Using MPEG-7 for Automatic Annotation of Audiovisual Content in eLearning Digital Libraries

In this paper we present a prototype system to enrich audiovisual contents with annotations, which exploits existing technologies for automatic extraction of metadata (such as OCR, speech recognition, cut detection, visual descriptors, etc.). The prototype relies on a metadata model that unifies MPEG-7 and LOM descriptions to edit and enrich audiovisual contents, and it is based on MILOS, a general purpose Multimedia Content Management System created to support design and effective implementation of digital library applications. MILOS supports the storage and content based retrieval of any multimedia documents whose descriptions are provided by using arbitrary metadata models represented in XML. As a result, the indexed digital material can be retrieved by means of content based retrieval on the text extracted and on the MPEG-7 visual descriptors (via similarity search), assisting the user of the e-Learning Library (student or teacher) to retrieve the items not only on the basic bibliographic metadata (title, author, etc.).