Abstract: Video coding technique based on 3D wavelet transform has been paid more attention.In this paper，an improved algorithm of temporal decomposition is studied，and the importance analysis of each frame after temporal decomposition is given.After that，a new video coding based on 3D wavelet transform and motion compensation is presented.Video sequence is firstly separated into two groups according to the parity of each frame.Then the improved algorithm of temporal decomposition is applied to each group separately，which resulting several high frequency frames and one low frequency frame in each group.After that，the motion compensation is only performed in the two low frequency frames in order to further eliminate the inter-frame redundancies.The optimal bit rate is allocated according to the importance of each frame according to the target bit rate.Experimental results show that the proposed scheme has better coding performance.

Key words: video image, 3D wavelet transform, motion compensation

摘要： 基于三维小波变换的视频编码技术成为当今研究的热点。研究了一种时间轴小波分解的改进结构，给出了时间轴分解后各帧的重要性分析，在此基础上提出了一种结合运动补偿的三维小波视频编码新方法。该算法首先将视频序列按帧序的奇偶性分成两组，对各组分别进行改进的时间轴小波分解，然后对两组中的低频帧进行运动补偿，可以进一步减少数据量。在所要达到的目标码率条件下，对各帧根据其重要性分配最优的压缩码率，并利用SPIHT算法进行压缩。实验结果表明，该方法可以获得较好的压缩效果。

关键词: 视频图像, 三维小波变换, 运动补偿