Describing Topological Relationships in Words: Refinements

In earlier work, we introduced a method for generating linguistic descriptions of the topological relationships between two-dimensional objects. The input to the system is a pair of rasterized objects and the output is a set of propositions about their spatial relationships expressed in natural language. The method relies on finding one or two Allen relations that best describe the relationships along a direction of major object interaction. In this paper, we address some of the issues related to the use of Allen relations for describing two-dimensional object configurations, and we propose two extensions in order to solve problems encountered in the original algorithm. Global subsethood-based information is used to suppress counter-intuitive descriptions and an ancillary method for generating alternative descriptions is introduced.