Lexical Mediation for Ontology-Based Annotation of Multimedia

In the last decade, the annotation of multimedia has evolved toward the use of ontologies, as a way to bridge the semantic gap between low level features of media objects and high level concepts. In many cases, the annotation terms refer to structured ontologies. Such ontologies, however, are often light scale domain oriented knowledge bases, whereas the employment of wide, commonsense ontologies would improve interoperability and knowledge sharing, with beneficial effects on search and navigation. In this chapter, we present an approach to the semantic annotation of media objects through a meaning negotiation approach that requires natural language lexical terms as interface and employs large scale commonsense ontologies. As a test case, we apply the annotation to narrative media objects, using a meta–ontology, called Drammar, to describe their structure. We present the annotation schema, the software architecture for integrating several large scale ontologies, and the lexical interface for negotiating the ontological term. We also describe an evaluation of the proposed approach, conducted through experiments with annotators.