AN OBJECT-ORIENTED APPROACH TO TEMPORAL MULTIMEDIA DATA MODELING

This paper discusses an object-oriented approach to temporal multimedia data modeling in OMEGA; a multimedia database management system under development at the University of Library and Information Science, An object-orientated approach is necessary to integrate various types of heterogeneous multimedia data, but it has become clear that current object-oriented data models are not sufficient to represent multimedia data, particularly when they are temporal. For instance, the current object-oriented data models cannot describe objects whose attribute values change time-dependently. Also, they cannot represent temporal relationships among temporal multimedia objects. We characterize temporal objects as instances of a subclass of class TimeInterval with the temporal attributes and the temporal relationships. This temporal multimedia data model is designed upward compatible with the ODMG-93 standard object model. To organize a temporal multimedia database, a five temporal axes model for representing temporal multimedia objects is also introduced. The five temporal axes - an absolute, an internal, a quasi-, a physical, and a presentation time axis- are necessary to describe time-dependent properties of multimedia objects in modeling, implementing and use. A concrete example of this organization method is also illustrated.