Data Compression
lastmod 2026-02-13created 2014-09-165 edits
Data compression refers to techniques for efficiently recording data in less storage space, or to the practical application of those techniques.
It broadly consists of an encoding process that converts data into a smaller size and a decoding process that reads the stored data back and restores it to its original form. The ratio of the data size before encoding to the data size after encoding is called the compression ratio.
Depending on the type of compression technique, there is lossless compression, which can decode the data exactly as it was without changing its content, and lossy compression, which achieves higher compression ratios but sacrifices some of the fine detail of the decoded data. Representative lossless compression algorithms include run-length encoding and Huffman coding. Lossy compression algorithms raise the compression ratio by exploiting the characteristics of human sensory organs, so different algorithms are used depending on the type of data, such as audio, still images, and video. MPEG standard compression technologies are widely used.
Data Compression Methods
| Lossless | Entropy encoding | Shannon-Fano, Shannon-Fano-Elias, Huffman (Adaptive, Canonical, Modified), Arithmetic, Range, Golomb, Universal (Gamma, Exp-Golomb, Fibonacci, Levenstein) |
| Dictionary | RLE, Byte pair encoding, DEFLATE, Lempel-Ziv (LZ77/78, LZSS, LZW, LZWL, LZO, LZMA, LZX, LZRW, LZJB, LZS, LZT, ROLZ), Statistical Lempel Ziv | |
| Others | CTW, BWT, PPM, DMC, Delta | |
| Audio | Theory | Companding, Convolution, Dynamic range, Latency, Sampling, Nyquist-Shannon theorem, Sound quality |
| Audio codec parts | LPC (LAR, LSP), WLPC, CELP, ACELP, A-law, μ-law, ADPCM, DPCM, MDCT, Fourier transform, Psychoacoustic model | |
| Others | Bit rate (CBR, ABR, VBR), Speech compression, Sub-band coding | |
| Image | Terms | Color space, Pixel, Chroma subsampling, Compression artifact, Image resolution |
| Methods | RLE, Fractal, Wavelet, EZW, SPIHT, LP, DCT, Chain code, KLT | |
| Others | Test images, PSNR quality measure, Quantization | |
| Video | Terms | Video characteristics, Frame, Frame rate, Interlace, Frame types, Video quality, Video resolution |
| Video codec parts | Motion compensation, DCT, Quantization | |
| Others | Video codecs, Bit rate (CBR, ABR, VBR) | |
Multimedia compression and container formats
| Video | ISO/IEC | MJPEG, Motion JPEG 2000, MPEG-1, MPEG-2(Part 2), MPEG-4(Part 2/ASP, Part 10/AVC), HEVC |
| ITU-T | H.120, H.261, H.262, H.263, H.264, HEVC | |
| Others | AVS, Bink, CineForm, Cinepak, Dirac, DV, Indeo, Microsoft Video 1, OMS Video, Pixlet, Prores, RealVideo, RTVideo, SheerVideo, Smacker, Sorenson Video & Spark, Theora, VC-1, VC-2, VC-3, VP3, VP6, VP7, VP8, VP9, WMV, XEB, AV1 | |
| Audio | ISO/IEC | MPEG-1 Layer III (MP3), MPEG-1 Layer II (Multichannel), MPEG-1 Layer I, AAC, HE-AAC, MPEG Surround, MPEG-4 ALS, MPEG-4 SLS, MPEG-4 DST, MPEG-4 HVXC, MPEG-4 CELP, USAC |
| ITU-T | G.711, G.718, G.719, G.722, G.722.1, G.722.2, G.723, G.723.1, G.726, G.728, G.729, G.729.1 | |
| Others | AC-3, AMR, AMR-WB, AMR-WB+, ALAC, Asao, ATRAC, CELT, DRA, DTS, EVRC, EVRC-B, FLAC, GSM-HR, GSM-FR, GSM-EFR, iLBC, iSAC, Monkey's Audio, TTA (True Audio), MT9, A-law, µ-law, Musepack, OptimFROG, Opus, OSQ, QCELP, RealAudio, RTAudio, SD2, SHN, SILK, Siren, SMV, Speex, SVOPC, TwinVQ, VMR-WB, Vorbis, WavPack, WMA | |
| Image | ISO/IEC/ITU-T | JPEG, JPEG 2000, JPEG XR, Lossless JPEG, JBIG, JBIG2, PNG, TIFF/EP, TIFF/IT |
| Others | APNG, BMP, DjVu, EXR, GIF, ICER, ILBM, MNG, PCX, PGF, TGA, QTVR, TIFF, WBMP, WebP | |
| Containers | ISO/IEC | MPEG-PS, MPEG-TS, ISO base media file format, MPEG-4 Part 14, Motion JPEG 2000, MPEG-21 Part 9 |
| ITU-T | H.222.0, T.802 | |
| Others | 3GP and 3G2, AMV, ASF, AIFF, AVI, AU, Bink, DivX Media Format, DPX, EVO, Flash Video, GXF, M2TS, Matroska, MXF, Ogg, QuickTime File Format, ratDVD, RealMedia, REDCODE RAW, RIFF, Smacker, MOD and TOD, VOB & IFO and BUP, WAV, WebM | |
Data Compression Software
| Free software | 7-Zip, Ark, File Roller, FreeArc, Info-ZIP, KGB Archiver, PAQ, PeaZip, The Unarchiver (decompression only), tar, UPX, Xarchiver, Zipeg | ||
| Freeware | Filzip, IZArc, LHA, StuffIt Expander (decompression only), TUGZip, ZipGenius, Bandizip, ZIPj | ||
| Commercial | ARC, ALZip, Archive Utility, ARJ, BetterZip, JAR, MacBinary, PKZIP/SecureZIP, PowerArchiver, StuffIt, WinAce, WinRAR, WinZip | ||
| Lossless data compression | Free software | bzip2, compress, gzip, lzip, lzop, rzip, xz | |
| Lossy | Freeware Advanced Audio Coder (FAAC), Helix DNA Producer, l3enc, LAME, TooLAME, libavcodec, libcelt, libspeex, Musepack, libvorbis, Windows Media Encoder | ||
| Lossless | ALAC, FLAC, libavcodec, Monkey's Audio, mp4als, OptimFROG, Shorten, TTA (True Audio), WavPack | ||
| Lossy | MPEG-4 ASP | 3ivx, DivX, Nero Digital, FFmpeg, HDX4, Xvid | |
| H.264/MPEG-4 AVC | CoreAVC, Blu-code, DivX, FFmpeg, Nero Digital, QuickTime, x264 | ||
| Others | CineForm, Cinepak, DNxHD, Helix DNA Producer, Indeo, libavcodec, Schrödinger (Dirac), SBC, Sorenson, VP7, libtheora, libvpx, Windows Media Encoder | ||
| Lossless | FFV1, Huffyuv, Lagarith, MSU Lossless, SheerVideo, YULS | ||
See also
- Algorithms#Data compression
- ZXC - high-performance asymmetric lossless compression library optimized for content delivery