) ?
        MagickTrue : MagickFalse;
      (void) WriteBlobMSBShort(image,(unsigned short)
        (monochrome != MagickFalse ? 1 : image->depth > 8 ? 16 : 8));
      (void) WriteBlobMSBShort(image,(unsigned short)
        (monochrome != MagickFalse ? BitmapMode : GrayscaleMode));
    }
  else
    {
      (void) WriteBlobMSBShort(image,(unsigned short) (image->storage_class ==
        PseudoClass ? 8 : image->depth > 8 ? 16 : 8));

      if (((image_info->colorspace != UndefinedColorspace) ||
           (image->colorspace != CMYKColorspace)) &&
          (image_info->colorspace != CMYKColorspace))
        {
          (void) TransformImageColorspace(image,sRGBColorspace,exception);
          (void) WriteBlobMSBShort(image,(unsigned short)
            (image->storage_class == PseudoClass ? IndexedMode : RGBMode));
        }
      else
        {
          if (image->colorspace != CMYKColorspace)
            (void) TransformImageColorspace(image,CMYKColorspace,exception);
          (void) WriteBlobMSBShort(image,CMYKMode);
        }
    }
  if ((IsImageGray(image) != MagickFalse) ||
      (image->storage_class == DirectClass) || (image->colors > 256))
    (void) WriteBlobMSBLong(image,0);
  else
    {
      /*
        Write PSD raster colormap.
      */
      (void) WriteBlobMSBLong(image,768);
      for (i=0; i < (ssize_t) image->colors; i++)
        (void) WriteBlobByte(image,ScaleQuantumToChar(image->colormap[i].red));
      for ( ; i < 256; i++)
        (void) WriteBlobByte(image,0);
      for (i=0; i < (ssize_t) image->colors; i++)
        (void) WriteBlobByte(image,ScaleQuantumToChar(
          image->colormap[i].green));
      for ( ; i < 256; i++)
        (void) WriteBlobByte(image,0);
      for (i=0; i < (ssize_t) image->colors; i++)
        (void) WriteBlobByte(image,ScaleQuantumToChar(image->colormap[i].blue));
      for ( ; i < 256; i++)
        (void) WriteBlobByte(image,0);
    }
  /*
    Image resource block.
  */
  length=28; /* 0x03EB */
  bim_profile=(StringInfo *) GetImageProfile(image,"8bim");
  icc_profile=GetImageProfile(image,"icc");
  if (bim_profile != (StringInfo *) NULL)
    {
      bim_profile=CloneStringInfo(bim_profile);
      if (icc_profile != (StringInfo *) NULL)
        RemoveICCProfileFromResourceBlock(bim_profile);
      RemoveResolutionFromResourceBlock(bim_profile);
      length+=PSDQuantum(GetStringInfoLength(bim_profile));
    }
  if (icc_profile != (const StringInfo *) NULL)
    length+=PSDQuantum(GetStringInfoLength(icc_profile))+12;
  (void) WriteBlobMSBLong(image,(unsigned int) length);
  WriteResolutionResourceBlock(image);
  if (bim_profile != (StringInfo *) NULL)
    {
      (void) WriteBlob(image,GetStringInfoLength(bim_profile),
        GetStringInfoDatum(bim_profile));
      bim_profile=DestroyStringInfo(bim_profile);
    }
  if (icc_profile != (StringInfo *) NULL)
    {
      (void) WriteBlob(image,4,(const unsigned char *) "8BIM");
      (void) WriteBlobMSBShort(image,0x0000040F);
      (void) WriteBlobMSBShort(image,0);
      (void) WriteBlobMSBLong(image,(unsigned int) GetStringInfoLength(
        icc_profile));
      (void) WriteBlob(image,GetStringInfoLength(icc_profile),
        GetStringInfoDatum(icc_profile));
      if ((MagickOffsetType) GetStringInfoLength(icc_profile) !=
          PSDQuantum(GetStringInfoLength(icc_profile)))
        (void) WriteBlobByte(image,0);
    }
  if (status != MagickFalse)
    {
      MagickOffsetType
        size_offset;

      size_t
        size;

      size_offset=TellBlob(image);
      SetPSDSize(&psd_info,image,0);
      status=WritePSDLayersInternal(image,image_info,&psd_info,&size,
        exception);
      size_offset+=WritePSDSize(&psd_info,image,size+
        (psd_info.version == 1 ? 8 : 16),size_offset);
    }
  (void) WriteBlobMSBLong(image,0);  /* user mask data */
  /*
    Write composite image.
  */
  if (status != MagickFalse)
    {
      CompressionType
        compression;

      compression=image->compression;
      if (image->compression == ZipCompression)
        image->compression=RLECompression;
      if (WritePSDChannels(&psd_info,image_info,image,image,0,MagickFalse,
          exception) == 0)
        status=MagickFalse;
      image->compression=compression;
    }
  (void) CloseBlob(image);
  return(status);
}