/*Converts a RGB bitmap to YCbCr*/
private void generateYcbcrBitmap(Bitmap uncompressed, ref double[,] Y, ref double[,] Cb, ref double[,] Cr) {
YCbCr[,] ycbcrPixels = new YCbCr[uncompressed.Width, uncompressed.Height];
Color pixel;
RGB rgb = new RGB();
for (int y = 0; y < ycbcrPixels.GetLength(1); y++)
{
for (int x = 0; x < ycbcrPixels.GetLength(0); x++)
{
if (x / 2 >= Cb.GetLength(0) || y / 2 >= Cb.GetLength(1)) continue;
pixel = uncompressed.GetPixel(x, y);
rgb.setRed(pixel.R);
rgb.setGreen(pixel.G);
rgb.setBlue(pixel.B);
ycbcrPixels[x, y] = convertRgbToYCbCr(rgb);
Y[x, y] = ycbcrPixels[x, y].getY();
Cb[x/2,y/2] = ycbcrPixels[x, y].getCb();
Cr[x/2, y/2] = ycbcrPixels[x, y].getCr();
}
}
}
/*Converts RGB pixel to YCbCr*/
private YCbCr convertRgbToYCbCr(RGB rgb) {
YCbCr output = new YCbCr();
output.setY(16+(rgb.getRed() * 0.257 + rgb.getGreen() * 0.504 + rgb.getBlue() * 0.098));
output.setCb(128+(rgb.getRed() * -0.148 + rgb.getGreen() * -0.291 + rgb.getBlue() * 0.439));
output.setCr(128+(rgb.getRed() * 0.439 + rgb.getGreen() * -0.368 + rgb.getBlue() * -0.071));
return output;
}
//------------------------------------------------------------------------------------------------------------------
/**
Old code for saving to custom fileType. not useable anymore.
**/
public void oldSavingStuff(double[,] Y) {
int width = Y.GetLength(0);
int height = Y.GetLength(1);
YCbCr[,] ycbcrPixels = new YCbCr[width,height];
Bitmap testBitmap = new Bitmap(width, height);
//testBitmap = generateRgbBitmap(ycbcrPixels);
testBitmap.Save("SubsampledImage.bmp", ImageFormat.Bmp);
byte[] bytesToSave = new byte[width * height * 3 + 8];
int byteOffset = 0;
RGB rgb = new RGB();
byte[] widthBytes = BitConverter.GetBytes(width);
byte[] heightBytes = BitConverter.GetBytes(height);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(widthBytes);
Array.Reverse(heightBytes);
}
//Saving image width to beginning of byte array.
for (int i = 0; i < widthBytes.Length; i++)
{
bytesToSave[byteOffset++] = widthBytes[i];
}
//saving image Height to beginning of byte array.
for (int i = 0; i < heightBytes.Length; i++)
{
bytesToSave[byteOffset++] = heightBytes[i];
}
//Saving image data to byte array.
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
rgb = convertYCbCrToRgb(1,2,3);
bytesToSave[y * width + x + byteOffset++] = (byte)rgb.getRed();
bytesToSave[y * width + x + byteOffset++] = (byte)rgb.getGreen();
bytesToSave[y * width + x + byteOffset] = (byte)rgb.getBlue();
//Debug.WriteLine(uncompressed.GetPixel(x,y));
//Debug.WriteLine(testBitmap.GetPixel(x,y));
}
}
File.WriteAllBytes("TestFile.cmpr", bytesToSave);
}
