Is there an algorithm that does (what I would call) "localized" gamma correction?

That is, applying different gamma corrections on different parts of an image, using a masking filter or something along those lines.

I have two images that seem to be correlated by a mix of exposure and gamma corrections, but not equally on the whole image:

First image

enter image description here

Second image

enter image description here

For further details on how these images were created, please refer to this (unanswered) earlier post.

  • $\begingroup$ Gamma Correction is Pixel Wise operation So what stopping you from doing it easily? $\endgroup$ – Royi Aug 23 '19 at 10:49
  • $\begingroup$ I did not mention it in this post, but the images are noisy. Although, I can generate them at any resolution. So, I have a collection of noisy first and second images, and I am trying to figure out what is the transformation from the first to the second image. $\endgroup$ – phil5 Aug 23 '19 at 15:12
  • $\begingroup$ Also, the second image is generated (rendered) at half the lighting intensity of the first image. The solution has to hold for all intensities... $\endgroup$ – phil5 Aug 23 '19 at 15:15
  • $\begingroup$ Could you share few images in full resolution? $\endgroup$ – Royi Aug 27 '19 at 11:02
  • $\begingroup$ Update: the "local gamma" approach seems to work. I rendered images at various lighting intensities and fitted a gamma curve for each pixel. The family of curves that gamma correction provides seems like a good model, especially for a single stored value. To filter out some noise, I rendered at a higher resolution (supersampled?) and scaled down. I also clipped the negative (HDR) and very small values to zero and locked the gamma to 1 (linear) for those pixels. $\endgroup$ – phil5 Aug 28 '19 at 6:25

Gamma Correction is Pixel Wise operation.
Hence what you can do is estimate it per pixel and then average it per local area.


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.