This book provides an introduction to Fourier optics in the light of new developments in the area of computational imaging over the last couple of decades. The text is divided into three parts. The first part provides an in-depth discussion of relevant mathematical methods such as Fourier analysis, linear systems theory, random processes, and optimization-based image reconstruction techniques that are essential for understanding the working of modern computational imaging systems. The second part of the book explains the concepts in optics including diffraction phenomena, coherent and incoherent imaging systems, and some aspects of optical coherence theory. These traditional topical areas in Optics are covered from systems theory perspective. For example the diffraction theory is directly introduced in the angular spectrum formalism instead of the historical perspective taken by traditional Optics books. The third part of the book builds on the material in the first two parts and describes several system ideas combining optical hardware design and image reconstruction algorithms. In particular several advanced topics such as digital holography, iterative phase retrieval, super-resolution imaging, point spread function engineering for enhanced depth-of-focus, projection based imaging, single-pixel or ghost imaging, etc. are introduced. Each chapter contains a few exercises and thought problems that are meant to make the readers aware of interesting developments in the computational imaging literature. The book can serve as an introductory textbook for advanced undergraduate and Masters/PhD level students from Physics, EE or Applied Mathematics backgrounds who may be interested in exploring the exciting world of imaging research and development. About the Book 1 Introduction Part I Mathematical preliminaries 2 Fourier series and transform 3 Sampling theorem 4 Operational introduction to fast Fourier transform 5 Linear systems formalism and introduction to inverse problems in imaging 6 Optimization approach to image reconstruction 7 Random Processes Part II Concepts in Optics 8 Geometrical Optics Essentials 9 Wave Equation and Diffraction of Light 10 Coherence of light fields 11 Polarization of light 12 Analysis of optical systems 13 Imaging from information point of view Part III Computational imaging systems 14 Digital Holography 15 Non-interferometric phase retrieval 16 Compact Multi-lens Imaging Systems 17 PSF Engineering 18 Structured Illumination Imaging 19 Image reconstruction from projections 20 Correlation imaging Index About the Authors Prof. Kedar Khare is currently an Institute Chair Associate Professor at Optics and Photonics Centre and Department of Physics, Indian Institute of Technology Delhi. He additionally serves as an Associate Editor for Journal of Modern Optics. Prior to joining IIT Delhi as a faculty member, he worked as a Lead Scientist for over five years at General Electric Global Research in Niskayuna, NY. His research interests span wide ranging problems in computational imaging. Prof. Khare received his MSc in Physics from Indian Institute of Technology Kharagpur with highest honors, and his PhD in Optics from The Institute of Optics, University of Rochester. Prof. Khare is a Senior Member of Optica (formerly OSA). Mansi Butola is currently a PhD student at the Department of Physics, Indian Institute of Technology Delhi. Her research interests include computational imaging systems in general and her thesis work has focused on iterative phase retrieval algorithms for coherent diffraction imaging. She is a member of the Optica Student Chapter at IIT Delhi and has actively participated in organizing multiple seminars/workshops and outreach activities. Sunaina Rajora is currently a PhD student in the Department of Physics at Indian Institute of Technology, Delhi. Her research interests include inverse problems in imaging, optimization algorithms, quantitative phase imaging, digital holography and tomographic reconstruction. She is a member of the Optica Student Chapter at IIT Delhi and has actively participated in organizing seminars/workshops and outreach activities.