Transformation invariant image indexing and retrieval for image databases

This paper presents a novel design of an image database system which supports storage, indexing and retrieval of images by content. The image retrieval methodology is based on the observation that images can be discriminated by the presence of image objects and their spatial relations. Images in the database are first automatically segmented into sets of image object descriptions. Then, transformation invariant quantities of image object descriptions are derived and used as keys to index images, described by their image objects, in a hash table. A query corresponding to a sample image or sketch of image segments provided by the user on input is analyzed, invariants are computed and then used to lookup images in the table. This query processing methodology avoids exhaustive searching through the image database and offers constant time image retrieval independent of the size of the image database and the complexity of the imaging process. Performance of the proposed image database system has been evaluated by experiments for a simple application.