<title>Similarity retrieval of NOAA satellite imagery by graph matching</title>

Abstract

An attributed relational graph (ARG) is introduced into our NOAA satellite image database system. The node and the branch of an ARG denotes a classified region and a spatial relationship between adjacent regions, respectively. Furthermore, a few attributes of a node/branch help to express numerical shape features of regions. Similarity retrieval thereby turns out to be equivalent to graph matching. The similarity retrieval process of the system is as follows: (1) select a visual example image as a query and generate its graph structure, (2) calculate an optimal graph matching cost between a query graph and an archived graph in the database, utilizing algorithm A<SUP>*</SUP> with heuristic information, (3) choose archived images in the ascending order of a corresponding matching cost.