A new filtering scheme for processing the chromatic signals of color images: definition and properties

This paper presents a new filtering scheme for processing the chromatic components of color images, expressed by the CIE u´ and v´ chromaticity coordinates. The new scheme extends to image filtering the center of gravity law of color mixture which describes the mixing of two colors within u´v´ chromaticity diagrams. The most interesting property of the proposed filtering framework is the elimination of the annoying hue shifts along edges between bright and dark areas, which would be introduced by the simple linear filtering of the u´ and v´ signals. Four examples of lowpass filtering reported and discussed in the paper that clearly demonstrate this important feature.