Digital filtering of surface topography: Part II. Applications of robust and valley suppression filters

This is the second part of the paper “Digital filtering of surface topography”. In part I Gaussian regression filter that works without running-in and running-out profile fragments as well as profile spline filter were compared. The performance of Gaussian regression filter was better than that of spline filter.Part II discusses digital filtering of stratified surface textures. Gaussian robust profile filtering technique was established. Several typical robust weight functions were adopted. Valley suppression Rk filter was also included. The results of filtration of deterministic and random profiles of symmetric ordinate distribution were analysed and compared with those obtained after using Gaussian regression filter. In these cases the waviness and roughness parameters after using Gaussian and other filters should be similar. The computer generated profiles, profiles having triangular scratches and measured stratified surfaces were also subjected to filtration. The surface topography distortion and computation time were compared. Based on the comparison results, some digital filters were recommended.