At this moment I got some cooperation which not let me to share PC with SPIP or other commercial software for afm's files manipulation. So, I wonder if Gwyddion or WSxM (both freewares) can measure the surface and plane surface or choosen region? As I remember in Gwyddion Statistics there is information what I looking for, but have no idea how to change the unit from um to nm. Someone needs to measure Real surface / plane surface.