Yaaay!!!! Finally it sounds like there will be something reliable!
ImageJ is pretty good, but it's not fun to learn. (
Click and scroll down for a small tutorial and link)
Then there a bunch of
these... which have been shown to be way too inaccurate to even bother with.
Thanks for the links, PleaseExplain! That made my night! Imagine, no more faked paranormal/ufo pics. Just download the Photoshop plugin, point, and laugh... at least at the fakers. Even if it takes a year longer than they expect, they're working on it! Awesome!!!