ABSTRACT
The interior of a closed object boundary is considered object pixels and the exterior as background pixels. Let S denote a set of object pixels in an image. The function d mapping from a binary image containing S to a matrix of nonnegative integers is called a distance function, if it satis es the following three criteria:
(a) Positive defi nite: That is d(p, q) ≥ 0, and = 0, if and only if p = q, for all p, q S.
