private bool CbCr(Color c)
        {
            YCbCr y = c.ToYCbCr();

            if (
                (y.cr <= 1.5682F * y.cb + 20) &
                (y.cr <= 0.3448F * y.cb + 76.2069F) &
                (y.cr <= -4.5652F * y.cb + 234.5652F) &
                (y.cr <= -1.15F * y.cb + 301.75F) &
                (y.cr <= -2.2857F * y.cb + 432.85F)
              )
                return true;
            else
                return false;
        }