Using MPQF for Querying MPEG-7 RDF Descriptions

MPEG-7 and MPEG Query Format (MPQF) are two related standards developed by the Moving Picture Experts Group (MPEG) to address the multimedia retrieval problem. MPEG-7 aims to provide standardized comprehensive set of tools for description of audiovisual content, while MPQF aims to provide a standardized interface which unifies the retrieval over different multimedia repositories. However, both standards have some limitations. On one hand, MPEG-7 is based on XML Schema, therefore, does not have formal semantics, which makes difficult to be managed by computers. Machine understandable metadata forms the main prerequisite for the intelligent services envisaged in a Web, which going beyond mere data exchange and provides for effective content access, sharing and reuse. Consequently, there have been several attempts to move MPEG-7 to the Semantic Web to provide it with formal semantics. On the other hand, MPQF is limited to querying XML-based multimedia metadata. Therefore if MPQF is intended to support queries on non-XML multimedia metadata, mapping of MPQF to the specific database query language is necessary. In this paper MPQF is used to query semantic MPEG-7RDF descriptions. A set of rules are proposed for converting MPQF query into SPARQL query without introducing new construct to MPQF. These rules are mainly based on the new features added in SPARQL1.1.