Method for locating the center of a fiducial mark

摘要

In a method for locating the center of a fiducial mark contained in an image, a certain region covering every fiducial mark in the image is defined. A region containing each fiducial mark within the certain region is extracted. The center of the fiducial mark within the region containing each fiducial mark is located to pixel accuracy. The center of the fiducial mark within the region containing each fiducial mark is located to sub-pixel accuracy according to the pixel level locating of the center of the fiducial mark.