How to estimate the effective surface area of a rough surface by image processing ?

When examined at higher resolutions, the seemingly flat surface often contains hills and valleys. My area of interest rough surface of 1m by 1m. Therefore, area is 1m^2. Now, as we know that the surface is not flat. Therefore, the effective surface area is not 1m^2. I want to know that is there a technique by image processing to analyse such surface and calculate the effective surface area. Simply, I will put it this way, Assume you have a piece of paper and then u crumple it now the surface area will change. How to measure this effective surface area.

[KSSV]

It would be better to attach image..

[Adam]

I imagine it depends what the data encoded in the image represents. If it is elevation data then sure, if it is just a photo then I doubt it is possible to distinguish height changes from colour changes, but I'm not an expert.

[Sumit Chaudhary]

Is there any imaging setup which will be able to capture the surface hills and valleys ?