Abstract

A new method has been developed for rotation-invariant pattern recognition. One component of the circular harmonic expansion of the target is used in the preparation of the reference. Correlations between the input and reference objects are accomplished by FFT and multiplication in the frequency domain. In an experience with targets from an image with 192 × 192 pixels, target orientations were detected with an accuracy of ~0.1°. This method is also suitable for optical implementation.

© 1982 Optical Society of America

Optical pattern recognition using circular harmonic expansion

Yuan-Neng Hsu and H. H. Arsenault
Appl. Opt. 21(22) 4016-4019 (1982)

Properties of the circular harmonic expansion for rotation-invariant pattern recognition

Henri H. Arsenault and Yunlong Sheng
Appl. Opt. 25(18) 3225-3229 (1986)

Contrast-invariant pattern recognition using circular harmonic components

Henri H. Arsenault and Claude Delisle
Appl. Opt. 24(14) 2072-2075 (1985)

Rotation-invariant digital pattern recognition using circular harmonic expansion: a comment

Per-Erik Danielsson
Appl. Opt. 28(9) 1613-1614 (1989)

Statistical performance of the circular harmonic filter for rotation-invariant pattern recognition

Yuan-Neng Hsu and Henri H. Arsenault
Appl. Opt. 22(18) 2804-2809 (1983)