// Determine if an image only has indexed frames in it and
// that all frames have the same pixel format.
public static bool IsGifEncodable(PortableImage image)
{
int index;
Frame frame;
PixelFormat format = (PixelFormat)(-1);
if (image.NumFrames == 0)
{
return(false);
}
for (index = 0; index < image.NumFrames; ++index)
{
frame = image.GetFrame(index);
if ((frame.PixelFormat & PixelFormat.Indexed) == 0)
{
return(false);
}
if (format != (PixelFormat)(-1) &&
format != frame.PixelFormat)
{
return(false);
}
format = frame.PixelFormat;
}
return(true);
}
public PortableImage Reformat(PixelFormat newFormat)
{
PortableImage newImage = new PortableImage(this, newFormat);
for (int i = 0; i < frames.Length; i++)
newImage.AddFrame(frames[i].Reformat(newFormat));
return newImage;
}
private PortableImage(PortableImage image, PixelFormat format)
{
Width = image.Width;
Height = image.Height;
pixelFormat = image.pixelFormat;
LoadFormat = image.LoadFormat;
if (image.Palette != null)
{
Palette = (int[]) (image.Palette.Clone());
}
TransparentPixel = image.TransparentPixel;
}
public static void Load(Stream stream, PortableImage image)
{
// This just reads enough headers to set size.
var ms = new MemoryStream();
stream.CopyTo(ms);
var data = new ReadOnlySequence <byte>(ms.ToArray());
var decoder = new JpegDecoder();
decoder.SetInput(data);
decoder.Identify();
if (decoder.NumberOfComponents != 1 && decoder.NumberOfComponents != 3)
{
// We only support Grayscale and YCbCr.
throw new NotSupportedException("This color space is not supported");
}
image.Width = decoder.Width;
image.Height = decoder.Height;
image.LoadFormat = PortableImage.Jpeg;
image.imageFlags = decoder.NumberOfComponents == 1 ? ImageFlags.ColorSpaceGray : ImageFlags.ColorSpaceRgb;
/*
* // TODO: bring in the huge complexity that is the JPEG read/write format.
* // The PDF stuff doesn't need to read frames, so it would be neat to have this 'lazy'
* // Add a frame to the image object.
* Frame frame = image.AddFrame(image.Width, image.Height, PixelFormat.Format24bppRgb);
*
* if (decoder.Precision == 8)
* {
* // This is the most common case for JPEG, and we have an optimised implementation.
* decoder.SetOutputWriter(new JpegBufferOutputWriter8Bit(image.Width, image.Height, 3, frame.data));
* }
* else if (decoder.Precision < 8)
* {
* decoder.SetOutputWriter(new JpegBufferOutputWriterLessThan8Bit(image.Width, image.Height, decoder.Precision, 3, frame.data));
* }
* else
* {
* decoder.SetOutputWriter(new JpegBufferOutputWriterGreaterThan8Bit(image.Width, image.Height, decoder.Precision, 3, frame.data));
* }
*
* decoder.Decode();
* // TODO: our frame buffer should now be populated with Y,Cr,Cb data. It should get converted to RGB.
*/
}
// Stretch this image to a new size.
public PortableImage Stretch(int width, int height)
{
Width = width;
Height = height;
PortableImage newImage = null;
for (int i = 0; i < frames.Length; i++)
{
if (i == 0)
newImage = new PortableImage(this, frames[0].Scale(width, height));
else
newImage.AddFrame(frames[i].Scale(width, height));
}
return newImage;
}
// Save a BMP image to the specified stream.
public static void Save(Stream stream, PortableImage image)
{
byte[] buffer = new byte [1024];
int bitCount;
int offset;
int size;
// We can only save the first frame in BMP formats.
Frame frame = image.GetFrame(0);
if (frame == null)
{
return;
}
// Determine the size of the bitmap and the offset to it.
bitCount = Utils.FormatToBitCount(frame.pixelFormat);
size = frame.Stride * frame.Height;
offset = 14 + 40;
if (bitCount <= 8)
{
offset += (1 << bitCount) * 4;
}
// Build and write the BITMAPFILEHEADER structure.
buffer[0] = (byte)'B';
buffer[1] = (byte)'M';
Utils.WriteInt32(buffer, 2, offset + size);
buffer[6] = (byte)0;
buffer[7] = (byte)0;
buffer[8] = (byte)0;
buffer[9] = (byte)0;
Utils.WriteInt32(buffer, 10, offset);
stream.Write(buffer, 0, 14);
// Build and write the BITMAPINFO details.
SaveBitmapInfo(stream, frame, bitCount, size, buffer,
frame.Height);
// Write the bitmap data in the frame to the stream.
SaveBitmapData(stream, frame, false, false);
}
private PortableImage(PortableImage image, Frame thisFrameOnly) :
this(image, image.PixelFormat)
{
if (thisFrameOnly != null)
{
NumFrames = 1;
frames = new Frame [1];
frames[0] = thisFrameOnly.CloneFrame(this);
}
else
{
NumFrames = image.NumFrames;
if (image.frames != null)
{
int frame;
frames = new Frame [NumFrames];
for (frame = 0; frame < NumFrames; ++frame)
{
frames[frame] =
image.frames[frame].CloneFrame(this);
}
}
}
}
// Save a GIF image to the specified stream. This uses the "ungif"
// approach of writing uncompressed code samples to avoid infringing
// on the LZW patent. The patent may have expired already, but we
// aren't taking any chances. Use PNG instead - it compresses better.
public static void Save(Stream stream, PortableImage image)
{
byte[] buffer = new byte [1024];
Frame frame0, frame;
int bitCount, index;
int[] palette;
// Get the first frame in the image and the image's bit depth.
frame0 = image.GetFrame(0);
bitCount = Utils.FormatToBitCount(frame0.PixelFormat);
// Write the GIF file header.
buffer[0] = (byte)'G';
buffer[1] = (byte)'I';
buffer[2] = (byte)'F';
buffer[3] = (byte)'8';
buffer[4] = (byte)'9';
buffer[5] = (byte)'a';
Utils.WriteUInt16(buffer, 6, image.Width);
Utils.WriteUInt16(buffer, 8, image.Height);
buffer[10] = (byte)((bitCount - 1) |
((bitCount - 1) << 4) | 0x80);
if (frame0.TransparentPixel != -1)
{
// Use the transparent pixel as the background color.
buffer[11] = (byte)(frame0.TransparentPixel);
}
else
{
// Assume that index zero is the background color.
buffer[11] = (byte)0x00;
}
buffer[12] = (byte)0x00; // No aspect ratio specified.
stream.Write(buffer, 0, 13);
// Write the global color table, which is the palette
// for the first frame. We use local color tables only
// if the palette changes for subsequent frames.
palette = frame0.Palette;
WriteGifPalette(stream, palette, bitCount, buffer);
// Write out the frames.
for (index = 0; index < image.NumFrames; ++index)
{
// Get the object for this frame.
frame = image.GetFrame(index);
// Write a graphics control extension for transparencies.
if (frame.TransparentPixel != -1)
{
buffer[0] = (byte)0x21;
buffer[1] = (byte)0xF9;
buffer[2] = (byte)0x04;
buffer[3] = (byte)0x01;
buffer[4] = (byte)0x00;
buffer[5] = (byte)0x00;
buffer[6] = (byte)(frame.TransparentPixel);
buffer[7] = (byte)0x00;
stream.Write(buffer, 0, 8);
}
// Write the image descriptor header.
buffer[0] = (byte)0x2C;
Utils.WriteUInt16(buffer, 1, frame.OffsetX);
Utils.WriteUInt16(buffer, 3, frame.OffsetY);
Utils.WriteUInt16(buffer, 5, frame.Width);
Utils.WriteUInt16(buffer, 7, frame.Height);
if (frame.Palette != palette)
{
buffer[9] = (byte)((bitCount - 1) | 0x80);
}
else
{
buffer[9] = (byte)0x00;
}
stream.Write(buffer, 0, 10);
// Write the local color table if necessary.
if (frame.Palette != palette)
{
WriteGifPalette
(stream, frame.Palette, bitCount, buffer);
}
// Compress and output the frame's contents.
Compress(stream, buffer, bitCount, frame);
}
// Write the GIF file terminator.
buffer[0] = (byte)0x3B;
stream.Write(buffer, 0, 1);
}
// Save a PNG image to the specified stream.
public static void Save(Stream stream, PortableImage image)
{
Frame frame = image.GetFrame(0);
byte[] buffer = new byte [1024];
ChunkWriter writer = new ChunkWriter(stream);
int colorType, bitDepth;
int sigRed, sigGreen, sigBlue, sigAlpha;
int paletteSize, posn;
int[] palette;
ZlibCompressor compressor;
ScanlineWriter scanlineWriter;
OutputFunc func;
int y;
// Determine the color type and bit depth for the image.
sigRed = -1;
sigGreen = -1;
sigBlue = -1;
sigAlpha = -1;
paletteSize = 0;
switch (frame.PixelFormat)
{
case PixelFormat.Format16bppRgb555:
{
sigRed = 5;
sigGreen = 5;
sigBlue = 5;
colorType = 2;
bitDepth = 8;
}
break;
case PixelFormat.Format16bppRgb565:
{
sigRed = 5;
sigGreen = 6;
sigBlue = 5;
colorType = 2;
bitDepth = 8;
}
break;
case PixelFormat.Format24bppRgb:
case PixelFormat.Format32bppRgb:
{
colorType = 2;
bitDepth = 8;
}
break;
case PixelFormat.Format1bppIndexed:
{
colorType = 3;
bitDepth = 1;
paletteSize = 2;
}
break;
case PixelFormat.Format4bppIndexed:
{
colorType = 3;
bitDepth = 4;
paletteSize = 16;
}
break;
case PixelFormat.Format8bppIndexed:
{
colorType = 3;
bitDepth = 8;
paletteSize = 256;
}
break;
case PixelFormat.Format16bppArgb1555:
{
sigRed = 5;
sigGreen = 5;
sigBlue = 5;
sigAlpha = 1;
colorType = 6;
bitDepth = 8;
}
break;
case PixelFormat.Format32bppPArgb:
case PixelFormat.Format32bppArgb:
{
colorType = 6;
bitDepth = 8;
}
break;
case PixelFormat.Format16bppGrayScale:
{
colorType = 0;
bitDepth = 16;
}
break;
case PixelFormat.Format48bppRgb:
{
colorType = 2;
bitDepth = 16;
}
break;
case PixelFormat.Format64bppPArgb:
case PixelFormat.Format64bppArgb:
{
colorType = 6;
bitDepth = 16;
}
break;
default: throw new FormatException("unknown format");
}
// Write out the PNG magic number.
stream.Write(magic, 0, magic.Length);
// Write the header chunk.
Utils.WriteInt32B(buffer, 0, frame.Width);
Utils.WriteInt32B(buffer, 4, frame.Height);
buffer[8] = (byte)bitDepth;
buffer[9] = (byte)colorType;
buffer[10] = (byte)0; // Compression method.
buffer[11] = (byte)0; // Filter method.
buffer[12] = (byte)0; // Interlace method.
writer.Write(PngReader.IHDR, buffer, 0, 13);
// Write the significant bits chunk if necessary.
if (sigAlpha != -1)
{
buffer[0] = (byte)sigRed;
buffer[1] = (byte)sigGreen;
buffer[2] = (byte)sigBlue;
buffer[3] = (byte)sigAlpha;
writer.Write(PngReader.sBIT, buffer, 0, 4);
}
else if (sigRed != -1)
{
buffer[0] = (byte)sigRed;
buffer[1] = (byte)sigGreen;
buffer[2] = (byte)sigBlue;
writer.Write(PngReader.sBIT, buffer, 0, 3);
}
// Write the palette and transparency chunks.
if (paletteSize > 0)
{
Array.Clear(buffer, 0, buffer.Length);
palette = frame.Palette;
if (palette != null)
{
for (posn = 0; posn < palette.Length &&
posn < paletteSize; ++posn)
{
buffer[posn * 3] = (byte)(palette[posn] >> 16);
buffer[posn * 2 + 1] = (byte)(palette[posn] >> 8);
buffer[posn * 2 + 2] = (byte)(palette[posn]);
}
}
writer.Write(PngReader.PLTE, buffer, 0, paletteSize * 3);
if (frame.TransparentPixel >= 0 &&
frame.TransparentPixel < paletteSize)
{
for (posn = 0; posn < paletteSize; ++posn)
{
buffer[posn] = (byte)0xFF;
}
buffer[frame.TransparentPixel] = (byte)0x00;
writer.Write(PngReader.tRNS, buffer, 0,
frame.TransparentPixel + 1);
}
}
// Compress and write the scanlines to the output stream.
compressor = new ZlibCompressor(writer);
scanlineWriter = new ScanlineWriter
(compressor, frame.Width, frame.PixelFormat);
func = GetOutputFunc(frame.PixelFormat);
for (y = 0; y < frame.Height; ++y)
{
func(frame, y, scanlineWriter.Buffer);
scanlineWriter.FlushScanline();
}
compressor.Finish();
// Write the end chunk.
writer.Write(PngReader.IEND, buffer, 0, 0);
}
// Load a Windows icon image from the specified stream. The first
// 4 bytes have already been read and discarded. If "hotspots" is
// "true", then the image is actually a Windows cursor with hotspots.
public static void Load(Stream stream, PortableImage image, bool hotspots)
{
byte[] buffer = new byte [1024];
int offset = 4;
int numImages, index;
int width, height, bpp;
PixelFormat format;
Frame frame;
int[] palette;
int paletteCount;
int paletteIndex;
// Read the number of images in the file.
if (stream.Read(buffer, 0, 2) != 2)
{
throw new FormatException();
}
numImages = Utils.ReadUInt16(buffer, 0);
offset += 2;
// Read the resource directory.
int[] offsetList = new int [numImages];
int[] hotspotX = null;
int[] hotspotY = null;
if (hotspots)
{
hotspotX = new int[numImages];
hotspotY = new int[numImages];
}
for (index = 0; index < numImages; ++index)
{
if (stream.Read(buffer, 0, 16) != 16)
{
throw new FormatException();
}
offset += 16;
if (hotspots)
{
hotspotX[index] = Utils.ReadUInt16(buffer, 4);
hotspotY[index] = Utils.ReadUInt16(buffer, 6);
}
offsetList[index] = Utils.ReadInt32(buffer, 12);
}
// Read the contents of the images in the stream.
for (index = 0; index < numImages; ++index)
{
// Seek to the start of the image.
Utils.Seek(stream, offset, offsetList[index]);
offset = offsetList[index];
// Read the DIB header.
if (stream.Read(buffer, 0, 40) != 40)
{
throw new FormatException();
}
offset += 40;
width = Utils.ReadUInt16(buffer, 4);
// The DIB height is the mask and the bitmap.
height = Utils.ReadUInt16(buffer, 8) / 2;
bpp = Utils.ReadUInt16(buffer, 14);
if (bpp == 1)
{
format = PixelFormat.Format1bppIndexed;
}
else if (bpp == 4)
{
format = PixelFormat.Format4bppIndexed;
}
else if (bpp == 8)
{
format = PixelFormat.Format8bppIndexed;
}
else if (bpp == 24)
{
format = PixelFormat.Format24bppRgb;
}
else if (bpp == 32)
{
format = PixelFormat.Format32bppArgb;
}
else
{
throw new FormatException();
}
// Create a new frame for this icon.
frame = new Frame(image, width, height, format);
image.AddFrame(frame);
if (hotspots)
{
frame.HotspotX = hotspotX[index];
frame.HotspotY = hotspotY[index];
}
// Copy some of the format information up to the image.
if (frame.Width > image.Width)
{
image.Width = frame.Width;
}
if (frame.Height > image.Height)
{
image.Height = frame.Height;
}
if (image.NumFrames == 1)
{
image.PixelFormat = format;
}
// If indexed, get the palette.
if ((frame.pixelFormat & PixelFormat.Indexed) != 0)
{
paletteCount =
(1 << Utils.FormatToBitCount(frame.pixelFormat));
if (stream.Read(buffer, 0, paletteCount * 4)
!= paletteCount * 4)
{
throw new FormatException();
}
offset += paletteCount * 4;
palette = new int [paletteCount];
for (paletteIndex = 0; paletteIndex < paletteCount;
++paletteIndex)
{
palette[paletteIndex] = Utils.ReadBGR
(buffer, paletteIndex * 4);
}
frame.Palette = palette;
}
// Read the main part of the icon or cursor.
BmpReader.LoadBitmapData(stream, frame, false, true);
offset += frame.Height * frame.Stride;
// Read the mask.
BmpReader.LoadBitmapData(stream, frame, true, true);
offset += frame.Height * frame.MaskStride;
// Invert the mask, because we want 1 to mean "active".
InvertMask(frame);
}
// Set the appropriate load format.
if (hotspots)
{
image.LoadFormat = PortableImage.Cursor;
}
else
{
image.LoadFormat = PortableImage.Icon;
}
}
// Save a Windows icon image to the specified stream. If "hotspots"
// is "true", then the image is actually a Windows cursor with hotspots.
public static void Save(Stream stream, PortableImage image, bool hotspots)
{
byte[] buffer = new byte [1024];
int numImages = image.NumFrames;
int offset, index, size, bitCount;
int[] offsetList;
int[] sizeList;
Frame frame;
// Write the image header.
buffer[0] = 0;
buffer[1] = 0;
buffer[2] = (byte)(hotspots ? 2 : 1);
buffer[3] = 0;
Utils.WriteUInt16(buffer, 4, numImages);
stream.Write(buffer, 0, 6);
// Infer the starting offsets and sizes for each of the images.
offset = 6 + numImages * 16;
offsetList = new int [numImages];
sizeList = new int [numImages];
for (index = 0; index < numImages; ++index)
{
frame = image.GetFrame(index);
size = 40;
if ((frame.pixelFormat & PixelFormat.Indexed) != 0)
{
size +=
4 * (1 << Utils.FormatToBitCount(frame.pixelFormat));
}
size += frame.Height * (frame.Stride + frame.MaskStride);
offsetList[index] = offset;
sizeList[index] = size;
offset += size;
}
// Write the contents of the resource directory.
for (index = 0; index < image.NumFrames; ++index)
{
frame = image.GetFrame(index);
bitCount = Utils.FormatToBitCount(frame.pixelFormat);
buffer[0] = (byte)(frame.Width);
buffer[1] = (byte)(frame.Height);
buffer[2] = (byte)(1 << bitCount);
buffer[3] = 0;
if (hotspots)
{
Utils.WriteUInt16(buffer, 4, frame.HotspotX);
Utils.WriteUInt16(buffer, 6, frame.HotspotY);
}
else
{
Utils.WriteUInt16(buffer, 4, 0);
Utils.WriteUInt16(buffer, 6, 0);
}
Utils.WriteInt32(buffer, 8, sizeList[index]);
Utils.WriteInt32(buffer, 12, offsetList[index]);
stream.Write(buffer, 0, 16);
}
// Write each of the images.
for (index = 0; index < image.NumFrames; ++index)
{
frame = image.GetFrame(index);
bitCount = Utils.FormatToBitCount(frame.pixelFormat);
BmpWriter.SaveBitmapInfo
(stream, frame, bitCount,
(frame.Stride + frame.MaskStride) * frame.Height,
buffer, frame.Height * 2);
BmpWriter.SaveBitmapData(stream, frame, false, false);
BmpWriter.SaveBitmapData(stream, frame, true, true);
}
}
// Load a GIF image from the specified stream. The first 4 bytes
// have already been read and discarded. We always load GIF's
// as 8bpp because that makes it easier to handle decompression.
// GIF's with lower bit depths will be expanded appropriately.
public static void Load(Stream stream, PortableImage image)
{
byte[] buffer = new byte [1024];
int logicalWidth, logicalHeight;
int flags, bitCount, numColors, tag;
int[] palette;
int transparentPixel;
int imageWidth, imageHeight;
Frame frame;
// Read the rest of the GIF header and validate it.
if (stream.Read(buffer, 0, 9) != 9)
{
throw new FormatException();
}
if ((buffer[0] != (byte)'7' && buffer[0] != (byte)'9') ||
buffer[1] != (byte)'a')
{
throw new FormatException();
}
logicalWidth = Utils.ReadUInt16(buffer, 2);
logicalHeight = Utils.ReadUInt16(buffer, 4);
flags = buffer[6];
// buffer[7] is the background index, which we ignore.
// buffer[8] is the aspect ratio, which we ignore.
if (logicalWidth == 0 || logicalHeight == 0)
{
throw new FormatException();
}
// Set the global image information.
bitCount = (flags & 0x07) + 1;
numColors = (1 << bitCount);
image.Width = logicalWidth;
image.Height = logicalHeight;
image.PixelFormat = PixelFormat.Format8bppIndexed;
image.LoadFormat = PortableImage.Gif;
// Read the global color table, if present.
if ((flags & 0x80) != 0)
{
image.Palette = ReadGifPalette(stream, buffer, numColors);
}
// Process the image and extension blocks in the image.
transparentPixel = -1;
while (stream.Read(buffer, 0, 1) == 1)
{
tag = buffer[0];
if (tag == 0x2C)
{
// Read the image descriptor.
if (stream.Read(buffer, 0, 9) != 9)
{
throw new FormatException();
}
imageWidth = Utils.ReadUInt16(buffer, 4);
imageHeight = Utils.ReadUInt16(buffer, 6);
flags = buffer[8];
if (imageWidth == 0 || imageHeight == 0)
{
throw new FormatException();
}
frame = image.AddFrame(imageWidth, imageHeight,
image.PixelFormat);
frame.TransparentPixel = transparentPixel;
frame.OffsetX = Utils.ReadUInt16(buffer, 0);
frame.OffsetY = Utils.ReadUInt16(buffer, 2);
transparentPixel = -1;
// Read the local color table, if any.
if ((flags & 0x80) != 0)
{
tag = (1 << ((flags & 0x07) + 1));
frame.Palette = ReadGifPalette
(stream, buffer, tag);
}
// Decompress the image into the frame.
Decompress(stream, buffer, frame, (flags & 0x40) != 0);
}
else if (tag == 0x21)
{
// Process an extension.
if (stream.Read(buffer, 0, 1) != 1)
{
throw new FormatException();
}
if (buffer[0] == (byte)0xF9)
{
// Graphic control extension sub-block.
if (stream.Read(buffer, 0, 1) != 1)
{
throw new FormatException();
}
tag = buffer[0];
if (stream.Read(buffer, 0, tag) != tag)
{
throw new FormatException();
}
if (tag >= 4)
{
if ((buffer[0] & 0x01) != 0)
{
transparentPixel = buffer[3];
}
else
{
transparentPixel = -1;
}
}
}
// Skip the remaining extension sub-blocks.
SkipSubBlocks(stream, buffer);
}
else if (tag == 0x3B)
{
// End of the GIF file.
break;
}
else
{
// Invalid GIF file.
throw new FormatException();
}
}
}
// Load a BMP image from the specified stream. The first 4 bytes
// have already been read and discarded.
public static void Load(Stream stream, PortableImage image)
{
byte[] buffer = new byte [1024];
int width, height, planes, bitCount;
int compression;
bool quads;
// Read the rest of the BITMAPFILEHEADER.
if (stream.Read(buffer, 0, 10) != 10)
{
throw new FormatException();
}
int bfOffBits = Utils.ReadInt32(buffer, 6);
// The current file offset at the end of the BITMAPFILEHEADER.
int offset = 14;
// Get the size of the BITMAPINFOHEADER structure that follows,
// and then read it into the buffer.
if (stream.Read(buffer, 0, 4) != 4)
{
throw new FormatException();
}
int size = Utils.ReadInt32(buffer, 0);
if (size <= 4 || size > 1024)
{
throw new FormatException();
}
if (stream.Read(buffer, 4, size - 4) != (size - 4))
{
throw new FormatException();
}
offset += size;
if (size >= 40)
{
// This is a BITMAPINFOHEADER structure (Windows bitmaps).
width = Utils.ReadInt32(buffer, 4);
height = Utils.ReadInt32(buffer, 8);
planes = Utils.ReadUInt16(buffer, 12);
bitCount = Utils.ReadUInt16(buffer, 14);
compression = Utils.ReadInt32(buffer, 16);
quads = true;
}
else if (size == 12)
{
// This is a BITMAPCOREHEADER structure (OS/2 bitmaps).
width = Utils.ReadUInt16(buffer, 4);
height = Utils.ReadUInt16(buffer, 6);
planes = Utils.ReadUInt16(buffer, 8);
bitCount = Utils.ReadUInt16(buffer, 10);
compression = 0; // BI_RGB
quads = false;
}
else
{
throw new FormatException();
}
// Perform a sanity check on the header values.
if (width <= 0 || planes != 1)
{
throw new FormatException();
}
if (bitCount != 1 && bitCount != 4 && bitCount != 16 &&
bitCount != 8 && bitCount != 24)
{
// TODO: non-traditional BMP formats.
throw new FormatException();
}
if (compression != 0 && compression != 3 /*BI_BITFIELDS*/)
{
// TODO: RLE bitmaps
throw new FormatException();
}
// Set the basic image properties.
image.Width = width;
image.Height = height < 0 ? -height : height;
image.PixelFormat = Utils.BitCountToFormat(bitCount);
image.LoadFormat = PortableImage.Bmp;
// Do the unusual 16 bit formats.
if (compression == 3)
{
if (stream.Read(buffer, 0, 3 * 4) != (3 * 4))
{
throw new FormatException();
}
int redMask = Utils.ReadInt32(buffer, 0);
int greenMask = Utils.ReadInt32(buffer, 4);
int blueMask = Utils.ReadInt32(buffer, 8);
if (blueMask == 0x001F && redMask == 0x7C00 && greenMask == 0x03E0)
{
image.PixelFormat = PixelFormat.Format16bppRgb555;
}
else if (blueMask == 0x001F && redMask == 0xF800 && greenMask == 0x07E0)
{
image.PixelFormat = PixelFormat.Format16bppRgb565;
}
else
{
throw new FormatException();
}
}
// Read the palette into memory and set it.
if (bitCount <= 8)
{
int colors = (1 << bitCount);
int index;
int[] palette = new int [colors];
if (quads)
{
// The RGB values are specified as RGBQUAD's.
if (stream.Read(buffer, 0, colors * 4) != (colors * 4))
{
throw new FormatException();
}
offset += colors * 4;
for (index = 0; index < colors; ++index)
{
palette[index] = Utils.ReadBGR(buffer, index * 4);
}
}
else
{
// The RGB values are specified as RGBTRIPLE's.
if (stream.Read(buffer, 0, colors * 3) != (colors * 3))
{
throw new FormatException();
}
offset += colors * 3;
for (index = 0; index < colors; ++index)
{
palette[index] = Utils.ReadBGR(buffer, index * 3);
}
}
image.Palette = palette;
}
// Seek to the start of the bitmap data.
Utils.Seek(stream, offset, bfOffBits);
// Add a frame to the image object.
Frame frame = image.AddFrame();
// Load the bitmap data from the stream into the frame.
LoadBitmapData(stream, frame, false, height > 0);
}
