Fig. 1. Parabolic interpolation at sub-pixel peak position of correlation function

Fig. 2. Original image(640 pixel×640 pixel)

Fig. 3. Image after reducing resolution(64 pixel×64 pixel)

Fig. 4. Errors of the correlated centroid algorithm versus window size and threshold of correlation function under different signal-to-noise ratios. (a) RSN=1∶1; (b) RSN=2∶1; (c) RSN =3∶1; (d) RSN=5∶1

Fig. 5. Errors comparison of centroid algorithm and parabolic interpolation algorithm under different signal-to-noise ratios.(a) RSN=2∶1; (b) RSN=3∶1; (c) RSN=5∶1; (d) without noise

Fig. 6. Schematic diagram of the experimental optical paths

Fig. 7. Object image obtained on CCD

Fig. 8. Comparison of estimated errors in the experiment