AUGMENTED TRANSITION NETWORKS AS SEMANTIC MODELS FOR MULTIbAEDIA PRESENTATIONS, MULTIMEDIA DATABASE SEAR.CHING, AND MULTIMEDIA BROWSING

As more information sources become available in multimedia systems, the development of abstract semantic models for video, audio, text, and image data becomes very important. An abstract semantic model has two requirements. First, it should be rich enolugh to provide a friendly interface of multimedia presentation synchronization schedules to tlie users. Second, it should be a good programming data structure for implementation t o control multimedia playback. An abstract semantic model based on an augmented transition network (ATN) is presented. Tlle inputs for ATNs are modeled by multimedia input strings. Multimedia input strings provide an efficient means for iconic indexing of the temporal/spatial relations of media streams and semantic objects. An ATN and its subnetworks are used to represent the appearing sequence of media streams and semantic objects. The arc libel is a substring of a multimedia input string. In this design, a presentation is driven by a ~nultimedia input string. Each subnetwork has its own multimedia input string. Database queries relative to text, image, and video can be answered via substring matching at subnetworks. Subnetworks also can ble some existing multimedia presentations to be embedded in other presentations to make module design possible in a multimedia authoring environment. The conditions are checked to see whether certain criteria are satisfied. If they are, a set of corresponding actions are activated. Multimedia browsing allows users the flexibility to select any part of the presentation they prefer t o see. This means that an ATN and its suklnetworks can be included in a multimedia database system which is controlled by a database management system (DBMS). User interactions and loops are also provided in an ATN. Therefore, ATNs provide three major capabilities: multimedia presentations, temporal/spatial multimedia database searching, and multimedia browsing.