4 research outputs found
A multi-camera approach to image-based rendering and 3-D/Multiview display of ancient chinese artifacts
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End-to-end 3D video communication over heterogeneous networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Three-dimensional technology, more commonly referred to as 3D technology, has revolutionised many fields including entertainment, medicine, and communications to name a few. In addition to 3D films, games, and sports channels, 3D perception has made tele-medicine a reality. By the year 2015, 30% of the all HD panels at home will be 3D enabled, predicted by consumer electronics manufacturers. Stereoscopic cameras, a comparatively mature technology compared to other 3D systems, are now being used by ordinary citizens to produce 3D content and share at a click of a button just like they do with the 2D counterparts via sites like YouTube. But technical challenges still exist, including with autostereoscopic multiview displays. 3D content requires many complex considerations--including how to represent it, and deciphering what is the best compression format--when considering transmission or storage, because of its increased amount of data. Any decision must be taken in the light of the available bandwidth or storage capacity, quality and user expectations. Free viewpoint navigation also remains partly unsolved. The most pressing issue getting in the way of widespread uptake of consumer 3D systems is the ability to deliver 3D content to heterogeneous consumer displays over the heterogeneous networks. Optimising 3D video communication solutions must consider the entire pipeline, starting with optimisation at the video source to the end display and transmission optimisation. Multi-view offers the most compelling solution for 3D videos with motion parallax and freedom from wearing headgear for 3D video perception. Optimising multi-view video for delivery and display could increase the demand for true 3D in the consumer market. This thesis focuses on an end-to-end quality optimisation in 3D video communication/transmission, offering solutions for optimisation at the compression, transmission, and decoder levels.Brunel University - Isambard Research Scholarshi
Visualization of Four-Dimensional Spacetimes
Dokument1.pdf enthält den Text dieser Arbeit, Dokument2.html verweist auf elektronische Filme.
In dieser Arbeit werden neue und verbesserte Methoden zur Visualisierung vierdimensionaler Raumzeiten dargestellt. Der erste Teil behandelt die flache Raumzeit der speziellen Relativitätstheorie. Fragestellungen, die sich auf Beleuchtung, Farbsehen, Transformation von Eigenschaften des Lichts und die Kinematik beschleunigter Körper beziehen, werden diskutiert. Es wird gezeigt, wie relativistische Beleuchtungseffekte in bekannten Darstellungsverfahren berücksichtigt werden können. Relativistisches Radiosity und textur- und bildbasiertes relativistisches Rendering werden als neue Darstellungsmethoden vorgestellt. Interaktive virtuelle Umgebungen zur Erkundung der speziellen Relativitätstheorie werden beschrieben, einschließlich der Relativistic-Vehicle-Control-Metapher zur Navigation bei hohen Geschwindigkeiten.
Der zweite Teil dieser Arbeit behandelt gekrümmte vierdimensionale Raumzeiten der allgemeinen Relativitätstheorie. Durch nichtlineares Raytracing wird die visuelle Wahrnehmung eines Beobachters in einer allgemeinrelativistischen Umgebung visualisiert. Es werden Erweiterungen des Raytracings in einer einzelnen Karte vorgeschlagen, um das differentialgeometrische Konzept eines Atlanten zu implementieren. Zudem wird gezeigt, wie die Visualisierung von Gravitationslinsen innerhalb eines Raytracing-Systems berücksichtigt werden kann. Der Caustic Finder wird eingeführt als eine numerische Methode zur Bestimmung der zweidimensionalen Kaustiken einer Gravitationslinse. Die innere Geometrie von zweidimensionalen räumlichen Hyperflächen kann durch isometrische Einbettung in den dreidimensionalen euklidschen Raum visualisiert werden. Eine Methode zur Einbettung von Flächen mit sphärischer Topologie wird beschrieben. Schließlich wird ein Algorithmus zur adaptiven Triangulierung von Höhenfeldern als eine spezielle Anwendung in der klassischen Visualisierung vorgestellt.Dokument1.pdf contains this text of the thesis, Dokument2.html is an index to accompanying electronic videos.
In this thesis, new and improved methods for the visualization of four-dimensional spacetimes are presented. The first part of this thesis deals with the flat spacetime of special relativity. Issues of illumination, color vision, transformation of properties of light, and the kinematics of accelerating bodies are discussed. It is shown how relativistic effects on illumination can be included in well-known rendering techniques. Relativistic radiosity, texture-based relativistic rendering, and image-based relativistic rendering are proposed as new rendering methods. Interactive virtual environments for the exploration of special relativity are introduced, including the relativistic-vehicle-control metaphor for navigating at high velocities.
The second part of the thesis deals with curved four-dimensional spacetimes of general relativity. Direct visualization of what an observer would see in a general relativistic setting is achieved by means of non-linear ray tracing. Extensions to single-chart general relativistic ray tracing are proposed to incorporate the differential-geometric concept of an atlas. Furthermore, it is shown how the visualization of gravitational lensing can be included in a ray tracing system. The caustic finder is proposed as a numerical method to identify two-dimensional caustic structures induced by a gravitational lens. The inner geometry of two-dimensional spatial hypersurfaces can be visualized by isometric embedding in three-dimensional Euclidean space. A method is described which can embed surfaces of spherical topology. Finally, an algorithm for the adaptive triangulation of height fields is presented as a specific application in classical visualization