A new approach for filtering of surface profiles using morphological operations

Among different filtering approaches used to remove waviness and obtain roughness, envelope and motif techniques are considered to be suitable for functional characterization. Morphological filtering being closely related to envelope technique can be used for filtering of surfaces. This paper discusses a new approach combining morphological operations namely closing and opening with circle as structuring element in a unique way to generate the reference profile representing waviness. The reference profile generated by this method is smooth without any slope discontinuities and robust against deep valleys present in the profile. Analysis of the proposed method for robustness and form-approximation capabilities is presented in this paper. Comparison is also made with envelope and morphological closing filters as well as Gaussian regression filter to bring out the effectiveness of this approach.