Photography Comparison Software

[Heptarchone]

I'm not sure if this is the forum I should be in.

I am looking for software that compares digital photo's and identifies differences. Is there such a thing?

Thanks,

Paul

[PaulB]

I would imagine that such software is out there somewhere. Perhaps with the surveillance/security services/NSA/CIA/MI6 crowd - must use it for satellite image comparisons, (like photo-reconnaissance used rapid switching between projected images to detect differences).
Getting your hands on it may be problematical!

[cloudless]

Perhaps you can do it with Photoshop. Convert picture A as dual tone (green on white), and picture B as (red on white). Now add picture B as a layer on picture A. Adjust the opacity of the new layer to 50%. Now the parts of the pictures that are the same should be completely overlap, yet the differences should have different levels of mixed colors.

I have never tried it, would it work?

[maderito]

IMatch is a image database management application. Among its features is an image matching capability which can search for similar images (based on colors, features, etc) in the database. It also identifies "binary duplicate" image files.

IMatch was originally an experimental image matching program that evolved into a sophisticated database application. I'm not sure that it meets your specific needs, but it's worth checking out, and there's a free download.

See:
http://www.photools.com/

And look at this question on the FAQ: "How does image matching work and what can I expect from it?"
http://www.photools.com/imatchfaq.php#26