Patent attributes
Embodiments for registering features in a repeating pattern are described. These embodiments can include providing an object having a repeating pattern of features and a fiducial. These embodiment can also include obtaining a target image of the object, where the target image includes the repeating pattern of features and the fiducial. These embodiment can also include comparing the fiducial in the target image to reference data, where the reference data includes xy coordinates for a virtual fiducial. These embodiment can also include determining locations for the features in the target image based on the comparison of the virtual fiducial in the reference data to the fiducial in the data from the target image. The fiducial can have at least concentric circles that produce three different signal levels. The locations of the features can be determined at a variance of less than 5 μm.