The Mellin radial harmonic filter and the logarithmic harmonic filter are useful for performing optical scale- and projection-invariant pattern recognition, respectively. To our knowledge, on the basis of the harmonic-function method, no one has been able to obtain more than one invariant property (in addition to the shift invariance) when using the matched-filter approach. A new method of combining the scale-, the projection-, and the shift-invariance properties is proposed, based on two decomposition stages of the input pattern. Computer simulations are presented as well as preliminary experimental results.
© 1995 Optical Society of America
Original Manuscript: February 25, 1994
Revised Manuscript: August 15, 1994
Published: January 10, 1995
David Mendlovic, Zeev Zalevsky, Irena Kiryuschev, and Guy Lebreton, "Composite harmonic filters for scale-, projection-, and shift-invariant pattern recognition," Appl. Opt. 34, 310-316 (1995)