public static PixelValue CopyPixel(this BitmapSource bs, int x, int y)
{
if (bs == null)
{
throw new ArgumentNullException(nameof(bs) + " is null.");
}
if (x >= bs.PixelWidth || x < 0)
{
throw new ArgumentOutOfRangeException(nameof(x));
}
if (y >= bs.PixelHeight || y < 0)
{
throw new ArgumentOutOfRangeException(nameof(y));
}
var chn = bs.GetChannelCount();
var value = new byte[chn];
Array.Clear(value, 0, value.Length);
bs.CopyPixels(
new Int32Rect(x, y, 1, 1),
value,
(bs.Format.BitsPerPixel * bs.PixelWidth + 7) / 8,
0);
var pixelValue = new PixelValue
{
Alpha = PixelValue.AlphaDefault
};
switch (chn)
{
case 1:
pixelValue.Red = pixelValue.Green = pixelValue.Blue = value[0];
break;
case 3:
pixelValue.Red = value[2];
pixelValue.Green = value[1];
pixelValue.Blue = value[0];
break;
case 4:
pixelValue.Red = value[2];
pixelValue.Green = value[1];
pixelValue.Blue = value[0];
pixelValue.Alpha = value[3];
break;
default:
throw new NotImplementedException();
}
return(pixelValue);
}
