  Recently, Ferreira da Silva et al. [3] have performed a gradient pattern
analysis of a canonical sample set (CSS) of scanning force microscopy (SFM)
images of p-Si. They applied the so-called Gradient Pattern Analysis to images
of three typical p-Si samples distinguished by different absorption energy
levels and aspect ratios. Taking into account the measures of spatial
asymmetric fluctuations they interpreted the global porosity not only in terms
of the amount of roughness, but rather in terms of the structural complexity
(e.g., walls and fine structures as slots). This analysis has been adapted in
order to operate in a OpenGL flyby environment (the StrFB code), whose
application give the numerical characterization of the structure during the
flyby real time. Using this analysis we compare the levels of asymmetric
fragmentation of active porosity related to different materials as p-Si and
"porous diamond-like" carbon. In summary we have shown that the gradient
pattern analysis technique in a flyby environment is a reliable sensitive
method to investigate, qualitatively and quantitatively, the complex morphology
of active nanostructures.
