[OPTICAL REVIEW Vol. 3, No. 3 (1996) 171-176]

Real-Time Pattern Recognition by VanderLugt Correlator Using Amplitude and Phase Modulation Properties of the Epson Liquid-Crystal TV

Christophe GORECKI,* Bertrand TROLARD and Luc ORIAT

Laboratoire d'Optique P.M. Duffieux, (URA CNRS 214), UniversitEde Franche-ComtE 16 Route de Gray, 25030 Besanč¼Ÿn cedex, France

(Received January 25, 1996; Accepted April 10, 1996)

We have built an optical VanderLugt-type correlator that uses two Epson liquid crystal televisions (LCTVs) separately generating the amplitude and phase modulation properties. The input scene is displayed in amplitude-mostly regime on the first LCTV. Thereafter a phase-only filter with a different level of phase quantization is addressed in phase-mostly regime on the second LCTV. To characterize this device, the phase and amplitude modulations were experimentally measured and investigated in pattern recognition application where the grey-level input scenes and multilevel kinoforms are displayed on the LCTVs.

Key words: optical correlation, liquid crystal TV, pattern recognition, phase-only filter