/// <summary>
/// Convert from RGB to YCbCr color space (Rec 601-1 specification).
/// </summary>
///
/// <param name="rgb">Source color in <b>RGB</b> color space.</param>
///
/// <returns>Returns <see cref="YCbCr"/> instance, which represents converted color value.</returns>
///
public static YCbCr FromRGB(RGB rgb)
{
YCbCr ycbcr = new YCbCr();
FromRGB(rgb, ycbcr);
return ycbcr;
}
/// <summary>
/// Convert from YCbCr to RGB color space.
/// </summary>
///
/// <param name="ycbcr">Source color in <b>YCbCr</b> color space.</param>
/// <param name="rgb">Destination color in <b>RGB</b> color spacs.</param>
///
public static void ToRGB(YCbCr ycbcr, RGB rgb)
{
// don't warry about zeros. compiler will remove them
float r = Math.Max(0.0f, Math.Min(1.0f, (float)(ycbcr.Y + 0.0000 * ycbcr.Cb + 1.4022 * ycbcr.Cr)));
float g = Math.Max(0.0f, Math.Min(1.0f, (float)(ycbcr.Y - 0.3456 * ycbcr.Cb - 0.7145 * ycbcr.Cr)));
float b = Math.Max(0.0f, Math.Min(1.0f, (float)(ycbcr.Y + 1.7710 * ycbcr.Cb + 0.0000 * ycbcr.Cr)));
rgb.Red = (byte)(r * 255);
rgb.Green = (byte)(g * 255);
rgb.Blue = (byte)(b * 255);
rgb.Alpha = 255;
}
/// <summary>
/// Convert from RGB to YCbCr color space (Rec 601-1 specification).
/// </summary>
///
/// <param name="rgb">Source color in <b>RGB</b> color space.</param>
/// <param name="ycbcr">Destination color in <b>YCbCr</b> color space.</param>
///
public static void FromRGB(RGB rgb, YCbCr ycbcr)
{
float r = (float)rgb.Red / 255;
float g = (float)rgb.Green / 255;
float b = (float)rgb.Blue / 255;
ycbcr.Y = (float)(0.2989 * r + 0.5866 * g + 0.1145 * b);
ycbcr.Cb = (float)(-0.1687 * r - 0.3313 * g + 0.5000 * b);
ycbcr.Cr = (float)(0.5000 * r - 0.4184 * g - 0.0816 * b);
}
