Comparing two JPEG IMAGES and displaying differences

Question

Images are of the same object taken at different time intervals. Software solutions - to be implemented in hardware. High rate of performance most important in hardware implementation

Answer 1

I believe Perceptual Diff does what you want...

http://pdiff.sourceforge.net/

Answer 2

Despite the fact the question seems to be after hardware and some kind of technique rather than a tool, for the sake of posterity it's worth mentioning that you can do this with Beyond Compare plugins.

Not free but worth the money in my humble opinion: http://www.scootersoftware.com