多媒体上涨趋势.docVIP

多媒体数据压缩方法研究及发展的趋势 摘 要 在现今的电子信息技术领域，正发生着一场有长远影响的数字化革命。由于数字化的多媒体信息尤其是数字视频、音频信号的数据量特别庞大，如果不对其进行有效的压缩就难以得到实际的应用。因此，数据压缩技术已成为当今数字通信、广播、存储和多媒体娱乐中的一项关键的共性技术。 对于数据压缩技术而言，最基本的要求就是要尽量降低数字化的在码事，同时仍保持一定的信号质量。不难想象，数据压缩的方法应该是很多的，但本质上不外乎上述完全可逆的冗余度压缩和实际上不可逆的嫡压缩两类。冗余度压缩常用于磁盘文件、数据通信和气象卫星云图等不允许在压缩过程中有丝毫损失的场合中，但它的压缩比通常只有几倍，远远不能满足数字视听应用的要求。在实际的数字视听设备中，差不多都采用压缩比更高但实际有损的嫡压缩技术。只要作为最终用户的人觉察不出或能够容忍这些失真，就允许对数字音像信号进一步压缩以换取更高的编码效率。摘压缩主要有特征抽取和量化两种方法，指纹的模式识别是前者的典型例子，后者则是一种更通用的摘压缩技术。 关键字：数据压缩 冗余度 失真 编码效率 Abstract: In todays electronic and information technology, is undergoing a long-term impact of the digital revolution. As the digital multimedia information, especially digital video, audio signals particularly large amount of data, if not its effective compression can hardly be practical application. Therefore, the data compression technology has become the digital communication, broadcasting, storage, and multimedia entertainment in a key common technologies. For data compression technology, the basic requirement is to minimize the number of things in the code, while still maintaining a certain degree of signal quality. Not difficult to imagine, the data compression should be many, but essentially nothing more than the fully reversible compression and redundancy is actually two types of irreversible entropy compression. Redundancy compression commonly used in disk files, such as data communications and meteorological satellite cloud in the compression process does not allow the slightest loss of occasions, but its compression ratio is usually only a few times, can not meet the requirements of digital audio-visual applications. In practice, the number of audio-visual equipment, almost all use a higher compression ratio but the actual lossy compression technique entropy. As long as people perceive as the end user or can not tolerate these distortions, it allows further compression of digital audio and video signals in exchange for higher coding efficiency. Abstract compression are two methods