Eye gaze tracking for human computer interaction [Elektronische Ressource] / Heiko Drewes

Heiko Drewes

Sujets

• Mathematics

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2010
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Eye Gaze Tracking for
Human Computer Interaction




Heiko Drewes









Dissertation
an der LFE Medien-Informatik
der Ludwig-Maximilians-Universität
München







München 2010































Erstgutachter: Professor Dr. Heinrich Hußmann
Zweitgutachter: Professor Dr. Albrecht Schmidt
Externer Gutachter: Professor Dr. Alan Dix
Tag der mündlichen Prüfung: 18.3.2010


Abstract
With a growing number of computer devices around us, and the increasing time we spend for interacting with
such devices, we are strongly interested in finding new interaction methods which ease the use of computers or
increase interaction efficiency. Eye tracking seems to be a promising technology to achieve this goal.
This thesis researches interaction methods based on eye-tracking technology. After a discussion of the limitations
of the eyes regarding accuracy and speed, including a general discussion on Fitts’ law, the thesis follows three
different approaches on how to utilize eye tracking for computer input. The first approach researches eye gaze as
pointing device in combination with a touch sensor for multimodal input and presents a method using a touch
sensitive mouse. The second approach examines people’s ability to perform gestures with the eyes for computer
input and the separation of gaze gestures from natural eye movements. The third approach deals with the
information inherent in the movement of the eyes and its application to assist the user. The thesis presents a
usability tool for recording of interaction and gaze activity. It also describes algorithms for reading detection.
All approaches present results based on user studies conducted with prototypes developed for the purpose.
Zusammenfassung
Mit einer wachsenden Zahl von Computergeräten um uns herum und zunehmender Zeit die wir mit der
Bedienung dieser Geräte zubringen, haben wir ein großes Interesse daran, Interaktionsmethoden zu finden,
welche die Benutzung der Computer erleichtern oder effizienter machen. Blickverfolgung scheint eine viel
versprechende Technologie zu sein um dieses Ziel zu erreichen.
Die vorliegende Arbeit untersucht Interaktionsmethoden, die auf Blickverfolgertechnik beruhen. Nach einer
Diskussion der Beschränkungen des Auges in Bezug auf Genauigkeit und Geschwindigkeit, die eine generelle
Diskussion des Fitts’ Law enthält, verfolgt die Arbeit drei verschiedene Ansätze wie Blickverfolgung für
Computereingaben benutzt werden kann. Der erste Ansatz untersucht den Blick als Zeigegerät in Kombination
mit einem Berührungssensor für multimodale Eingabe und stellt eine Methode mit einer berührungsempfind-
lichen Maus vor. Der zweite Ansatz untersucht die Fähigkeit von Menschen Gesten mit den Augen für
Computereingaben durchzuführen und wie diese Blickgesten von natürlichen Augenbewegungen unterschieden
werden können. Der dritte Ansatz beschäftigt sich mit der Information, die den Augenbewegungen entnommen
werden kann, und ihrer Anwendung zur Unterstützung der Benutzer. Es wird ein Usability-Werkzeug zum Auf-
zeichnen von Interaktions- und Blickaktivität vorgestellt. Außerdem werden Algorithmen zur Leseerkennung
beschrieben.
Für alle Ansätze werden Ergebnisse präsentiert, die auf durchgeführten Benutzerstudien mit speziell entwickel-
ten Prototypen beruhen.
2 Table of Contents

1 Introduction 6
1.1 Motivation 6
1.2 Eye Gaze and Human Communication 7
1.3 Eye Gaze for Computer Input 9
1.4 Methods and Approach 11
1.5 Thesis Outline
1.6 Contributions 12
2 Overview and Related Work 14
2.1 Definition of Eye Tracking 14
2.2 History of Eye Tracking 15
2.3 Application Domains for Eye Tracking 16
2.4 Technological Basics of Eye Tracking 18
2.4.1 Methods of Eye Tracking 18
2.4.2 Video-Based Eye Tracking 19
2.4.3 The Corneal Reflection Method 20
2.5 Available Video-Based Eye Tracker Systems 21
2.5.1 Types of Video-Based Eye Trackers 21
2.5.2 Low-Cost Open Source Eye Trackers for HCI 22
2.5.3 Commercial Eye Trackers for HCI 23
2.5.4 Criteria for the Quality of an Eye Tracker 25
2.6 The ERICA Eye Tracker 26
2.6.1 Specifications 26
2.6.2 Geometry of the Experimental Setup 27
2.6.3 The ERICA-API 27
2.7 Related Work on Interaction by Gaze 29
2.8 Current Challenges 31
3 The Eye and its Movements 33
3.1 Anatomy and Movements of the Eye 33
3.2 Accuracy, Calibration and Anatomy 35
Table of Contents 3

3.3 Statistics on Saccades and Fixations 38
3.3.1 The Data 39
3.3.2 Saccades Lengths
3.3.3 Saccade Speed 42
3.3.4 Fixation Times 43
3.3.5 Summary of Statistics 45
3.4 Speed and Accuracy 47
3.4.1 Eye Speed Models 47
3.4.2 Fitts’ Law 48
3.4.3 The Debate on Fitts’ Law for Eye Movements 56
3.4.4 The Screen Key Experiment 63
3.4.5 The Circle Experiment 65
3.4.6 Ballistic or Feedback-Controlled Saccades 69
3.4.7 Conclusions on Fitts’ Law for the Eyes 72
4 Eye Gaze as Pointing Device 74
4.1 Overview on Pointing Devices 74
4.1.1 Properties of Pointing Devices
4.1.2 Problems with Traditional Pointing Devices 75
4.1.3 Problems with Eye Gaze as Pointing Device 76
4.2 Related Work for Eye Gaze as Pointing Device 77
4.3 MAGIC Pointing with a Touch-Sensitive Mouse Device 79
4.4 User Studies with the Touch-Sensitive Mouse Device 81
4.4.1 First User Study – Testing the Concept 81
4.4.2 Second User Study – Learning and Hand-Eye Coordination 87
4.4.3 Third User Study – Raw and Fine Positioning 94
4.5 A Deeper Understanding of MAGIC Touch 95
4.6 Summary on the Results for Eye Gaze as Pointing Device 97
4.7 Conclusions on Eye Gaze as Pointing Device 97
5 Gaze Gestures 99
5.1 Related Work on Gaze Gestures 99
4 Table of Contents

5.2 The Concept of Gaze Gestures 100
5.2.1 The Firefox/Opera Mouse Gestures 100
5.2.2 The EdgeWrite Gestures1
5.3 The Gaze Gesture Recognition Algorithm 101
5.4 User Studies and Experiments with Gaze Gestures 103
5.4.1 First User Study – Testing the Concept 103
5.4.2 Experiments – When to Use Gaze Gestures7
5.4.3 Second User Study – Optimizing the Parameters9
5.4.4 Mobile Phone User Study 111
5.4.5 PIN-Entry User Study4
5.5 The Gaze Gesture Alphabet 117
5.6 Separation of Gaze Gestures from Natural Eye Movements 119
5.7 Summary of the Results for Gaze Gestures 122
5.8 Conclusions for Gaze Gestures 123
6 Eye Gaze as Context Information 124
6.1 Eye Gaze and Context Awareness 124
6.2 Related Work for Eye Gaze as Context Information 125
6.3 A Usability Tool to Record Eye Movements 127
6.3.1 Explanation of UsaProxy 127
6.3.2 Extending UsaProxy to Record Eye Movements8
6.3.3 Discussion of UsaProxy’s Extension 130
6.4 Reading Detection 132
6.4.1 Analysis of the Gaze Path while Reading2
6.4.2 An Algorithm for Reading Detection3
6.4.3 User Study for Reading Detection 135
6.4.4 Values for the Quality of Reading6
6.5 Gaze-Awareness in E-Learning Environments 138
6.6 Summary of the Results for Eye Gaze as Context Information 138
6.7 Conclusions on Eye Gaze as Context Information 139
7 140
Table of Contents 5

7.1 Summary of the Results 140
7.2 Conclusions for Eye Gaze User Interfaces 141
7.3 How to go on with Eye-Tracking Research for Interaction 145
7.4 The Future of Gaze-Aware Systems 146
References 149
Web References162
Acknowledgements 164
1 Introduction 6

Eye Gaze Tracking for Human Computer
Interaction
1 Introduction
With the invention of the computer in the middle of the last century there was also the need of an interface for
users. In the beginning experts used teletype to interface with the computer. Due to the tremendous progress in
computer technology in the last decades, the capabilities of computers increased enormously and working with a
computer became a normal activity for nearly everybody. With all the possibilities a computer can offer, humans
and their interaction with computers are now a limiting factor. This gave rise to a lot of research in the field of
HCI (human computer interaction) aiming to make interaction easier, more intuitive, and more efficient.
Interaction with computers is not limited to keyboards and printers anymore. Different kinds of pointing devices,
touch-sensitive surfaces, high-resolution displays, microphones, and speakers are normal devices for computer
interaction nowadays. There are new modalities for computer interaction like speech interaction, input by
gestures or by tangible objects with sensors. A further input modality is eye gaze which nowadays finds its
application in accessibility systems. Such systems typically use eye gaze as the sole input, but outside the field of
accessibility eye gaze can be combined with any other in