JPEG

In computing, JPEG (pronounced jay-peg) is a commonly used standard method of lossy compression for photographic images. The file format which employs this compression is commonly also called JPEG; the most common file extensions for this format are .jpeg, .jfif, .jpg, .JPG, or .JPE although .jpg is the most common on all platforms.

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The name stands for Joint Photographic Experts Group.

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JPEG itself specifies only how an image is transformed into a stream of bytes,

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but not how those bytes are encapsulated in any particular storage medium.

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A further standard, created by the Independent JPEG Group, called JFIF (JPEG File Interchange Format)

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specifies how to produce a file suitable for computer storage and transmission

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(such as over the Internet) from a JPEG stream.

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In common usage, when one speaks of a "JPEG file" one generally means a JFIF file, or sometimes an Exif JPEG file.

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There are, however, other JPEG-based file formats, such as JNG.

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JPEG/JFIF is the most common format used for storing and transmitting photographs on the World Wide Web.

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It is not as well suited for line drawings and other textual or iconic graphics because its compression method performs badly on these types of images (the PNG and GIF formats are in common use for that purpose;

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GIF, having only 8 bits per pixel is not well suited for colour photographs,

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PNG can be used to losslessly store photographs but the filesize makes it largely unsuitable for putting photographs on the web).

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The MIME media type for JPEG is image/jpeg (defined in RFC 1341).

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Computing: Originally, the word computing was synonymous with counting and calculating, and a science that deals with the original sense of computing mathematical calculations....

Lossy compression: A lossy compression method is one where compressing data and then decompressing it retrieves data that is different from the original, but is close enough to be useful in some way. Lossy compression is most commonly used to compress multimedia data (audio, video, still images), especially in applica...

File format: A file format is a particular way to encode information for storage in a computer file....