Commit message: https://github.com/ImageMagick/ImageMagick/issues/1178
CVE: CVE-2018-12600
CWE: CWE-787
Vulnerability description: In ImageMagick 7.0.8-3 Q16, ReadDIBImage and WriteDIBImage in coders/dib.c allow attackers to cause an out of bounds write via a crafted file.

Project: ImageMagick
File: dib.c

static Image *ReadDIBImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  DIBInfo
    dib_info;

  Image
    *image;

  MagickBooleanType
    status;

  MemoryInfo
    *pixel_info;

  Quantum
    index;

  register ssize_t
    x;

  register Quantum
    *q;

  register ssize_t
    i;

  register unsigned char
    *p;

  size_t
    bytes_per_line,
    length;

  ssize_t
    bit,
    count,
    y;


  unsigned char
    *pixels;

  /*
    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);
    }
  /*
    Determine if this a DIB file.
  */
  (void) memset(&dib_info,0,sizeof(dib_info));
  dib_info.size=ReadBlobLSBLong(image);
  if (dib_info.size != 40)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  /*
    Microsoft Windows 3.X DIB image file.
  */
  dib_info.width=ReadBlobLSBSignedLong(image);
  dib_info.height=ReadBlobLSBSignedLong(image);
  dib_info.planes=ReadBlobLSBShort(image);
  dib_info.bits_per_pixel=ReadBlobLSBShort(image);
  if (dib_info.bits_per_pixel > 32)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  dib_info.compression=ReadBlobLSBLong(image);
  dib_info.image_size=ReadBlobLSBLong(image);
  dib_info.x_pixels=ReadBlobLSBLong(image);
  dib_info.y_pixels=ReadBlobLSBLong(image);
  dib_info.number_colors=ReadBlobLSBLong(image);
  dib_info.colors_important=ReadBlobLSBLong(image);
  if ((dib_info.bits_per_pixel != 1) && (dib_info.bits_per_pixel != 4) &&
      (dib_info.bits_per_pixel != 8) && (dib_info.bits_per_pixel != 16) &&
      (dib_info.bits_per_pixel != 24) && (dib_info.bits_per_pixel != 32))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  if ((dib_info.compression == BI_BITFIELDS) &&
      ((dib_info.bits_per_pixel == 16) || (dib_info.bits_per_pixel == 32)))
    {
      dib_info.red_mask=(unsigned short) ReadBlobLSBLong(image);
      dib_info.green_mask=(unsigned short) ReadBlobLSBLong(image);
      dib_info.blue_mask=(unsigned short) ReadBlobLSBLong(image);
    }
  if (EOFBlob(image) != MagickFalse)
    ThrowReaderException(CorruptImageError,"UnexpectedEndOfFile");
  if (dib_info.width <= 0)
    ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
  if (dib_info.height == 0)
    ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
  if (dib_info.planes != 1)
    ThrowReaderException(CorruptImageError,"StaticPlanesValueNotEqualToOne");
  if ((dib_info.bits_per_pixel != 1) && (dib_info.bits_per_pixel != 4) &&
      (dib_info.bits_per_pixel != 8) && (dib_info.bits_per_pixel != 16) &&
      (dib_info.bits_per_pixel != 24) && (dib_info.bits_per_pixel != 32))
    ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
  if ((dib_info.bits_per_pixel < 16) &&
      (dib_info.number_colors > (unsigned int) (1UL << dib_info.bits_per_pixel)))
    ThrowReaderException(CorruptImageError,"UnrecognizedNumberOfColors");
  if ((dib_info.compression == 1) && (dib_info.bits_per_pixel != 8))
    ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
  if ((dib_info.compression == 2) && (dib_info.bits_per_pixel != 4))
    ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
  if ((dib_info.compression == 3) && (dib_info.bits_per_pixel < 16))
    ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
  switch (dib_info.compression)
  {
    case BI_RGB:
    case BI_RLE8:
    case BI_RLE4:
    case BI_BITFIELDS:
      break;
    case BI_JPEG:
      ThrowReaderException(CoderError,"JPEGCompressNotSupported");
    case BI_PNG:
      ThrowReaderException(CoderError,"PNGCompressNotSupported");
    default:
      ThrowReaderException(CorruptImageError,"UnrecognizedImageCompression");
  }
  image->columns=(size_t) MagickAbsoluteValue((ssize_t) dib_info.width);
  image->rows=(size_t) MagickAbsoluteValue((ssize_t) dib_info.height);
  image->depth=8;
  image->alpha_trait=dib_info.bits_per_pixel == 32 ? BlendPixelTrait :
    UndefinedPixelTrait;
  if ((dib_info.number_colors > 256) || (dib_info.colors_important > 256))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  if ((dib_info.number_colors != 0) || (dib_info.bits_per_pixel < 16))
    {
      size_t
        one;

      image->storage_class=PseudoClass;
      image->colors=dib_info.number_colors;
      one=1;
      if (image->colors == 0)
        image->colors=one << dib_info.bits_per_pixel;
    }
  if (image_info->size)
    {
      RectangleInfo
        geometry;

      MagickStatusType
        flags;

      flags=ParseAbsoluteGeometry(image_info->size,&geometry);
      if (flags & WidthValue)
        if ((geometry.width != 0) && (geometry.width < image->columns))
          image->columns=geometry.width;
      if (flags & HeightValue)
        if ((geometry.height != 0) && (geometry.height < image->rows))
          image->rows=geometry.height;
    }
  status=SetImageExtent(image,image->columns,image->rows,exception);
  if (status == MagickFalse)
    return(DestroyImageList(image));
  if (image->storage_class == PseudoClass)
    {
      size_t
        packet_size;

      unsigned char
        *dib_colormap;

      /*
        Read DIB raster colormap.
      */
      if (AcquireImageColormap(image,image->colors,exception) == MagickFalse)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      length=(size_t) image->colors;
      dib_colormap=(unsigned char *) AcquireQuantumMemory(length,
        4*sizeof(*dib_colormap));
      if (dib_colormap == (unsigned char *) NULL)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      packet_size=4;
      count=ReadBlob(image,packet_size*image->colors,dib_colormap);
      if (count != (ssize_t) (packet_size*image->colors))
        {
          dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
          ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
        }
      p=dib_colormap;
      for (i=0; i < (ssize_t) image->colors; i++)
      {
        image->colormap[i].blue=(MagickRealType) ScaleCharToQuantum(*p++);
        image->colormap[i].green=(MagickRealType) ScaleCharToQuantum(*p++);
        image->colormap[i].red=(MagickRealType) ScaleCharToQuantum(*p++);
        if (packet_size == 4)
          p++;
      }
      dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
    }
  /*
    Read image data.
  */
  if (dib_info.compression == BI_RLE4)
    dib_info.bits_per_pixel<<=1;
  bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
  length=bytes_per_line*image->rows;
  pixel_info=AcquireVirtualMemory((size_t) image->rows,MagickMax(
    bytes_per_line,image->columns+256UL)*sizeof(*pixels));
  if (pixel_info == (MemoryInfo *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
  pixels=(unsigned char *) GetVirtualMemoryBlob(pixel_info);
  if ((dib_info.compression == BI_RGB) ||
      (dib_info.compression == BI_BITFIELDS))
    {
      count=ReadBlob(image,length,pixels);
      if (count != (ssize_t) (length))
        {
          pixel_info=RelinquishVirtualMemory(pixel_info);
          ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
        }
    }
  else
    {
      /*
        Convert run-length encoded raster pixels.
      */
      status=DecodeImage(image,dib_info.compression ? MagickTrue : MagickFalse,
        pixels,image->columns*image->rows);
      if (status == MagickFalse)
        {
          pixel_info=RelinquishVirtualMemory(pixel_info);
          ThrowReaderException(CorruptImageError,
            "UnableToRunlengthDecodeImage");
        }
    }
  /*
    Initialize image structure.
  */
  image->units=PixelsPerCentimeterResolution;
  image->resolution.x=(double) dib_info.x_pixels/100.0;
  image->resolution.y=(double) dib_info.y_pixels/100.0;
  /*
    Convert DIB raster image to pixel packets.
  */
  switch (dib_info.bits_per_pixel)
  {
    case 1:
    {
      /*
        Convert bitmap scanline.
      */
      for (y=(ssize_t) image->rows-1; y >= 0; y--)
      {
        p=pixels+(image->rows-y-1)*bytes_per_line;
        q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < ((ssize_t) image->columns-7); x+=8)
        {
          for (bit=0; bit < 8; bit++)
          {
            index=(Quantum) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
            SetPixelIndex(image,index,q);
            q+=GetPixelChannels(image);
          }
          p++;
        }
        if ((image->columns % 8) != 0)
          {
            for (bit=0; bit < (ssize_t) (image->columns % 8); bit++)
            {
              index=(Quantum) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
              SetPixelIndex(image,index,q);
              q+=GetPixelChannels(image);
            }
            p++;
          }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
              image->rows-y-1,image->rows);
            if (status == MagickFalse)
              break;
          }
      }
      (void) SyncImage(image,exception);
      break;
    }
    case 4:
    {
      /*
        Convert PseudoColor scanline.
      */
      for (y=(ssize_t) image->rows-1; y >= 0; y--)
      {
        p=pixels+(image->rows-y-1)*bytes_per_line;
        q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < ((ssize_t) image->columns-1); x+=2)
        {
          index=(Quantum) ConstrainColormapIndex(image,(ssize_t) (*p >> 4) &
            0xf,exception);
          SetPixelIndex(image,index,q);
          q+=GetPixelChannels(image);
          index=(Quantum) ConstrainColormapIndex(image,(ssize_t) *p & 0xf,
            exception);
          SetPixelIndex(image,index,q);
          p++;
          q+=GetPixelChannels(image);
        }
        if ((image->columns % 2) != 0)
          {
            index=(Quantum) ConstrainColormapIndex(image,(ssize_t) (*p >> 4) &
              0xf,exception);
            SetPixelIndex(image,index,q);
            q+=GetPixelChannels(image);
            p++;
          }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
              image->rows-y-1,image->rows);
            if (status == MagickFalse)
              break;
          }
      }
      (void) SyncImage(image,exception);
      break;
    }
    case 8:
    {
      /*
        Convert PseudoColor scanline.
      */
      if ((dib_info.compression == BI_RLE8) ||
          (dib_info.compression == BI_RLE4))
        bytes_per_line=image->columns;
      for (y=(ssize_t) image->rows-1; y >= 0; y--)
      {
        p=pixels+(image->rows-y-1)*bytes_per_line;
        q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          index=(Quantum) ConstrainColormapIndex(image,(ssize_t) *p,exception);
          SetPixelIndex(image,index,q);
          p++;
          q+=GetPixelChannels(image);
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
              image->rows-y-1,image->rows);
            if (status == MagickFalse)
              break;
          }
      }
      (void) SyncImage(image,exception);
      break;
    }
    case 16:
    {
      unsigned short
        word;

      /*
        Convert PseudoColor scanline.
      */
      image->storage_class=DirectClass;
      if (dib_info.compression == BI_RLE8)
        bytes_per_line=2*image->columns;
      for (y=(ssize_t) image->rows-1; y >= 0; y--)
      {
        p=pixels+(image->rows-y-1)*bytes_per_line;
        q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          word=(*p++);
          word|=(*p++ << 8);
          if (dib_info.red_mask == 0)
            {
              SetPixelRed(image,ScaleCharToQuantum(ScaleColor5to8(
                (unsigned char) ((word >> 10) & 0x1f))),q);
              SetPixelGreen(image,ScaleCharToQuantum(ScaleColor5to8(
                (unsigned char) ((word >> 5) & 0x1f))),q);
              SetPixelBlue(image,ScaleCharToQuantum(ScaleColor5to8(
                (unsigned char) (word & 0x1f))),q);
            }
          else
            {
              SetPixelRed(image,ScaleCharToQuantum(ScaleColor5to8(
                (unsigned char) ((word >> 11) & 0x1f))),q);
              SetPixelGreen(image,ScaleCharToQuantum(ScaleColor6to8(
                (unsigned char) ((word >> 5) & 0x3f))),q);
              SetPixelBlue(image,ScaleCharToQuantum(ScaleColor5to8(
                (unsigned char) (word & 0x1f))),q);
            }
          q+=GetPixelChannels(image);
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
              image->rows-y-1,image->rows);
            if (status == MagickFalse)
              break;
          }
      }
      break;
    }
    case 24:
    case 32:
    {
      /*
        Convert DirectColor scanline.
      */
      for (y=(ssize_t) image->rows-1; y >= 0; y--)
      {
        p=pixels+(image->rows-y-1)*bytes_per_line;
        q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          SetPixelBlue(image,ScaleCharToQuantum(*p++),q);
          SetPixelGreen(image,ScaleCharToQuantum(*p++),q);
          SetPixelRed(image,ScaleCharToQuantum(*p++),q);
          if (image->alpha_trait != UndefinedPixelTrait)
            SetPixelAlpha(image,ScaleCharToQuantum(*p++),q);
          q+=GetPixelChannels(image);
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
              image->rows-y-1,image->rows);
            if (status == MagickFalse)
              break;
          }
      }
      break;
    }
    default:
      pixel_info=RelinquishVirtualMemory(pixel_info);
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  }
  pixel_info=RelinquishVirtualMemory(pixel_info);
  if (strcmp(image_info->magick,"ICODIB") == 0)
    {
      int
        c;

      /*
        Handle ICO mask.
      */
      image->storage_class=DirectClass;
      image->alpha_trait=BlendPixelTrait;
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        register ssize_t
          x;

        register Quantum
          *magick_restrict q;

        q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < ((ssize_t) image->columns-7); x+=8)
        {
          c=ReadBlobByte(image);
          for (bit=0; bit < 8; bit++)
            SetPixelAlpha(image,c & (0x80 >> bit) ? TransparentAlpha :
              OpaqueAlpha,q+x*GetPixelChannels(image)+bit);
        }
        if ((image->columns % 8) != 0)
          {
            c=ReadBlobByte(image);
            for (bit=0; bit < (ssize_t) (image->columns % 8); bit++)
              SetPixelAlpha(image,c & (0x80 >> bit) ? TransparentAlpha :
                OpaqueAlpha,q+x*GetPixelChannels(image)+bit);
          }
        if (image->columns % 32)
          for (x=0; x < (ssize_t) ((32-(image->columns % 32))/8); x++)
            c=ReadBlobByte(image);
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
      }
    }
  if (EOFBlob(image) != MagickFalse)
    ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
      image->filename);
  if (dib_info.height < 0)
    {
      Image
        *flipped_image;

      /*
        Correct image orientation.
      */
      flipped_image=FlipImage(image,exception);
      if (flipped_image != (Image *) NULL)
        {
          DuplicateBlob(flipped_image,image);
          image=DestroyImage(image);
          image=flipped_image;
        }
    }
  (void) CloseBlob(image);
  return(GetFirstImageInList(image));
}

Project: ImageMagick
File: dib.c

static MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image,
  ExceptionInfo *exception)
{
  DIBInfo
    dib_info;

  MagickBooleanType
    status;

  register const Quantum
    *p;

  register ssize_t
    i,
    x;

  register unsigned char
    *q;

  size_t
    bytes_per_line;

  ssize_t
    y;

  unsigned char
    *dib_data,
    *pixels;

  /*
    Open output 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);
  /*
    Initialize DIB raster file header.
  */
  (void) TransformImageColorspace(image,sRGBColorspace,exception);
  if (image->storage_class == DirectClass)
    {
      /*
        Full color DIB raster.
      */
      dib_info.number_colors=0;
      dib_info.bits_per_pixel=(unsigned short) (image->alpha_trait ? 32 : 24);
    }
  else
    {
      /*
        Colormapped DIB raster.
      */
      dib_info.bits_per_pixel=8;
      if (image_info->depth > 8)
        dib_info.bits_per_pixel=16;
      if (SetImageMonochrome(image,exception) != MagickFalse)
        dib_info.bits_per_pixel=1;
      dib_info.number_colors=(unsigned int) (dib_info.bits_per_pixel == 16 ? 0 :
        (1UL << dib_info.bits_per_pixel));
    }
  bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
  dib_info.size=40;
  dib_info.width=(int) image->columns;
  dib_info.height=(int) image->rows;
  dib_info.planes=1;
  dib_info.compression=(unsigned int) (dib_info.bits_per_pixel == 16 ?
    BI_BITFIELDS : BI_RGB);
  dib_info.image_size=(unsigned int) (bytes_per_line*image->rows);
  dib_info.x_pixels=75*39;
  dib_info.y_pixels=75*39;
  switch (image->units)
  {
    case UndefinedResolution:
    case PixelsPerInchResolution:
    {
      dib_info.x_pixels=(unsigned int) (100.0*image->resolution.x/2.54);
      dib_info.y_pixels=(unsigned int) (100.0*image->resolution.y/2.54);
      break;
    }
    case PixelsPerCentimeterResolution:
    {
      dib_info.x_pixels=(unsigned int) (100.0*image->resolution.x);
      dib_info.y_pixels=(unsigned int) (100.0*image->resolution.y);
      break;
    }
  }
  dib_info.colors_important=dib_info.number_colors;
  /*
    Convert MIFF to DIB raster pixels.
  */
  pixels=(unsigned char *) AcquireQuantumMemory(dib_info.image_size,
    sizeof(*pixels));
  if (pixels == (unsigned char *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
  (void) memset(pixels,0,dib_info.image_size);
  switch (dib_info.bits_per_pixel)
  {
    case 1:
    {
      register unsigned char
        bit,
        byte;

      /*
        Convert PseudoClass image to a DIB monochrome image.
      */
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        p=GetVirtualPixels(image,0,y,image->columns,1,exception);
        if (p == (const Quantum *) NULL)
          break;
        q=pixels+(image->rows-y-1)*bytes_per_line;
        bit=0;
        byte=0;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          byte<<=1;
          byte|=GetPixelIndex(image,p) != 0 ? 0x01 : 0x00;
          bit++;
          if (bit == 8)
            {
              *q++=byte;
              bit=0;
              byte=0;
            }
           p+=GetPixelChannels(image);
         }
         if (bit != 0)
           {
             *q++=(unsigned char) (byte << (8-bit));
             x++;
           }
        for (x=(ssize_t) (image->columns+7)/8; x < (ssize_t) bytes_per_line; x++)
          *q++=0x00;
        status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      break;
    }
    case 8:
    {
      /*
        Convert PseudoClass packet to DIB pixel.
      */
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        p=GetVirtualPixels(image,0,y,image->columns,1,exception);
        if (p == (const Quantum *) NULL)
          break;
        q=pixels+(image->rows-y-1)*bytes_per_line;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          *q++=(unsigned char) GetPixelIndex(image,p);
          p+=GetPixelChannels(image);
        }
        for ( ; x < (ssize_t) bytes_per_line; x++)
          *q++=0x00;
        status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      break;
    }
    case 16:
    {
      unsigned short
        word;
      /*
        Convert PseudoClass packet to DIB pixel.
      */
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        p=GetVirtualPixels(image,0,y,image->columns,1,exception);
        if (p == (const Quantum *) NULL)
          break;
        q=pixels+(image->rows-y-1)*bytes_per_line;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          word=(unsigned short) ((ScaleColor8to5((unsigned char)
            ScaleQuantumToChar(GetPixelRed(image,p))) << 11) | (ScaleColor8to6(
            (unsigned char) ScaleQuantumToChar(GetPixelGreen(image,p))) << 5) |
            (ScaleColor8to5((unsigned char) ScaleQuantumToChar((unsigned char)
            GetPixelBlue(image,p)) << 0)));
          *q++=(unsigned char)(word & 0xff);
          *q++=(unsigned char)(word >> 8);
          p+=GetPixelChannels(image);
        }
        for (x=(ssize_t) (2*image->columns); x < (ssize_t) bytes_per_line; x++)
          *q++=0x00;
        status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      break;
    }
    case 24:
    case 32:
    {
      /*
        Convert DirectClass packet to DIB RGB pixel.
      */
      for (y=0; y < (ssize_t) image->rows; y++)
      {
        p=GetVirtualPixels(image,0,y,image->columns,1,exception);
        if (p == (const Quantum *) NULL)
          break;
        q=pixels+(image->rows-y-1)*bytes_per_line;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          *q++=ScaleQuantumToChar(GetPixelBlue(image,p));
          *q++=ScaleQuantumToChar(GetPixelGreen(image,p));
          *q++=ScaleQuantumToChar(GetPixelRed(image,p));
          if (image->alpha_trait != UndefinedPixelTrait)
            *q++=ScaleQuantumToChar(GetPixelAlpha(image,p));
          p+=GetPixelChannels(image);
        }
        if (dib_info.bits_per_pixel == 24)
          for (x=(ssize_t) (3*image->columns); x < (ssize_t) bytes_per_line; x++)
            *q++=0x00;
        status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      break;
    }
  }
  if (dib_info.bits_per_pixel == 8)
    if (image_info->compression != NoCompression)
      {
        size_t
          length;

        /*
          Convert run-length encoded raster pixels.
        */
        length=2UL*(bytes_per_line+2UL)+2UL;
        dib_data=(unsigned char *) AcquireQuantumMemory(length,
          (image->rows+2UL)*sizeof(*dib_data));
        if (dib_data == (unsigned char *) NULL)
          {
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
          }
        dib_info.image_size=(unsigned int) EncodeImage(image,bytes_per_line,
          pixels,dib_data);
        pixels=(unsigned char *) RelinquishMagickMemory(pixels);
        pixels=dib_data;
        dib_info.compression = BI_RLE8;
      }
  /*
    Write DIB header.
  */
  (void) WriteBlobLSBLong(image,dib_info.size);
  (void) WriteBlobLSBLong(image,(unsigned int) dib_info.width);
  (void) WriteBlobLSBLong(image,(unsigned int) dib_info.height);
  (void) WriteBlobLSBShort(image,(unsigned short) dib_info.planes);
  (void) WriteBlobLSBShort(image,dib_info.bits_per_pixel);
  (void) WriteBlobLSBLong(image,dib_info.compression);
  (void) WriteBlobLSBLong(image,dib_info.image_size);
  (void) WriteBlobLSBLong(image,dib_info.x_pixels);
  (void) WriteBlobLSBLong(image,dib_info.y_pixels);
  (void) WriteBlobLSBLong(image,dib_info.number_colors);
  (void) WriteBlobLSBLong(image,dib_info.colors_important);
  if (image->storage_class == PseudoClass)
    {
      if (dib_info.bits_per_pixel <= 8)
        {
          unsigned char
            *dib_colormap;

          /*
            Dump colormap to file.
          */
          dib_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
            (1UL << dib_info.bits_per_pixel),4*sizeof(*dib_colormap));
          if (dib_colormap == (unsigned char *) NULL)
            ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
          q=dib_colormap;
          for (i=0; i < (ssize_t) MagickMin(image->colors,dib_info.number_colors); i++)
          {
            *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].blue));
            *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].green));
            *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].red));
            *q++=(Quantum) 0x0;
          }
          for ( ; i < (ssize_t) (1L << dib_info.bits_per_pixel); i++)
          {
            *q++=(Quantum) 0x0;
            *q++=(Quantum) 0x0;
            *q++=(Quantum) 0x0;
            *q++=(Quantum) 0x0;
          }
          (void) WriteBlob(image,(size_t) (4*(1 << dib_info.bits_per_pixel)),
            dib_colormap);
          dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
        }
      else
        if ((dib_info.bits_per_pixel == 16) &&
            (dib_info.compression == BI_BITFIELDS))
          {
            (void) WriteBlobLSBLong(image,0xf800);
            (void) WriteBlobLSBLong(image,0x07e0);
            (void) WriteBlobLSBLong(image,0x001f);
          }
    }
  (void) WriteBlob(image,dib_info.image_size,pixels);
  pixels=(unsigned char *) RelinquishMagickMemory(pixels);
  (void) CloseBlob(image);
  return(MagickTrue);
}