New asymptotic bounds and improvements on the Lempel-Ziv data compression algorithm

New results, which follow from a data compression algorithm proposed by A. Lempel and J. Ziv (1977), are presented. The authors describe the original Lempel-Ziv algorithm, and present an improved Lempel-Ziv data compression algorithm. They state and prove some asymptotic bounds on the compression ratio that the improved algorithm achieves. For completeness, they describe the Lempel-Ziv-Welch data compression algorithm presented by T. A. Welch (1984). A software implementation for both the original and the improved Lempel-Ziv algorithms is given, and the algorithms are compared with each other as well as with the Lempel-Ziv-Welch algorithm.