Quantitative Image Analysis
You just have to stop at a page with a title "Quantitative Image Analysis by NIH-Image (freeware and really good)!" True or not, that`s how Andreas Becker (firstname.lastname@example.org.) starts off his page and description of NIH-Image, a free image-processing package from the US National Institutes of Health. From this site, you can download a copy of the program and look at on-line documentation. You can also get information on a Gel Plotting Macro for NIH-Image-Macro Version II, as well as spinoffs that include GelScan 1.0 and Brain Image 2.1x.