摘要
在多媒体通信中，低码率信道上的视频传输正成为一个日益重要的研究领域．因此，必须在保证主观可接受视频质量的前提下，尽可能提高编码效率．本文提出了一种把ＪＮＤ概念引入Ｈ．２６３编码器的方法．首先，我们回顾了时－空域的ＪＮＤ概念；然后把ＪＮＤ概念从象素级推广到宏块级，使之适用于Ｈ．２６３编码器．实验结果表明：与ｔｍｍ５编码器相比，在相同的主观质量下，本文提出的方法可以大大降低码率，并且与Ｈ．２６３标准完全兼容．
Video communication over bandwidth limited channels is becoming a more and more important service in multimedia communications, so it is necessary to improve the coding efficiency of the video coder while maintaining subjectively acceptable quality. In this paper, we propose a novel method to incorporate the just noticeable distortion(JND) concept into the H.263 coder. We first review the basic concept of JND in the spatial temporal domain, then derive it to the macro block(MB) level to make it usable in the H.263 coder. While producing the same subjective quality, simulation results show that this method can considerably reduce the consumed bits compared with tmn 5 coder without sacrificing the compatibility with the H.263 standard.
