How to detect color alterations in before/after picture of a painting?

Hi, I’m coding an app to check if a painting has been damaged using two high resolution pictures taken before and after it’s shipping.

I have already managed to detect physical alterations (scratches, holes,…).

I know need to check if there is any color alterations: has the painting colors been globally or locally altered. Is there a way to detect such colors changes between the before and after pictures with opencv ?

My app is coded in c# so any answer using emgu.cv would be great but if you only know the answer in python it will be ok too.

so you want to dive into color science?

crosspost:

Obvioisly, you need to shoot both paintings in similas lighting, similar camera settings etc., and colour calibrated either during shooting or afterwards - with the help of a calibration color chart / strip in the photos.

After that, one of the geometrically similar images can be deduced from the other and the other way around, and then you can detect non-zero (allowing some tolerance) areas and areas with funny textures. This done for HSV channels. Dome preparation may depend on the style of the paintings and accuracy on the captures.