Profile filters seperate profiles into long wave and short wave components. The λc profile filter separates the roughness profile from long wave components (e.g. waviness).

Mean line is generated by a phase correct filter by calculating the weighted average for each point of the profile.

Weighting function indicates for each point of the profile the assessment factor with which the adjacent profile points enter into averaging (Gaussian curve).

R-profile (roughness profile) represents the deviations of the primary profile from the mean line of the λc profile filter. When presenting the roughness profile, the mean line is the zero line.