L7, an MPEG-7 Query Framework

Many vendors of multimedia databases and many providers of multimedia search and retrieval services already offer advanced indexing and retrieval techniques for multimedia contents. However, the solutions differ and do not interoperate. The already completed ISO/IEC IS 15938, formally called the multimedia content description interface (better known as MPEG-7), provides a rich model for multimedia content description. We propose a unified query framework for multimedia repositories based on MPEG-7. The framework consists of a query language and a service interface. The query language is based on XML and includes four complementary parts defining a relational-like algebra, an expression language, an input query structure and the output response format. The service interface acts as a set of views over the query language and is based in two different bindings: An extensible web services-based (SOAP) binding and an alternative and simple HTTP (REST-like) interface.