Practical implementations of HDR rendering have been available in imaging techniques for more than 500 years, and the book begins with an introduction to the history of the discipline. This covers painting, photography, and electronic imaging that all successfully reproduce scenes with a greater dynamic range of light than available in the reproduction medium. These early chapters also explain how human vision is more interested in the relationship of image pixel values than a pixel''s absolute value, and the importance of spatial image processing. The second part focuses on optics and psychophysics, describing experiments that measure the physical ranges of light that can be recorded by cameras, and detected by humans, and the importance of light distribution in the scene being captured. The third part on vision science describes human responses to HDR images, looking at how the two spatial mechanisms, optical glare and visual contrast, tend to counteract each other. It describes the correlation of appearance and calculated retinal images, explains why image-dependent glare sets the dynamic range of usable HDR information, evaluates whether HDR displays require a new definition of uniform colour spaces, and explores how HDR affects colour appearances. The final part looks at digital imaging, discussing current technological practices. Whilst silver-halide, pixel-based photography presented a challenge to HDR techniques, the development of digital photography and electronic imaging allowed an image to achieve the same effect as human vision. Spatial algorithms can automatically mimic vision and automatically process all images, and these processes are discussed in digital cameras printers, displays, and image processing software and hardware. This book brings together the relevant thinking on the topic, learning from the disparate experiences of artists (painters and photographers), scientists (optics and vision science), imaging engineers (silver-halide film, silicon sensors and camera-, printer- and display-designers), and image processing experts (algorithms and computer hardware).

Leseprobe

Series Editor Preface. Preface. Acknowledgements. Section A HISTORY OF HDR IMAGING. 1 HDR Imaging. 1.1 Topics. 1.2 Introduction. 1.3 Replicas and Reproductions. 1.4 A Choice of Metaphors for HDR Reproduction. 1.5 Reproduction of Scene Dynamic Range. 1.6 HDR Disciplines. 1.7 Outline of the Text. 1.8 Summary. 1.9 References. 2 HDR Tools and Definitions. 2.1 Topics. 2.2 Introduction. 2.3 Pixels. 2.4 Dynamic Ranges. 2.5 Measuring Light. 2.6 Measuring Color Spaces. 2.7 Image Reproduction. 2.8 Contrast. 2.9 Digital Imaging. 2.10 Summary. 2.10 References. 3 HDR in Natural Scenes. 3.1 Topics. 3.2 Appearance in HDR and Color Constancy. 3.3 Summary. 3.4 References. 4 HDR in Painting. 4.1 Topics. 4.2 Introduction. 4.3 Ancient Painting. 4.3 Su "Children Playing on a Winter Day", detail in Sung dynasty scroll (1130-1160), National Palace Museum, Taipei. 4.4 Perspective. 4.5 Chiaroscuro. 4.6 Gerritt van Honthorst (Gherardo delle Notti). 4.7 Rembrandt van Vijn. 4.8 John Constable. 4.9 John Martin. 4.10 Impressionism. 4.11 Photorealism. 4.12 Summary. 4.13 References. 5 HDR in Film Photography. 5.1 Topics. 5.2 Introduction. 5.3 Multiple exposures in the 1850's. 5.4 H. P. Robinson. 5.5 Hurter & Driffield-Scientific Calibration of AgX Film Sensitivity. 5.6 Sheppard and Mees. 5.7 19th Century - Professional Amateur Photography. 5.8 20th Century - Corporate Photography. 5.9 20th Century Control of Dynamic Range. 5.9 O ther Silver-Halide Stories. 5.10 Summary. 5.11 References. 6 Ansel Adams's Zone System. 6.1 Topics. 6.2 Introduction. 6.3 Compressing the HDR World into the LDR Print. 6.4 Visualization. 6.5 Scene Capture. 6.6 "Performing the Score". 6.7 Moonrise, Hernandez. 6.8 Apparent vs. Physical Contrast. 6.9 Summary. 6.10 References. 7 HDR Electronic Image Processing. 7.1 Topics. 7.2 Introduction. 7.3 Human Spatial Vision. 7.4 E lectronic HDR Image Processing. 7.5 Summary. 7.6 References. 8 Computer Graphics. 8.1 Topics. 8.2 Introduction. 8.3 E arly Years: the 60's. 8.3 E arly Digital Image Synthesis: the 70's. 8.4 The turning point: the 80's. 8.5 Computational Photorealism: from 90's. 8.7 Summary. 8.8 References. 9 Review of HDR History. 9.1 Topics. 9.2 Summary of Disciplines. 9.3 Review. 9.4 Summary. 9.5 References. Section B MEASURED DYNAMIC RANGES. 10 Actual Dynamic Ranges. 10.1 Topics. 10.2 Introduction. 10.3 Dynamic Range of Light Sensors. 10.4 Bits per Pixel. 10.5 Dynamic Range of Display Devices. 10.6 Interactions of Pixels in Images. 10.7 Summary. 10.8 References. 11 Limits of HDR Scene Capture. 11.1 Topics. 11.2 Introduction. 11.3 HDR Test Targets. 11.4 Camera veiling glare limits. 11.5 Glare in Film Cameras. 11.6 Review. 11.7 Summary. 11.8 References. 12 Limits of HDR in Humans. 12.1 Topics. 12.2 Introduction. 12.3 Visual Appearance of HDR Displays. 12.4 The von Honthorst's Painting and the 4scaleBlack HDR Target. 12.5 HDR Displays and Black and White Mondrian. 12.6 HDR and Tone Scale Maps. 12.7 HDR Displays and Contrast. 12.8 Summary. 12.9 References. 13 Why does HDR improve images? 13.1 Topics. 13.2 Introduction. 13.3 Why are HDR images better? 13.4 Are ...