A generalized approach leads to spatial filters that accept changes of scale by a factor of 4. The procedure employs phase filters with reduced tolerance requirements and achieves high discrimination capability and efficient light throughput. Computer simulations and laboratory experiments show the advantages of this novel approach.
© 1989 Optical Society of America
Original Manuscript: December 15, 1987
Published: January 15, 1989
Joseph Rosen and Joseph Shamir, "Scale invariant pattern recognition with logarithmic radial harmonic filters," Appl. Opt. 28, 240-244 (1989)