pub fn index_colors<Pix, Map>(
    image: &ImageBuffer<Pix, Vec<u8>>,
    color_map: &Map
) -> ImageBuffer<Luma<u8>, Vec<u8>>
where Map: ColorMap<Color = Pix> + ?Sized, Pix: Pixel<Subpixel = u8> + 'static,
Expand description

Reduces the colors using the supplied color_map and returns an image of the indices