Patent ID: 7657077

Claim:
A method of detecting defects in a plurality of images having essentially the same image contents, comprising the steps of: recording a plurality of individual images of a surface of a disk-like object; storing the individual images in an intermediate memory; carrying out a comparison operation once three fully comparable images having essentially the same image contents are present in the intermediate memory, wherein the stored individual images are randomly accessed and wherein the recording operation of the individual images is carried out in parallel to the comparison operation; in that a first difference is formed of the first and second recorded individual images, a second difference is formed of the second and third recorded individual images and a third difference is formed of the third and first recorded individual images, and in that by means of a comparison between the third difference and the first difference, by means of a comparison between the first difference and the second difference and by means of a comparison between the second difference and the third difference the presence of a defect in the recorded individual images is determined; wherein the defects found in the individual images are tested as to the presence of false majority decisions and wherein, when a false majority decision is present, the detection is repeated with other comparison partners.