Deflate

This article is about the data compression algorithm. For other uses, see Deflation (disambiguation).

In computing, Deflate (stylized as DEFLATE, and also called Flate[1][2]) is a lossless data compression file format that uses a combination of LZ77 and Huffman coding. It was designed by Phil Katz, for version 2 of his PKZIP archiving tool. Deflate was later specified in RFC 1951 (1996).[3]

Katz also designed the original algorithm used to construct Deflate streams. This algorithm was patented as U.S. patent 5,051,745, and assigned to PKWARE, Inc.[4][5] As stated in the RFC document, an algorithm producing Deflate files was widely thought to be implementable in a manner not covered by patents.[3] This led to its widespread use – for example, in gzip compressed files and PNG image files, in addition to the ZIP file format for which Katz originally designed it. The patent has since expired.

  1. ^ The Go Authors. "flate package - compress/flate - Go Packages". The Go Programming Language. Google. Retrieved 5 September 2023. Package flate implements the DEFLATE compressed data format, described in RFC issue 1951.
  2. ^ Adobe Systems Incorporated. "PDF 32000-1:2008: Document management — Portable document format — Part 1: PDF 1.7" (PDF). Adobe Open Source. Adobe. p. 23. Retrieved 5 September 2023. FlateDecode [...] Decompresses data encoded using the zlib/deflate compression method
  3. ^ a b Deutsch, L. Peter (May 1996). DEFLATE Compressed Data Format Specification version 1.3. IETF. p. 1. sec. Abstract. doi:10.17487/RFC1951. RFC 1951. Retrieved 2014-04-23.
  4. ^ US patent 5051745, Katz, Phillip W., "String Searcher, and Compressor Using Same", published 1991-09-24, issued 1991-09-24, assigned to PKWare Inc. 
  5. ^ David, Salomon (2007). Data Compression: The Complete Reference (4 ed.). Springer. p. 241. ISBN 978-1-84628-602-5.