European CHronicles On-line e Technology Implementation Plan

The ECHO (http://pc-erato2.iei.pi.cnr.it/echo/) Digital Library system supports the indexing and retrieval of A/V documentaries. The indexing is semi-automatic. Using a high-quality speech recogniser, the sound track of each video source is converted to a textual transcript, and then stored in a full-text information retrieval system. Likewise, video and image analysis techniques are used for extracting visual features and segmenting video sequences by automatically locating boundaries of shots, scenes, and conversations. Metadata (described according to the ECHO metadata model) are then manually associated with film documentaries in order to complete their classification. Search and retrieval on wide area networks is performed by expressing queries on the audio transcript, on metadata or by image similarity retrieval. Retrieved documentaries or their abstract, are then presented to the user.