public void Write(Chunk chunk)
{
Write(PngHelper.DWordToInt(chunk.Length));
Write(chunk.Type);
Write(chunk.Data,0,chunk.Data.Length);
Write(PngHelper.DWordToInt((int)Crc32.Calc(chunk.Type,chunk.Data)));
}
public static DateTime ConvertTIME(Chunk chunk)
{
byte[] data = chunk.Data;
int ofs = 0;
int year = WordToInt(BitConverter.ToUInt16(data,ofs)); ofs+=sizeof(Int16);
byte month = data[ofs++];
byte day = data[ofs++];
byte hour = data[ofs++];
byte min = data[ofs++];
byte sec = data[ofs++];
return new DateTime(year,month,day,hour,min,sec);
}
public static PngHeader ConvertIHDR(Chunk chunk)
{
byte[] data = chunk.Data;
int ofs = 0;
int columns = DWordToInt(BitConverter.ToInt32(data,ofs)); ofs += 4;
int rows = DWordToInt(BitConverter.ToInt32(data,ofs)); ofs += 4;
// bit depth: number of bits per channel
byte bitdepth = data[ofs++];
byte colormodel = data[ofs++];
byte compmeth = data[ofs++];
byte filmeth = data[ofs++];
byte interlaced = data[ofs++];
if(interlaced>0)
throw new NotSupportedException("interlaced png");
return new PngHeader(columns,rows,bitdepth,(ColorModel)colormodel);
}
public static RenderingIntent ConvertSRGB(Chunk chunk)
{
return (RenderingIntent)chunk.Data[0];
}