Joint Photographic Experts Group (JPEG) Image format

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Standard for variable compression of black-and-white (gray scale) and full color still images. Named after the committee that wrote the original standard, its file name carries the extension 'jpg' or 'jpeg.' Unlike graphic interchange format (GIF) files, which can show only 256 colors, JPEG can show 16 million colors and is more suitable for photographs, naturalistic artwork, and similar material than for line drawings, lettering, and simple cartoons. It provides decent image quality at great reduction the final image may be as small as 2 percent of the original. Being a lossy format (see compression algorithm), it loses a degree of detail (which may not be obvious to the user) depending on the degree of compression.
Although some versions of JPEG allow from 24-bit losless compression (usually 2:1) to a smaller bit-size lossy compression (up to 60:1), the recommended ratio is between 25:1 to 35:1 for everyday graphics work. JPEG is the most popular image compression format on the internet, and has a related standard (MPEG) for moving images.


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