Delighting Texture
I started working on an egg and texturing it for our scene. In the process I wanted to texture paint in Mari but the reference image I was using was not perfectly lit so getting the details was proving troublesome. As a solution I recalled a process called high frequency separation that is used by retouchers for skin retouching. It uses a process of separating out the high frequency detail from an image and then mixing that on top of the low frequency detail. So in this case I wanted to remove the overall light change which was low frequency detail. So I set that to a solid color and then overlayed the high frequency detail on top giving me a much more usable texture to paint with.
This is the original image
This is the de-lit image