Introduction

DISIMA (Distributed Image Database Management System) was a research at the University of Alberta from 1995 to 1999. The research topics under investigation include: (i) the development of an object-oriented DBMS kernel that provides flexibility for user-defined classification of images, supports feature-based and spatial querying over image content (by means of salient objects), and enables reasoning over spatial relationships for query optimization; (ii) the development of query languages and primitives for querying image databases; and (iii) the provision of scalability and open access to image repositories. As a database, DISIMA integrates a query language, Multimedia Object Query Language (MOQL) [LÖSO97], which is an extension of the standard OQL language [CBB97]. To facilitate formulation of complex queries an equivalent visual query language (VisualMOQL) and a translator to translate a visual query into an MOQL query. VisualMOQL is described in [OÖX99] and was first demonstrated at the VDB-4 conference [OXÖ98]. The querying interface has been improved since and the the full system was demonstrated during the ICDE 2000 conference [OÖX00]. The prototype used in these previous demonstrations is local (single-site) and does not integrate any index for image similarity searches. The demonstration during SIGMOD 2000 presents a distributed version that integrates an index structure for color similarity searches.