摘要： PPM算法是一种文本无损压缩算法。它同广泛应用的相比具有很高的压缩比。后者主要应用了算法。而后者之所以能够WinZipL-Z得到广泛的应用主要是由于其易用性以及简单性。这正是算法主要的缺点。算法对算法进行了改进,提高了压缩率,并且使PPMPPM*PPM所需内存大大减少。用按照算法编制的软件应用于图像压缩领域,效果同以及另一种压缩算法相比要好。PPM*CWinZipL-Z-W

关键词: PPM, PPM*, 图像压缩

Abstract: The PPM data compression scheme has set the performance standard in lossless compression through the past decade. PPM is a finite-context statistical modeling technique that can be viewed as blending together several fixed-order context models to predict the next character in the input sequence. This paper gives a brief introduction to PPM, and describes a variant of the algorithm, called PPM*, which exploits contexts of unbounded length. It provides a useful tool for image compression. ;;

中图分类号: 

• TP391.7