Multimedia Database Systems

Though there are now numerous examples of multimedia systems in the commercial market, these systems have been developed primarily on a case-by-case basis. The large-scale development of such systems requires a principled characterization of multimedia systems which is independent of any single application. It requires a uniied query language framework to access these diierent structures in a variety of ways. It requires algorithms that are provably correct in processing such queries and whose eeciency can be appropriately evaluated. In this paper, we develop a framework for characterizing multimedia information systems which builds on top of the implementations of individual media, and provides a logical query language that integrates such diverse media. We develop indexing structures and algorithms to process such queries and show that these algorithms are sound and complete and relatively eecient (polynomial-time). We show that the generation of media-events (i.e. generating diierent states of the diierent media concurrently) can be viewed as a query processing problem, and that synchronization can be viewed as constraint solving. This observation allows us to introduce the notion of a media presentation as a sequence of media-events that satisfy a sequence of queries. We believe this paper represents a rst step towards the development of multimedia theory.