A Study on Video Coding Based on Combination of Motion Compensation and Waveform Coding

在本研究中，我们提出了一种新的基于运动补偿和波形编码无缝结合的视频编码方案。1.作为波形编码方法的匹配跟踪算法的研究我们研究了一种称为匹配跟踪的算法，该算法使用过完备的基函数迭代逼近信号，并针对所提出的方案对其进行了改进。2.迭代运动补偿技术的发展发展了迭代运动补偿预测方法。在该方案中，将前一帧的解码图像作为当前帧的初始预测，并采用基于块的局部运动补偿来迭代地减小预测误差。3.运动补偿和波形编码的结合我们将上述两种技术结合起来，实现了高效的视频编码。为了在所提出的编码方案的每个迭代步骤中交替执行这两种技术中的一种，引入了表示率失真斜率的代价函数。为了提高编码效率，引入了不可分基函数匹配跟踪、重叠块运动补偿、亚像素精度运动估计和基于算术编码的自适应熵编码等技术。5.基于软件编解码器的性能评估该视频编码方案最终实现为基于软件的编解码器，并对各种视频序列进行了测试。结果表明，该方案在码率失真方面优于被称为最有效的视频编码标准的H.264/AVC方案。

In this study, we have proposed a new video coding scheme based on seamless combination of motion compensation and waveform coding. The obtained results are summarized as follows.1.Investigation of the matching pursuits algorithm as a waveform coding methodWe investigated an algorithm called matching pursuits, which iteratively approximates a signal using overcomplete basis-functions, and modified it for the proposed scheme.2.Development of an Iterative motion compensation techniqueAn iterative motion-compensated prediction method was developed. In this scheme, a decoded image of the previous frame is used as an initial prediction of the current frame and the prediction errors are iteratively reduced by applying block-based motion compensation of local areas.3.Combination of motion compensation and waveform codingWe combined the above two techniques for efficient video coding. In order to perform one of the two techniques alternatively at each iteration step of the proposed coding scheme, a cost-function which represents the rate-distortion slope was introduced. It enables well-balanced bit allocation between motion compensation and waveform coding.4.Improvement of coding efficiencyTo improve coding efficiency, several techniques such as matching pursuits using non-separable basis-functions, overlapped block motion compensation, motion estimation with sub-pel accuracy and adaptive entropy coder using arithmetic code were introduced into the proposed scheme.5.Performance evaluation using the software-based codecThe proposed video coding scheme was finally implemented as software-based codec and tested for various video sequences. As a result, it was shown that the proposed scheme outperforms the H.264/AVC scheme which is known as the most efficient video coding standard in terms of a rate-distortion sense.