Audio/video digital libraries: the ECHO experience

Wide access to large information collections is of great importance in many aspects of everyday life. However, limitations in information and communication technologies have, so far, prevented the average person from taking much advantage of existing resources. Digital Libraries tend to fill the gap between users and systems by providing services for the indexing, archival, management and retrieval of documents. Among other types of information, Audio/Video can be considered today as a primarily mean of communication, due to its richness in informative content and to its appeal. This implies that the development of Digital Libraries supporting the management of Audio/Video documents is of primarily importance to enable the access to the general public as well as to professional users of a significant asset of today life. This chapter presents the approach adopted in the ECHO (European CHronicles On line) system to provide an effective support for indexing, retrieval and management of historical documentary films. In order to achieve an effective and inexpensive indexing and a powerful support to content-based retrieval of Audio/Video material, a combination of automatic and manual indexing has been adopted.