Unsupervised News Video Segmentation by Combined Audio-Video Analysis

Segmenting news video into stories is among key issues for achieving efficient treatment of news-based digital libraries. In this paper we present a novel unsupervised algorithm that combines audio and video information for automatic partitioning news videos into stories. The proposed algorithm is based on the detection of anchor shots within the video. In particular, a set of audio/video templates of anchorperson shots is first extracted in an unsupervised way, then shots are classified by comparing them to the templates using both video and audio similarity. Finally, a story is obtained by linking each anchor shot with all successive shots until another anchor shot, or the end of the news video, occurs. Audio similarity is evaluated by means of a new index and helps to achieve better performance in anchor shot detection than pure video approach. The method has been tested on a wide database and compared with other state-of-the-art algorithms, demonstrating its effectiveness with respect to them.