The simulated annealing (SA) algorithm based on entropy optimization is a technique of synthesizing distortion-invariant matched filters capable of discriminating very similar images. The synthesis of rotation-invariant filters using modified SA-based filter equations and their tolerance to distortions are studied. The filters are trained with true class images rotated in-plane at 3° intervals between 0° and 360°.
A total of seven filters are required over the whole range for both CCD or thermal images. Optical correlation in a hybrid digital-optical correlator results in an unwanted zero-order dc along with two first-order
© 2007 Optical Society of America
Original Manuscript: October 24, 2006
Revised Manuscript: February 20, 2007
Manuscript Accepted: March 1, 2007
Published: June 20, 2007
Soumika Munshi, V. K. Beri, and A. K. Gupta, "Hybrid digital-optical correlation employing a chirp-encoded simulated-annealing-based rotation-invariant and distortion-tolerant filter," Appl. Opt. 46, 4304-4319 (2007)