3D Filtering (Areal Filtering)
Long Wavelength Pass Filter (S-Filter)
The S-Filter is used to attenuate the short
spatial wavelength structures that may be present in the measurement from
sources such as electronic noise or other measurement artifacts. Additionally,
some surfaces may physically contain short spatial wavelength structures
which are not relevant to the attended application and may affect subsequent
analyses. The figure below demonstrates an
S-filter used to eliminate the shorter spatial wavelength components comprising the texture.
When only an S-filter is used, the type of filtering is termed Long Wavelength Pass.