Mechanisms of color constancy in trichromats and dichromats [Elektronische Ressource] / von Sven Nicklas

Sujets

• Psychologie

Informations

• Publié par: martin-luther-universitat_halle-wittenberg
• Publié le: 01 janvier 2008
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Mechanisms of Color Constancy
in Trichromats and Dichromats
Dissertation
zur Erlangung des
Doktorgrades (Dr. phil.)
vorgelegt
der Philosophischen Fakult¨at I
der Martin-Luther-Universita¨t Halle-Wittenberg,
von Sven Nicklas
geb. am 20.05.1975 in Wittenberg
Gutachter: Prof. Dr. Dieter Heyer
Prof. Dr. Laurence T. Maloney
Tag der Verteidigung: 18.07.2008
urn:nbn:de:gbv:3-000014355
[http://nbn-resolving.de/urn/resolver.pl?urn=nbn%3Ade%3Agbv%3A3-000014355]Acknowledgements
This work would not have been possible without the encouragement and support
fromanumber ofsignificant people. Theleast Icandoistoexpress mygratitude
to them.
First of all I am indebted to my advisor Dieter Heyer who introduced me pa-
tientlytothefieldofcolorscience andsharpenedmyunderstandingoftheoretical
concepts. I heartily thank Larry Maloney for sharing his knowledge and for the
opportunity to conduct some of the experiments in his lab. Gisela Mu¨ller–Plath
contributed her patience and time as a member of my committee. I am grateful
to Eike Richter and Katja Doerschner for fruitful discussions on color issues and
for helping me with the experimental setup. I would also like to thank Franz
Faul for providing his extensive C++ color library and Katrin Heier for run-
ning the experiments on increment-decrement asymmetries. I amindebted tomy
dearfriendFidelindoLimwhohelpedmeimprovingthelanguageandstyleofthe
present thesis. Onthelongwaythateventually ledtothisthesismyparentshave
always supported me. At this point I would like to express my love and gratitude
to them. My beloved wife Stefanie encouraged me with her cheerfulness and her
creative way of thinking. I am grateful to have her on my side.
This work was supported by a doctoral scholarship from the federal state of
Saxony-Anhalt and in part by a grant from DAAD.Contents
1 Introduction 1
2 Basic Color Theory 4
2.1 Primary Color Coding . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 The Experimental Paradigm . . . . . . . . . . . . . . . . . 5
2.1.2 The Grassmann Laws . . . . . . . . . . . . . . . . . . . . . 6
2.1.3 Primary Color Codes . . . . . . . . . . . . . . . . . . . . . 7
2.1.4 Receptor Codes . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2 Dichromacy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.1 Dichromatic Color Spaces . . . . . . . . . . . . . . . . . . 14
2.2.2 Classes of Dichromats . . . . . . . . . . . . . . . . . . . . 15
2.2.3 Diagnostics of Color Vision Deficiencies . . . . . . . . . . . 17
2.2.4 Genetics of Color Vision Deficiencies . . . . . . . . . . . . 18
2.2.5 Recent Results . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3 Opponent Colors Theory . . . . . . . . . . . . . . . . . . . . . . . 21
2.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.3.2 Quantitative Aspects of the Theory . . . . . . . . . . . . . 22
2.3.3 Opponent Color Codes . . . . . . . . . . . . . . . . . . . . 24
3 Color Constancy 28
3.1 The Problem of Color Constancy . . . . . . . . . . . . . . . . . . 28
3.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.2 Simultaneous and Successive Color Constancy . . . . . . . 31
3.1.3 Methods for Investigating Color Constancy . . . . . . . . . 33
3.2 Models of Color Constancy . . . . . . . . . . . . . . . . . . . . . . 36
3.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2.2 Relational Models of Color Constancy . . . . . . . . . . . 37
3.2.3 Computational Models of Color Constancy . . . . . . . . . 41
3.3 Color Constancy in the Shape World . . . . . . . . . . . . . . . . 45
3.3.1 Bidirectional Reflectance Density Functions . . . . . . . . 46
3.3.2 The Lambertian Model . . . . . . . . . . . . . . . . . . . . 48
3.3.3 Cues to the Illuminant . . . . . . . . . . . . . . . . . . . . 49
iCONTENTS ii
4 Experiments I 53
4.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.1.2 Questions Addressed in this Study . . . . . . . . . . . . . 55
4.1.3 Hypotheses . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.2 General Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.2.1 Diagnostics of Dichromatic Observers . . . . . . . . . . . . 67
4.2.2 Stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.2.3 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2.4 Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2.5 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.2.6 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.3 Experiment 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.3.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.4 Experiment 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.4.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.5 Experiment 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
4.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 93
4.5.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
4.5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.6 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.6.2 The Reduction Hypothesis . . . . . . . . . . . . . . . . . . 102
4.6.3 The Daylight Hypothesis . . . . . . . . . . . . . . . . . . . 103
4.6.4 Increment-Decrement Asymmetries . . . . . . . . . . . . . 104
4.6.5 Models of Color Constancy . . . . . . . . . . . . . . . . . . 105
4.6.6 Limitations of the Present Study . . . . . . . . . . . . . . 106
5 Experiments II 108
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.1.2 Measuring Color Constancy . . . . . . . . . . . . . . . . . 109
5.1.3 The Speigle-Brainard conjecture . . . . . . . . . . . . . . . 110
5.1.4 Models of the environment . . . . . . . . . . . . . . . . . . 110
5.1.5 The Role of Daylights . . . . . . . . . . . . . . . . . . . . 111
5.1.6 The Role of Chromatic Adaptation . . . . . . . . . . . . . 111
5.1.7 Hypotheses . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.2 General Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.2.1 Stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112CONTENTS iii
5.2.2 Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
5.2.3 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.2.4 Data analysis . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.3 Experiment 1: 3D Scenes – Hue Scalings . . . . . . . . . . . . . . 119
5.3.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
5.3.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
5.4 Experiment 2: Blocked Control . . . . . . . . . . . . . . . . . . . 124
5.4.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
5.4.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
5.5 Experiment 3: Random Control . . . . . . . . . . . . . . . . . . . 127
5.5.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
5.5.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
5.6 Experiment 4: 3D Scenes – Achromatic Settings . . . . . . . . . . 128
5.6.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
5.6.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
5.7 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
6 General Discussion 134
6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
6.2 Discussion of Central Findings . . . . . . . . . . . . . . . . . . . . 134
6.2.1 The Reduction Hypothesis . . . . . . . . . . . . . . . . . . 134
6.2.2 Increment-Decrement Separation . . . . . . . . . . . . . . 135
6.2.3 The Daylight Hypothesis . . . . . . . . . . . . . . . . . . . 137
6.2.4 Measures of Color Constancy . . . . . . . . . . . . . . . . 137
6.2.5 Chromatic Adaptation . . . . . . . . . . . . . . . . . . . . 138
6.3 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Bibliography 140
Appendices 153
A Approximating Daylight Spectra 153
B Stimuli and Simulated Illuminants 157
C Supplementary Data 160
D Color Plates 165
E Zusammenfassung 168Chapter 1
Introduction
The perception of color is an important feature of our visual system which main-
tains our orientation in the world. As a matter of course, we assign colors to
objects assuming implicitly that color is a stable attribute of the object. How-
ever, the pattern of light that reaches the eye from an object is the result of a
complex interaction between the incident illumination and the object’s surface
properties. T