Dictionary Based Data Compression

Abstract

Abstract Data compression has gained increased attention of researchers and developers in the last few decades. It comes handy when users have limited storage capacity or transmission bandwidth as it reduces the size of data without much loss. There have been many types of compression techniques proposed by researchers so far, Lempel-Ziv series of algorithms, for example. Lempel-Ziv series of algorithms are lossless algorithms and follow a dictionary-based approach to data compression where a dictionary is used to keep references of repeated text or words and are omitted to reduce size of data. Out of all the Lempel-Ziv algorithms, this study focuses on Lempel-Ziv-Ross-Williams (LZRW) algorithm and its implementation, which was proposed by Ross Williams in 1991. There is a brief introduction in the study which talks about basics of data compression followed by the compression techniques. Various dictionary-based algorithms have also been compared with each other discussing along with their weaknesses and advantages. Not only that, there is also a brief description on how data compression works for L1 cache. The design issues faced by the designers while implementing data cache compression have also been noted in this study.