Triangular spatial relationship : a new approach for spatial knowledge representation

摘要

In this paper, an important aspect of problems in symbolic image database retrieval (SIDR) is addressed. The problems in conventional pairwise spatial relationships, particularly the 9DLT--matrix-based approach, used to rep- resent a symbolic image in SID are discussed. A new concept called triangular spatial relationship (TSR) is introduced as an improved, invariant spatial relationship to take care of object transformations. A set of quadruples is used to preserve the TSR among the components in a symbolc image. The proposed method is based on principal component analysis. The first principal component vector (PCV) of the set of quadruples is used to represent a symbolc image in SID. The proposed algorithm requires O(log n ) search time in the worst case in the recognition phase, where n is the number of symbolic images stored in the symbolic image database.