Foreground/background detector

摘要

A detector for detecting the foreground or background vector near a discontinuity in a vector field has a covering-uncovering detector (3)for determining whether covering or uncovering situation exists. The detector further has calculating means (1,2,4) for calculating at the position {right arrow over (x1 of the discontinuity:a first position {right arrow over (xa in the previous (covering) or next (uncovering) vector field by shifting {right arrow over (x1 over the first vector at one side of the discontinuity,a second position {right arrow over (xb in the previous (covering) or next (uncovering) vector field by shifting {right arrow over (x1 over the second vector at the other side of the discontinuityand a third intermediate position between {right arrow over (xa and {right arrow over (xb.Furthermore, the detector has means (5) for fetching the background vector with v{right arrow over (av at the third position in the previous (covering) or next (uncovering) vector field.