Filename extension | .jbg, .jbig |
---|---|
Internet media type | image/jbig |
Developed by | ISO, IEC, ITU-T |
Initial release | 1993 |
Type of format | Image file formats |
Extended to | JBIG2 |
Standards | ISO/IEC 11544, ITU-T Recommendations T.82, T.85 |
JBIG is an early 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 in March 1993. [1] It is widely implemented in fax machines. Now that the newer bi-level image compression standard JBIG2 has been released, JBIG is also known as JBIG1. JBIG was designed for compression of binary images, particularly for faxes, but can also be used on other images. In most situations JBIG offers between a 20% and 50% increase in compression efficiency over Fax Group 4 compression, and in some situations, it offers a 30-fold improvement.
JBIG is based on a form of arithmetic coding developed by IBM (known as the Q-coder) that also uses a relatively minor refinement developed by Mitsubishi, resulting in what became known as the QM-coder. It bases the probability estimates for each encoded bit on the values of the previous bits and the values in previous lines of the picture. JBIG also supports progressive transmission, which generally incurs a small overhead in bit rate (around 5%).
Doubts about patent licence requirements for JBIG1 implementations by IBM, Mitsubishi and AT&T prevented the codec from being widely implemented in open-source software. [2] For example, as of 2012, none of the commonly used web browsers supported it. Since 2012, there are now no more JBIG1 patents in force – the last ones to expire were Mitsubishi's patents in Canada and Australia (on 25 February 2011) and in the United States (on 4 April 2012). [2] [3]
Fax, sometimes called telecopying or telefax, is the telephonic transmission of scanned printed material, normally to a telephone number connected to a printer or other output device. The original document is scanned with a fax machine, which processes the contents as a single fixed graphic image, converting it into a bitmap, and then transmitting it through the telephone system in the form of audio-frequency tones. The receiving fax machine interprets the tones and reconstructs the image, printing a paper copy. Early systems used direct conversions of image darkness to audio tone in a continuous or analog manner. Since the 1980s, most machines transmit an audio-encoded digital representation of the page, using data compression to more quickly transmit areas that are all-white or all-black.
H.263 is a video compression standard originally designed as a low-bit-rate compressed format for videotelephony. It was standardized by the ITU-T Video Coding Experts Group (VCEG) in a project ending in 1995/1996. It is a member of the H.26x family of video coding standards in the domain of the ITU-T.
JPEG is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015.
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard.
JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi, with the intention of superseding their original JPEG standard, which is based on a discrete cosine transform (DCT), with a newly designed, wavelet-based method. The standardized filename extension is .jp2 for ISO/IEC 15444-1 conforming files and .jpx for the extended part-2 specifications, published as ISO/IEC 15444-2. The registered MIME types are defined in RFC 3745. For ISO/IEC 15444-1 it is image/jp2.
The JPEG File Interchange Format (JFIF) is an image file format standard published as ITU-T Recommendation T.871 and ISO/IEC 10918-5. It defines supplementary specifications for the container format that contains the image data encoded with the JPEG algorithm. The base specifications for a JPEG container format are defined in Annex B of the JPEG standard, known as JPEG Interchange Format (JIF). JFIF builds over JIF to solve some of JIF's limitations, including unnecessary complexity, component sample registration, resolution, aspect ratio, and color space. Because JFIF is not the original JPG standard, one might expect another MIME type. However, it is still registered as "image/jpeg".
Tag Image File Format or Tagged Image File Format, commonly known by the abbreviations TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processing, optical character recognition, image manipulation, desktop publishing, and page-layout applications. The format was created by the Aldus Corporation for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an Adobe Systems copyright after the latter acquired Aldus in 1994. Several Aldus or Adobe technical notes have been published with minor extensions to the format, and several specifications have been based on TIFF 6.0, including TIFF/EP, TIFF/IT, TIFF-F and TIFF-FX.
The Joint Photographic Experts Group (JPEG) is the joint committee between ISO/IEC JTC 1/SC 29 and ITU-T Study Group 16 that created and maintains the JPEG, JPEG 2000, JPEG XR, JPEG XT, JPEG XS, JPEG XL, and related digital image standards. It also has the responsibility for maintenance of the JBIG and JBIG2 standards that were developed by the former Joint Bi-level Image Experts Group.
Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distribution of video content, used by 91% of video industry developers as of September 2019. It supports a maximum resolution of 8K UHD.
libjpeg is a free library with functions for handling the JPEG image data format. It implements a JPEG codec alongside various utilities for handling JPEG data. It is written in C and distributed as free software together with its source code under the terms of a custom permissive (BSD-like) free software license, which demands attribution. The original variant is maintained and published by the Independent JPEG Group (IJG). Meanwhile, there are several forks with additional features.
The Joint Bi-level Image Experts Group (JBIG) is a group of experts nominated by national standards bodies and major companies to work to produce standards for bi-level image coding. The "joint" refers to its status as a committee working on both ISO and ITU-T standards. It is one of two sub-groups of ISO/IEC Joint Technical Committee 1, Subcommittee 29, Working Group 1, whose official title is Coding of still pictures.
Mixed raster content (MRC) is a method for compressing images that contain both binary-compressible text and continuous-tone components, using image segmentation methods to improve the level of compression and the quality of the rendered image. By separating the image into components with different compressibility characteristics, the most efficient and accurate compression algorithm for each component can be applied.
H.262 or MPEG-2 Part 2 is a video coding format standardised and jointly maintained by ITU-T Study Group 16 Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG), and developed with the involvement of many companies. It is the second part of the ISO/IEC MPEG-2 standard. The ITU-T Recommendation H.262 and ISO/IEC 13818-2 documents are identical.
MPEG-4 Part 2, MPEG-4 Visual is a video compression format developed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC standards. It uses block-wise motion compensation and a discrete cosine transform (DCT), similar to previous standards such as MPEG-1 Part 2 and H.262/MPEG-2 Part 2.
JBIG2 is an image compression standard for bi-level images, developed by the Joint Bi-level Image Experts Group. It is suitable for both lossless and lossy compression. According to a press release from the Group, in its lossless mode JBIG2 typically generates files 3–5 times smaller than Fax Group 4 and 2–4 times smaller than JBIG, the previous bi-level compression standard released by the Group. JBIG2 was published in 2000 as the international standard ITU T.88, and in 2001 as ISO/IEC 14492.
JPEG XR is an image compression standard for continuous tone photographic images, based on the HD Photo specifications that Microsoft originally developed and patented. It supports both lossy and lossless compression, and is the preferred image format for Ecma-388 Open XML Paper Specification documents.
The Video Coding Experts Group or Visual Coding Experts Group is a working group of the ITU Telecommunication Standardization Sector (ITU-T) concerned with standards for compression coding of video, images, audio, and other signals. It is responsible for standardization of the "H.26x" line of video coding standards, the "T.8xx" line of image coding standards, and related technologies.
A video coding format is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation. A specific software, firmware, or hardware implementation capable of compression or decompression in a specific video coding format is called a video codec.
Motion JPEG 2000 is a file format for motion sequences of JPEG 2000 images and associated audio, based on the MP4 and QuickTime format. Filename extensions for Motion JPEG 2000 video files are .mj2 and .mjp2, as defined in RFC 3745.
JPEG XS is an interoperable, visually lossless, low-latency and lightweight image and video coding system used in professional applications. Applications of the standard include streaming high quality content for virtual reality, drones, autonomous vehicles using cameras, gaming, and broadcasting. In this respect, JPEG XS is unique, being the first ISO codec ever designed for this specific purpose. JPEG XS, built on core technology from both intoPIX and Fraunhofer IIS, is formally standardized as ISO/IEC 21122 by the Joint Photographic Experts Group with the first edition published in 2019. Although not official, the XS acronym was chosen to highlight the eXtra Small and eXtra Speed characteristics of the codec. Today, the JPEG committee is still actively working on further improvements to XS, with the second edition scheduled for publication and initial efforts being launched towards a third edition.
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