Class of algorithms for real-time subpixel registration

TLDR: Intense investigation of the proposed algorithms led to the new approach: by interpolating the template instead of the reference image, and by applying sort of an error- correction to the resulting subpixel-value, both computation time and accuracy can be improved.

Abstract: In 1972, Barnea and Silverman presented a new approach to the wide field of template matching, the SSD-algorithm. Further work has been done to adapt the method to gain subpixel accuracy. Intense investigation of the proposed algorithms led to our new approach: by interpolating the template instead of the reference image, and by applying sort of an error- correction to the resulting subpixel-value, both computation time and accuracy can be improved. Exhaustive experiments with a CCD-camera and various kinds of reference images showed that a maximum error of 10% of the pixel period can be expected. Depending on the kind of image, mean square errors range from 0.4% to 4%.