Design And Implementation Of Content-based News Video Retrieval Prototype System

Multimedia information represented by news video plays increasing role in people's daily life and current society. The news video retrieval system based on traditional text has already not met the demand of retrieving news video, it of increasing importance to retrieve news video information from plenty of news video data. This paper, combining with character of depending on news video in the form of text and news video retrieval technology, puts forward some new improved algorithm, designs and realizes one news video retrieval prototype system in the view of content. The major work is as follows:1) This paper makes analysis on hierarchical structure and characteristics of news video based on status quo of research at home and abroad, it also finds key steps in news video retrieval in the view of content, namely shot segmentation, key frame extraction as well as video identification.2) The first step is shot boundary detection in realizing news video retrieval. This paper has access to an improved dual threshold algorithm based on summarizing algorithm of the originally available shot boundary detection. As the traditional dual threshold algorithm which ignores influence resulting from flash lamp and abrupt shot's selection on image frame is taken into consideration, which also innovates and adds detection on flash lamp. The test reveals that the modified algorithm is rather ideal for detection result of shot cut.3) The key is how to extract the dynamic key frame after making research on approaches of the available key frame extraction. Selection on distribution of video image frame in each pixel gray value in the same position is those representative gray values which are collected as the gray value assemblage, and consist of one dynamic frame. The result of experiment reveals that the key frame, fidelity and compression ratio are excellent according to distance between each frame and the dynamic image in the video.4) Based on making analysis and concluding the relevant shot gathering approaches, K mean value shot gathering algorithm is innovated, the simulated annealing approach is applied to the original algorithm for the sake of improving overall capability of gaining superiority in K mean value shot gathering algorithm, and the integral effect of shot gathering is perfected.5) The news video retrieval prototype system is constructed based on the algorithm in the paper; the retrieval of news video is thus realized.