A method of enhancing the tonal and spatial characteristics of a digital image, includes receiving a source digital image including a plurality of pixels; producing a tone scale function that can be used to enhance the tonal characteristics of the source digital image; classifying the tone scale function...http://www.google.com.au/patents/US20040081363?utm_source=gb-gplus-sharePatent US20040081363 - Enhancing the tonal and spatial characteristics of digital images using selective spatial filters
