A simple method for optical implementation of a composite filter in a joint transform correlator is presented. A composite filter in object space is a real function, but by adding an appropriate constant value, only positive values are obtained. As a drawback, the bias introduced decreases the relative height of the correlation peaks in the recognition process. Non-linear effects in a joint transform correlator are used to increase discrimination by using positive composite filters. Digital simulation and optical implementation of the process has been carried out, achieving the non-linearities by means of saturation effects on the intensity detection process.

Date Published: 1 November 1991
PDF: 9 pages
Proc. SPIE 1564, Optical Information Processing Systems and Architectures III, (1 November 1991); doi: 10.1117/12.49717

Published in SPIE Proceedings Vol. 1564:
Optical Information Processing Systems and Architectures III
Bahram Javidi, Editor(s)