Lempel-Ziv-Storer-Szymanski

Lempel-Ziv-Storer-Szymanski, known as LZSS, is a lossless data compression algorithm derived from LZ77. James Storer and Thomas Szymanski created it in 1982 and described it in the article Data compression via textual substitution in the Journal of the ACM. It is a dictionary coding technique that replaces a string of symbols with a reference to an earlier location of the same string. Its main difference from LZ77 is that a reference is omitted whenever it would be no shorter than the text it replaces, so a reference is only used above a break-even length. LZSS also uses one-bit flags to mark whether the next item is a literal byte or an offset and length pair. Many archivers, among them ARJ, RAR, ZOO and LHarc, use LZSS as their main compression algorithm, and most implementations descend from free code by Haruhiko Okumura. The Game Boy Advance BIOS and Apple macOS kernel compression also use LZSS variants.