Blotch Detection Using a Background Subtraction Method in Old Film Sequences

In this paper, a blotch detection method in old film sequences is proposed. The proposed method uses a background image as a reference image for blotch detection to obtain high per-formance when the appearance probability of blotch is high. The background image is estimated by applying filters selec-tively which are a double window modified trimmed mean (DW-MTM) filter, a median filter and a mean filter to the se-quences in temporal direction at each pixel. This paper de-rives the correct detection rate and the false alarm rate of the conventional methods and the proposed method to the appear-ance probability of blotch. Moreover, it is evaluated the per-formance of these blotch detectors in high appearance proba-bility of blotch from an experiment for blotch detection with an artificial degraded sequence. As a result, it is shown the proposed method is a robust blotch detection method compar-ing conventional methods for the high appearance probability of blotch and it is confirmed the proposed method can detect a region that blotch appeared at the same spatially location in the consecutive frame. Finally, it is confirmed the proposed method can detect blotches in an old film sequence. 1