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Light Field Analysis and Its Applications In ABSTRACT Title of Document: Light field Analysis and Its Applications in Adaptive Optics and Surveillance Systems Mohammed Ali Eslami, Doctorate of Philosophy, 2012 Directed By: Professor, Christopher C. Davis, Department of Electrical and Computer Engineering An image can only be as good as the optics of a camera or any other imaging system allows it to be. An imaging system is merely a transformation that takes a 3D world coordinate to a 2D image plane. This can be done through both linear/non-linear transfer functions. Depending on the application at hand it is easier to use some models of imaging systems over the others in certain situations. The most well- known models are the 1) Pinhole model, 2) Thin Lens Model and 3) Thick lens model for optical systems. Using light-field analysis the connection through these different models is described. A novel figure of merit is presented on using one optical model over the other for certain applications. After analyzing these optical systems, their applications in plenoptic cameras for adaptive optics applications are introduced. A new technique to use a plenoptic camera to extract information about a localized distorted planar wave front is described. CODEV simulations conducted in this thesis show that its performance is comparable to those of a Shack-Hartmann sensor and that they can potentially increase the dynamic range of angles that can be extracted assuming a paraxial imaging system. As a final application, a novel dual PTZ-surveillance system to track a target through space is presented. 22X optic zoom lenses on high resolution pan/tilt platforms recalibrate a master-slave relationship based on encoder readouts rather than complicated image processing algorithms for real-time target tracking. As the target moves out of a region of interest in the master camera, it is moved to force the target back into the region of interest. Once the master camera is moved, a precalibrated lookup table is interpolated to compute the relationship between the master/slave cameras. The homography that relates the pixels of the master camera to the pan/tilt settings of the slave camera then continue to follow the planar trajectories of targets as they move through space at high accuracies. LIGHT FIELD ANALYSIS AND ITS APPLICATIONS IN ADAPTIVE OPTICS AND SURVEILLANCE SYSTEMS By Mohammed Ali Eslami Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park, in partial fulfillment of the requirements for the degree of Doctorate of Philosophy 2012 Advisory Committee: Professor Christopher C. Davis, Chair Professor Gilmer Blankenship Professor Rama Chellappa Professor Thomas E. Murphy Professor John T. Fourkas, Dean’s Representative © Copyright by Mohammed Ali Eslami 2012 Dedication To my parents for keeping me in their prayers… To my brother for granting me his support… To my wife for giving me the final push… And to Mohebban-e-Fatemeh (SA) for granting me purpose… ii Acknowledgements I begin this dissertation in the name of Allah (SWT) for all praise and thanks belongs to Him. He has truly showered my life with blessings and mercy. I would like to next thank my adviser Dr. Chris Davis for his continued support, both through research fellowships and mentoring, that ultimately guided me to putting the appropriate “optics” touch on this project. I would like to thank the committee members for their participation in reviewing this thesis, in particular to Dr. Rama Chellappa who pulled my project out of a simple “calibration” oriented thesis to a more optics oriented look at camera systems during my proposal. This push along with Dr. Davis’ expertise in the field helped pave the way for me to add my niche in the world of science and technology. I also must thank TRX Systems for providing the funding to the Maryland Optics Group from the awarded DARPA project to make this thesis possible. I truly appreciate all the time and mentorship provided by the CTO and Chairman, Dr. Carole Teolis. I would also like to thank TRX engineers Dr. John Karvounis and Jared Napora particularly for their help in understanding OpenCV and guiding a MATLAB programmer through C# and then through C++. I would also like to thank all the members of the Maryland Optics Group, in particular Dr. Quirino Balzano, for his help on all of my RF related projects, Dr. Navik Aggrawal for the opportunity to bounce ideas off of him and extend different areas in my thesis, and last but not least, John Rzasa who led all the hardware design for the high-resolution gimbals and assisted with the acquisition of the appropriate cameras and lenses we used in the experiments of this project. I can say with the iii utmost certainty that had John not been around, my project would have probably been too expensive/difficult for any university student to be able to complete. I promised him a page long dedication for all his help in setting up experiments/hardware in my thesis but I’m sure this will suffice in him knowing that I am truly grateful for all his help throughout these past years particularly the evenings and weekends we would meet for experiments. On a more personal note, I would like to thank my family for all of their support and push to even begin graduate school. My parents have always provided me with everything I needed to ensure that I could focus on my school work and not worry about anything else. My brother was a great listener at times when I was stuck and even though he rarely understood what I was saying managed to say one to two useful things to have that light-bulb in my mind turn on. In the last year of my graduate school, I was blessed to marry a wonderful wife who provided me with that final push/burst of motivation to ensure that I had the right focus to finish my thesis. Although TRX Systems was waiting for monthly reports, my wife was waiting for nightly reports every evening to ensure I completed enough throughout the day to be able to graduate. I would also like to thank her for drawing all of my figures. Lastly, I end this section by acknowledging a group that I grew up with, the group mentioned in the dedication of this thesis, Mohebban-e-Fatemeh(SA). Watching the members of that group grow both in quantity (from 2 to 60 in five years) and quality always kept my head on straight to ensure that I never lost sight of my ultimate goal, and that was to become an accomplished, successful engineer to be able to help mentor /guide others along the path that I traveled. Thank you all. iv Table of Contents Dedication ..................................................................................................................... ii Acknowledgements ...................................................................................................... iii Table of Contents .......................................................................................................... v List of Figures ............................................................................................................ viii 1 Introduction ........................................................................................................... 1 1.1 Brief History ................................................................................................. 1 1.2 Light Field Analysis ...................................................................................... 2 1.3 Adaptive Optics ............................................................................................ 4 1.4 Surveillance Systems .................................................................................... 6 2 Review of Imaging Systems ............................................................................... 13 2.1 Introduction ................................................................................................. 13 2.2 Pinhole Model for Optical System .............................................................. 14 2.2.1 Introduction ............................................................................................. 14 2.2.2 Calibration of Imaging System Using the Pinhole Model ...................... 17 2.3 Thin Lens Model of Optical System ........................................................... 22 2.3.1 Introduction ............................................................................................. 22 2.3.2 Extension to the Pinhole Model .............................................................. 25 2.3.3 Positive and Negative Thin Lenses ......................................................... 27 2.4 Thick/Compound Lens Model .................................................................... 30 2.4.1 Introduction ............................................................................................. 31 2.4.2 Matrix Optics .......................................................................................... 34 2.4.3 Other Optical Considerations .................................................................. 40 v 2.5 Closure ........................................................................................................ 45 3 Light field Analysis............................................................................................. 47 3.1 Introduction ................................................................................................. 47 3.2 Mathematical Formulation .......................................................................... 49 3.2.1 Describing a Light Source and Reflecting Surface ................................
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