Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 82-87). Also available in electronic version.

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This thesis analyzes the problem of acquiring stereoscopic images in all gazing directions around a reference viewpoint in space with the purpose of creating stereoscopic panoramas of non-static scenes. The generation of immersive stereoscopic imagery suitable to stimulate human stereopsis requires images from two distinct viewpoints with horizontal parallax in all gazing directions, or to be able to simulate this situation in the generated imagery. The available techniques to produce omnistereoscopic imagery for human viewing are not suitable to capture dynamic scenes stereoscopically. This is a not trivial problem when considering acquiring the entire scene at once while avoiding self-occlusion between multiple cameras. In this thesis, the term omnidirectional refers to all possible gazing directions in azimuth and a limited set of directions in elevation. The acquisition of dynamic scenes restricts the problem to those techniques suitable for collecting in one simultaneous exposure all the necessary visual information to recreate stereoscopic imagery in arbitrary gazing directions. The analysis of the problem starts by defining an omnistereoscopic viewing model for the physical magnitude to be measured by a panoramic image sensor intended to produce stereoscopic imagery for human viewing. Based on this model, a novel acquisition model is proposed, which is suitable to describe the omnistereoscopic techniques based on horizontal stereo. From this acquisition model, an acquisition method based on multiple cameras combined with the rendering by mosaicking of partially overlapped stereoscopic images is identified as a good candidate to produce omnistereoscopic imagery of dynamic scenes. Experimental acquisition and rendering tests were performed for different multiple-camera configurations. Furthermore, a mosaicking criterion between partially overlapped stereoscopic images based on the continuity of the perceived depth and the prediction of the location and magnitude of unwanted vertical disparities in the final stereoscopic panorama are two main contributions of this thesis. In addition, two novel omnistereoscopic acquisition and rendering techniques were introduced. The main contributions to this field are to propose a general model for the acquisition of omnistereoscopic imagery, to devise novel methods to produce omnistereoscopic imagery, and more importantly, to contribute to the awareness of the problem of acquiring dynamic scenes within the scope of omnistereoscopic research.

This thesis analyzes the problem of acquiring stereoscopic images in all gazing directions around a reference viewpoint in space with the purpose of creating stereoscopic panoramas of non-static scenes. The generation of immersive stereoscopic imagery suitable to stimulate human stereopsis requires images from two distinct viewpoints with horizontal parallax in all gazing directions, or to be able to simulate this situation in the generated imagery. The available techniques to produce omnistereoscopic imagery for human viewing are not suitable to capture dynamic scenes stereoscopically. This is a not trivial problem when considering acquiring the entire scene at once while avoiding self-occlusion between multiple cameras. In this thesis, the term omnidirectional refers to all possible gazing directions in azimuth and a limited set of directions in elevation. The acquisition of dynamic scenes restricts the problem to those techniques suitable for collecting in one simultaneous exposure all the necessary visual information to recreate stereoscopic imagery in arbitrary gazing directions. The analysis of the problem starts by defining an omnistereoscopic viewing model for the physical magnitude to be measured by a panoramic image sensor intended to produce stereoscopic imagery for human viewing. Based on this model, a novel acquisition model is proposed, which is suitable to describe the omnistereoscopic techniques based on horizontal stereo. From this acquisition model, an acquisition method based on multiple cameras combined with the rendering by mosaicking of partially overlapped stereoscopic images is identified as a good candidate to produce omnistereoscopic imagery of dynamic scenes. Experimental acquisition and rendering tests were performed for different multiple-camera configurations. Furthermore, a mosaicking criterion between partially overlapped stereoscopic images based on the continuity of the perceived depth and the prediction of the location and magnitude of unwanted vertical disparities in the final stereoscopic panorama are two main contributions of this thesis. In addition, two novel omnistereoscopic acquisition and rendering techniques were introduced. The main contributions to this field are to propose a general model for the acquisition of omnistereoscopic imagery, to devise novel methods to produce omnistereoscopic imagery, and more importantly, to contribute to the awareness of the problem of acquiring dynamic scenes within the scope of omnistereoscopic research.

[pt] As comunicações à distância estão crescendo consideravelmente pelo uso de aplicações através da Internet e de ambientes virtuais. Interaçõoes sociais e pessoais têm recebido especial enfoque, sobretudo a videoconferência, acarretando uma grande demanda de tecnologia apropriada para esses sistemas. Resultados de pesquisas em Presença, alguns deles obtidos nesta tese, permitiram inferir os quatro pilares da proposta: 1. visualização é muito importante nas interações sociais/pessoais; 2. tecnologia simples pode promover presença social; 3. imagens de câmera são mais satisfatórias do que avatares para algumas interações sociais/pessoais; 4. estereoscopia influência presença positivamente. Sob a restrição de usar tecnologia simples e de baixo custo, a tese propõe o uso de visualização estereoscópica para webcams, em tempo real. Porque webcams são equipamentos simples com baixa resolução de imagem, a obtenção de um estéreo com qualidade torna- se um desafio. Partindo do princípio que o olho humano não se comporta da mesma forma para ver de perto e de longe, a pesquisa analisou o processamento de estéreo natural do olho humano, e com base em resultados psicofísicos e fisiológicos da visão binocular, a tese propõe um modelo para o processamento de imagens estereoscópicas a serem visualizadas em curta distância, e usa este modelo na implementação apresentada. Os resultados obtidos foram satisfatórios para a visualização de imagens estéreo com webcams, em tempo real, e principalmente, eliminaram a necessidade de reajuste de paralaxe das imagens e do reposicionamento das câmeras a cada movimentação do observador, dando assim mais liberdade de visualização ao observador. / [en] The improvement of communication among remotely located people constitutes a very comprehensive prominent subject nowadays. Among applications to attain this goal, some aim to support social and personal interactions to meet partners, friends and family in distance. Presence research results, some obtained as part of this thesis, allowed to infer the four pillars of the proposal: 1. visualization is very important in social/personal interactions, mainly when people have close social/personal relationship; 2. simple technology can afford social presence; 3. camera images are more satisfactory than avatars during some social/personal interactions; 4. stereoscopy influences presence positively. Under the constraint of using simple technology without adding any special hardware to a PC system, the thesis proposes the use of stereoscopy through webcams, in real- time, as one solution to add 3D features to camera images. Since webcams are simple equipments with low resolution, to obtain stereo images in good quality is a challenge. Considering the fact that human eyes treat short and long distance in a different way, this research analysed the natural stereo processing of human eye, and based on psychophysical and physiological features of binocular vision, the thesis proposes a model to process stereoscopic images to be visualized in short distance, and implemented it as a proof of concept. The obtained results are satisfactory for stereoscopic images visualization through webcams, in real-time, and mainly, eliminated the need of adjusting images parallax and cameras position for each viewer´s movement, allowing more freedom to the viewer.

The success of recent 3-D stereoscopic movies such as Avatar has created a lot of attention for 3-D in the home. Almost all major consumer electronics (CE) manufacturers have launched their 3-D stereoscopic displays in the market. A problem with those solutions is that viewers have to wear glasses. Glasses-free autostereoscopic 3-D displays typically use lenticular lenses or barriers to create multiple views. However these displays suffer from a number of issues: inverted views at viewing cone transitions, cross-talk between views, and need for multi-view content.  As Philips Electronics research group, we believe that some of these issues can be reduced by using pupil tracking. In the research process, we began with an extensive literature study on people detection and tracking techniques that helped us to understand the benefits and the shortcomings of different applications. Addition to literature studies, we greatly benefited from constant experimentation with prototypes and the hands-on experience with variety of digital and optical components under different conditions. As a result, we designed a multi-person infrared pupil tracker and multi-view renderer for 3D display to adapt the view rendering in real-time according to viewer’s position. Together with the integration of these two applications, the integrated 3D TV successfully adapts the center view according to position of the viewer and able to provide a smooth transition while the viewer actively changes her position from a notable distance under ambient illumination. However, even though the pupil tracker is implemented for multiple people, because of the time limitation and the complexity of the problem regarding multi-view renderer, the integrated system functions only for one person.   Exploring the employed technique, in-depth description and detailed illustration of designed applications and the conclusions drawn from the implemented system; we believe that this paper forms a substantial guidance and show-how source for further research in the field of 3D display and people tracking methods.

Title: Stereoscopic Projection Author: Jana Vlachová Department: Department of Mathematics Education Supervisor: RNDr. Jana Hromadová, Ph.D. Supervisor's e-mail address: Jana.Hromadova@mff.cuni.cz Abstract: This graduation thesis deals with a special case of a double-central projection - the stereoscopic projection, whereas the position of the centres of projection and the projection plane is adjusted to the conditions of the human vision. The thesis introduces a brief historical development of the imaging and the stereoscopy itself, basic biological and optical characteristics of a human eye and vision and the principles of stereoscopic projection. Furthermore it occupies with the procedures of making stereoscopic drawings and photographs along with the methods of their observation and creating some necessary tools using generally available materials. The end of this thesis is devoted to the possibilities of not only practical usage of the stereoscopy, but mainly of its application in the descriptive geometry teaching. The thesis includes many stereoscopic pictures, some of them are viewable with the lens- glasses or the anaglyph-glasses accompanied in the end of this thesis. Keywords: double-central projection, stereoscopic projection, anaglyph

Ambientes virtuais tridimensionais imersivos são frequentemente utilizados como apoio às estratégias de treinamento ou educação conduzidas em ambientes reais. Técnicas estereoscópicas como as de anaglifos, obturação e polarização da luz são recursos que oferecem a sensação de imersão nesses ambientes virtuais. É crescente o interesse em pesquisas acerca de como os humanos percebem o espaço e interagem em ambientes virtuais, investigando como componentes de sistemas imersivos afetam a percepção humana. Essa percepção é importante para várias tarefas, como mover objetos e identificar estruturas, que requerem a interpretação e entendimento das informações do espaço. Apesar de tal interesse, não são encontrados na literatura modelos de mensuração de tal percepção. Este cenário constitui um desafio no que concerne à necessidade de criação de modelos para mensurar, independentemente da aplicação, a percepção da tridimensionalidade proporcionada pelas técnicas estereoscópicas citadas. Este projeto de mestrado define, implementa e valida um modelo extensível capaz de avaliar a percepção da tridimensionalidade em sistemas de realidade virtual estereoscópicos no contexto de ambientes que envolvem interação com manipulação de objetos. O escopo da presente pesquisa foi definido mediante a realização de uma Revisão Sistemática, que identificou métodos e parâmetros utilizados na avaliação de ambientes estereoscópicos. Para atingir os objetivos deste trabalho, foram conduzidos experimentos que serviram de base para a definição do modelo. Os resultados dos experimentos indicaram que o modelo elaborado é capaz de compor um veredicto sobre a percepção de tridimensionalidade fornecida por uma técnica, assim como auxiliar na tomada de decisões acerca da utilização de técnicas estereoscópicas em sistemas de RV / Three-Dimensional immersive virtual environments are often used as support for training strategies or education conducted in real environments. Stereoscopic techniques such as anaglyph, shutter glasses and polarized glasses can offer a sense of immersion in these virtual environments. There is a growing interest in research how humans perceive space and interact in virtual environments, investigating how components of immersive systems affect different understanding of space in virtual reality systems. This perception is important for various tasks, such as moving objects and identify structures that require interpretation and understanding of space information. This scenario is a challenge regarding the establishment of models to measure, independently of the application, the perception of three-dimensionality provided by the stereoscopic techniques cited. This master project defines and validates an extensible model able to evaluate the three-dimensionality perception in different virtual reality systems with stereoscopy that involves objects manipulation. The scope of this study was defined with a systematic review that identified methods and parameters used to assess stereoscopic environments. To achieve the objectives of this study, experiments was conducted as the basis to define the model. The results of the experiments indicated that the model developed is able to set a verdict about three-dimensionality perception provided by a stereoscopic technique and assist decision-making regarding the use of stereoscopic techniques in VR systems

Ambientes virtuais tridimensionais imersivos são frequentemente utilizados como apoio às estratégias de treinamento ou educação conduzidas em ambientes reais. Técnicas estereoscópicas como as de anaglifos, obturação e polarização da luz são recursos que oferecem a sensação de imersão nesses ambientes virtuais. É crescente o interesse em pesquisas acerca de como os humanos percebem o espaço e interagem em ambientes virtuais, investigando como componentes de sistemas imersivos afetam a percepção humana. Essa percepção é importante para várias tarefas, como mover objetos e identificar estruturas, que requerem a interpretação e entendimento das informações do espaço. Apesar de tal interesse, não são encontrados na literatura modelos de mensuração de tal percepção. Este cenário constitui um desafio no que concerne à necessidade de criação de modelos para mensurar, independentemente da aplicação, a percepção da tridimensionalidade proporcionada pelas técnicas estereoscópicas citadas. Este projeto de mestrado define, implementa e valida um modelo extensível capaz de avaliar a percepção da tridimensionalidade em sistemas de realidade virtual estereoscópicos no contexto de ambientes que envolvem interação com manipulação de objetos. O escopo da presente pesquisa foi definido mediante a realização de uma Revisão Sistemática, que identificou métodos e parâmetros utilizados na avaliação de ambientes estereoscópicos. Para atingir os objetivos deste trabalho, foram conduzidos experimentos que serviram de base para a definição do modelo. Os resultados dos experimentos indicaram que o modelo elaborado é capaz de compor um veredicto sobre a percepção de tridimensionalidade fornecida por uma técnica, assim como auxiliar na tomada de decisões acerca da utilização de técnicas estereoscópicas em sistemas de RV / Three-Dimensional immersive virtual environments are often used as support for training strategies or education conducted in real environments. Stereoscopic techniques such as anaglyph, shutter glasses and polarized glasses can offer a sense of immersion in these virtual environments. There is a growing interest in research how humans perceive space and interact in virtual environments, investigating how components of immersive systems affect different understanding of space in virtual reality systems. This perception is important for various tasks, such as moving objects and identify structures that require interpretation and understanding of space information. This scenario is a challenge regarding the establishment of models to measure, independently of the application, the perception of three-dimensionality provided by the stereoscopic techniques cited. This master project defines and validates an extensible model able to evaluate the three-dimensionality perception in different virtual reality systems with stereoscopy that involves objects manipulation. The scope of this study was defined with a systematic review that identified methods and parameters used to assess stereoscopic environments. To achieve the objectives of this study, experiments was conducted as the basis to define the model. The results of the experiments indicated that the model developed is able to set a verdict about three-dimensionality perception provided by a stereoscopic technique and assist decision-making regarding the use of stereoscopic techniques in VR systems

A partir da investigação de elementos que remontam o passado de técnicas de ilusão e imersão na arte da representação da imagem, bem como teorias que condicionam a existência de uma linguagem audiovisual própria, este trabalho tem o objetivo de analisar e identificar a existência de uma linguagem própria pertinente à estereoscopia. A pesquisa toma como ponto de análise estereoscópica o filme Coraline [2009] de Henry Selick, uma animação stop motion, concebida e lançada nos cinemas 3D estereoscópicos / Through an investigation of the history of techniques of illusion and immersion in popular art and entertainment, as well as theories that determine the existence of a distinct visual language, this work aims to analyse and identify the existence of a unique narrative language exclusive to 3-D stereoscopic film-making. The research takes as its point of stereoscopic analysis the stop-motion animation movie Coraline (2009, Henry Selick) designed and launched in cinemas using the stereoscopic technique.