Removal of film scratches using exemplar-based inpainting with directional median filter

A method for removing film scratches in old video is proposed. This method is realized as combination of spacio-temporal exemplar-based inpainting and directional median filtering. The spacio-temporal inpainting restores scratch areas with image pixels in a similar undamaged image area in the same and the adjacent frames. If such a similar image area exist, the inpainting method works effectively, however, it does not always exist. In this paper, a method to switch the spacio-temporal inpaiting and a directional median filter is proposed to remove film scratches. Here, if the matching error of inpainting is not small enough, which means that a similar undamaged image area does not exist in the neighborhood, the scratch area is restored using the directional median filter. The directional median filter performs one-dimensional median filtering in the direction of the straight line component detected around the scratch. This method works effectively, even if a similar undamaged image area is not obtained. Computer simulations show the high performance of the proposed method for actual video frames.