Research On Content-based News Video Summary

With the rapid development of multimedia and network techniques, effective video management, browsing and retrieval become more and more important due to the large amount of information video provided. News video has its own structure: frame-shot-story-video. The technique of news video summary has been widely investigated because of its applications in video browsing, retrieval and transmission.In this dissertation, the structure of news video is described and some video analysis features, such as visual feature, audio feature, text feature and MPEG domain feature in video processing are also introduced first. Second, shot boundary detection, news story segmentation and key frame extraction are analyzed. All of them are the key parts of video summary. After that, three new algorithms for key frame extraction are presented, which are based on clustering algorithm with adaptive threshold, based on covariance and based on conditional entropy. The first method uses the watershed algorithm and Otsu algorithm to find the adaptive threshold. The last two method use the character that most video frames are similar to their adjacent ones to reduce the redundant information between key frames. The experimental results prove the effectiveness and efficiency of the three methods.In order to satisfy different people's demand, a video summary method based on hierarchy is proposed, which adjusts the number of key frames according to subjective perception. At last, a COM-based video summary system is devised and implemented.