An apparatus for sharpening an image, the apparatus including a processor adapted to receive a data set including at least one color plane indicative of the image; and the processor extracting an initial luminance channel from the data set, the initial luminance channel being in a color space different to that of the at least one color plane; the processor sharpening the initial luminance channel to form a revised luminance channel; and the processor adding the revised luminance channel to at least one of the color planes of the data set.