kramer at rullf2.LeidenUniv.nl (C Kramer) writes:
> I am searching for information about describing the complexity or
> roughness of surfaces. [ . . . ]
The descriptor you are looking for is called the "fractal dimension".
There are a number of books explaining how to compute it, most of them
having the word "fractal" somewhere in their title -- the original
book by Mandelbrot might be the most useful to start with.