The RELIEF retrieval system

Introduces the RELIEF retrieval system, a system for image retrieval based on the conceptual graph formalism. Conceptual graphs can be used as a simple and expressive language for indexing and retrieving non-textual documents. In this formalism, the implementation of the matching function between a query and a document is obtained by using the so-called projection operator between two conceptual graphs. However, the first implementations of this operator have shown its lack of efficiency, as it is based on an exponential algorithm. The RELIEF system supports a new polynomial matching function for conceptual graphs which turns out to be equivalent to the projection operator but it has the important feature that it incorporates reasoning about relations. This allows for better qualitative results as well as improved time performance compared to the original system implementing the classical projection. RELIEF is developed on top of the object-oriented DBMS O₂, and any WWW navigator with Java facilities can be used to access its interface