Novel Optical Technique for Real-Time Pattern/Image Recognition

(Abstract) We propose a novel real-time joint-Transform correlation (JTC) technique for optical pattern recognition. To replace the film recording aspect of performing optical correlation, conventional real-time joint-Transform correlation (JTC) optical systems make use of a spatial light modulator (SLM) located in the Fourier plane to record the interference intensity to achieve real-time processing. However, the use of a SLM in the Fourier plane, is a major drawback in these systems since SLMs are limited in resolution, phase uniformity and contrast ratio. Thus, they are not desirable for robust applications. In this thesis, we developed a hybrid (optical/electronic) processing technique to achieve real-time joint-Transform correlation (JTC). The technique employs acousto-optic heterodyning scanning. The proposed real-time JTC system does not require a SLM in the Fourier plane as in conventional real-time JTC systems. This departure from the conventional scheme is extremely important, as the proposed approach does not depend on SLM issues. We have developed the theory of the technique and substantiated it with optical experimental as well as computer simulation results. III Acknowledgments I would first like to express my sincere appreciation to my advisor, Dr. Ting-understanding and support throughout my research work, and giving me this opportunity to study with him. Special thanks are due to Dr. Guy J. Indebetouw for supplying some of the patterns used in the experiment and serving on the advisory committee, and to Dr. Roger Stolen for being my instructor for two semesters and serving on the advisory committee. I also thank my fellow students at the Optical Image Processing Laboratory at Virginia Tech for all their help and advice. Special thanks are given to Bill Yoder, who helped me throughout my research study: I wish him good luck in his graduate study. Finally, I give my sincere love and thanks to my dear husband, for his love, caring, and understanding. I thank my whole family for their endless love.