Fuzzy region connection calculus: An interpretation based on closeness

One of the key strengths of the region connection calculus (RCC) — its generality — is also one of its most important drawbacks for practical applications. The semantics of all the topological relations of the RCC are based on an interpretation of connection between regions. Because of the manner in which the spatial relations are defined, given a particular interpretation of connection, the RCC relations are often hard to evaluate, and their semantics difficult to grasp. Our generalization of the RCC, in which the spatial relations can be fuzzy relations, inherits this limitation of the RCC. To cope with this, in this paper, we provide specific characterizations of the fuzzy spatial relations, corresponding to the particular case where connection is defined in terms of closeness between fuzzy sets. These characterizations pave the way for practical applications in which the notion of connection is graded rather than black-and-white.