JPEG

• Joint Photographic Experts Group
• Continuous-tone (photographic) still image compression standard
• sponsored by ITU-T and ISO/IEC
• supports both lossy and lossless compression
• utilizes DCT (Discrete Cosine Transform)
• The JPEG standard only defines the bitstream of the encoded compressed image data, as it would be sent down the communication line in photographic quality videotext. For data processing purposes the bitstream needs to be encapsulated within a file format, with some additional header information to provide a context for the reconstituted stream of pixels.
• compress ratios definable by user and can be as high as 35:1.

Find out more about JPEG on Usenet FAQ on JPEG