Lossless compression

losslesslossless data compressioncompressiondata compressionlossless audiolossless digital downloadcompresscompressedlossless codeclossless encoding
Lossless compression is a class of data compression algorithms that allows the original data to be perfectly reconstructed from the compressed data.wikipedia
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Lossy compression

lossylossy data compressioncompressed
By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes).
This is opposed to lossless data compression (reversible data compression) which does not degrade the data.

Zip (file format)

ZIPZIP file.zip
For example, it is used in the ZIP file format and in the GNU tool gzip.
ZIP is an archive file format that supports lossless data compression.

Portable Network Graphics

PNG.pngPNG image
Some image file formats, like PNG or GIF, use only lossless compression, while others like TIFF and MNG may use either lossless or lossy methods. Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters.
Portable Network Graphics (PNG, pronounced or ) is a raster-graphics file-format that supports lossless data compression.

Huffman coding

HuffmanHuffman codeHuffman encoding
The primary encoding algorithms used to produce bit sequences are Huffman coding (also used by DEFLATE) and arithmetic coding.
In computer science and information theory, a Huffman code is a particular type of optimal prefix code that is commonly used for lossless data compression.

Arithmetic coding

arithmetic coderarithmetic encodingarithmetic code
The primary encoding algorithms used to produce bit sequences are Huffman coding (also used by DEFLATE) and arithmetic coding.
Arithmetic coding is a form of entropy encoding used in lossless data compression.

Lempel–Ziv–Markov chain algorithm

LZMALZMA2Lempel-Ziv-Markov chain algorithm
The Lempel–Ziv–Markov chain algorithm (LZMA) is an algorithm used to perform lossless data compression.

Lempel–Ziv–Oberhumer

LZO
Lempel–Ziv–Oberhumer (LZO) is a lossless data compression algorithm that is focused on decompression speed.

DEFLATE

deflateddeflate-decodeDeflate64
The primary encoding algorithms used to produce bit sequences are Huffman coding (also used by DEFLATE) and arithmetic coding. Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters.
In computing, Deflate is a lossless data compression file format that uses a combination of LZSS and Huffman coding.

Lempel–Ziv–Welch

LZWLempel-Ziv-WelchLempel-Ziv-Welch algorithm
Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch.

XZ Utils

xzliblzmaxz-compressed
XZ Utils (previously LZMA Utils) is a set of free software command-line lossless data compressors, including LZMA and xz, for Unix-like operating systems and, from version 5.0 onwards, Microsoft Windows.

Lempel–Ziv–Storer–Szymanski

LZSS
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.

LZ77 and LZ78

LZ77Lempel-ZivLempel–Ziv
Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters.
LZ77 and LZ78 are the two lossless data compression algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978.

GIF

animated GIF.gifGraphics Interchange Format
Some image file formats, like PNG or GIF, use only lossless compression, while others like TIFF and MNG may use either lossless or lossy methods. Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters.
GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality.

LZFSE

Apple LZFSELempel–Ziv Finite State Entropy
LZFSE (Lempel–Ziv Finite State Entropy) is an open source lossless data compression algorithm created by Apple Inc.

Run-length encoding

RLErun length encodingrun-length encoded
Run-length encoding (RLE) is a form of lossless data compression in which runs of data (sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original run.

Joint encoding

Joint stereochannel couplingintensity encoded
It is also often used as a component within lossy data compression technologies (e.g. lossless mid/side joint stereo preprocessing by MP3 encoders and other lossy audio encoders).
Lossless codecs such as FLAC or Monkey's Audio use M/S stereo coding because of this characteristic.

Apple Lossless

ALACApple Lossless Audio Codec.m4a
Apple Lossless, also known as Apple Lossless Audio Codec (ALAC), or Apple Lossless Encoder (ALE), is an audio coding format, and its reference audio codec implementation, developed by Apple Inc. for lossless data compression of digital music.

FLAC

Free Lossless Audio Codec.flacFLAC
FLAC (Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, and is also the name of the free software project producing the FLAC tools, the reference software package that includes a codec implementation.

Dolby TrueHD

TrueHDDolby 3D
Dolby TrueHD is a lossless multi-channel audio codec developed by Dolby Laboratories which is used in home-entertainment equipment such as Blu-ray Disc players and A/V receivers.

Audio Lossless Coding

MPEG-4 ALSALS
MPEG-4 Audio Lossless Coding, also known as MPEG-4 ALS, is an extension to the MPEG-4 Part 3 audio standard to allow lossless audio compression.

DTS-HD Master Audio

DTS-HDDTS HD Master AudioDTS-HD MA 5.1
DTS-HD Master Audio (DTS-HD MA) is a combined lossless/lossy audio codec created by DTS (formerly Digital Theater Systems), commonly used for surround-sound movie soundtracks on Blu-ray Disc.

Bit rate

bitratedata ratedata transfer rate
By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes).
A theoretical lower bound for the encoding bit rate for lossless data compression is the source information rate, also known as the entropy rate.

Meridian Lossless Packing

MLPlosslessMLP (Meridian Lossless Packing)
Meridian Lossless Packing, also known as Packed PCM (PPCM), is a lossless compression technique for compressing PCM audio data developed by Meridian Audio, Ltd. MLP is the standard lossless compression method for DVD-Audio content (often advertised with the Advanced Resolution logo) and typically provides about 1.5:1 compression on most music material.

Monkey's Audio

APE.apeMonkey's Audio (APE)
Monkey's Audio is an algorithm and file format for lossless audio data compression.

TTA (codec)

TTATrue Audio.tta
True Audio (TTA) is a lossless compressor for multichannel 8, 16 and 24 bits audio data.