Surface topography analysis plays a very significant role in determining the functional performance for many engineering surfaces. In this paper, feature characterization techniques, based on the 'wolf pruning' method are implemented to characterize micro and nano-scale features which have a dominant effect on the functional lifespan of flexible photovoltaic (PV) modules. The densities and dimensions of the potential significant features are calculated by means of the feature 'characterization toolbox'. The outcome of this study has shown the potential of areal feature segmentation for detecting functionally significant defects present in atomic layer deposition barrier coatings of Al2O3 on polymer films. The analysis provides the basis for the development in process metrology for roll-to-roll production of barrier coatings as applied to flexible PV arrays and is a first step in the demonstration of in-process use of feature parameters.