A new Shack-Hartmann(S-H) spot detection algorithm was proposed in this paper for finding the location coordinates of S-H reference wavefront spot in dependent of lenslet shapes, rotational alignment error of lenslet, reference laser beam shape. It consists of five main processing module: 1) Parameter setting, 2) Noise measurement & compensation, 3) Segmentation, 4) Coarse localization, 5) Fine localization. Through some simulated experiments, the proposed algorithm showed that it could robustly detect a variety of S-H spot patterns e.g. rectangular shape, triangular shape, sandglass shape, X-shape, center-void shape, rotated rectangular shape. The detection precision of the proposed algorithm was measured with the root squared sum of the estimated coordinates difference with values less than 10^-4 pixel till signal to noise ratio S/N=3. It is firstly intended for application of infrared S-H sensor but can be adopted in visible S-H sensor.

Date Published: 18 May 2016
PDF: 10 pages
Proc. SPIE 9846, Long-Range Imaging, 98460H (18 May 2016); doi: 10.1117/12.2228949

Published in SPIE Proceedings Vol. 9846:
Long-Range Imaging
Eric J. Kelmelis, Editor(s)