Modeling temporal aspects of visual and textual objects in multimedia databases

We consider the problem of modeling temporal aspects of visual and related textual entities in multimedia databases, within the framework of an object-oriented temporal data model. We distinguish two different time aspects in multimedia visual data: intrinsic time, i.e., the time managed according to the sequence of frames composing a visual data item, and extrinsic time, i.e., the (valid) time of the real world represented by the visual data item. We also propose a three-layered approach for composing temporal visual data. Relationships between visual data and related textual data are then considered: we propose a taxonomy for temporal textural observations on visual data, based on their temporal properties. In relation to textural temporal data and visual data, we consider the existing contraints along their valid times, possibly given different granularities and with indeterminacy.