In this paper we present a study of ZnS thin films thermally deposited on glass substrates, with different optical thicknesses. On topography micrographs and feature parameters obtained by Atomic Force Microscope, we pursued the islands formation and growing in ZnS thin films even on the same optical thickness of the film. For doing so, we analyzed the micrographs surface, using Watershed Segmentation and Wolf pruning that allow the detection of significant features on surfaces, Grain sorting operator and Parameter Distribution Study.