Delta Compression Techniques
Delta Compression Techniques
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DOI：
10.1007/978-3-319-63962-8_63-1
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发表时间：
2019
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影响因子：
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通讯作者：
Torsten Suel
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文献类型：
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作者：
Torsten Suel
增量压缩技术相对于一个或多个参考文件对目标文件进行编码，使得可以访问相同参考文件的解码器可以从压缩数据重新创建目标文件。增量压缩通常应用于目标文件和引用文件之间存在高度冗余的情况，从而导致压缩大小比仅压缩目标文件本身所能实现的要小得多。典型的应用场景包括修订控制系统和版本化文件系统，这些系统通过网络存储文件或软件或内容更新的多个版本，而接收者已经拥有旧版本的数据。Delta压缩技术的研究主要集中在文本和二进制文件上，但它也可以应用于多媒体和结构化数据。Delta压缩不应与Elias delta码（一种对整数值进行编码的技术）混淆，也不应与通过先取连续值之间的差（或delta）来对整数序列进行编码的思想混淆。此外，增量压缩要求编码器具有参考文件的完整知识，因此不同于用于网络和存储系统中的冗余消除的更一般的技术，在网络和存储系统中，编码器具有有限的参考文件知识或甚至不具有参考文件知识，尽管与该工作线的边界没有明确定义。
Delta compression techniques encode a target file with respect to one or more reference files, such that a decoder who has access to the same reference files can recreate the target file from the compressed data. Delta compression is usually applied in cases where there is a high degree of redundancy between target and references files, leading to a much smaller compressed size than could be achieved by just compressing the target file by itself. Typical application scenarios include revision control systems and versioned file systems that store many versions of a file or software or content updates over networks where the recipient already has an older version of the data. Most work on delta compression techniques has focused on the case of textual and binary files, but the concept can also be applied to multimedia and structured data.Delta compression should not be confused with Elias delta codes, a technique for encoding integer values, or with the idea of coding sorted sequences of integers by first taking the difference (or delta) between consecutive values. Also, delta compression requires the encoder to have complete knowledge of the reference files and thus differs from more general techniques for redundancy elimination in networks and storage systems where the encoder has limited or even no knowledge of the reference files, though the boundaries with that line of work are not clearly defined.