How do I determine if an image has been photoshopped?

views:

answers:

+1 Q:

How do I determine if an image has been photoshopped?

Does anyone know how to tell if an image has been photoshopped?

edit Specifically, I want to determine if regions or pixels in the image have been altered by photoshop. I'm not as interested in finding errors in the photoshop job (missing shadows, errors in reflections, etc)

I seem to remember something like a high-pass filter that you could use that would determine the noise levels. Edited regions would have less noise, or at least changes in noise. I'm having a hard time finding information on this or other approaches.

Thanks for your help!

+3 A:

HOWTO spot a photoshop job
How To Tell If A JPG Image Has Been Photoshopped (Windows)

Google is your friend for many relevant results.

zengr 2010-10-20 06:40:02

Thanks! I did a horrible job of asking that question. I'm really trying to understand how a photo has been altered deceptively. Quantitative methods to classify pixels or regions of pixels as different in nature from the others (e.g. analyzing noise, or cross-correlations for repeating structures) are what I was hoping for. Know of any?

Tim 2010-10-20 17:31:21

I would give a try with error level analysis:
http://www.errorlevelanalysis.com/
Follow the links on that site and maybe get in contact with the author, I'm sure they can give you the needed pointers.

Agos 2010-10-28 10:40:53

ansaurus

tags:

views:

answers:

How do I determine if an image has been photoshopped?

related questions