Differential Operators for Edge Detection (opens in new tab)

Differential Operators for Edge Detection Torre, V.; Poggio, Tomaso A We present several results characterizing two differential operators used for edge detection: the Laplacian and the second directional derivative along the gradient. In particular, (a)we give conditions for coincidence of the zeros of the two operators, and (b) we show that the second derivative along the gradient has the same zeros of the normal curvature in the gradient direction. Biological implications are also discuss...