Strategies for Diagram Understanding: Generalized Equivalence, ObjectlSpatial Data Pyramids, and Animate Vision

Virtually all scientific documents contain informational diagrams. To build knowledge bases representing this literature, the diagrams must be semantically analyzed. In our system, diagrams are represented as collections of geometric objects. The fundamental organizing principle for these objects is the Generalized Equivalence Relation (GER). Examples include Near, Parallel, and Aligned. These relations can be computed efficiently using GOSSAMER, a pyramidal data structure that allows spatially associative access to objects. Animate Vision (AV), in which the image is scanned either continuously or discontinuously, is used to mimic the efficient strategy used by humans to view diagrams. The system is implemented in Common Lisp and is being applied to data graphs and gene diagrams in the biological literature. 1