【作者】 孟颜；

【导师】 张二虎； 刘世昌；

【作者基本信息】 西安理工大学 ， 信号与信息处理， 2002， 硕士

【摘要】 由于通信系统的信道不可避免的存在噪声，传输数据流必然存在误码。对于H.26X的视频编码流，由于空域和时域的压缩方法以及熵编码方法的应用，即使是一个比特的错误，常会影响一个区域的图像不能正确解码，同时错误的图像还会扩散影响后续数帧图像。因此有必要在标准解码程序的基础上，添加容错功能。对于实际的解码系统，所设计的误码掩盖算法，不但要考虑图像恢复的质量，还要考虑算法的效率，不能影响后续帧的解码速度。本课题对前向错误控制、后处理错误掩盖、编解码器端交互的错误掩盖这三大类容错方法进行了详细的研究，分析了现有算法的一些局限性，基于空域插值和时域补偿这两种基本的掩盖算法，提出了一种混合容错算法。该算法的原理为：当运动向量较大时，图像的空间相关性要大于时间的相关性；此时利用空间相关性进行掩盖就比利用时间相关性掩盖好。这种方法的准则是：如果检测出的错误宏块的运动向量的水平分量或者垂直分量大于某个阈值时，则使用空域插值方法进行错误掩盖，反之则利用时域补偿方法进行掩盖。 课题在开放的H.263测试模型TMN8中实现了该算法，实现过程包括误码的检测，定位和误码部分数据的恢复等工作，并与标准H.263的结果进行了比较，模拟结果表明，经检错和掩盖之后，解码图像质量有了显著的改善，证明了算法的正确性和实用性。 目前在国际上，移动视频通信和网络视频通信已经成为许多公司追求的未来电信市场目标，而容错能力研究又是多媒体通信特别是移动视频通信的研究热点之一，因此，本文所做的工作是具有一定的实用价值的。更多还原

【Abstract】 RESEARCH OF ERROR RESILIENCETECHNOLOGY FOR VIDEO COMMUNICATION BASED ON H.263CODECMajor: Signal and Information Processing Data: Author: Meng Yan Signature:Tutor: Zhang Erhu Liu Shichang Signature:ABSTRACTThe reconstructed image quality can be degraded substantially by errors during the transmitting over the communication channel, especially when the video is compressed by temporal and spatial coding ways, which leads to error propagation in frame sequence, so the error resilience procedure should be performed to improve the reconstruction quality. This thesis discusses the research status and typical algorithms of error resilience at home and abroad, whose performance are analyzed, too. The error resilience technology means that the decoder can detect errors, skip the inextricable errors, and rectify the errors as soon as possible, one important way of which is error concealment. Recovering the video quality by temporal compensation and spatial interpolation is the basic principle, and the error concealing process includes the detecting, and the binding, and the synchronizing, and the data recovering. Based on the one and a half year’ s lucubration, the author gets one new error concealment way with better combination between efficiency and running time in processing the errors in video communication.According to the experiment results and relative data analysis, we can get a certain conclusion, which is that the algorithms are correct and useful. At present, mobile video communication and IP video communication are future market goals for most companies in the communication field. At the same time, the error resilience technology is one of the keys in realizing a video communication system. So, you can see, the work of this thesis is meaningful and valuable.更多还原