Tracking and MAP reconstruction of line scratches in degraded motion pictures

Abstract.

A suitable detection and reconstruction approach is proposed for removing line scratches from degraded motion picture films. The detection procedure consists of two steps. First, a simple 1D-extrema detector provides line scratch candidates. Unlike impulsive distortions, which appear randomly in an image, line artifacts persist across several frames. Furthermore, the detection process is complicated by the fact that lines occur as a natural part in interesting scenes. Therefore, we add a validation step for separating possible line defects from false detections. It consists in tracking the potential line artifacts over the frames using a Kalman filter. A new Bayesian restoration technique, dealing with both low and high frequencies around and inside the detected deteriorations, is investigated to achieve a nearly invisible reconstruction of damaged areas.