1

I have two images that are the same, except that one has an adjustment in its brightness.

Is there a way to compute the difference of these images in Photoshop somehow to see what has changed from one image to another?

Image 1:

original

Image 2 (with brightness adjustment):

with brightness adjustment

  • What exactly are you looking for as the output? A map of the pixels that have changed? A numeric value representing the amount of change (perhaps in "stops"?) Or something else? What do you want to do with this information once you have it? – mattdm Oct 6 '13 at 18:57
  • @mattdm I want to the brightness factor that transforms the one into the other image. – confile Oct 6 '13 at 20:15
2

If you layer those in Photoshop and use subtract or difference blend modes, you'll end up with a result that should show the relative difference of each pixel.

Use that result to create a mask (Image > Apply Image, target layer mask)

Then starting with the first image, add an exposure adjustment layer, and use the above mask - I would expect you'd get something close to the second image.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.