Embedding metadata in computer graphics for interaction [Elektronische Ressource] / von Henry Sonnet

Henry Sonnet

Sujets

• Informatik

Informations

• Publié par: otto-von-guericke-universitat_magdeburg
• Publié le: 01 janvier 2007
• Nombre de lectures: 24
• Langue: English
• Poids de l'ouvrage: 44 Mo

Extrait

Embedding Metadata in Computer Graphics for Interaction
Dissertation
zur Erlangung des akademischen Grades
Doktoringenieur (Dr.-Ing.)
angenommen durch die Fakultat¨ fur¨ Informatik
der Otto-von-Guericke-Universit¨at Magdeburg
von
Dipl.-Ing. Henry Sonnet
geboren am 28.10.1975 in Magdeburg
Gutachterinnen/Gutachter:
Prof. Dr. Thomas Strothotte
Prof. Dr. Heidrun Schumann
Prof. Dr. Jana Dittmann
Ort und Datum des Promotionskolloquiums:
Magdeburg, 25. April 2007Abstract
Digital media such as 2D images or 3D visualizations often need to be augmented with
information that assists the viewer in understanding what is portrayed or that provides
additional knowledge which is in relation to the medium’s content. The data representa-
tion of such descriptive metadata is a challenging task since digital media can be stored in
various forms each of which provides, if at all, its own specific method for integrating its
assigned metadata. Those methods are analyzed and classified in this research, and the
approach of employing digital watermarking which has emerged as an applicable technique
for storing descriptive metadata is discussed. In this regard, several Illustration Water-
marking techniques are proposed, an end-user tool which was implemented is introduced,
andtheresultsofevaluatingaselectionofthosewatermarkingtechniquesduringanexper-
imental study are presented. Besides the internal representation of descriptive metadata,
its visual representation is another aspect addressed in this research. Since display space
is limited so that descriptive metadata is typically not shown in the original view but on
explicit user request, both techniques for guiding the viewer to those regions which are as-
sociated with the metadata sought and techniques for eventually presenting the metadata
are necessary. Adapting the appearance of the mouse cursor or integrating a down-scaled
focus+context view in the original visualization are two techniques which are proposed to
provide information that facilitates exploring augmented images. As to metadata presen-
tation, the particular application scenario of integrating textual information in interactive
3Dvisualizationsisdealtwithforinstancebyintroducingaspecifictechniquethatattaches
text labels directly to their corresponding scene objects and by evaluating a selection of
techniques in the course of a user study which was conducted.
iiiZusammenfassung
Digitale Medien wie zum Beispiel 2D-Graphiken oder 3D-Visualisierungen werden h¨aufig
mit zus¨atzlichen Informationen angereichert, die zu einem besseren Verst¨andnis des Bild-
inhaltes beitragen oder die weitere Details bezugl¨ ich der Darstellung vermitteln. Die in-
terne Repr¨asentation derartiger Metadaten ist mit zahlreichen Schwierigkeiten verbunden,
da kein einheitliches Format zur Speicherung digitaler Medien existiert. Darub¨ er hin-
aus verfugen¨ nur wenige Spezifikationen ub¨ er geeignete Strukturen, die eine Integration
von Metadaten ermogl¨ ichen. In der vorliegenden Arbeit wurden Techniken untersucht
und klassifiziert, die das Speichern von mit zus¨atzlichen Informationen angereicherten Me-
dien erlauben. Dazu z¨ahlen auch Techniken zum Speichern digitaler Wasserzeichen, ob-
wohl deren Hauptanwendungen auf dem Gebiet des Urheberschutzes zu finden sind. Es
stellte sich jedoch heraus, dass diese Techniken durchaus geeignet sind, auch umfangrei-
chere Metadaten direkt im Medium zu speichern. Ein Teil der Arbeit beinhaltet daher
zahlreiche sogenannte Illustrations-Wasserzeichen Techniken, die entwickelt und zum Teil
w¨ahrend einer Benutzer-Studie evaluiert wurden sowie ein Endbenutzer-Werkzeug, das
in diesem Zusammenhang implementiert wurde. Neben der internen Repr¨asentation der
Daten ist die visuelle Pr¨asentation von Metadaten ein weiterer in der vorliegenden Arbeit
behandelter Aspekt. Da Metadaten aufgrund der begrenzten Darstellungs߬ache im Allge-
meinen zun¨achst ausgeblendet werden, sind geeignete Techniken erforderlich, die dem Be-
trachtersignalisieren, wosichdiegesuchtenMetadatenbefindenundmitdenendieseletzt-
endlich auch dargestellt werden k¨onnen. Eine gezielte Verand¨ erung des Mauszeigers zur
Unterstutzun¨ g der Navigation sowie die Integration einer verkleinerten “Fokus+Kontext”
Ansicht sind zwei entwickelte Techniken, mit denen die Erkundung von mit Metadaten an-
gereicherten Medien unterstu¨tzt werden kann. Bezugl¨ ich der Darstellung von Metadaten
wirdinsbesondereeineTechnikvorgestellt,mitderAnnotationendirektmitObjekteneiner
3D-Visualisierung verknup¨ ft werden k¨onnen. Desweiteren wurden verschiedene Techniken
zur Integration von textuellen Informationen in interaktiven 3D-Visualisierungen im Rah-
meneinerBenutzerstudieuntersucht, derenErgebnisseindieserArbeitvorgestelltwerden.
vAcknowledgments
Mostof this research was done at theDepartmentofSimulationandGraphicsattheOtto-
von-GuerickeUniversityofMagdeburgduringthepastnearlyfouryears. Duringthistime,
I was supervised by Prof. Dr. Thomas Strothotte to whom I am particularly grateful. We
had fruitful discussions, got in touch with companies and other research institutes, and
he encouraged me to stay at the Department of Computer Science at the University of
Calgary in Canada for a few months which was a great experience for me. In this regard,
I would like to thank Dr. Sheelagh Carpendale for making possible this stay and for the
helpful discussions we had concerning the research that I did.
I would also like to thank my additional reviewers Prof. Dr. Heidrun Schumann and
Prof. Dr. Jana Dittmann for immediately agreeing to examine my research.
I am very grateful to Dr. Tobias Isenberg for our joint work and for the many advices
he gave me throughout the work on the dissertation. I would also like to thank Lothar
Schlesier for his great support during the work on the Smage project. My special thanks
also go to Andrea Unger, Silvio Lange, Nguyen Dinh Quyen, and Michael Specht for their
significant contributions to my work. Parts of this thesis have been published in collab-
oration with Dr. Sheelagh Carpendale, Dr. Wallace Chigona, Prof. Dr. Jana Dittmann,
Dr. Knut Hartmann, Dr. Tobias Isenberg, Silvio Lange, Dr. Felix Ritter, Lothar Schlesier,
Prof. Dr. Thomas Strothotte, Andrea Unger, and Thomas Vogel, who therefore deserve
my sincere thanks.
IwouldliketothankTimoGotz¨ elmann,NiklasR¨ober,andMartinSpindlerwhosharedthe
office with me and with whom I hadinteresting discussions andwho were the first contacts
I could ask when I had problems regarding my work. I should not forget Joachim B¨ottger
with whom I had interesting discussions as well and who helped me in many situations. I
also wish to thank Anand Agarawala, Michael Boyle, Carman Neustaedter, Stacey Scott,
Anthony Tang, and the other members of the Interactions Research Lab at the University
of Calgary. We had a great time at work and after work.
I am indebted to Petra Schumann, Petra Specht, and Beate Traor´e for the many questions
they have answered and the many problems they have solved. I would also like to express
my gratitude to Heiko Dorwarth, Dr. Volkmar Hinz, and Thomas Rosenburg for always
giving their best to keep the technique running.
Last but not least I would like to thank my girlfriend Anja, my brother Christian, and my
parents for their support whenever I needed it and for reminding me that there is much
more in life than doing research and writing a thesis.
viiContents
1 Introduction 1
1.1 Aim of this Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Problem Analysis and Concept Formation . . . . . . . . . . . . . . . . . . . 3
1.3 Overview of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Thesis Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Linking Media with Descriptive Metadata 9
2.1 Illustrative Media and their Components . . . . . . . . . . . . . . . . . . . . 9
2.1.1 Digital Media as Communication Tools . . . . . . . . . . . . . . . . 9
2.1.2 The Layers of an Illustrative Medium . . . . . . . . . . . . . . . . . 11
2.1.3 Layer Subdivision in Related Work . . . . . . . . . . . . . . . . . . . 13
2.2 The Challenge of Layer Representation . . . . . . . . . . . . . . . . . . . . . 13
2.2.1 Basic Requirements for Layer Storage . . . . . . . . . . . . . . . . . 14
2.2.2 Survey and Classification of Storage Techniques . . . . . . . . . . . . 15
2.2.3 Layer Storage Exemplified . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.4 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 Digital Watermarking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 Digital Watermarking—A Subdiscipline of Information Hiding . . . 20
2.3.2 Applications and Properties of Digital Watermarking . . . . . . . . . 22
2.3.3 Digital Watermarking Techniques . . . . . . . . . . . . . . . . . . . . 23
2.4 The Concept of Illustration Watermarking . . . . . . . . . . . . . . . . . . . 28
2.4.1 Digital Watermarks as Carriers of Descriptive Metadata . . . . . . . 28
2.4.2 Properties of Illustration Watermarks . . . . . . . . . . . . . . . . . 29
2.4.3 Classification of Illustration Watermarking . . . . . . . . . . . . . . 30
2.5 Comparison of Tech