p081fig02.36 Informational noise suppression in network with Gaussian on-center and off-surround function as contour detectors that are sensitive to ratio-contrast.<BR>||  Noise suppression and contour detection.<BR>If B*sum[k=1 to n: Cki] <= D*sum[k=1 to n: Eki] then: <UL><LI>uniform patterns are suppressed<LI>contrasts are selectively enhanced<LI>contours are detected</ul>Ii vs i, xi vs i<BR>Responses are selective to [REFLECTANCE, SPATIAL SCALE], eg color [feature, surface] contours.