Catalin Calistru

Data Organization and Search in Multimedia Databases: Databases and Information Retrieval Catalin Calistru

The wealth of multimedia items and their increasing complexity make data organization and search essential. Without efficient storage, accurate search and informative retrieval, it is hard to explore a multimedia repository to its full potential. We argue that the problems of managing large and heterogeneous multimedia repositories can be alleviated by bringing improvements in several aspects: storage model, high-dimensional indexing, and retrieval. Three main contributions are proposed: a database model, a high-dimensional indexing method and a faceted retrieval system. The database model accounts for content organization and its association to metadata. It is a hybrid relational-XML database model. For search within the high-dimensional data, an indexing method called BitMatrix is proposed. It constructs bit signatures that can be efficiently processed with bitwise operations. Our experiments have shown that the use of the BitMatrix as a high-dimensional indexing method is beneficial for the retrieval process. Finally, a retrieval system called MetaMedia was developed, in which the proposed database model and the BitMatrix index are instantiated.