Scratch detection and removal from static images using simple statistics and genetic algorithms

This paper investigates the removal of line scratches from old movies and gives a twofold contribution. First, it presents simple technique for detecting the scratches, based on an analysis of the statistics of the grey levels. Second, the scratches removal is approached as an optimisation problem, and it is solved by using a genetic algorithm. The method can be classified as a static approach, as it works independently on each single frame of the sequence. It does not require any a-priori knowledge of the absolute position of the scratch, nor an external starting population of chromosomes for genetic algorithm. The central column of the line scratch once detected is changed with a conventional linear interpolation; this transformation is the starting point of the optimisation process.