Class of algorithms for realtime subpixel registration

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 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 per cent of the pixel period can be expected. Depending on the kind of image, mean square errors range from 0.4 per cent to 4 per cent.