Openings can introduce zero crossings in boundary curvature

Abstract

Chen and Yan (1989) presented a result on zero crossings of boundary curvature under morphological openings. In this correspondence, it is shown, by means of a counter example, that this result is not correct. An analysis of the counter example shows where Chen and Yan go wrong and determines a class of images for which their theorem holds.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>