Calvin Hass has several articles on JPEG, including lossless transformations. http://www.impulseadventure.com/photo/ http://www.impulseadventure.com/photo/ Bet

Calvin Hass has several articles on JPEG, including lossless transformations. http://www.impulseadventure.com/photo/ http://www.impulseadventure.com/photo/ Better JPEG sells a library, Photoshop plugin, and (relatively simple) standalone program that allow lossless editing (only changed blocks are recompressed). http://www.betterjpeg.com/ http://www.betterjpeg.com/