The Reproduction of Colour 6e

Robert Hunt, formerly Assistant Director of Research, Kodak Research Laboratories in Harrow, England, is an independent colour consultant and visiting Professor of Colour Science at the University of Derby. He has been Chairman of the Colour Group of Great Britain (1961-63); Chairman of the Colorimetry Committee of the CIE (1975-83); and President of the International Colour Association (1981-85). He has written over a hundred papers on colour, vision, colour reproduction, and colour measurement. He is an Honorary Fellow of the Royal Photographic Society and a member of the Royal Institution where he served as Vice-President (1985-87). He has been awarded the Progress Medal of the Royal Photographic Society, the Judd-AIC Medal of the International Colour Association, and the Gold Medal of the Institute of Printing.

Series Preface. Preface to the Sixth Edition. PART ONE. FUNDAMENTALS. 1. Spectral Colour Reproduction. 1.1 Introduction. 1.2 The spectrum. 1.3 The micro-dispersion method of colour photography. 1.4 The Lippmann method. 1.5 Use of identical dyes. 1.6 Approximate spectral colour reproduction. 1.7 A simplified approach. 2. Trichromatic Colour Reproduction and the Additive Principle. 2.1 Introduction. 2.2 Maxwell's method. 2.3 The physiology of human colour vision. 2.4 Spectral sensitivity curves of the retina. 2.5 Unwanted stimulations. 3. Additive Methods. 3.1 Introduction. 3.2 The successive frame method. 3.3 The mosaic method. 3.4 The lenticular method. 3.5 The virtual-image method. 3.6 The diffraction method. 3.7 Errors in additive methods. 4. The Subtractive Principle. 4.1 Introduction. 4.2 The subtractive principle. 4.3 Defects of the subtractive principle. 5. Visual Appreciation. 5.1 Introduction. 5.2 The basis of judgement. 5.3 Variations of hue. 5.4 Variations of lightness. 5.5 Variations of colourfulness. 5.6 Priorities. 5.7 Factors affecting apparent colour balance. 5.8 Integrating to grey. 5.9 The perception of depth. 6. Tone Reproduction. 6.1 Introduction. 6.2 Identical viewing conditions. 6.3 Characteristic curves. 6.4 Different luminance levels. 6.5 Different surround conditions. 6.6 Complications with solid objects. 6.7 Comparisons of transparencies and reflection prints. 6.8 Colourfulness. 6.9 Exposure latitude. 6.10 Tone reproduction in duplicating. 6.11 Tone reproduction in television. 6.12 Lighting geometry. 6.13 Conclusions. 7. The Colour Triangle. 7.1 Introduction. 7.2 Colour terminology. 7.3 Trichromatic matching. 7.4 Colour-matching functions. 7.5 The colour triangle. 7.6 The centre of gravity law. 7.7 Other colour triangles. 7.8 Additive colour reproduction. 7.9 The Ives-Abney-Yule compromise. 7.10 Colour gamuts of reflecting and transmitting colours. 7.11 Two-colour reproductions. 8. Colour Standards and Calculations. 8.1 Introduction. 8.2 Standard illuminants. 8.3 The Standard Observers. 8.4 Colour transformations. 8.5 Properties of the XYZ system. 8.6 Uniform chromaticity diagrams. 8.7 Nomograms. 8.8 Uniform colour spaces. 8.9 Subjective effects. 8.10 Haploscopic matching. 8.11 Subjective colour scaling. 8.12 Physical colour standards. 8.13 Whiteness. 9. The Colorimetry of Subtractive Systems. 9.1 Introduction. 9.2 Subtractive chromaticity gamuts. 9.3 Subtractive gamuts in the colour solid. 9.4 Spectral sensitivities for block dyes. 9.5 Spectral sensitivities for real dyes. 9.6 MacAdam's analysis. 9.7 Umberger's analysis. 9.8 Two-colour subtractive systems. 9.9 Subtractive quality. 10. Light Sources. 10.1 Introduction. 10.2 Tungsten lamps. 10.3 Spectral-power converting filters. 10.4 Daylight. 10.5 Fluorescent lamps. 10.6 Sodium, mercury, and metal-halide lamps. 10.7 Xenon arcs. 10.8 Carbon arcs. 10.9 Photographic flash-bulbs. 10.10 The red-eye effect. 10.11 Correlated colour temperatures of commonly used light sources. 10.12 Colour rendering of light sources. 10.13 Visual clarity. 10.14 Polarization. 10.15 Light Emitting Diodes (LEDs). 11. Objectives in Colour Reproduction. 11.1 Introduction. 11.2 Comparative methods. 11.3 Absolute methods. 11.4 Spectral colour reproduction. 11.5 Colorimetric colour reproduction. 11.6 Exact colour reproduction. 11.7 Equivalent colour reproduction. 11.8 Colorimetric colour reproduction as a practical criterion. 11.9 Corresponding colour reproduction. 11.10 Preferred colour reproduction. 11.11 Degree of metamerism. 11.12 Conclusions. PART TWO. COLOUR PHOTOGRAPHY. 12. Subtractive Methods in Colour Photography. 12.1 Introduction. 12.2 Relief images. 12.3 Colour development. 12.4 Integral tripacks. 12.5 Processing with the couplers incorporated in the film. 12.6 Reversal processing. 12.7 Processing with the couplers in developers. 12.8 The philosophy of colour negatives. 12.9 Subtractive methods for amateur use in still photography. 12.10 Subtractive methods for professional use in still photography. 12.11 Subtractive methods for motion-picture use. 12.12 Motion-picture frame rates. 13. Reflection Prints in Colour. 13.1 Introduction. 13.2 Direct reflection-print systems. 13.3 Reversal-reversal (positive-positive) systems. 13.4 Negative-positive systems. 13.5 Internegative systems. 13.6 Printing from electronic images. 13.7 Basic difficulties in reflection prints. 13.8 Effect of surround. 13.9 Inter-reflections in the image layer. 13.10 Luminance ranges. 13.11 Luminance levels. 13.12 Geometry of illumination and viewing. 14. Quantitative Colour Photography. 14.1 Introduction. 14.2 Sensitometric pictures. 14.3 Sensitometric wedges. 14.4 Uniformity of illumination. 14.5 Exposure time. 14.6 Light sources for sensitometry. 14.7 Transmission colour of lenses. 14.8 Selective exposure of layers. 14.9 Latent image changes. 14.10 Controlled processing. 14.11 Visual evaluation. 14.12 Logarithmic scales. 14.13 Densitometers. 14.14 Specular and diffuse transmission densities. 14.15 Printing densities. 14.16 Integral densities. 14.17 Some effects of curve shape. 14.18 Colorimetric densities. 14.19 Spectral densities. 14.20 Analytical densities. 14.21 Reflection densities. 14.22 Analytical reflection densities. 14.23 Exposure densities. 14.24 Scales of equal visual increments. 14.25 Tri-linear plots. 14.26 Stability of dye images. 14.27 Photographic speed. 15. Masking and Coloured Couplers. 15.1 Introduction. 15.2 Contrast masking. 15.3 Unsharp masking. 15.4 Coloured couplers. 15.5 Inter-image effects. 15.6 Masking when making separations. 15.7 Masking for colorimetric colour reproduction. 15.8 Masking for approximate colour reproduction. 15.9 Calculation of mask gammas. 16. Printing Colour Negatives. 16.1 Introduction. 16.2 Printing studio negatives. 16.3 Printing motion-picture negatives. 16.4 Printing amateurs' negatives. 16.5 The variables to be corrected. 16.6 Early printers. 16.7 Integrating to grey. 16.8 The 1599 printer. 16.9 Variable time printers. 16.10 Subtractive printers. 16.11 Colour enlargers. 16.12 Automatic classification. 16.13 Factors affecting slope control. 16.14 Methods of slope control. 16.15 Electronic printing. 17. The Chemistry of Colour Photography. 17.1 Colour development. 17.2 Developing agents. 17.3 Couplers. 17.4 Coloured couplers. 17.5 The dye-coupling reaction. 17.6 The physical form of dye images. 17.7 Colour developing solutions. 17.8 Silver bleaching. 17.9 Processing sequences. 17.10 Dye-bleach and dye-removal systems. 17.11 Development-inhibitor-releasing (DIR) couplers. 18. Image Structure in Colour Photography. 18.1 Introduction. 18.2 Magnifications. 18.3 Graininess and granularity. 18.4 Granularity of silver images. 18.5 Noise power spectra. 18.6 Graininess in prints. 18.7 Granularity of colour images. 18.8 Reducing granularity of colour systems. 18.9 Sharpness. 18.10 Focusing. 18.11 Depth of field. 18.12 Modulation transfer functions. 18.13 Photographic modulation transfer functions. 18.14 Acutance. 18.15 Sharpness of colour images. 18.16 Increasing sharpness of colour films. 18.17 Mottle on papers. 18.18 Image structure in transfer systems. PART THREE . COLOUR TELEVISION. 19. The Transmission of Colour Television Signals. 19.1 Historical introduction. 19.2 Bandwidth. 19.3 Interlacing. 19.4 Single side-band transmission. 19.5 The field sequential system. 19.6 Blue saving. 19.7 Band saving. 19.8 Colour-difference signals. 19.9 Band sharing. 19.10 The effect of band sharing on monochrome receivers. 19.11 Carrier sharing. 19.12 The effects of signal processing on colour reproduction. 19.13 Gamma correction. 19.14 Noise reduction. 19.15 Direct broadcasting by satellite (DBS). 19.16 High definition television (HDTV). 19.17 Signals used in video-compression systems. 19.18 Videoconferencing. 20. Electronic Cameras. 20.1 Introduction. 20.2 Early camera tubes. 20.3 Tubes suitable for colour. 20.4 Spectral sensitivities of television camera tubes. 20.5 Charge-coupled device (CCD) sensors. 20.6 Camera arrangements. 20.7 Image equality in colour cameras. 20.8 R-Y-B cameras. 20.9 Four-sensor cameras. 20.10 Automatic registration. 20.11 Spectral sensitivities used in cameras. 20.12 Aperture correction. 20.13 Electronic news gathering (ENG). 20.14 Camcorders. 20.15 Electronic still cameras. 21. Display Devices for Colour Television. 21.1 Introduction. 21.2 The trinoscope. 21.3 Triple projection. 21.4 The shadow-mask tube. 21.5 The Trinitron. 21.6 Self-converging tubes. 21.7 Light-valve projectors. 21.8 Liquid crystal displays (LCDs). 21.9 Laser displays. 21.10 Beam-penetration tubes. 21.11 Light emitting diode (LED) displays. 21.12 Plasma displays. 21.13 Phosphors for additive receivers. 21.14 The chromaticity of reproduced white. 21.15 The luminance of reproduced white. 21.16 Reflective displays. 22. The N.T.S.C. and Similar Systems of Colour Television. 22.1 Introduction. 22.2 N.T.S.C. chromaticities. 22.3 The luminance signal. 22.4 (R)(G)(B) to (X)(Y)(Z) transformation equations. 22.5 The effects of variations in chrominance-signal magnitude. 22.6 The effect of gamma correction on ER - EY and EB - EY. 22.7 The effect of gamma correction on EY. 22.8 The P.A.L. and S.E.C.A.M. systems. 22.9 The N.T.S.C. system. 22.10 Blue saving in the N.T.S.C. system. 22.11 Gamma correction in the N.T.S.C. system. 22.12 Maximum signal amplitudes. 22.13 Cross-talk between EI' and EQ '. 22.14 The effect of the chrominance sub-carrier on the display. 22.15 Comparison of the N.T.S.C., P.A.L., and S.E.C.A.M. systems. 22.16 Some useful graphical constructions. 22.17 Some useful equations. 23. The Use of Colour Film in Colour Television. 23.1 Introduction. 23.2 Filming and televising techniques. 23.3 Combined film and television cameras. 23.4 Choice of film. 23.5 Deriving television signals from colour film. 23.6 Telecines using fast pull-down. 23.7 Telecines using camera-tubes. 23.8 Telecines giving 6o fields per second. 23.9 Flying-spot scanners. 23.10 Telecines using solid-state sensors. 23.11 Telerecording. 23.12 Electronic adjustment of signals derived from colour film. 23.13 Electronic masking. 23.14 Overall transfer characteristics. 23.15 Reviewing colour films for television. 24. Video Cassettes. 24.1 Introduction. 24.2 Magnetic tape. 24.3 Magnetic tape with helical scanning. 24.4 Recording on discs. 24.5 The Teldec system. 24.6 Capacitance discs. 24.7 Discs using lasers. 24.8 Photo CD. 24.9 The duplication of programmes on video cassettes and discs. 25. Pictures from Computers. 25.1 Introduction. 25.2 Coloured captions. 25.3 Chroma-key. 25.4 Teletext. 25.5 Colour video display units. 25.6 Video graphics. 25.7 Computer assisted cartoons. 25.8 Colour coding in pictures. 25.9 Colour ranges. 25.10 Colorization and restoration of films. PART FOUR. COLOUR PRINTING. 26. Photomechanical Principles. 26.1 Introduction. 26.2 Letterpress. 26.3 Lithography. 26.4 Gravure (Intaglio). 26.5 Superimposed dye images. 26.6 Superimposed dot images. 26.7 Colorimetric colour reproduction with dot images. 26.8 Colour correction by masking. 26.9 Contact screens. 26.10 Autoscreen film. 26.11 Colour photocopying. 27. Preparing the Copy and Checking the Results. 27.1 Introduction. 27.2 Duplicating and converting originals. 27.3 Duplicating transparencies. 27.4 Converting reflection prints to transparencies. 27.5 Producing second originals on paper. 27.6 Working from colour negatives. 27.7 Facsimile transmission. 27.8 A practical system of transparency duplication. 27.9 Comparing transparencies. 27.10 Comparing reflection prints and transparencies. 27.11 Prepress colour proofing. 28. Practical Masking in Making Separations. 28.1 Introduction. 28.2 A two-mask system. 28.3 A four-mask system. 28.4 Masking procedures. 28.5 Special colour films for masking. 28.6 A direct screening system. 28.7 Two-stage masking. 28.8 Highlight masking in making separations. 28.9 Camera-back masking. 28.10 Choice of filters for making masks and separations. 28.11 Patches for controlling masking procedures. 28.12 Inks used in practice. 28.13 The subtractive colour triangle. 28.14 Standard inks. 28.15 Effects of printing procedures. 28.16 The use of extra coloured inks. 29. Colour Scanners. 29.1 Introduction. 29.2 The Hardy and Wurzburg scanners. 29.3 The P.D.I. scanner. 29.4 Other drum scanners. 29.5 Other flat-bed mechanical scanners. 29.6 Optical feed-back scanners. 29.7 Scanners with variable magnification. 29.8 Scanner outputs. 29.9 Electronic retouching. 29.10 Electronic page make-up. 29.11 Logic circuits in scanners. 29.12 Unsharp masking in scanners. 29.13 Differential masking in scanners. 29.14 Grey component replacement (GCR). 29.15 Under colour correction. 29.16 Typical scanner signal sequences. 29.17 Monitor image display. 29.18 Spectral sensitivities of scanners. 29.19 Calibration targets. 29.20 Scanners for desktop publishing. PART FIVE DIGITAL IMAGING. 30. Bit Requirements. 30.1 Introduction. 30.2 Tonal digitisation. 30.3 Spatial digitisation. 30.4 Tonal and spatial digitisation. 30.5 Allowing for overall image density. 30.6 Using non-linear scales for tonal digitisation. 30.7 Allowing for the limited reproduction gamut. 30.8 Using luminance and chrominance signals to achieve bit reduction. 30.9 Allowing for the modulation transfer function of the eye. 30.10 High definition television (HDTV). 30.11 Digital cinema. 30.12 Conclusions. 31. Camcorders and Digital Still Cameras. 31.1 Introduction. 31.2 Filter arrays. 31.3 Memory. 31.4 Spectral sensitivities. 31.5 Speed. 31.6 Numbers of pixels. 31.7 Electronic camera flow chart. 31.8 Digital still camera signal processing. 31.9 White balance in electronic cameras. 31.10 A proposed standard default colour space, sRGB. 32. Digital Scanners. 32.1 Introduction. 32.2 Scanning Methods. 32.3 Light sources. 32.4 Detectors. 32.5 Obtaining the red, green, and blue signals. 32.6 Colorimetry. 32.7 Scanner targets. 32.8 Spatial resolution. 32.9 Tonal resolution. 33. Digital Printing. 33.1 Introduction. 33.2 Number of tone levels required. 33.3 Dot gain. 33.4 Comparison of visual, continuous tone, half-tone, and micro-dot resolutions. 33.5 Digital proofing. 33.6 Desktop printing methods. 33.7 Photographic imaging. 33.8 Laser electrophotography. 33.9 Thermal dye transfer. 33.10 Thermal wax transfer. 33.11 Ink jet. 33.12 Hybrid continuous-tone and half-tone systems. 33.13 Colour management systems. 33.14 Device dependency. 33.15 Viewing conditions. 33.16 Gamut mapping. 33.17 Device stability 582 33.18 Electronic image enhancement. 33.19 Glossary of terms used in desktop printing. PART SIX. EVALUATING COLOUR APPEARANCE. 34. Chromatic Adaptation Transforms and a Colour Inconstancy Index. 34.1 Introduction. 34.2 Illuminant colorimetric shift. 34.3 Adaptive colour shift. 34.4 Chromatic adaptation transforms. 34.5 The 1997 chromatic adaptation transform (CAT97). 34.6 The 1997 colour inconstancy index (CON97). 34.7 Reversing the 1997 chromatic adaptation transform (CAT97). 35. CIECAM97s Model of Colour Appearance. 35.1 Introduction. 35.2 Visual areas in the observing field. 35.3 Chromatic adaptation. 35.4 Spectral sensitivities of the cones. 35.5 Cone response functions. 35.6 Luminance adaptation. 35.7 Criteria for achromacy and for constant hue. 35.8 Effects of luminance adaptation. 35.9 Criteria for unique hues. 35.10 Redness-greenness, a, and yellowness-blueness, b. 35.11 Hue angle, h. 35.12 Correlate of saturation, s. 35.13 Correlates of hue, H and HC. 35.14 Comparison with the Natural Colour System (NCS). 35.15 The achromatic response, A. 35.16 Correlate of lightness, J. 35.17 Correlate of brightness, Q. 35.18 Correlates of chroma, C, and colourfulness, M. 35.19 Testing model CIECAM97s. 35.20 Filtration of projected slides. 35.21 Effect of screen luminance on quality of projected pictures. 35.22 Steps for using the CIECAM97s model. 35.23 Steps for using the CIECAM97s model in reverse mode. 35.24 Worked example for the model CIECAM97s. 35.25 Using reversed colour models. 36 Models of Colour Vision for Comprehensive Purposes and for Unrelated Colours. 36.1 Introduction. 36.2 Steps for using the 1997 comprehensive colour appearance model, CAM97c. 36.3 Reversing the 1997 comprehensive colour appearance model, CAM97c. 36.4 Unrelated colours, model CAM97u. 36.5 Steps involved in using the model CAM97u for unrelated colours. 37. Colour Reproduction Indices. 37.1 Introduction. 37.2 Steps in using a colour reproduction index. 37.3 Using the colour reproduction index in practice. APPENDICES. Appendix 1. Matrix Algebra. A1.1 General principles. A1.2 Application to colorimetry. Appendix 2 . Colorimetric Tables. A2.1 Calculating colorimetric measures. A2.2 Formulae and tables. Appendix 3 Photometric Units. A3.1 Relations between units of luminance. A3.2 Relations between units of luminance and illumination. A3.3 Some useful conversion factors. A3.4 Typical levels of luminance and illumination. A3.5 Typical levels of illumination from projectors. Appendix 4. Photographic Parameters. A4.1 Film speeds. A4.2 Film dimensions. A4.3 Motion picture parameters. A4.4 Lens apertures. A4.5 Flash guide numbers. Appendix 5. Advanced Colour Difference Formulae. A5.1 Introduction. A5.2 CIE 94 colour difference formula. A5.3 CMC (l:c) colour difference formula. A5.4 CIEDE2000 colour difference formula. Appendix 6. A Replacement for CIECAM97s. A6.1 Introduction. A6.2 Forward model. A6.3 Reverse model. A6.4 Worked example. Appendix 7. Spectral Luminous Efficiency Functions. Index.