reduxA page I made extolling the virtues of the Portable Video Research Group JPEG implementations. This is an old and obscure tool that I feel needs more recognition.
[2005 Feb 10] [/computers/software/jpeg] [#]
The comp.graphics.misc frequently asked questions list, with answers, about JPEG compression and JFIF files. Last modified in 1999, some of the questions are quite dated, but many are still relevant.
[2005 Jan 31] [/computers/software/jpeg] [#]
The W3C page on the image/jpeg file format is brief, but it has links to two PDF files documenting the JPEG FIle Format, the standard way to contain images compressed with the JPEG mechanism.
[2005 Jan 31] [/computers/software/jpeg] [#]
An organization (or individual?) that provides improvements to jpeg manipulation tools, such as tweaking the ILJ 'cjpeg' compressor to allow different compression quality settings on different channels.
[2005 Jan 31] [/computers/software/jpeg] [#]
A good non-mathematically introduction to the technical aspects of JPEG compression, with lots of illustrations of what different settings do to images.