This paper presents conditional versions of Lempel-Ziv (LZ) algorithm for settings where compressor and decompressor have access to the same side information. We propose a fixed-length-parsing LZ algorithm with side information, motivated by the Willems algorithm, and prove the optimality for any stationary processes. In addition, we suggest strategies to improve the algorithm which lower the d...

This paper clari es two variable-toxed length codes which achieve optimum large deviations performance of empirical compression ratio. One is Lempel-Ziv code with xed number of phrases, and the other is an arithmetic code with xed codeword length. It is shown that Lempel-Ziv code is asymptotically optimum in the above sense, for the class of nite-alphabet and nite-state sources, and that the ar...

We introduce a new approach to LZ77 factorization that uses O(n/d) words of working space and O(dn) time for any d ≥ 1 (for polylogarithmic alphabet sizes). We also describe carefully engineered implementations of alternative approaches to lightweight LZ77 factorization. Extensive experiments show that the new algorithm is superior in most cases, particularly at the lowest memory levels and for...

A risk stratification system to discriminate congestive heart failure (CHF) subjects from healthy subjects is proposed. All the previous research to detect CHF patients using Lempel-Ziv complexity measure had used binary coarsegraining (BLZC). In this work, we show that employing multi-valued coarsegraining Lempel-Ziv complexity (MLZC) improves the performance of classification. This finding is...

Lempel-Ziv (LZ) is a popular lossless data compression algorithm that produces good compression performance, but suffers from relatively slow processing speed. This paper proposes an enhanced version of the Lempel-Ziv algorithm, through incorporation of a neural pre-processor in the popular predictor-encoder implementation. It is found that in addition to the known dramatic performance increase...

Lempel–Ziv Welch (LZW) algorithm is a well-known powerful data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. The algorithm is designed to be fast to implement but is not usually optimal because it performs only limited analysis of the data. A modified LZW algorithm on source coding will be proposed in this paper to improve the compression efficiency of the existin...