Patent attributes
An apparatus for detecting a position of a region, corresponding to a mark, in image data, as a mark position, the mark including periodically arranged patterns. A first unit obtains a real-space energy distribution which corresponds to an energy spectrum distribution of each partial area of the image data. A probability distribution obtaining unit obtains a probability distribution based on the real-space energy distribution, the probability distribution indicating repetitive positions of the periodically arranged patterns and the intensity of periodicity at this position. A second unit obtains a degree of correlation between each probability distribution obtained by the probability distribution obtaining unit and a pre-registered probability distribution of the mark, and a third unit obtains the mark position based upon the degrees of correlation obtained by the second unit.
