SPATIAL MATCH RETRIEVAL BASED ON DIRECTION SIGNATURES USING MULTIPLE KEY HASHING SCHEME

The spatial relationships among pictorial objects are important spatia l characteristics in image database systems. Based on the concept of 9 -DLT representation, we propose a new method for effective storage uti lization and picture retrieval. First, we transform a symbolic picture into a set of triples associated with pairwise spatial relationships among objects. Then, an associated normalized signature record with ni ne attributes is specified. Finally, each normalized record of this im age database can be well allocated by using our proposed multiple key hashing scheme and can be fast accessed for spatial match retrieval. T he performance formula for spatial picture retrieval is presented and the theoretically optimal solutions to the bit lengths of all the attr ibutes are derived in certain case. Also, we give a systematic method to solve the feasible bit lengths for the attributes based on the meth od proposed by Chang. (C) 1997 John Wiley & Sons, Inc.