Advances in nanotechnology in the past two decades have placed scanning probe microscopy (SPM)[1] among the most common and powerful techniques in surface science for analysing and manipulating a wide range of nanomaterials. SPM allows materials to be characterised with high resolution, which reaches single-atom spatial resolution in atomic force microscopy (AFM) images [2] or single-electron resolution in electrostatic measurements by electrostatic force microscopy (EFM).[3] SPM is extremely versatile, as it can be employed in a wide range of environments (vacuum, air and liquid), on all type of materials and allows structural evolution and dynamic processes to be investigated in real time.[4] These techniques can be utilized for simple imaging and for a quantitative analysis of a given property. The latter aspect, which includes interpretation of the chemicophysical properties of the sample by using the acquired SPM data, can be rather complicated due to the complex interaction between the scanning probe and the sample. In general, SPM data are collected as a matrix of MN pixels forming the image, in which each data point z is linked to the corresponding position (x, y) on the surface. A wide range of mathematical tools (FFT analysis, autocorrelation functions)[5–8] can be successfully applied to study systems with an irregular surface morphology, such as interfaces grown under nonequilibrium conditions. These tools reveal that irregularities are only apparent, and that they can be discussed in terms of the scaling properties of the surface fluctuations.[8–10] Greater attention has been devoted to the statistical distribution of the …