Andy Rowlands - Physics of Digital Photography

IOP Series: Emerging Technologies in Optics and Photonics

Series Editor

R Barry Johnson a Senior Research Professor at Alabama A&M University, has been involved for over 40 years in lens design, optical systems design, electro-optical systems engineering, and photonics. He has been a faculty member at three academic institutions engaged in optics education and research, employed by a number of companies, and provided consulting services.

Dr Johnson is an SPIE Fellow and Life Member, OSA Fellow, and was the 1987 President of SPIE. He serves on the editorial board of Infrared Physics & Technology and Advances in Optical Technologies. Dr Johnson has been awarded many patents, has published numerous papers and several books and book chapters, and was awarded the 2012 OSA/SPIE Joseph W Goodman Book Writing Award for Lens Design Fundamentals, Second Edition. He is a perennial co-chair of the annual SPIE Current Developments in Lens Design and Optical Engineering Conference.

Foreword

Until the 1960s, the field of optics was primarily concentrated in the classical areas of photography, cameras, binoculars, telescopes, spectrometers, colorimeters, radiometers, etc. In the late 1960s, optics began to blossom with the advent of new types of infrared detectors, liquid crystal displays (LCD), light emitting diodes (LED), charge coupled devices (CCD), lasers, holography, fiber optics, new optical materials, advances in optical and mechanical fabrication, new optical design programs, and many more technologies. With the development of the LED, LCD, CCD and other electo-optical devices, the term photonics came into vogue in the 1980s to describe the science of using light in development of new technologies and the performance of a myriad of applications. Today, optics and photonics are truly pervasive throughout society and new technologies are continuing to emerge. The objective of this series is to provide students, researchers, and those who enjoy self-teaching with a wide-ranging collection of books that each focus on a relevant topic in technologies and application of optics and photonics. These books will provide knowledge to prepare the reader to be better able to participate in these exciting areas now and in the future. The title of this series is Emerging Technologies in Optics and Photonics where emerging is taken to mean coming into existence, coming into maturity, and coming into prominence. IOP Publishing and I hope that you find this Series of significant value to you and your career.

Andy Rowlands

IOP Publishing, Bristol, UK

IOP Publishing Ltd 2017

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Andy Rowlands has asserted his right to be identified as the author of this work in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988.

ISBN 978-0-7503-1242-4 (ebook)
ISBN 978-0-7503-1243-1 (print)
ISBN 978-0-7503-1244-8 (mobi)

DOI 10.1088/978-0-7503-1242-4

Version: 20170401

IOP Expanding Physics
ISSN 2053-2563 (online)
ISSN 2054-7315 (print)

British Library Cataloguing-in-Publication Data: A catalogue record for this book is available from the British Library.

Published by IOP Publishing, wholly owned by The Institute of Physics, London

IOP Publishing, Temple Circus, Temple Way, Bristol, BS1 6HG, UK

US Office: IOP Publishing, Inc., 190 North Independence Mall West, Suite 601, Philadelphia, PA 19106, USA

For my parents, Ann and Gareth.

My aim in writing this book is to provide a theoretical overview of the photographic imaging chain. The book is intended for use by graduate students and researchers entering imaging science, and for photographers with a graduate level technical background. For existing researchers, it should serve as a link between imaging science and photographic practice.

Chapter continues the imaging chain by providing an introduction to digital output, before going on to discuss exposure strategy in digital photography. The aim is to produce a digital output image file with specified characteristics such as a standard brightness.

Chapter .

Chapter describes the physical principles behind some of the main steps involved in converting the raw data into a viewable output image. A large part of the chapter is devoted to colour theory and the implementation of white balance in digital cameras.

Chapter explains the theory required for interpreting image quality metrics used by reviewers of digital cameras and lenses. Theory for cross-format comparisons is described in detail. Practical strategies for maximising the full image quality potential of a camera system are also discussed.

Data obtained from the Olympus E-M1 camera has been used to illustrate various examples in this book.

Certain topics have been omitted which I believe are already well-covered elsewhere. In particular, I have chosen to concentrate on the physics of digital photography itself rather than the underlying camera technology. The book Camera Technology: the Dark Side of the Lens by N Goldberg is an excellent resource on this topic. Although it is written about film cameras, many of the concepts carry over to digital cameras. Furthermore, many excellent books have been written about sensor technology and signal processing, and I highly recommend Image Sensors and Signal Processing for Digital Still Cameras edited by J Nakamura.

I would like to thank Professor R Barry Johnson and Dr Rafal Mantiuk for helpful discussions and suggestions. Dave Coffin provided some useful information about his dcraw raw converter, and the late Dr Hubert Nasse kindly gave permission to reproduce several figures from his articles. Finally, I would like to thank the production staff at IOP Publishing, and in particular Dr John Navas, for overseeing the commissioning and publication of this book.

Andy Rowlands, January 2017

Derwyn Andrew Rowlands

Andy Rowlands gained a first class joint honours degree in Mathematics and Physics in 2000, and received his PhD in Physics in 2004 from the University of Warwick, UK. For his PhD he developed a method for treating short-range order in the first-principles quantum description of substitutionally disordered metallic systems.

He was subsequently awarded a Fellowship in Theoretical Physics from the Engineering and Physical Sciences Research Council (EPSRC) which he held at the University of Bristol, UK, from 2004 to 2007. This was followed by a further postdoctoral position at Lawrence Livermore National Laboratory (LLNL) in California, USA, in 2008.