1. A method for processing a source digital image, comprising the steps of: accessing the source digital image comprised of a plurality of pixels; applying a spatial filter to the source digital image to produce an enhanced digital image; applying an inverse spatial filter to the enhanced digital image to produce an estimated digital image, the inverse spatial filter being matched to the spatial filter; and producing a difference digital image from the estimated digital image and the source digital image, the difference digital image being representative of a difference between the source digital image and the estimated digital image.