Contents

Preface xi

Acknowledgments xiv

Introduction xv

CHAPTER 1
Human Color Vision 1

1.1 Optics of the Eye 3
1.2 The Retina Revisited 8
1.3 Visual Signal Processing 16
1.4 Mechanisms of Color Vision 21
1.5 Spatial and Temporal Properties of Color Vision 30
1.6 Color-vision Deficiencies 34
1.7 Key Features for Color Appearance Modeling 38

CHAPTER 2
Psychophysics 41

2.1 Psychophysics Defined 43
2.2 Historical Context 45
2.3 Hierarchy of Scales 48
2.4 Threshold Techniques 50
2.5 Matching Techniques 53
2.6 One-dimensional Scaling 54

2.7 Multidimensional Scaling 56
2.8 Design of Psychophysical Experiments 58
2.9 Importance of Psvchophvsics in Color Appearance Modeling 60

CHAPTER 3
Colorimetry 61

3.1 Basic and Advanced Colorimetry 63
3.2 Why Is Color? 1 64
3.3 Light Sources ancpllluminants 65
3.4 Colored Materials 73
3.5 The Human Visual Response 77
3.6 Tristimulus Values and Color-matching Functions 8 1
3.7 Chromaticity Diagrams 90
3.8 CIE Color Spaces 91
3.9 Color-difference Specification 94
3.10 The Next Step 95

CHAPTER 4
Color-appearance Terminology 97

4.1 Importance of Definitions 99
4.2 Color 100
4.3 Hue 101
4.4 Brightness and Lightness 102
4.5 Colorfulness and Chroma 103
4.6 Saturation 104
4.7 Unrelated and Related Colors 105
4.8 Definitions in Equations 106
4.9 Brightness-Colorfulness Versus Lightness-Chroma 107

CHAPTER 5
Color-order Systems 111

5.1 Overview and Requirements 113
5.2 The Munsell Book of Color 115
5.3 The Swedish Natural Color System 119
5.4 The Colorcurve System 122
5.5 Other Color-order Systems 123
5.6 Uses of Color-order Systems 126
5.7 Color-naming Systems 129

CHAPTER 6
Color-appearance Phenomena 131

6.1 What Are Color-appearance Phenomena? 133
6.2 Simultaneous Contrast, Crispening, and Spreading 135
6.3 Bezold-Briicke Hue Shift (Hue Changes with Luminance) 139
6.4 Abney Effect (Hue Changes with Colorimetric Purity) 140
6.5 Helmholtz-Kohlrausch Effect (Brightness Depends on Luminance and Chromaticity) 141
6.6 Hunt Effect (Colorfulness Increases with Luminance) 144
6.7 Stevens Effect (Contrast Increases with Luminance) 145
6.8 Helson-judd Effect (Hue of Non'selective Samples) 146
6.9 Bartleson-Breneman Equations (image Contrast Changes with Surround) 149
6.10 Discounting-the-Illuminant 150
6.11 OtherContextandStructuralEffects 151
6.12 Color Constancy? 156

CHAPTER 7
Viewing Conditions 159

7.1 Configuration of the Viewing Field 161
7.2 Colorimetric Specification of the Viewing Field 165
7.3 Modes of Viewing 168
7.4 Unrelated and Related Colors Revisited 172

CHAPTER 8
Chromatic Adaptation 173

8.1 Light, Dark, and Chromatic Adaptation 176
8.2 Physiology 180
8.3 Sensory and Cognitive Mechanisms 186
8.4 Corresponding-colors Data 189
8.5 Models 193
8.6 Computational Color Constancy 195

CHAPTER 9
Chromatic-adaptation Models 197

9.1 von Kries Model 201
9.2 Retinex Theory 204
9.3 Nayatani et al. Model 205
9.4 Guth's Model 208
9.5 Fairchild's Model 211

CHAPTER 10
Color Appearance Models 215

10.1 Definition of Color Appearance Model 217
10.2 Construction of Color Appearance Models 218
10.3 CIELAB 219
10.4 Why Not Use Just CIELAB? 228
10.5 What About CIELUV? 229

CHAPTER 11
The Nayatani et al. Model 231

11.1 Objectives and Approach 233
11.2 Input Data 234
11.3 Adaptation Model 235
11.4 Opponent-color Dimensions 237
11.5 Brightness 238
11.6 Lightness 239
11.7 Hue 240
11.8 Saturation 240
11.9 Chroma 241
11.10 Colorfulness 241
11.11 Inverse Model 242
11.12 Phenomena Predicted 242
11.13 Why Not Use Just the Nayatani Model? 244

CHAPTER 12
The Hunt Model 245

12.1 Objectives and Approach 247
12.2 Input Data 248
12.3 Adaptation Model 249
12.4 Opponent-color Dimensions 255
12.5 Hue 255
12.6 Saturation 257
12.7 Brightness 258
12.8 Lightness 260
12.9 Chroma 260
12.10 Colorfulness 260
12.11 Inverse Model 261
12.12 Phenomena Predicted 263
12.13 Why Not Use Just the Hunt Model? 264

CHAPTER 13
The RLAB Model 267

13.1 Objectives and Approach 269
13.2 Input Data 271
13.3 AdaptationModel 272
13.4 Opponent-color Dimensions 274
13.5 Lightness 276
13.6 Hue 276
13.7 Chroma 277
13.8 Saturation 277
13.9 Inverse Model 279
13.10 Phenomena Predicted 280
13.11 Why Not Use Just the RLAB Model? 281

CHAPTER 14
Other Models 283

14.1 Overview 285
14.2 ATD Model 286
14.3 LLAB Model 292

CHAPTER 15
Testing Color Appearance Models 301

15.1 Overview 303
15.2 Qualitative Tests 304
15.3 Corresponding-colors Data 308
15.4 Magnitude-estimation Experiments 310
15.5 Direct Model Tests 312
15.6 CIE Activities 318
15.7 A Pictorial Review of Color Appearance Models 320

CHAPTER 16
Traditional Colorimetric Applications 325

16.1 Color Rendering 327
16.2 Color Differences 329
16.3 Indices of Metamerism 332
16.4 A General System of Colorimetry? 334

CHAPTER 17
Device-independent Color Imaging 337

17.1 The Problem 340
17.2 Levels of Color Reproduction 341
17.3 General Solution 346
17.4 Device Calibration and Characterization 347
17.5 The Need for Color Appearance Models 352
17.6 Definition of Viewing Conditions 353
17.7 Viewing-conditions-independent Color Space 355
17.8 Gamut Mapping 355
17.9 Color Preferences 359
17.10 Inverse Process 360
17.11 Example System 360
17.12 ICC Implementation 362

CHAPTER 18
The Future 367

18.1 Will There Be One Color Appearance Model? 369
18.2 Other Color Appearance Models 370
18.3 Ongoing Research to Test Models 370
18.4 Ongoing Model Development
18.5 What to Do Now 371

APPENDIX A
The CIE Color Appearange Model (1997) 373

A.1 Historical Develdpment, Ob'ectives, and Approach 375
A.2 Bradford-Hunt 96S (Simple) Model 378
A.3 Bradford-Hunt 96C (Comprehensive) Model 382
A.4 The CIE TCl-34 Model, CIECAM97s 384
A.5 The ZLAB Color Appearance Model 389
A.6 Outlook 392

References 395

Index 409