Abstract

We have previously proposed a jointtransform correlator incorporating an optical disk as a reference library, for which the reference image is parallelly read out and directly used to obtain joint transform with the real-time input image. The architecture combines the features of the conventional jointtransform correlator and the compact disk optical head. In this paper we shall propose two joint-transform correlator schemes that use optical disks; namely, the equal-image-dimension (EID) and the direct-joint-transform (DJT) schemes. In both schemes a real-time input image is obtained through a video camera and is displayed on an electrically addressable spatial light modulator (SLM). To alleviate the dimensional mismatch of the input images, the reference image is first magnified and then displayed on an SLM by means of the EID scheme. For the DJT scheme, the Fourier transform of the input image is magnified before being combined with the Fourier spectrum of the reference image. Systems analysis and design of both architectures are presented, and experimental demonstrations of these two techniques are also provided.

© 1990 Optical Society of America