A method for sharpening an image, the method including the steps of: (a)
receiving a data set including at least one colour plane indicative of
the image; and (b) extracting an initial luminance channel from the data
set, the initial luminance channel being in a colour space different to
that of the at least one colour plane; the method being characterized by
the further steps of: (c) sharpening the initial luminance channel to
form a revised luminance channel; and (d) adding the revised luminance
channel to at least one of the colour planes of the data set.