Abstract

Optical configurations are capable of performing essentially any linear operation, such as correlation, convolution, and Fourier transformation, on a function of two variables. Many signal processing techniques for radar and sonar applications require nonlinear transforms. Although a few nonlinear processing techniques have been developed, several drawbacks are associated with them. The main disadvantage of these techniques is that they do not operate in real-time. In many cases the processing period needs to be less than 10⁻⁵ s. However, no successful techniques for doing this have been reported. In the present paper we propose an optical feedback system that can be used to implement the real-time logarithmic transform. We will use two pictures as input objects to demonstrate the capability of this nonlinear processing system.

© 1990 Optical Society of America