Human colour perception. A psychophysical study of human colour perception for real and computer- simulated two-dimensional and three-dimensional objects. Item Type Thesis Authors Hedrich, Monika Rights <a rel="license" href="http://creativecommons.org/licenses/ by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by- nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http:// creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. Download date 04/10/2021 11:53:02 Link to Item http://hdl.handle.net/10454/4304 1 Table of contents 1 INTRODUCTION .................................................................................................... 6 1.1 OVERVIEW OF THE FOLLOWING CHAPTERS......................................................... 8 2 PHYSIOLOGY OF COLOUR VISION .................................................................. 10 2.1 THEORIES OF COLOUR VISION ......................................................................... 15 3 COLOUR SPACES .............................................................................................. 17 3.1 INTRODUCTION ............................................................................................... 17 3.1.1 Arranging colour in a three-dimensional space......................................... 18 3.2 DEVELOPMENT OF THE CIE 1931 XYZ COLOUR SPACE.................................... 19 3.2.1 Metamers.................................................................................................. 22 3.2.2 Blackbody locus........................................................................................ 22 3.3 CIE 1976 L*A*B* ............................................................................................ 23 3.4 NATURAL COLOR SYSTEM .............................................................................. 26 3.4.1 NCS colour space..................................................................................... 26 3.4.2 Colour notation ......................................................................................... 28 3.5 RGB COLOUR SPACE...................................................................................... 29 3.6 COLOUR APPEARANCE MODELS....................................................................... 30 4 COLOUR MEMORY............................................................................................. 32 4.1 INTRODUCTION TO MEMORY ............................................................................ 32 4.2 INTRODUCTION TO COLOUR MEMORY............................................................... 33 4.3 COLOUR MEMORY OVER TIME.......................................................................... 35 4.3.1 Summary .................................................................................................. 39 4.4 MEMORY COLOURS FOR FAMILIAR OBJECTS..................................................... 42 4.5 RELATION BETWEEN COLOUR TERMS AND COLOUR MEMORY ............................ 49 4.6 GENERAL SUMMARY ....................................................................................... 51 4.6.1 Measuring colour memory ........................................................................ 53 4.6.2 Shifts in colour memory ............................................................................ 53 5 COLOUR CONSTANCY ...................................................................................... 55 5.1 INTRODUCTION ............................................................................................... 55 5.1.1 Discriminating illuminant and surface changes......................................... 56 5.1.2 Why should the visual system be colour constant? .................................. 57 2 5.1.3 Overview of the chapter............................................................................ 58 5.2 METHODS OF MEASURING COLOUR CONSTANCY .............................................. 59 5.2.1 Matching to an internal standard .............................................................. 59 5.2.2 Asymmetric colour matching..................................................................... 60 5.2.3 Colour naming .......................................................................................... 60 5.2.4 Instructions ............................................................................................... 61 5.3 MECHANISMS AND CUES CONTRIBUTING TO COLOUR CONSTANCY .................... 62 5.3.1 Chromatic adaptation................................................................................ 62 5.3.2 Cone-excitation ratio................................................................................. 63 5.3.3 Shadows ................................................................................................... 64 5.3.4 Specular highlights ................................................................................... 65 5.3.5 Mutual illumination .................................................................................... 65 5.3.6 Cues to depth ........................................................................................... 66 5.4 APPROACHES TOWARDS COLOUR CONSTANCY RESEARCH ............................... 68 5.4.1 Two-dimensional abstract stimuli.............................................................. 70 5.4.2 Two-dimensional images of natural (three-dimensional) scenes.............. 70 5.4.3 Rendered images viewed stereoscopically............................................... 71 5.4.4 Real three-dimensional objects ................................................................ 72 5.4.5 Observers’ tasks in experiments using real 3D objects ............................ 76 5.5 QUANTIFYING COLOUR CONSTANCY ................................................................ 78 5.6 FINAL REMARK................................................................................................ 81 6 COLOUR CATEGORIES ..................................................................................... 82 6.1 INTRODUCTION ............................................................................................... 82 6.2 ORIGIN OF COLOUR CATEGORISATION – NATURE VERSUS NURTURE.................. 82 6.3 BASIC COLOUR TERMS .................................................................................... 83 6.4 COLOUR CATEGORIES IN OTHER AREAS OF VISION RESEARCH .......................... 83 6.4.1 Colour memory within and across colour categories ................................ 87 6.5 SUMMARY ...................................................................................................... 88 7 CROSS-MEDIA STUDIES IN VISION RESEARCH............................................. 89 7.1 TECHNOLOGICAL APPROACH TOWARDS COLOUR REPRODUCTION ..................... 90 7.1.1 Testing colour appearance models under varying viewing conditions...... 91 7.2 PERFORMANCE COMPARABILITY FOR CROSS-MEDIA STUDIES ........................... 95 7.2.1 Comparing CRT and Munsell focal colours .............................................. 96 7.2.2 Matching surface and displayed colours................................................... 97 7.2.3 Comparing lightness matching across media ........................................... 98 3 7.2.4 Contrasting observers’ performance for real-world and computer-simulated scenes 100 7.3 SUMMARY .................................................................................................... 101 8 METHODS.......................................................................................................... 103 8.1 REAL WORLD................................................................................................ 103 8.1.1 Experimental setup ................................................................................. 103 8.1.2 Illuminants............................................................................................... 103 8.1.3 Stimuli ..................................................................................................... 107 8.1.4 Learning and test palettes ...................................................................... 109 8.1.5 Three-dimensional scene ....................................................................... 111 8.1.6 Analysis of the stimuli ............................................................................. 112 8.1.6.1 Metamerism-analysis ...................................................................... 113 8.1.6.2 Colour differences-analysis............................................................. 114 8.1.6.3 Level of difficulty ............................................................................. 118 8.2 COMPUTER SIMULATION................................................................................ 121 8.2.1 Setup ...................................................................................................... 121 8.2.2 Material ................................................................................................... 121 8.2.3 Monitor check ......................................................................................... 122 8.2.4 Transformation of the experimental colours............................................ 123 8.2.5 Accuracy of the simulated colours .......................................................... 124 8.2.6 Learning and test palettes ...................................................................... 126 8.2.7 Three-dimensional