/// <summary>
/// Convert an image to grayscale.
/// </summary>
/// <param name="src">The image buffer (RGBA pixels).</param>
/// <param name="srcPos">Initial position on the source buffer.</param>
/// <param name="width">The width of the image.</param>
/// <param name="height">The height of the image.</param>
/// <param name="stride">The distance, in bytes, between rows of the image buffer.</param>
static void GrayscaleImage(byte[] src, int srcPos, int width, int height, int stride)
{
int pos = srcPos;
for (int y = 0; y < height; y++, pos += stride - width * 4)
{
for (int x = 0; x < width; x++, pos += 4)
{
ColorRGBA srcColor = ColorRGBA.Read(src, pos);
ColorRGBA grayscaleColor = ColorRGBA.FromIntensityAlpha(srcColor.Intensity(), srcColor.a);
grayscaleColor.Write(src, pos);
}
}
}
public static ColorRGBA IA4ToColor(byte v)
{
return(ColorRGBA.FromIntensityAlpha(Bits4To8[v & 0x0F], Bits4To8[v >> 4]));
}
public static ColorRGBA I8ToColor(byte v)
{
return(ColorRGBA.FromIntensityAlpha(v, 0xFF));
}
public static ColorRGBA I4ToColor(byte v)
{
return(ColorRGBA.FromIntensityAlpha(Bits4To8[v], 0xFF));
}