public static Bitmap ExtractWatermarkUsingYiq(Bitmap targetImage, Bitmap watermarkImage)
{
var(redTarget, greenTarget, blueTarget) = BitmapUtils.GetRGB(targetImage);
var(redWatermark, greenWatermark, blueWatermark) = BitmapUtils.GetRGB(watermarkImage);
var(yTarget, iTarget, qTarget) = ColorConverter.ConvertRgbToYiq(redTarget, greenTarget, blueTarget);
var grayscaleWatermark = TransformColorSpaceIntoGreyscale(redWatermark);
return(ExtractDwtDctWatermark(iTarget, grayscaleWatermark));
}
private static Bitmap ConvertYiqColorToImage(double[,] y, double[,] i, double[,] q)
{
var width = y.GetLength(0);
var height = y.GetLength(1);
var watermarkedImage = new Bitmap(width, height);
var(watermarkedR, watermarkedG, watermarkedB) = ColorConverter.ConvertYiqToRgb(y, i, q);
for (var k = 0; k < height; k++)
{
for (var j = 0; j < width; j++)
{
var red = BitmapUtils.NormalizePixelValue(watermarkedR[k, j]);
var green = BitmapUtils.NormalizePixelValue(watermarkedG[k, j]);
var blue = BitmapUtils.NormalizePixelValue(watermarkedB[k, j]);
watermarkedImage.SetPixel(k, j, Color.FromArgb(0, red, green, blue));
}
}
return(watermarkedImage);
}