Abstract

An optical system that employs holographic recording in a photorefractive material is proposed and experimentally demonstrated for the implementation of a wavelet transform of two-dimensional images. A scaling operation, to derive the family of wavelet filters from a mother wavelet filter, is performed by the use of an optical feedback loop. The selection of a desired wavelet filter from the family and the correlation for a wavelet transformation are made by the use of a holographic recording in a photorefractive material. The principle of operation of the system relies on the frequency detuning introduced inside the loop and the subsequent variation in the holographic grating diffraction. Experimental results on wavelet-filter selection and wavelet transformation are presented. This nonlinear optical wavelet-transform system is advantageous for pattern recognition applications.

© 1995 Optical Society of America

Optical realization of the wavelet transform for two-dimensional objects

David Mendlovic and Naim Konforti
Appl. Opt. 32(32) 6542-6546 (1993)

Two-dimensional wavelet transform achieved by computer-generated multireference matched filter and Dammann grating

David Mendlovic, Ido Ouzieli, Irena Kiryuschev, and Emanuel Marom
Appl. Opt. 34(35) 8213-8219 (1995)

Wavelet transform as a bank of the matched filters

Harold Szu, Yunlong Sheng, and Jing Chen
Appl. Opt. 31(17) 3267-3277 (1992)

Joint wavelet-transform correlator for image feature extraction

Wenlu Wang, Guofan Jin, Yingbai Yan, and Minxian Wu
Appl. Opt. 34(2) 370-376 (1995)

Hologram reconstruction by use of optical wavelet transform

Denis Lebrun, Samir Belaïd, and Cafer Özkul
Appl. Opt. 38(17) 3730-3734 (1999)