IMAGE REGISTRATION

A technique for rapidly and efficiently registering binary images, contemplates incorporating one or more reference features, referred to as fiducials, into the binary image at a known displacement from a feature of interest in the image, subjecting the image to an operation (typically a morphological operation and possibly a thresholded reduction) that projects out the fiducial(s), determining the position of the fiducial(s), and thereby determining the position of the feature of interest. The fiducial(s) must have at least one characteristic that is absent from the remaining (or at least from neighboring) portions of the image. In one set of embodiments, each fiducial includes horizontal and vertical line segments that are longer than any line segments expected to be found in the binary image. Projecting out the fiducial entails erosions using hit-miss structuring elements. In another embodiment, each fiducial is a small finely textured region.