// yet
private void WriteChunkIHDR()
{
byte[] temp4Bytes = new byte[4];
byte[] buf = new byte[13];
switch (colorType)
{
case PNG.PNG_COLOR_TYPE_RGB:
if (bitDepth != 8 && bitDepth != 16)
{
throw new Exception("Invalid bit depth for RGB image.");
}
break;
default:
throw new Exception("Can't deal with color type without RGB.");
}
// actually, need to verify these parameter
// colorType, bitDepth, compressionMethod, filterMethod, interlaceMethod
PNGUtil.GetBigEndian32(temp4Bytes, (uint)width);
Array.Copy(temp4Bytes, 0, buf, 0, temp4Bytes.Length);
PNGUtil.GetBigEndian32(temp4Bytes, (uint)height);
Array.Copy(temp4Bytes, 0, buf, 4, temp4Bytes.Length);
buf[8] = bitDepth;
buf[9] = colorType;
buf[10] = compressionMethod;
buf[11] = filterMethod;
buf[12] = interlaceMethod;
WriteChunk(PNGUtil.chunkNameIHDR, buf);
}
// yet
private void WriteChunk(byte[] chunkName, byte[] data)
{
byte[] temp4Bytes = new byte[4];
PNGUtil.GetBigEndian32(temp4Bytes, (uint)data.Length);
dataStream.Write(temp4Bytes, 0, temp4Bytes.Length);
dataStream.Write(chunkName, 0, chunkName.Length);
dataStream.Write(data, 0, data.Length);
uint crc = CRCChecker.CRC(chunkName, data);
PNGUtil.GetBigEndian32(temp4Bytes, crc);
dataStream.Write(temp4Bytes, 0, temp4Bytes.Length);
}