NationMaster - Encyclopedia: Graphics Interchange Format

The Graphics Interchange Format (GIF) is an 8-bit-per-pixel bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability. GIF may refer to: GIF (Graphics Interchange Format), bitmap image format GIF Sundsvall, Swedish football club Gifford-Inchelium Ferry, on the Columbia River in Washington Winter Havens Gilbert Airport (IATA airport code: GIF) in Winter Haven, Florida, United States Generation IV International Forum Gif may also refer to the... Image File history File links No higher resolution available. ... A filename extension is a suffix to the name of a computer file applied to show its format. ... For mime as an art form, see mime artist. ... A type code is a mechanism used in pre-Mac OS X versions of the Macintosh operating system to denote a files format, in a manner similar to file extensions in other operating systems. ... A Uniform Type Identifier (UTI) is a string that uniquely identifies the type of a class of items. ... In computer programming, the term magic number has multiple meanings. ... CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... Imagine the smiley face in the top left corner as an RGB bitmap image. ... See also Category:Graphics file formats Here is a summary of the most common graphics file formats: Some file formats, e. ... Image File history File links Size of this preview: 505 Ã— 599 pixelsFull resolution (1160 Ã— 1376 pixel, file size: 955 KB, MIME type: image/gif) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 505 Ã— 599 pixelsFull resolution (1160 Ã— 1376 pixel, file size: 955 KB, MIME type: image/gif) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... 8-bit colour graphics is a method of storing image information in a computers memory or in an image file, such that each pixel is represented by one 8-bit byte. ... Imagine the smiley face in the top left corner as an RGB bitmap image. ... See also Category:Graphics file formats Here is a summary of the most common graphics file formats: Some file formats, e. ... CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... Year 1987 (MCMLXXXVII) was a common year starting on Thursday (link displays 1987 Gregorian calendar). ... WWWs historical logo designed by Robert Cailliau The World Wide Web (commonly shortened to the Web) is a system of interlinked, hypertext documents accessed via the Internet. ...

The format uses a palette of up to 256 distinct colors from the 24-bit RGB color space. It also supports animations and allows a separate palette of 256 colors for each frame. The color limitation makes the GIF format unsuitable for reproducing color photographs and other images with continuous color, but it is well-suited for more simple images such as graphics or logos with solid areas of color.

GIF images are compressed using the Lempel-Ziv-Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. This compression technique was patented in 1985. Though the relevant patents have all since expired, the controversy over the licensing agreement between the patent holder, Unisys, and CompuServe in 1994 led to the development of the Portable Network Graphics (PNG) standard. LZW (Lempel-Ziv-Welch) is a lossless data compression algorithm. ... Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. ... Unisys Corporation (NYSE: UIS), based in Blue Bell, Pennsylvania, United States, and incorporated in Delaware[3], is a global provider of information technology services and solutions. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ...

History

CompuServe introduced the GIF format in 1987 to provide a color image format for their file downloading areas, replacing their earlier RLE format, which was black and white only. GIF became popular because it used LZW data compression, which was more efficient than the run-length encoding that formats such as PCX and MacPaint used, and fairly large images could therefore be downloaded in a reasonable amount of time, even with very slow modems. CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... Year 1987 (MCMLXXXVII) was a common year starting on Thursday (link displays 1987 Gregorian calendar). ... Run-length encoding (RLE) is a very simple form of data compression in which runs of data (that is, 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. ... Source coding redirects here. ... Run-length encoding (RLE) is a very simple form of data compression in which runs of data (that is, 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. ... PCX is an image file format that uses a simple form of run-length encoding (a type of lossless compression algorithm). ... MacPaint is a bitmap-based image editing computer program that was produced by Apple Computer for bundling with their Macintosh personal computer. ... For other uses, see Modem (disambiguation). ...

The original version of the GIF format was called 87a. In 1989, CompuServe devised an enhanced version, called 89a,^[1] that added support for multiple images in a stream, interlacing and storage of application-specific metadata. The two versions can be distinguished by looking at the first six bytes of the file, which, when interpreted as ASCII, read "GIF87a" and "GIF89a", respectively. Year 1989 (MCMLXXXIX) was a common year starting on Sunday (link displays 1989 Gregorian calendar). ... For the computer industry magazine, see Byte (magazine). ... Image:ASCII fullsvg There are 95 printable ASCII characters, numbered 32 to 126. ...

When the World Wide Web gained popularity, GIF became one of the two image formats commonly used on Web sites, the other being the black and white XBM.^{[citation needed]} JPEG came later with the Mosaic browser. XBM (X BitMap) is an ASCII monochrome image format used by the X Window System and is used for storing cursor and icon bitmaps that are used in the X GUI. XBM files are quite different from most image files in that they are actually C language source files that... JPG redirects here. ... Mosaic is a web browser (client) for the World Wide Web written at the National Center for Supercomputing Applications (NCSA). ...

The GIF89a feature of storing multiple images in one file, accompanied by control data, is used extensively on the web to produce simple animations. The optional interlacing feature, which stored image scan lines out of order in such a fashion that even a partially downloaded image was somewhat recognizable, also helped GIF's popularity,^{[citation needed]} as a user could abort the download if it was not what was required. Computer animation is the art of creating moving images via the use of computers. ...

Pronunciation

Most people pronounce GIF with a hard "G" reflecting the way it is pronounced in its own acronym (Graphics Interchange Format) ^[2]. However, the creators of the format pronounced GIF with a soft "g", IPA: [dʒ], as in "George". According to the creator of the GIF format, Steve Wilhite, the pronunciation deliberately echoes that of an American peanut butter brand, Jif, and the employees of CompuServe would often say "Choosy developers choose GIF", spoofing this brand's television commercials.^{[citation needed]} This pronunciation was also identified by CompuServe in their documentation of a graphics display program called CompuShow.^[3]. Both pronunciations are given as correct by the Oxford English Dictionary^[4] and the American Heritage Dictionary.^[5] For other uses, see G (disambiguation). ... IPA may refer to: The International Phonetic Alphabet or India Pale Ale ... Steve Whilhite of CompuServe Invented the GIF Format which went on to become the de facto standard for 8-bit images on the Internet. ... Jar of creamy Jif. ... CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... The Oxford English Dictionary print set The Oxford English Dictionary (OED) is a dictionary published by the Oxford University Press (OUP), and is the most successful dictionary of the English language, (not to be confused with the one-volume Oxford Dictionary of English, formerly New Oxford Dictionary of English, of... The American Heritage Dictionary of the English Language (AHD) is a dictionary of American English published by Boston publisher Houghton-Mifflin, the first edition of which appeared in 1969. ...

Usage

Image File history File links BananaShoeShine. ... Image File history File links BananaShoeShine. ... JPG redirects here. ... 10 MP Nikon D200 and a Nikon film scanner The Canon EOS 350D The Canon PowerShot A95 Digital photography, as opposed to film photography, uses electronic devices to record and capture the image as binary data. ... Original Image (lossless PNG, 60. ... DIB redirects here. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... MNG (pronounced in IPA) is a public file format for animated images. ... The Animated Portable Network Graphics (APNG) file format is an extension to the Portable Network Graphics (PNG) specification proposed by Stuart Parmenter and Vladimir Vukicevic of the Mozilla Corporation. ...

Palettes

GIF is palette based: although any palette selection can be one of millions of shades, the maximum number that can be used in a frame is 256. These are stored in a "palette", a table that associates each palette selection number with a specific RGB value. The limitation to 256 colors seemed reasonable at the time of GIF's creation because few people could afford the hardware to display more. Simple graphics, line drawings, cartoons, and grey-scale photographs typically need fewer than 256 colors. In addition, one of the colors in the palette can optionally be set as fully transparent. A palette, in computer graphics, is a designated subset of the total range of colors supported by a computer graphics system. ... REDIRECT RGB color model ...

There exist ways to dither or diffuse photographs by using pixels of 2 or more different colors to approximate an in-between color, but this transformation inevitably loses some detail. The algorithms used to select the palette and to perform the dithering vary widely in output quality. Additionally, dithering significantly reduces the image's compressibility and thus works contrary to GIF's main purpose. This article or section should be merged with Dither An illustration of dithering. ... In mathematics, computing, linguistics, and related disciplines, an algorithm is a finite list of well-defined instructions for accomplishing some task that, given an initial state, will terminate in a defined end-state. ...

In the early days of graphical web browsers, graphics cards with 8-bit buffers (allowing only 256 colors) were common and it was fairly common to make GIF images using the websafe palette which was based on the common subset of the standard Windows and Macintosh palettes.^{[citation needed]} This ensured predictable display but severely limited the choice of colors. Now that 24-bit graphics cards are the norm, optimized palettes make less sense when creating images, though there are still many sites on web design that advise the use of the web safe palette.^{[citation needed]} Web colors are colors used in designing web pages, and the methods for describing and specifying those colors. ...

True color

Although the standard GIF format is limited to 256 colors, there is a hack^[6] that can overcome this limitation under certain circumstances. A hack in progress in Lobby 7 at MIT. Hack is a term in the slang of the technology culture which has come into existence over the past few decades. ...

GIF89a was designed based on the principle of rendering images (known as frames when used for animation) to a logical screen. Each image could optionally have its own palette, and the format provides flags to specify delay and waiting for user input between them (the latter is not widely supported by viewers). This is the feature that is used to create animated GIFs, but it can also be used to store a 24-bit RGB (truecolor) image by splitting it up into pieces small enough to be encoded into a 256 color palette and setting up the GIF to render these with no delay on the logical screen.^[7]^[8] However, most web browsers seem to assume that this multi-image feature will only be used for animation and insert a minimum delay between images. There will also be some file size bloat from doing this. There are few tools around that can easily produce 24-bit GIFs (e.g. ANGIF or SView5) - however it is rarely an appropriate format unless there is absolutely no other option. Truecolor (also spelled Truecolour; called Millions on a Macintosh) graphics is a method of storing image information in a computers memory such that each pixel is represented by three or more bytes. ...

Unisys and LZW patent enforcement

In 1977 and 1978, Jacob Ziv and Abraham Lempel published a pair of papers on a new class of lossless data-compression algorithms, now collectively referred to as "LZ77" and "LZ78". In 1983, Terry Welch developed a fast variant of LZ78 which was named LZW.^[9]^[10] Jacob Ziv, along with Abraham Lempel, developed the lossless LZ77 compression algorithm. ... Abraham Lempel is a computer scientist and one of the fathers of the LZ family of lossless data compression algorithms. ... LZ77 and LZ78 are the names for the two lossless data compression algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978. ... LZ77 and LZ78 are the names for the two lossless data compression algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978. ... Terry Welch, along with Abraham Lempel and Jacob Ziv, developed the lossless LZW compression algorithm which was published in 1984. ...

Welch filed a patent application for the LZW method in June 1983. The resulting patent, US patent 4558302, granted in December 1985, was assigned to Sperry Corporation who subsequently merged with Burroughs Corporation in 1986 and formed Unisys.^[9] Further patents were obtained in the United Kingdom, France, Germany, Italy, Japan and Canada. Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the twentieth century. ... William Seward Burroughs (1857-1898), US inventor William S. Burroughs (1914-1997), author and grandson of William Seward Burroughs Edgar Rice Burroughs (1875-1950), American author of Tarzan fame The Burroughs Corporation began in 1886 as the American Arithmometer Company in St. ... Unisys Corporation (NYSE: UIS), based in Blue Bell, Pennsylvania, United States, and incorporated in Delaware[3], is a global provider of information technology services and solutions. ...

In June 1984, an article by Welch was published in the IEEE magazine which publicly described the LZW technique for the first time.^[11] LZW became a popular data compression technique and, when the patent was granted, Unisys entered into licensing agreements with over a hundred companies.^[9]^[12] The Institute of Electrical and Electronics Engineers or IEEE (pronounced as eye-triple-ee) is an international non-profit, professional organization incorporated in the State of New York, United States. ...

The popularity of LZW led CompuServe to choose it as the compression technique for their GIF format, developed in 1987. At the time, CompuServe were not aware of the patent.^[9] Unisys became aware that the GIF format used the LZW compression technique and entered into licensing negotiations with CompuServe in January 1993. The subsequent agreement was announced on December 24, 1994.^[10] Unisys stated that they expected all major commercial on-line information services companies employing the LZW patent to license the technology from Unisys at a reasonable rate, but that they would not require licensing, or fees to be paid, for non-commercial, non-profit GIF-based applications, including those for use on the on-line services.^[12] CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... is the 358th day of the year (359th in leap years) in the Gregorian calendar. ... Year 1994 (MCMXCIV) The year 1994 was designated as the International Year of the Family and the International Year of the Sport and the Olympic Ideal by the United Nations. ...

Following this announcement, there was widespread condemnation of CompuServe and Unisys, and many software developers threatened to stop using the GIF format. The PNG format was developed in 1995 as an intended replacement.^[9]^[10]^[11] However, obtaining support from the makers of Web browsers and other software for the PNG format proved difficult and it was not possible to replace the GIF format entirely, although PNG has gradually increased in popularity.^[9]

In August 1999, Unisys changed the details of their licensing practice, announcing the option for owners of Billboard and Intra net Web sites to obtain licenses on payment of a one-time license fee of $5000 or $7500.^[13] Such licenses were not required for website owners or other GIF users who had used licensed software to generate GIFs. Nevertheless, Unisys was the subject of thousands of online attacks and abusive emails from users believing that they were going to be charged $5000 or sued for using GIFs on their websites.^[14]. Despite giving free licenses to hundreds of non-profit organizations, schools and governments, Unisys was completely unable to generate any good publicity and continued to be vilified by individuals and organizations such as the League for Programming Freedom who started the "Burn All GIFs" campaign^[15] League for Programming Freedom (LPF) was founded in 1989 by Richard Stallman to unite free software developers as well as developers of proprietary software to fight against software patents and the extension of the scope of copyright. ...

The US LZW patent expired on June 20, 2003. The counterpart patents in the United Kingdom, France, Germany and Italy expired on June 18, 2004, the Japanese counterpart patents expired on June 20, 2004 and the counterpart Canadian patent expired on July 7, 2004.^[16] Consequently, while Unisys has further patents and patent applications relating to improvements to the LZW technique,^[16] the GIF format may now be used freely. is the 171st day of the year (172nd in leap years) in the Gregorian calendar. ... Year 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... is the 169th day of the year (170th in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... is the 171st day of the year (172nd in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... is the 188th day of the year (189th in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...

Alternatives

Portable Network Graphics (PNG) was designed as a replacement for the GIF format in order to avoid infringement of Unisys' patent on the LZW compression technique.^[9] PNG offers better compression and more features than GIF. The format is more suitable than GIF in instances where true-color imaging, alpha transparency, or a lossless data format are required. MNG was originally developed as a PNG-based solution for animations, but has not been widely adopted. The GIF format is still preferred for animation over PNG, although true Animated Portable Network Graphics are under development by Mozilla and will be supported in the upcoming Firefox 3 release.^[17]^[18] PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... In computer graphics, alpha compositing is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a process called compositing. ... MNG (pronounced in IPA) is a public file format for animated images. ... The Animated Portable Network Graphics (APNG) file format is an extension to the Portable Network Graphics (PNG) specification proposed by Stuart Parmenter and Vladimir Vukicevic of the Mozilla Corporation. ... Mozilla was the official, public, original name of Mozilla Application Suite by the Mozilla Foundation, nowadays called SeaMonkey suite. ... Firefox redirects here. ...

Although it took time for the PNG format to be supported, new web browsers support the PNG format and GIF images can usually be replaced by PNG images if desired. However, Internet Explorer versions 6 and earlier do not support PNG's alpha channel transparency feature without using Microsoft-specific HTML extensions.^[19] Using standard HTML <img> tags for PNG images in Internet Explorer can produce a look different from that intended. Internet Explorer 7 supports alpha channel transparency without needing extensions.^[20] An example of a Web browser (Mozilla Firefox) A web browser is a software application that enables a user to display and interact with text, images, videos, music and other information typically located on a Web page at a website on the World Wide Web or a local area network. ... Windows Internet Explorer (formerly Microsoft Internet Explorer abbreviated MSIE), commonly abbreviated to IE, is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995. ... In computer graphics, alpha compositing is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a process called compositing. ...

There have been claims that PNG files are generally larger than GIFs.^{[citation needed]} PNG files can indeed be much larger than GIF files in situations where a GIF and a PNG file were created from a high-quality master image, as PNG is capable of storing more color depth and transparency information than GIF. However, identical 8-bit (or lower) image data rendered in PNG and GIF formats should yield similar sizes. Misinformation about PNG efficiency can generally be traced back to poor PNG support in older versions of some image manipulation programs, (for example Adobe Photoshop did not optimize PNGs for reduced color palettes by default).^{[citation needed]}MNG, a variant of PNG that supports animation, reached version 1.0 in 2001, but few applications support it. Animated GIF remains widely used as many applications are capable of creating the files, and it remains the only animated image format capable of being rendered in nearly all modern web browsers without the use of a plug-in.^{[citation needed]} Nevertheless, embedded Flash objects, MPEGs and other video formats are used in place of animated GIFs in many websites. Other approaches, such as individual frames served by AJAX, or SVG images may be animated via JavaScript. In 2004, a proposed extension to the PNG format called APNG was suggested. It was to provide the ability to animate PNG files, while retaining backwards compatibility in decoders that cannot understand the animation chunk. Older decoders would simply render the first frame of the animation. Photoshop redirects here. ... MNG (pronounced in IPA) is a public file format for animated images. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... // Ajax may refer to: Ajax the Great as a well known hero from the Trojan war and son of Telamon Ajax the Lesser son of the king of Locris, and another hero in the Trojan war Ajax (missionary), Arian missionary who converted the pagan Suevi c. ... SVG is also the IATA code for Stavanger Airport, Sola in Norway. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... The Animated Portable Network Graphics (APNG) file format is an extension to the Portable Network Graphics (PNG) specification proposed by Stuart Parmenter and Vladimir Vukicevic of the Mozilla Corporation. ...

See also

This is a comparison of graphics file formats. ... The following tables compare graphics compatibility and support for a number of layout engines. ... Image file formats provide a standardized method of organizing and storing image data. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... JPG redirects here. ... Software patent does not have a universally accepted definition. ...

References

CompuServe, (in full, CompuServe Information Services, or CIS), was the first major commercial online service in the United States. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... League for Programming Freedom (LPF) was founded in 1989 by Richard Stallman to unite free software developers as well as developers of proprietary software to fight against software patents and the extension of the scope of copyright. ... Slashdot, often abbreviated as /.[1], is a science, science fiction, and technology-related news website owned by SourceForge, Inc. ...

External links

Categories: All articles with unsourced statements | Articles with unsourced statements since February 2007 | Articles with unsourced statements since April 2007 | Articles with sections needing expansion | Graphics file formats | CompuServe Look up Multimedia in Wiktionary, the free dictionary. ... Source coding redirects here. ... Video compression refers to making a digital video signal use less data, without noticeably reducing the quality of the picture. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... Motion JPEG, also known as M-JPEG, is a video file format consisting of a sequence of individual JPEG images; unlike other video compression algorithms, each frame is an image unto itself. ... MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). ... MPEG-2 is a standard for the generic coding of moving pictures and associated audio information [1]. It is widely used around the world to specify the format of the digital television signals that are broadcast by terrestrial (over-the-air), cable, and direct broadcast satellite TV systems. ... MPEG-4 Part 2 is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standard (ISO/IEC 14496-2). ... H.264 is a standard for video compression. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... H.261 is an 1990 ITU video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. ... H.262 is an ITU-T digital video coding standard. ... H.263 is a video codec designed by the ITU-T as a low-bitrate encoding solution for videoconferencing. ... H.264 is a standard for video compression. ... Audio Video Standard, or AVS, is a compression codec for digital audio and video, and a possible alternative to H.264/AAC/Vorbis [1], meant to potentially replace MPEG-2. ... Bink is a video file format (extension . ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. ... Indeo Video (commonly known now simply as Indeo) is a video codec developed by Intel in 1992. ... Motion JPEG (M-JPEG) is an informal name for multimedia formats where each video frame or interlaced field of a digital video sequence is separately compressed as a JPEG image. ... Pixlet is a video codec created by Apple Computer and based on wavelets, designed to enable viewing of full resolution, high resolution movies in real time at low DV data rates. ... RealVideo is a proprietary video format developed by RealNetworks. ... RTVideo RTVideo is Microsofts default video codec for OCS. RTVideo is a proprietrary codec. ... Smacker video is a video file format (with the file extension) developed by RAD Game Tools and oftenly used in computer games. ... Theora is a video codec being developed by the Xiph. ... VC-1 is the informal name of the SMPTE 421M video codec standard initially developed by Microsoft. ... TrueMotion VP6 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3 and VP5. ... TrueMotion VP7 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3, VP5 and TrueMotion VP6. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ... This article is about a process which reduces the data rate or file size of digital audio signals. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... For other uses, see MP3 (disambiguation). ... MPEG-1 Audio Layer II (MP2, sometimes Musicam) is an audio codec defined by ISO/IEC 11172-3. ... MPEG-1 Audio Layer I, commonly abbreviated to MP1, is one of three audio codecs included in the MPEG-1 standard. ... MPEG-4 AAC DRM encoding as used in the iTunes Store Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... G.711 is an ITU-T standard for audio companding. ... G.722[1] is a ITU-T standard wideband speech codec operating at 48-64 kbit/s. ... G.722. ... Adaptive Multi Rate - WideBand or AMR-WB is a speech coding standard developed after the AMR using same technology like ACELP. The codec provides excellent speech quality due to wider speech bandwidth of 50 - 7000 Hz compared to narrowband speech codecs which in general are optimized for POTS wireline quality... This article is in need of attention from an expert on the subject. ... G.723. ... G.726 is ITU-T speech codec operating at bit rates of 16-40 kbit/s. ... G.728 is a ITU-T standard for speech coding operating at 16 kbit/s. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... Dolby Digital is the marketing name for a series of lossy audio compression technologies by Dolby Laboratories. ... Adaptive Multi-Rate (AMR) is an audio data compression scheme optimized for speech coding. ... Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is an audio codec developed by Apple Inc. ... Adaptive Transform Acoustic Coding (ATRAC) is a family of proprietary audio compression algorithms developed by Sony. ... Free Lossless Audio Codec (FLAC) is a popular file format for audio data compression. ... internet Low Bit Rate Codec (iLBC) is a royalty free narrowband speech codec, developed by Global IP Sound (GIPS). ... Monkeyâ€™s Audio is a file format for audio data compression. ... In telecommunication, a mu-law algorithm (Î¼-law) is a standard analog signal compression or companding algorithm, used in digital communications systems of the North American and Japanese digital hierarchies, to optimize (in other words, modify) the dynamic range of an audio analog signal prior to digitizing. ... Musepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160-180 kbit/s. ... Nellymoser is a single-channel (mono) format optimized for low-bitrate transmission of audio. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... RealAudio is a proprietary audio format developed by RealNetworks. ... RTAudio is a Microsoft produced adaptive wide-band speech codec. ... SHN (Shorten) is a file format used to losslessly compress CD-quality audio files (44. ... Speex is a free software speech codec that may be used on VoIP applications and podcasts. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... WavPack is a free, open source lossless audio compression format developed by David Bryant. ... Windows Media Audio (WMA) is an audio data compression technology developed by Microsoft. ... TAK (Toms lossless Audio Kompressor) is a lossless audio compressor which promises compression performance similar to Monkeys Audio â€œHighâ€ and decompression speed similar to FLAC. The codec also supports streaming (necessary headers for decompressing the audio are written to the stream every 2 seconds), error tolerance (single bit... Image compression is the application of Data compression on digital images. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... JPG redirects here. ... JPEG 2000 is a wavelet-based image compression standard. ... The Joint Photographic Experts Group, in addition to their well-known lossy image compression techniques, JPEG and JPEG 2000, also have three standards for lossless compression (of which JPEG-LS has a lossy mode): Lossless JPEG was developed as a late addition to JPEG in 1993, using a completely different... JBIG is a lossless image compression standard from the Joint Bi-level Image Experts Group, standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. ... JBIG2 is an image compression standard for bi-level images, developed by the Joint Bi-level Image Experts Group. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... Wireless Application Protocol Bitmap Format (shortened to Wireless Bitmap and with file extension . ... .BMP or . ... ICER is a wavelet-based image compression file format used by the NASA Mars Rovers. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... PCX is an image file format that uses a simple form of run-length encoding (a type of lossless compression algorithm). ... PGF (Progressive Graphics File) is a wavelet-based bitmapped image format that employs lossless and lossy data compression. ... Truevisions (now Pinnacle Systems) TGA File Format, often referred to as TARGA File Format, is a raster graphics file format. ... â€œTIFFâ€ redirects here. ... JPEG XR (formerly HD Photo (formerly Windows Media Photo) ) is a still image compression algorithm and file format for continuous tone photographic images, developed by Microsoft as a part of the Windows Media family. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... 3GP is a multimedia container format defined by the Third Generation Partnership Project (3GPP) for use on 3G mobile phones. ... Advanced Systems Format (formerly Advanced Streaming Format, Active Streaming Format) is Microsofts proprietary digital audio/digital video container format, especially meant for streaming media. ... // Audio-Video Interleaved, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. ... Bink is a video file format (extension . ... DivX is a video codec created by DivX, Inc. ... DPX is also the name given to a mounting medium, see Di-n-butylPhthalate in Xylene. ... Flash Video is the name of a file format used to deliver video over the Internet using Adobe Flash Player (formerly known as Macromedia Flash Player) version 6, 7, 8, or 9. ... // The Matroska Multimedia Container is an open standard free multimedia container format that can hold an unlimited number of video, audio, picture or subtitle tracks inside a single file. ... For other parts of the MPEG-4 standard, see MPEG-4. ... Material eXchange Format (MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards. ... NUT is a patent-free, multimedia container format originally conceived by a few MPlayer and FFmpeg developers that were dissatisfied with the limitations of all currently available multimedia container formats such as AVI or Matroska. ... Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. ... Ogg Media (OGM), meaning Ogg Media File, is a container format (for video, audio and subtitle streams). ... QuickTime is a multimedia framework developed by Apple Inc. ... RealMedia is a multimedia container format created by RealNetworks. ... Smacker video is a video file format (with the file extension) developed by RAD Game Tools and oftenly used in computer games. ... A VOB file (DVD-Video Object or Versioned Object Base) is a container format contained in DVD-Video media. ... Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data for personal computers and other electronic audio devices. ... The Au file format is a simple audio file format that consists of a header of 6 32-bit words and then the data (high-order byte comes first). ... WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. ...

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