Das Problem des fehlenden Augenkontaktes vermindert den Eindruck einer natürlichen Kommunikationssituation bei Videokonferenzen. Während eine Person auf den Bildschirm blickt, wird sie von Kameras aufgenommen, die sich normalerweise direkt daneben befinden. Mit dem Aufkommen von massiv paralleler Computer Hardware und ganz speziell den sehr leistungsstarken Spielegrafikkarten ist es möglich geworden, viele Eingabeansichten für eine Echtzeit 3D Rekonstruktion zu verarbeiten. Eine größere Anzahl von Eingabeansichten mildert Verdeckungsprobleme ab und führt zu vollständigeren 3D Daten. In dieser Arbeit werden neue Algorithmen vorgeschlagen, welche eine hochqualitative Echtzeit 3D Rekonstruktion, die kontinuierliche Anpassung der photometrischen Kameraparameter und die benutzerunabhängige Schätzung der Augenkontaktkameras ermöglichen. Die Echtzeit 3D Analyse besteht aus zwei komplementären Ansätzen. Einerseits gibt es einen Algorithmus, der auf der Verarbeitung geometrischer Formen basiert und auf der anderen Seite steht eine patchbasierte Technik, die 3D Hypothesen durch das Vergleichen von Bildtexturen evaluiert. Zur Vorbereitung für die Bildsynthese ist es notwendig, Texturen von verschiedenen Ansichten anzugleichen. Hierfür wird die Anwendung eines neuen Algorithmus zur kontinuierlichen photometrischen Justierung der Kameraparameter vorgeschlagen. Die photometrische Anpassung wird iterativ, im Wechsel mit einer 3D Registrierung der entsprechenden Ansichten, ausgeführt. So ist die Qualität der photometrischen Parameter direkt mit jener der Ergebnisse der 3D Analyse verbunden und vice versa. Eine weitere wichtige Voraussetzung für eine korrekte Synthese der Augenkontaktansicht ist die Schätzung einer passenden virtuellen Augenkontaktkamera. Hierfür wird die Augenkontaktkamera kontinuierlich an die Augenposition der Benutzer angeglichen. Auf diese Weise wird eine virtuelle Kommunikationsumgebung geschaffen, die eine natürlichere Kommunikation ermöglicht. / A major problem, that decreases the naturalness of conversations via video communication, is missing eye contact. While a person is looking on the display, she or he is recorded from cameras that are usually attached next to the display frame. With the advent of massively parallel computer hardware and in particular very powerful consumer graphics cards, it became possible to simultaneously process multiple input views for real-time 3D reconstruction. Here, a greater amount of input views mitigate occlusion problems and lead to a more complete set of 3D data that is available for view synthesis. In this thesis, novel algorithms are proposed that enable for high quality real-time 3D reconstruction, the on-line alignment of photometric camera parameters, and the automatic and user independent estimation of the eye contact cameras. The real-time 3D analysis consist of two complementary approaches. On the one hand, a shape based algorithm and on the other hand, a patch based technique that evaluates 3D hypotheses via comparison of image textures. Preparative to rendering, texture from multiple views needs to be aligned. For this purpose, a novel algorithm for photometric on-line adjustment of the camera parameters is proposed. The photometric adjustment is carried out iteratively in alternation with a 3D registration of the respective views. In this way, the quality of photometric parameters is directly linked to the 3D analysis results and vice versa. Based on the textured 3D data, the eye contact view is rendered. An important prerequisite for this task is the estimation of a suitable virtual eye contact camera. In this thesis, a novel approach is formulated that enables for an automatic adaptation to arbitrary new users. Therefor, the eye contact camera is dynamically adapted to the current eye positions of the users. In this way, a virtual communication environment is created that allows for a more natural conversation.

During face-to-face meetings, humans use multimodal information, including verbal information, visual information, body language, facial expressions, and other non-verbal gestures. In contrast, during computer-mediated-communication (CMC), humans rely either on mono-modal information such as text-only, voice-only, or video-only or on bi-modal information by using audiovisual modalities such as video teleconferencing. Psychologically, the difference between the two lies in the level of the subjective experience of presence, where people perceive a reduced feeling of presence in the case of CMC. Despite the current advancements in CMC, it is still far from face-to-face communication, especially in terms of the experience of presence. This thesis aims to introduce new concepts, theories, and technologies for presence design where the core is actions for creating presence. Thus, the contribution of the thesis can be divided into a technical contribution and a knowledge contribution. Technically, this thesis details novel technologies for improving presence experience during mediated communication (video teleconferencing). The proposed technologies include action robots (including a telepresence mechatronic robot (TEBoT) and a face robot), embodied control techniques (head orientation modeling and virtual reality headset based collaboration), and face reconstruction/retrieval algorithms. The introduced technologies enable action possibilities and embodied interactions that improve the presence experience between the distantly located participants. The novel setups were put into real experimental scenarios, and the well-known social, spatial, and gaze related problems were analyzed. The developed technologies and the results of the experiments led to the knowledge contribution of this thesis. In terms of knowledge contribution, this thesis presents a more general theoretical conceptual framework for mediated communication technologies. This conceptual framework can guide telepresence researchers toward the development of appropriate technologies for mediated communication applications. Furthermore, this thesis also presents a novel strong concept – presence through actions - that brings in philosophical understandings for developing presence- related technologies. The strong concept - presence through actions is an intermediate-level knowledge that proposes a new way of creating and developing future 'presence artifacts'. Presence- through actions is an action-oriented phenomenological approach to presence that differs from traditional immersive presence approaches that are based (implicitly) on rationalist, internalist views.

Abstracts in Afrikaans and English / Inklusiewe onderrig ondersteun die insluiting van alle leerders met verskillende behoeftes en vaardighede in klaskamers, wat baie keer te groot, of te verskillend vir doeltreffende onderrig is. Beweging as deel van ‘n vroeë leerervaring is noodsaaklik vir optimale neurale ontwikkeling. Dit beïnvloed organisasie en stimuleer die spesifieke neurologiese sisteme nodig vir optimale funksionering en ontwikkeling van die brein. Sensoriese integrasie disfunksie word gesien as die wortel van baie leerprobleme. Die vestibulêre sisteem is direk verbind met die sensoriese en motoriese sisteme. ‘n Sensoriese integrasie disfunksie het ‘n duidelike invloed op die vestibulêre sisteem. Die vestibulêre sisteem het baie interkonneksies met baie dele in die brein, byvoorbeeld propriosepsie en die tassisteem. Doeltreffende funksionering van die sensoriese, motoriese en vestibulêre sisteme word verlang vir ‘n hoë vlak van prestasieverrigting in sport en akademie. Wanneer die vestibulêre sisteem gestimuleer word, het dit ‘n direkte positiewe invloed op die sensoriese en motoriese ontwikkeling van leerders. Die doel van hierdie studie was om te bepaal wat die persepsie van grondslagfase-onderwysers en ouers is oor die rol en voordele wat vestibulêre oefeninge te weeg kan bring in die motoriese en sensoriese ontwikkeling van leerders. Leerders in graad 1 van ‘n privaatskool, asook van grade 2 en 3 van ‘n plaasskool is gekies as deelnemers in die studie. Die keuse van leerders was op grond van die bereidwilligheid van hulle en hul ouers om aan die studie deel te neem. Leerders het ‘n vestibulêre oefenprogram drie maal per week gedoen vir die tydperk van agt weke. Observasie-vraelyste is deur onderwysers en ouers ingevul na afloop van die derde sessie elke week. Vir die vraelys het ouers en onderwysers gekyk na die verbetering in aandagspan, konsentrasie, luistervaardigheid, oogkontak, sosiale interaksie en samewerking. Onderhoude is met ouers en onderwysers gedoen na aanleiding van die observasievraelyste wat vir die agt weke voltooi is. Transkripsies van die onderhoude is gedoen en afleidings is gemaak deur analise van die observasie-vraelyste en die getranskribeerde onderhoude. Al ses die ontwikkelingsareas by beide skole het verbetering getoon oor die agt weke. Dit dui daarop dat vestibulêre oefeninge wel ‘n invloed op die sensoriese en motoriese ontwikkeling het. / Inclusive education promotes the inclusion of learners with different needs and capabilities in classes which are often too big and diverse for effective teaching. Movement as an early learning experience is necessary for optimal neural development. It influences organisation and stimulates the specific neurological systems required for optimal functioning and development of the brain. Sensory integrative dysfunction is believed to be at the root of many learning disorders. The vestibular system is directly connected with the sensory and motor systems. The vestibular system will be directly affected when a sensory integrations dysfunction presents. In fact, the vestibular system has many interconnections with almost every other part of the brain like proprioception and the tactile system. Proper functioning of the sensory, motor and vestibular systems is required for higher level performance in sport and academics. When the vestibular system is stimulated, it will result in a positive influence on the sensory and motor development of learners. The aim of this study is to determine the perceptions of foundation phase teachers and parents regarding the role or benefits of vestibular exercises in promoting learners’ motor and sensory development. Learners in Grade 1 of a private school and Grade 2 and 3 learners of a farm school in the northern Free State were selected as participants in the research. Learners were selected on the basis of the willingness of them and their parents to participate in the research. The participants did exercise sessions three times a week for thirty minutes over a period of eight weeks. Observation sheets were completed for all eight weeks, for the duration of the exercise program, by teachers and parents. These sheets were completed weekly after the third sessions in that week. The observation sheets listed concentration, attention span, listening, eye contact, cooperation, social interaction and self-esteem as developmental areas. Interviews were done after the period of eight weeks with the parents and teachers. The interviews conducted with both parties were taped and meticulously transcribed. This helped the researcher to get a better understanding of the study and to analise data and draw conclusions.All six areas of development showed improvement at both schools over the period of eight weeks. This indicates that stimulating the vestibular system promotes sensory and motor development. / Inclusive Education / M. Ed. (Inklusiewe Onderwys)