Multimedia search and retrieval: new concepts, system implementation, and application

We first present new concepts applicable to the design of multimedia search and retrieval schemes in general, and to MPEG-7 in particular, the multimedia description standard in progress. Raw multimedia data is assumed to exist in the form of programs that typically consist of a combination of media types such as visual, audio, and text. We partition each such media stream into smaller units based on actual physical events. These physical events within each media stream can then be effectively indexed for retrieval. The concept of logical events is introduced next; we define logical events as those that can provide different "views" of the content as may be desired by a user. Such events usually result from either the correlation of events that cross different media types, of by merging recursively chosen events from a lower level within each media type. We then address the related issue of how to develop a practical multimedia information retrieval system that exploits the aforementioned concepts of physical and logical events as well as other aspects such as storage, representation and indexing to enable efficient search, retrieval, and browsing. Finally, we implement the proposed concepts and solutions within a multimedia system that addresses a real application, effective browsing of broadcast news, and evaluate its performance.