Time localisation of surface defects on optical discs

Abstract — Many have experienced problems with their Com-pact Disc player when a disc with a scratch or a finger print is tried played. One way to improve the playability of discs with such a defect, is to locate the defect in time and then handle it in a special way. As a consequence this time localisation is needed to be as good as possible. Fang’s algorithm for segmentation of the time axis is used since it has good performance in an application like this. Fang’s algorithm has a clear potential for time localisation for some defects and but not for other defects. Instead the normally used threshold is improved to handle eccentricity and localisation of the end of the defect better. I