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.
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