Well-composedness of digital sets

Abstract

A special class of subsets of binary digital images called `well-composed sets' are defined. The sets of this class have very nice topological properties; for example, the Jordan Curve Theorem holds, the Euler characteristic is locally computable, and there is only one connectedness relation, since 4- and 8-connectedness are equivalent. This implies that properties of algorithms used in Computer Vision can be stated and proved in a clear way, and that the algorithms themselves become simpler and faster.