6.2 Experimental Results

We have developed a technique for color image enhancement based on a model of the Human Visual System HVS A color image represented by RGB is rst transformed into a color space based on the HVS cone response characteristics Subsequently chromatic correlation reduction and energy compression is realized by using a multispectral Karhunen Lo eve transform KLT of the cone responses This yields a color opponent space related to the HVS characteristics Spatial energy distribution is highly skewed the chromatic channels contain signi cantly less relative energy than in standard opponent spaces such as Y UV A constant transform which closely approximates the input dependent KLT has been found In spite of the little spatial en ergy in the chromatic channels chromatic edge enhancement in this space does add signi cantly to the perception of image detail and enhances its chromatic delity as compared with stan dard edge enhancement of only the luminance channel Chromatic edge enhancement is also less sensitive to noise than achromatic edge enhancement Owing to the simplicity of the transform and enhancement processes they can be employed for processing real time video signals