Notes
Data compression methods | |||||||
|---|---|---|---|---|---|---|---|
| Lossless |
| ||||||
| Audio |
| ||||||
| Image |
| ||||||
| Video |
| ||||||
| Theory | |||||||
 | This computer science article is a stub. You can help Wikipedia by expanding it. |
Lempel–Ziv Ross Williams (LZRW) refers to variants of the LZ77 lossless data compression algorithms with an emphasis on improving compression speed through the use of hash tables and other techniques. This family was explored by Ross Williams, who published a series of algorithms [1] beginning with LZRW1 in 1991.
The variants are:
The LZJB algorithm used in ZFS is derived from LZRW1.
LZJB is a lossless data compression algorithm invented by Jeff Bonwick to compress crash dumps and data in ZFS. The software is CDDL license licensed. It includes a number of improvements to the LZRW1 algorithm, a member of the Lempel–Ziv family of compression algorithms.. The name LZJB is derived from its parent algorithm and its creator—Lempel Ziv Jeff Bonwick. Bonwick is also one of two architects of ZFS, and the creator of the Slab Allocator.
ZFS is a combined file system and logical volume manager designed by Sun Microsystems. ZFS is scalable, and includes extensive protection against data corruption, support for high storage capacities, efficient data compression, integration of the concepts of filesystem and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z, native NFSv4 ACLs, and can be very precisely configured. The two main implementations, by Oracle and by the OpenZFS project, are extremely similar, making ZFS widely available within Unix-like systems.
Data compression methods | |||||||
|---|---|---|---|---|---|---|---|
| Lossless |
| ||||||
| Audio |
| ||||||
| Image |
| ||||||
| Video |
| ||||||
| Theory | |||||||
| | This computer science article is a stub. You can help Wikipedia by expanding it. |
Lossless compression is a class of data compression algorithms that allows the original data to be perfectly reconstructed from the compressed data. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with improved compression rates.
zlib is a software library used for data compression. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. zlib is also a crucial component of many software platforms including Linux, Mac OS X, and iOS. It has also been used in gaming consoles such as the PlayStation 4, PlayStation 3, Wii U, Wii, Xbox One and Xbox 360.
Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. It was published by Welch in 1984 as an improved implementation of the LZ78 algorithm published by Lempel and Ziv in 1978. The algorithm is simple to implement and has the potential for very high throughput in hardware implementations. It is the algorithm of the widely used Unix file compression utility compress and is used in the GIF image format.
LZ77 and LZ78 are the two lossless data compression algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978. They are also known as LZ1 and LZ2 respectively. These two algorithms form the basis for many variations including LZW, LZSS, LZMA and others. Besides their academic influence, these algorithms formed the basis of several ubiquitous compression schemes, including GIF and the DEFLATE algorithm used in PNG and ZIP.
Lempel–Ziv–Oberhumer (LZO) is a lossless data compression algorithm that is focused on decompression speed.
Abraham Lempel is an Israeli computer scientist and one of the fathers of the LZ family of lossless data compression algorithms.
Yaakov Ziv is an Israeli electrical engineer who, along with Abraham Lempel, developed the LZ family of lossless data compression algorithms.
Lempel–Ziv–Storer–Szymanski (LZSS) is a lossless data compression algorithm, a derivative of LZ77, that was created in 1982 by James Storer and Thomas Szymanski. LZSS was described in article "Data compression via textual substitution" published in Journal of the ACM.
Grammar-based codes or Grammar-based compression are compression algorithms based on the idea of constructing a context-free grammar (CFG) for the string to be compressed. Examples include universal lossless data compression algorithms. To compress a data sequence , a grammar-based code transforms into a context-free grammar . The problem of finding a smallest grammar for an input sequence is known to be NP-hard, so many grammar-transform algorithms are proposed from theoretical and practical viewpoints. Generally, the produced grammar is further compressed by statistical encoders like arithmetic coding.
Terry Archer Welch was an American computer scientist. Along with Abraham Lempel and Jacob Ziv, he developed the lossless Lempel–Ziv–Welch (LZW) compression algorithm, which was published in 1984.
LZO may refer to:
LZR may refer to:
Ross Neil Williams is an Australian computer scientist and entrepreneur who has made significant contributions to data compression and data deduplication technologies. He is best known as the inventor of the U.S. Patent 5,990,810 and the founder of Rocksoft Pty Ltd.
Lempel–Ziv–Stac is a lossless data compression algorithm that uses a combination of the LZ77 sliding-window compression algorithm and fixed Huffman coding. It was originally developed by Stac Electronics for tape compression, and subsequently adapted for hard disk compression and sold as the Stacker disk compression software. It was later specified as a compression algorithm for various network protocols. LZS is specified in the Cisco IOS stack.
In computer science and information theory, Tunstall coding is a form of entropy coding used for lossless data compression.
LZFSE is an open source lossless data compression algorithm created by Apple Inc.
TERSE is an IBM archive file format that supports lossless compression. A TERSE file may contain a sequential data set, a partitioned data set (PDS) or partitioned data set extended (PDSE), or a large format dataset (DSNTYPE=LARGE). Any record format (RECFM) is allowed as long as the record length is less than 32 K. Records may contain printer control characters.