Content-Based Querying

Abstract

A Multimedia Database System MMDS deals with the storage, manipulation, and retrieval of all types of digitally-representable information objects such as text, still images, video, and sound [Gro94], [CK95]. Providing mechanisms that allow the user to retrieve desired multimedia information is an important issue in MMDSs. Information about the content of the multimedia objects is contained within the multimedia objects and is usually not encoded into attributes provided by the database schema. Because content equality is not well-defined, special techniques are needed for the retrieval of multimedia objects with content similar to that specified in the user’s query. In text databases, information-retrieval techniques allow one to retrieve a document if the document’s keywords are close to those specified in the query [Rij79], [CR86], [Sal89], [FBY92], [SAB94]. In image databases, one can retrieve an image if the image’s features, such as shape and spatial position of contained objects, are similar to those specified in the query [CH92]. In video databases, one can retrieve a video scene based on the (temporally-extended) actions of the conceptual objects appearing in the scene [SZ94], [JH94], [DG94], [DDI⁺95]. A multimedia document is a structured collection of attributes, text, image, video, and audio data. Multimedia document retrieval should be possible through the structure, attributes, and media content of the multimedia document [CTH⁺86b], [Tha90], [MRT91].