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基于软件视频会议系统是未来远程会议系统的发展趋势,而视频会议未来发展的主要关键技术之一是视频的编解码技术。针对视频会议中高带宽下显示帧访问引起视频解码器性能下降的问题,提出了一种基于软件视频会议显示帧的简单和有效的无损压缩算法。该算法基于字典编码、霍夫曼编码,提出了两种创新的编码方法,通过计算获得相邻每对像素差的分布情况和表征每对像素的空间位置LPM值,显著提高了视频显示帧的压缩比例。在定量分析视频显示帧特性的基础上,提出了一种两组分类方法。该方法将显示帧的所有像素分为三组,通过头码压缩方式减少码字的位数,以提高压缩效率。实验结果表明,相对于已有压缩算法,提出的无损压缩算法的压缩率提高了百分之二十。
Based on the software video conference system is the future development trend of teleconferencing system, and video conferencing one of the key technologies for the future development of video encoding and decoding technology. Aiming at the problem that the performance of the video decoder degrades due to the display frame access during the video conference under high bandwidth, a simple and effective lossless compression algorithm based on the display frame of the software video conference is proposed. Based on dictionary coding and Huffman coding, this algorithm proposes two innovative coding methods. By calculating the distribution of each pair of pixels’ difference and characterizing the spatial position LPM of each pair of pixels, the algorithm significantly improves the video display frame Compression ratio. Based on the quantitative analysis of video display frame characteristics, a two-group classification method is proposed. The method divides all the pixels of the display frame into three groups, and reduces the number of codewords by the header code compression to improve the compression efficiency. The experimental results show that the compression ratio of the proposed lossless compression algorithm is improved by 20% compared with the existing compression algorithms.