Abstract

A joint transform correlator (JTC) is suitable for real-time operation because it does not require a complex filter.1¹ The performance of a classical JTC can be enhanced greatly by using a binary JTC² where the joint power spectrum (JPS) is binarized by applying a threshold before the final inverse Fourier transform operation. However, JPS binarization involves significant computation time for determining the threshold for binarization. Also, false alarms are produced with multiple objects in the input scene. In this paper, we propose and investigate the multi-object joint transform correlation where the input joint image is first preprocessed by applying the Roberts edge enhancement operator before applying the joint transform operation. The main advantage of this scheme is that the preprocessing operation can be performed long before the image is introduced in the input plane, thereby eliminating any detrimental effect on the operational speed of the JTC. The proposed pre-processing technique is found to yield significantly high autocorrelation peaks while avoiding the false alarms associated with other JTCs.

© 1992 Optical Society of America