Morphological operations on engineering surfaces using a 3D-structuring element of an appropriate size

Using a line segment or circle as a structuring element, morphological operations have been carried out on surface profiles for filtering purposes. This paper brings out a new method of filtering surfaces with a combination of morphological operations using a 3D-structuring element, namely a toroid. A strategy to select appropriate radii for the structuring element depending on surface amplitudes and required amount of waviness separation is also proposed. The proposed filtering method is compared with envelope and closing filters which are also based on the concepts of morphological operations. An analysis of waviness transmission, distortion of roughness surface and effect of deep grooves on a reference surface is presented to bring out the advantages of the proposed method. Few examples of filtering of practical surfaces using the proposed method are also included to bring out the nature of the reference surfaces obtained. © 2006 IOP Publishing Ltd.