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JFIF
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 Digital container format, 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" (indicating its primary data format rather than the amended information). JFIF is #Compatibility, mutually incompatible with the newer Exchangeable image file format (Exif). Purpose JFIF defines a number of details that are left unspecified by the JPEG Part 1 standard (ISO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) 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 trade off between storage size and image quality. JPEG typically achieves 10:1 compression with noticeable, but widely agreed to be acceptable 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. The Joint Photographic Experts Group created the standard in 1992, based on the discrete cosine transform (DCT) algorithm. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet and later social media. JPEG compression is used in a number of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image File Format
An image file format is a file format for a digital image. There are many formats that can be used, such as JPEG, PNG, and GIF. Most formats up until 2022 were for storing 2D images, not 3D ones. The data stored in an image file format may be compressed or uncompressed. If the data is compressed, it may be done so using lossy compression or lossless compression. For graphic design applications, vector graphics, vector formats are often used. Some image file formats support Transparency (graphic), transparency. Raster formats are for 2D images. A 3D image can be represented within a 2D format, as in a stereogram or autostereogram, but this 3D image will not be a true light field, and thereby may cause the vergence-accommodation conflict. Image Computer file, files are composed of digital data in one of these formats so that the data can be displayed on a digital (computer) display or printed out using a printer. A common method for displaying digital image information has histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YCbCr
YCbCr, Y′CbCr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in digital video and digital photography, photography systems. Like YPbPr, YPBPR, it is based on RGB primaries; the two are generally equivalent, but YCBCR is intended for digital video, while YPBPR is designed for use in Analogue electronics, analog systems. Y′ is the Luma (video), luma component, and CB and CR are the B-Y, blue-difference and R-Y, red-difference chrominance, chroma components. Luma Y′ (with Prime (symbol), prime) is distinguished from relative luminance, luminance Y, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries. Y′CbCr color spaces are defined by a mathematical coordinate transformation from an associated RGB primaries and white point. If the underlying RGB color spaces, RGB color space is absolute, the Y′CbCr color space is an absolute color space as well; conversely, if the RGB spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Container Format
A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Notable examples of container formats include archive files (such as the ZIP format) and formats used for multimedia playback (such as Matroska, MP4, and AVI). Among the earliest cross-platform container formats were Distinguished Encoding Rules and the 1985 Interchange File Format. Design Although containers may identify how data or metadata is encoded, they do not actually provide instructions about how to decode that data. A program that can open a container must also use an appropriate codec to decode its contents. If the program doesn't have the required algorithm, it can't use the contained data. In these cases, programs usually emit an error message that complains of a missing codec, which users may be able to acquire. Container ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endianness
file:Gullivers_travels.jpg, ''Gulliver's Travels'' by Jonathan Swift, the novel from which the term was coined In computing, endianness is the order in which bytes within a word (data type), word of digital data are transmitted over a data communication medium or Memory_address, addressed (by rising addresses) in computer memory, counting only byte Bit_numbering#Bit significance and indexing, significance compared to earliness. Endianness is primarily expressed as big-endian (BE) or little-endian (LE), terms introduced by Danny Cohen (computer scientist), Danny Cohen into computer science for data ordering in an Internet Experiment Note published in 1980. Also published at The adjective ''endian'' has its origin in the writings of 18th century Anglo-Irish writer Jonathan Swift. In the 1726 novel ''Gulliver's Travels'', he portrays the conflict between sects of Lilliputians divided into those breaking the shell of a boiled egg from the big end or from the little end. By analogy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Aspect Ratio
A pixel aspect ratio (PAR) is a mathematical ratio that describes how the width of a pixel in a digital image compares to the height of that pixel. Most digital imaging systems display an image as a grid of tiny, square pixels. However, some imaging systems, especially those that must be compatible with standard-definition television motion pictures, display an image as a grid of rectangular pixels, in which the pixel width and height are different. Pixel aspect ratio describes this difference. Use of pixel aspect ratio mostly involves pictures pertaining to standard-definition television and some other exceptional cases. Most other imaging systems, including those that comply with SMPTE standards and practices, use square pixels. PAR is also known as ''sample aspect ratio'' and abbreviated ''SAR'', though it can be confused with storage aspect ratio. Introduction The ratio of the width to the height of an image is known as the aspect ratio, or more precisely the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoshop
Adobe Photoshop is a raster graphics editor developed and published by Adobe for Windows and macOS. It was created in 1987 by Thomas and John Knoll. It is the most used tool for professional digital art, especially in raster graphics editing, and its name has become genericised as a verb (e.g. "to photoshop an image", " photoshopping", and " photoshop contest") although Adobe disapproves of such use. Photoshop can edit and compose raster images in multiple layers and supports masks, alpha compositing and several color models. Photoshop uses its own PSD and PSB file formats to support these features. In addition to raster graphics, Photoshop has limited abilities to edit or render text and vector graphics (especially through clipping path for the latter), as well as 3D graphics and video. Its feature set can be expanded by plug-ins; programs developed and distributed independently of Photoshop that run inside it and offer new or enhanced features. Photoshop's naming sch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPTC Information Interchange Model
The Information Interchange Model (IIM) is a file structure and set of metadata attributes that can be applied to text, images and other media types. It was developed in the early 1990s by the International Press Telecommunications Council (IPTC) to expedite the international exchange of news among newspapers and news agencies. The full IIM specification includes a complex data structure and a set of metadata definitions. A new version of the user guide was released in May 2024. Although IIM was intended for use with all types of news items — including simple text articles — a subset found broad worldwide acceptance as the standard embedded metadata used by news and commercial photographers. Information such as the name of the photographer, copyright information and the caption or other description can be embedded either manually or automatically. IIM metadata embedded in images are often referred to as "IPTC headers", and can be easily encoded and decoded by most p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIME Type
In information and communications technology, a media type, content type or MIME type is a two-part identifier for file formats and content formats. Their purpose is comparable to filename extensions and uniform type identifiers, in that they identify the intended data format. They are mainly used by technologies underpinning the Internet, and also used on Linux desktop systems. The Internet Assigned Numbers Authority (IANA) is the official authority for the standardization and publication of these classifications. Media types were originally defined in Request for Comments (MIME) Part One: Format of Internet Message Bodies (Nov 1996) in November 1996 as a part of the ''MIME (Multipurpose Internet Mail Extensions)'' specification, for denoting type of email message content and attachments; hence the original name, ''MIME type''. Media types are also used by other internet protocols such as HTTP, document file formats such as HTML, and the XDG specifications implemented by Linux ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-Cube Microsystems
C-Cube Microsystems, Inc., was an early company in video compression technology as well as the implementation of that technology into semiconductor integrated circuits and systems. C-Cube was the first company to deliver on the market opportunity presented by the conversion of image and video data from analog to digital formats enabling markets such as VideoCD, DVD, DirecTV, digital cable, and non-linear editing systems. History C-Cube was founded on August 8, 1988 by Edmund Sun from Weitek and Alexandre Balkanski. Early funding came from VC firms Hambrecht & Quist and JAFCO America Ventures as well as Japanese farm equipment manufacturer Kubota Ltd. Image and video technology was just beginning to make the transition from analog (VHS, Betamax, etc.) to new digital-base formats. The key issue was the amount of bandwidth required to transmit or store the digital content. Digital video compression was a key enabling technology that made digital video practical. C-Cube engineers d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Request For Comments
A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, most prominently the Internet Engineering Task Force (IETF). An RFC is authored by individuals or groups of engineers and computer scientists in the form of a memorandum describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems. It is submitted either for peer review or to convey new concepts, information, or, occasionally, engineering humor. The IETF adopts some of the proposals published as RFCs as Internet Standards. However, many RFCs are informational or experimental in nature and are not standards. The RFC system was invented by Steve Crocker in 1969 to help record unofficial notes on the development of ARPANET. RFCs have since become official documents of Internet specifications, communications protocols, procedures, and events. According to Crocker, the docu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
