It is used to remove vertical stripes caused by poor quality
scanners. It works by adding a pattern that will interfere with
the image, removing stripes if setting is good. This
“negative” pattern is calculated from vertical elements
of the image, so don't be surprised if you see stripes on the
preview of an image that has none. And if pattern
“strength”; is too high, your image will be striped.
If, after a first pass, a stripe persists, rectangular-select it
and apply filter again (all other selection type may worsen the
result).
