Among a variety of optical correlators, the joint transform correlator (JTC) has some advantages over others and has been extensively studied. However, in some cases, a direct correlation of the input image with a reference image would not be able to find the matched pattern. Recently, morphological hit-or-miss transformation (HMT) has been used to improve the pattern recognition ability of JTC. In this paper we use the concepts of uncertain pixel to improve the distortion-invariant ability of morphological hit-or-miss transformation used in JTC. The novel method is called joint rank-order multi-value hit-or-miss transformation (JRMHMT), which reduces the decision effect of the pixels that is easily disturbed by rotation and scaling distortion. Without losing information of the input images, JRMHMT can realize the precision recognition between two images and has a better distortion-invariant ability in scaling and rotation than the ordinary HMT methods. The comparisons of JRMHMT with the ordinary HMT methods in theoretic analysis and experiments are given in this paper. Based on a single lens JTC and a novel multi-value complementary encoding method, joint rank-order multi-value hit-or-miss transformation correlator (JRMHMTC) is constructed for realized MVHMT in one step. The correlated result image can be thresholded with a high-level threshold so that correct justification can be achieved. The simulation results and experimental demonstrations are both listed.

Date Published: 9 October 1998
PDF: 10 pages
Proc. SPIE 3466, Algorithms, Devices, and Systems for Optical Information Processing II, (9 October 1998); doi: 10.1117/12.326791

Published in SPIE Proceedings Vol. 3466:
Algorithms, Devices, and Systems for Optical Information Processing II
Bahram Javidi; Demetri Psaltis, Editor(s)