为提高分布式视频编码压缩率,依据无线传感网络终端设备及 Wyner-Ziv 视频编码特点,针对 Bernd Girod 的频域Wyner-ziv 视频编码方案提出改进算法.该算法在编码端通过简单 DCT 运算提出将图像块分为 Skip 模式、低频模式和全频模式三种可选模式,在解码端根据相应的编码模式分别选择平均插值、自适应搜索运动估计插值和自适应搜索精细运动估计插值的边信息估算方法联合解码.该算法既能通过消除大量的帧间预测与熵编码实现低码率传输,又能以最小的解码代价获得更精确的边信息,从而有效地避免图像解码质量下降.实验结果表明,在相同峰值信噪比情况下,该算法的码率比 Bemd Girod 提出的频域 Wyner-Ziv 算法平均下降 40%.%According to the characteristic of wireless sensor network devices and the Wyner-Ziv video code, an improved method is given in this paper on transform domain Wyner-Ziv video coding proposed by Bernd Girod in orde to increase compression efficiency. The given method classifies image blocks into three modes,skip mode,low frequent mode and full frequent mode by simply computing the DCT coefficients on the encoders. On the decoder it chooses the average interpolation estimation, adaptive search motion compensated interpolation estimation and adaptive search refinement motion compensated interpolation estimation correspondingly. This scheme can achieve low bitrates transmission by eliminating most inter-frame prediction as well as precise side information with the lowest decoding cost,which avoids degradation of image quality. Experimental results show that the average bitrates of the proposed algorithm declines 40％ to the original transform domain Wyner-Ziv video coding system.
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