Contents
Contributor contact details xi
Woodhead Publishing Series in Textiles xv
Part I Theories, principles and methods of measuring colour 1
1 Colour vision: theories and principles 3
V. V. PÉREZ, D. DE FEZ SAIZ and F. MARTINEZ VERDÚ,
University of Alicante, Spain
1.1 Introduction 3
1.2 Human colour vision 6
1.3 Chromatic perception 10
1.4 Defective colour vision 12
1.5 Colour constancy 15
1.6 Bibliography 17
2 Scales for communicating colours 19
A. K. ROY CHOUDHURY, Government College of Engineering and Textile Technology, India
2.1 Introduction 19
2.2 Systematic arrangements of colours 22
2.3 Colour order systems 23
2.4 Various colour order systems 31
2.5 Comparison and interrelation of various systems 51
2.6 Accuracy of colour order systems 54
2.7 Computer-based systems 54
2.8 Universal colour language (UCL) 61
2.9 Future trends 63
2.10 References 65
3 Expressing colours numerically 70
V. C. GUPTE, Advanced Graphic Systems, India
3.1 Introduction 70
3.2 Colour specifications 70
3.3 The Commission Internationale de l’Eclairage (CIE) system 72
3.4 The CIE standard light sources/illuminants 72
3.5 The CIE Standard Observer and unreal primaries 74
3.6 Computation of tristimulus values 77
3.7 Refl ectance measurement 79
3.8 Chromaticity coordinates and chromaticity diagram 80
3.9 Usefulness of the CIE XYZ system 81
3.10 Limitations of the CIE system 82
3.11 Transformation and improvement of the CIE system 82
3.12 Future trends 86
3.13 References 86
4 Visual and instrumental evaluation of whiteness and yellowness 88
R. HIRSCHLER, SENAI/CETIQT Colour Institute, Brazil
4.1 Introduction: whiteness and yellowness 88
4.2 Visual assessment of whiteness 90
4.3 Measuring techniques and instruments 95
4.4 Indices for whiteness and yellowness 100
4.5 Applications in industry, cosmetics and dentistry 111
4.6 Future trends 115
4.7 Sources of further information and advice 117
4.8 References 119
5 Use of artificial neural networks (ANNs) in colour measurement 125
M. SENTHILKUMAR, PSG College of Technology, India
5.1 Introduction 125
5.2 Artificial neural networks (ANNs): basic principles 126
5.3 Architecture of an artifi cial neural network 127
5.4 Learning process 129
5.5 Feed-forward neural network 130
5.6 Training of an artificial neural network using back propagation algorithm 130
5.7 Application of artificial neural networks to colour measurement 132
5.8 Recipe prediction 135
5.9 Evaluation of the ANN method 140
5.10 Case studies 140
5.11 Future trends 141
5.12 Sources of further information and advice 144
5.13 References 144
6 Camera-based colour measurement 147
F. MARTÍNEZ-VERDÚ, E. CHORRO and E. PERALES, University of
Alicante, Spain, M. VILASECA and J. PUJOL, Technical University of
Catalonia, Spain
6.1 Introduction 147
6.2 Principles of camera-based colour measurement 149
6.3 Procedures of camera-based colour measurement 151
6.4 Strengths and weaknesses 154
6.5 Case studies 158
6.6 Future trends 162
6.7 Conclusions 163
6.8 Sources of further information and advice 163
6.9 References 163
7 Colour shade sorting 167
M. L. GULRAJANI, India Institute of Technology, India
7.1 Introduction 167
7.2 (555) Fixed-grid shade sorting system 168
7.3 Clemson Colour Clustering 174
7.4 K-means clustering 178
7.5 Modified CCC shade sorting method 180
7.6 Shade sequencing and clustering 180
7.7 References 182
8 Determining uncertainty and improving the accuracy of color measurement 184
J. A. LADSON, Color Science Consultancy, USA
8.1 Introduction to determining uncertainty 184
8.2 Uncertainty 185
8.3 Defi nitions 186
8.4 Tables of results 187
8.5 Conclusions: determining uncertainty 189
8.6 Improving accuracy: the absolute correction of instrumentally generated spectrometer values 190
8.7 Introduction to improving accuracy 190
8.8 Experimental modeling 191
8.9 Applications 193
8.10 Conclusions: improving accuracy 194
8.11 References 195
9 Colour measurement and fastness assessment 196
M. BIDE, Department of Textiles, Fashion Merchandising and
Design, University of Rhode Island, USA
9.1 Introduction: colour and colourfastness 196
9.2 The use and usefulness of colourfastness testing 197
9.3 Colourfastness test method development 199
9.4 Colourfastness test standard setting organizations 200
9.5 Standard colourfastness test format 201
9.6 Testing for colourfastness: specifi c tests 203
9.7 Colourfastness testing: assessment of results (colour measurement) 207
9.8 Conclusions 216
9.9 References 216
Part II Colour measurement and its applications 219
10 Colour measurement methods for textiles 221
N. S. GANGAKHEDKAR, Compute Spectra Color Pvt. Ltd., India
10.1 Introduction 221
10.2 Colour as numbers 222
10.3 Colour specifi cation 224
10.4 Metamerism 226
10.5 Reasons why colours do not match 231
10.6 Visual versus numerical pass/fail 232
10.7 Colour measurement techniques for textiles 236
10.8 On-line colour measurement 242
10.9 Colour of dry and wet fabrics 247
10.10 Inspection of colour of fi nished fabrics: a case study 248
10.11 Future trends 250
10.12 Conclusions 250
10.13 Sources of further information and advice 251
10.14 References 251
11 Grading of cotton by color measurement 253
B. XU, The University of Texas, USA
11.1 History of cotton color grading 253
11.2 USDA cotton color grades 253
11.3 HVI colorimeter 254
11.4 Factors affecting cotton color grade 255
11.5 Color measurement using color image analysis 259
11.6 Using neural networks 263
11.7 Using fuzzy logic 268
11.8 Conclusions 276
11.9 References 277
12 Colour measurement of paint fi lms and coatings 279
N. S. GANGAKHEDKAR, Compute Spectra Color Pvt. Ltd., India
12.1 Introduction 279
12.2 Quality control of paints 280
12.3 Sample preparation for colour measurement 291
12.4 Pigment quality control 292
12.5 Problems in match prediction: paint applications 295
12.6 Computer colour matching for paints 295
12.7 Colour control system 297
12.8 Measuring colour properties of wet paints 299
12.9 Instant colour matching at the paint shop 300
12.10 Colour matching of automotive paints 307
12.11 Future trends 309
12.12 Conclusions 309
12.13 Sources of further information and advice 310
12.14 References 310
13 Colour measurement of food: principles and practice 312
D. B. MACDOUGALL, Formerly of the University of Reading, UK
13.1 Introduction 312
13.2 Colour vision: trichromatic detection 313
13.3 The infl uence of ambient light and food structure 316
13.4 Appearance 317
13.5 Absorption and scatter 318
13.6 Colour description: the CIE system 319
13.7 Colour description: uniform colour space 320
13.8 Instrumentation 325
13.9 Food colour appearance measurement in practice 327
13.10 Illuminant spectra and uniform colour 336
13.11 Conclusions and future trends 337
13.12 References 339
14 Colorimetric evaluation of tooth colour 343
A. JOINER, Unilever Oral Care, UK
14.1 Introduction 343
14.2 The human dentition and its environment 344
14.3 Optical properties of teeth 345
14.4 The colour of teeth 347
14.5 Factors that impact tooth colour and its perception 348
14.6 Tooth whiteness 351
14.7 Measurement of tooth colour 352
14.8 Measurement of extrinsic stain 356
14.9 Methods to improve tooth colour 357
14.10 Future trends 361
14.11 Sources of further information and advice 362
14.12 References 363
15 Hair color measurement 371
D. J. TOBIN, University of Bradford, UK
15.1 Introduction 371
15.2 Background 371
15.3 Natural hair color 373
15.4 Gray hair and age 379
15.5 Effect of environment 382
15.6 Artificial hair coloring shades 383
15.7 Color measurement methods and instruments 386
15.8 Future trends 388
15.9 Sources of further information and advice 388
15.10 References 388
Index 393