“…Many other examples of the use of differential image structure by both machine and biological vision researchers can be found in the literature (e.g. Koenderink, 1984;Koenderink andvan Doorn, 1990, Koenderink andvan Doorn, 1994;Deriche et al, 1992;Deriche and Giraudon, 1993;Florack et al, 1992;Malik, 1987, Perona andMalik, 1990;Beaudet, 1978, Kitchen andRosenfeld, 1982;Krueger and Phillips, 1989).…”