| 摘要: |
| 视频检索是当前的一个研究热点.以前的检索方法大多在像素域中进行,需要较大的解码运算量;且不加区分地对所有视频片断采用统一的匹配算法,浪费了许多不必要的计算.提出了一种基于样本的分级检索MPEG视频的新方法:首先用I帧的dct_dc_size字段快速粗检,然后用断层摄影(tomography)法分析B帧运动矢量的时空分布特性以进一步缩小结果集,最后用DC图像的精确匹配方法验证检索结果.试验结果表明,本方法所需计算量较小,且可保证较高的检索精度. |
| 关键词: 视频检索 MPEG 分级 dct_dc_size 时空分析 DC图像 |
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| 基金项目:Supported by the National Grand Fundamental Research 973 Program of China under Grant No.G1998030407 (国家重点基础研究发展规划(973)); the Foundation of Beijing Science Committee of China under Grant No.H011710010123 (北京科委基金) |
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| A Hierarchical Retrieval Method for MPEG Video |
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LIU Yang,XU Song-Tao,WU Zhi-Mei
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| Abstract: |
| Video retrieval is a current hot research area. Most of the past algorithms are done in pixel domain, which need many decode calculations. What is more, the same matching algorithm is used to all the video clips in the same way, which wasts many unnecessary calculations. A new hierarchical retrieval method based on example video for MPEG video is proposed: firstly the dct_dc_size field in I frames is used to locate the suspected videos quickly, then the retrieval result scope can be further reduced by analyzing the spatiotemporal distribution of motion vector in B frames using tomography method, at last DC images precise matching analysis is used to validate the retrieval result. The experimental results show that this method needs a few calculations and has higher precision ratio. |
| Key words: video retrieval MPEG hierarchical dct_dc_size spatiotemporal analysis DC image |
