[OPTICAL REVIEW Vol. 4, No. 3 (1997) 366-369]

Real-time Optical Wavelet-Transform with Positive and Negative Signals*

Katsuhisa HIROKAWA,1 Kazuyoshi ITOH2 and Yoshiki ICHIOKA1

1Department of Material and Life Science, 2Department of Applied Physics, Osaka University, Yamada-oka 2-1, Suita, Osaka, 565 Japan

(Received May 9, 1996; Accepted February 14, 1997)

An opto-electronic hybrid system that is based on the joint transform correlator (JTC) is suggested for the implementation of real-time wavelet transform. Holographic encoding of both the object signal and wavelet function enables the JTC-based real-time correlator to execute the optical wavelet transformation involving positive and negative values. We suggest an interferometric method to retain the information about the polarity of the final wavelet transform. The principle of this method is verified by experiments.

Key words : wavelet transform, joint transform correlator, computer-generated hologram, liquid crystal television, interference