public static Color YcbcrToRgb(YCbCr ycbcr)
{
double Y = ycbcr.Y, Cb = ycbcr.Cb, Cr = ycbcr.Cr;
byte r = (byte)Math.Max(0, Math.Min(255, (Y + 1.402 * (Cr - 128))));
byte g = (byte)Math.Max(0, Math.Min(255, (Y - 0.344136 * (Cb - 128) - 0.714136 * (Cr - 128))));
byte b = (byte)Math.Max(0, Math.Min(255, (Y + 1.772 * (Cb - 128))));
return(Color.FromArgb(r, g, b));
}
public static YCbCr[,] ReadYCbCrs(Bitmap image)
{
int w = image.Width, h = image.Height;
// convert rgb array to ycbcr
var ycbcrs = new YCbCr[h, w];
for (int row = 0; row < h; ++row)
{
for (int col = 0; col < w; ++col)
{
ycbcrs[row, col] = ColorChannel.RgbToYcbcr(image.GetPixel(col, row));
}
}
return(ycbcrs);
}
// duplicate cb cr channels to reproduce ycbcr pixels
public static YCbCr[,] UpSample(YCbCrSubSample chans)
{
int h = chans.Y.GetLength(0), w = chans.Y.GetLength(1);
YCbCr[,] yCbCrs = new YCbCr[h, w];
for (int row = 0; row < h; ++row)
{
for (int col = 0; col < w; ++col)
{
yCbCrs[row, col].Y = chans.Y[row, col];
// fill up the square with top left number
int subR = row >> 1, subC = col >> 1;
yCbCrs[row, col].Cb = chans.Cb[subR, subC];
yCbCrs[row, col].Cr = chans.Cr[subR, subC];
}
}
return(yCbCrs);
}
