Multidimensional Index Structures

Abstract

As mentioned in Chapters 1 and 3, the shape representation of objects can be used to query and search the object databases for different purposes. For example, CAD/CAM, computer graphics, and multimedia applications try to find objects in a database that match a given object. Besides similarity matching, many other applications in the areas of cartography, computer vision, spatial reasoning, cognitive science, image and multimedia databases, and geographic applications require to represent and process spatial relations between objects. There are two obstacles for efficient execution of such queries. First, the general problem of comparing two 2D objects under rotation, scaling, and translation invariance is known to be computationally expensive [3]. Second, the size of the databases are growing and hence given a query object the matching objects should be retrieved without accessing all the objects in the database. Based on the discussions above we can identify an important basic problem: given a query object, a set of similar objects or objects satisfying some spatial relation should be retrieved without accessing all the objects in the database. Efficient solutions to this problem have important applications in database, image and multimedia information systems as well as other potential application domains.