interactive image processing using free software

[Dan Hitt]

First, what i'm looking for may be in the FAQ, but i can't
seem to locate a current faq for sci.image.processing
(there's one at
ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/image/processing/
but the title indicates it is limited to color and gamma, and
it is nearly a decade old besides).

So, i'd appreciate any help or URLs there.

Second, my actual question is for some piece of free software that can
display images (such as jpg) and interactively extract data (or form
models) from them.

So something along these lines is ImageJ, at least for starters.

But what would really be useful is a list of such programs,
and a little info about each (what it can do, what language
is it coded in, something about the authors, when it was
last updated, licensing terms if not gpl).

There are some writings on the net about this, for example,
on Murray Meehan's blog
http://murraymeehan.blogspot.com/2011/06/comparison-of-medical-image-processing.html
But in that case, for example, it is mainly about medical imaging.

So would appreciate any steering here----references to the right
ng, faqs, fine manuals, etc.

TIA!

dan