Color Vision and Colorimetry THEORY and APPLICATIONS SECOND EDITION

Daniel Malacara

SPIE PRESS Bellingham, Washington USA Contents

Preface to the Second Edition ix

Preface to the First Edition xi

Chapter 1 The Nature of Color 1 1.1 Introduction 1 1.2 Newton's Color Experiment 4 1.3 Theories and Experiments in Color Vision 4 1.4 Some Radiometric and Photometric Units 8 1.4.1 Radiometric units 8 1.4.2 Photometric units 10 1.5 Color Sensitivity of the Eye 14 1.6 How Materials are Colored or Modify Color 16 1.7 Absorption and Interference Filters 18 References 20

Chapter 2 Light Sources and llluminants 23 2.1 Introduction 23 2.2 Blackbody Radiation and Color Temperature 23 2.3 Tungsten Lamps 24 2.4 Gas Discharge and Fluorescent Lamps 26 2.5 Light-Emitting Diodes 28 2.6 Television and Computer Displays 31 2.7 Standard Light Sources and llluminants 33 2.8 Color-Rendering Index of Light Sources 35 References 38

Chapter 3 The Human Eye 41 3.1 Anatomy of the Eye 41 3.2 Eye Resolving Power and Eye Aberrations 44 3.3 Stiles-Crawford Effect 45 3.4 Eye Response to Pulsating Light 45 3.5 Visual Detectors in the Retina 47

v vi Contents

3.6 Observation of the Human Eye Retina 48 3.7 Cone Fundamentals 51 References 54

Chapter 4 Trichromatic Theory 59 4.1 Grassmann Laws 59 4.2 Maxwell's Triangle 59 4.3 Color-Matching Experiments 60 4.4 Color-Matching Functions г(Л), g(Ä), and Ъ{Л) 63 4.5 Tristimulus Values R, G, В 64 4.6 Chromaticity Coordinates r, g, b 68 References 72

Chapter 5 CIE Color Specification System 75 5.1 The CIE Color System 75 5.2 Color-Matching Functions х(Л), у(Л), and 2(Л) 76 5.3 Tristimulus Values X, Y,Z 82 5.4 Chromaticity Coordinates x,y,z 82 5.5 Dominant Wavelength and Correlated Color Temperature 85 5.6 The Color of a Transparent or Opaque Body 91 5.7 Color Discrimination Mechanisms 97 5.8 Use of Cone Sensitivities as Color-Matching Functions 99 References 101

Chapter 6 Uniform Color Systems 103 6.1 Introduction 103 6.2 Hue and Chroma in the CIE Diagram 104 6.3 The Munsell System 105 6.4 The 1960 CIE Luv Color Space 110 6.5 The 1976 CIE L*u*v* Color Space 112 6.6 The Hunter Lab Color Space 114 6.7 The 1976 CIE L*a*b* Color Space 116 6.8 Color-Difference Equation in the CIE L*a*b* Color Space 120 6.9 MacLeod and Boynton Chromaticity Diagram 125 6.10 Derrington, Krauskopf, and Lennie (DKL) Color Space 125 6.11 Other Color Spaces 127 References 127

Chapter 7 Color Mixtures and Colorants 131 7.1 Color Addition 131 7.2 RGB Color System for Cathode Ray Tubes 133 7.3 Color Subtraction 137 Contents vii

7.4 Metamerism 138 7.5 Colorants 140 7.6 Color Matching and Color Management 140 References 144

Chapter 8 Color Measurements and Color Defects 147 8.1 Introduction 147 8.2 Visual Chromatic Defects 147 8.3 Whiteness and White Standards 150 8.4 Pantone® Colors, GretagMacbeth ColorChecker®, and Spec- tralon® Standards 151 8.5 Optical Configurations to Measure Reflectance 152 8.6 Precision and Accuracy of Measuring Instruments 156 8.7 Spectrocolorimeters 157 8.8 Tristimulus Photocolorimeters 159 8.9 Visual Colorimeters 161 References 162

General References 165

Index 171

Biography 177