Abstract

Holographic matched filter pattern recognition has been plagued by too much sensitivity to such parameters as rotation and scale. We show here how to use that sensitivity to make rapid accurate estimations of those parameters. For the particular case studied, we made signal-magnitude independent measurements of four rotation angles from −15 to +15° using three matched filters at −15, 0, and 15° multiplexed onto a single hologram. This leads to obtaining a worst case accuracy (95% confidence) of 1.0° for intermediate angles. The composite filter allows a search to be made electronically in the output plane, thus avoiding any moving parts, i.e., object or matched filter.

© 1982 Optical Society of America

Computer recognition of 2-D patterns using generalized matched filters

H. J. Caulfield and M. H. Weinberg
Appl. Opt. 21(9) 1699-1704 (1982)

Real-time screen-aided multiple-image optical holographic matched-filter correlator

H. K. Liu and J. Graeme Duthie
Appl. Opt. 21(18) 3278-3286 (1982)

Hybrid optical processor for pattern recognition and classification using a generalized set of pattern functions

James R. Leger and Sing H. Lee
Appl. Opt. 21(2) 274-287 (1982)

Simplified realization of the holographic inverse filter: a new method

Christoph Zetzsche
Appl. Opt. 21(6) 1077-1079 (1982)

Color-coded character-recognition experiment with wavelength-triplexed, reflection-type holographic filters

Yukihiro Ishii and Kazumi Murata
Opt. Lett. 7(5) 230-232 (1982)