// 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);
}
// Save a PNG image to the specified stream.
public static void Save(Stream stream, Image 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);
}
