Die Virtuelle Videokamera: ein System zur Blickpunktsynthese in beliebigen, dynamischen Szenen

The Virtual Video Camera project strives to create free viewpoint video from casually captured multi-view data. Multiple video streams of a dynamic scene are captured with off-the-shelf camcorders, and the user can re-render the scene from novel perspectives. In this thesis the algorithmic core of the Virtual Video Camera is presented. This includes the algorithm for image correspondence estimation as well as the image-based renderer. Furthermore, its application in the context of an actual video production is showcased, and the rendering and image processing pipeline is extended to incorporate depth information.Das Virtual Video Camera Projekt dient der Erzeugung von Free Viewpoint Video Ansichten von Multi-View Aufnahmen: Material mehrerer Videoströme wird hierzu mit handelsüblichen Camcordern aufgezeichnet. Im Anschluss kann die Szene aus beliebigen, von den ursprünglichen Kameras nicht abgedeckten Blickwinkeln betrachtet werden. In dieser Dissertation wird der algorithmische Kern der Virtual Video Camera vorgestellt. Dies beinhaltet das Verfahren zur Bildkorrespondenzschätzung sowie den bildbasierten Renderer. Darüber hinaus wird die Anwendung im Kontext einer Videoproduktion beleuchtet. Dazu wird die bildbasierte Erzeugung neuer Blickpunkte um die Erzeugung und Einbindung von Tiefeninformationen erweitert

Flexible Stereoscopic 3D Content Creation of Real World Scenes

We propose an alternative over current approaches to stereoscopic 3D video content creation based on a free-viewpoint video. Acquisition and editing is greatly simplified. Our method is suitable for arbitrary real-world scenes. From unsynchronized multi-view video footage, our approach renders high-quality stereo sequences without the need to explicitly reconstruct any scene depth or geometry. By allowing to freely edit viewpoint, slow motion, freeze-rotate shots, depth-of-field, and many more effects, the presented approach extends the possibilities in stereo 3D movie creation.In diesem Report schlagen wir eine Alternative zu gegenwärtig in der Produktion von stereoskopischen Filmen verwendeten Techniken vor. Unser Ansatz basiert auf der Verwendung eines Systems zur Blickpunktnavigation. Die Aufnahme und die Editierung der Stereodaten wird dadurch erheblich vereinfacht. Unsere Methode generiert qualitativ hochwertige Stereosequenzen ohne dabei Szenengeometrie oder Szenetiefe explizit zu rekonstruieren. Das Verfahren ermöglicht es den Blickpunkt und die Wiedergabegeschwindigkeit zu ändern und visuelle Effekte zu integrieren, wodurch neue künstlerische Möglichkeiten in der stereoskopischen Filmproduktion erschlossen werden

Eine Ghosting-Artefakt Metrik zur Qualitätsmessung von interpolierten Bildern

We present a no-reference image quality metric for image interpolation. The approach is capable of detecting ghosting artifacts, e.g., in image based rendering scenarios. Based on the assumption that ghosting artifacts can be detected locally, perceived visual quality can be predicted from the amount of regions that are affected by ghosting. Because the approach does not require any reference image, it is very suitable, e.g., for assessing quality of image-based rendering techniques in general settings.Wir präsentieren ein referenzfreies Qualitätsmaß für interpolierte Bilder. Unser Ansatz kann Ghosting-Artefakte, welche z.B. in Bildbasierten Rendering-Verfahren auftreten, detektieren. Basierend auf der Annahme, dass Ghosting-Artefakte lokal detektiert werden können, kann die subjektiv wahrgenommene Bildqualität von der Anzahl der Regionen, in denen Ghosting detektiert wurde, prädiziert werden. Aufgrund der Tatsache, dass der Ansatz keine Referenzbilder benötigt, ist dieser sehr nützlich für die Qualitätskontrolle in Bildbasierten Rendering-Systemen

Spacetime Tetrahedra: Bildbasierte Blickpunktnavigation durch Raum und Zeit

We present a purely image-based rendering system to viewpoint-navigate through space and time of arbitrary dynamic scenes. Unlike previous methods, our approach does not rely on synchronized and calibrated multi-video footage as input. Instead of estimating scene depth or reconstructing 3D geometry, our approach is based on dense image correspondences, treating view interpolation equally in space and time. In a nutshell, we tetrahedrally partition the volume spanned by camera directions and time, determine the warp field along each tetrahedral edge, and warp-blend-interpolate any viewpoint inside a tetrahedron from the four video frames representing its vertices. Besides fast and easy acquisition to make outdoor recordings feasible, our space-time symmetric approach allows for smooth interpolation of view perspective and time, i.e., for simultaneous free-viewpoint and slow motion rendering

Metaphysics or Modernity? Contributions to the Bamberg Summer School 2012

This collection of essays originated in the Summer School ‘Metaphysics or Modernity?’, which was held at the University of Bamberg in August 2012. Designed as a forum for graduate students in philosophy, the Summer School brought together a highly diverse group of young academics who – more often than not – came from utterly different schools and traditions of thought. This pluralism is reflected in the pages of this book. While the volume is roughly divided into two halves – one with a more historical focus, the other with a more systematic focus – the reader will find an unusually wide array of topics and questions treated here. Since the aforementioned pluralism was one of the main strengths of our Summer School, this is something in which we take much prid

A β-Lactam Antibiotic Dampens Excitotoxic Inflammatory CNS Damage in a Mouse Model of Multiple Sclerosis

In multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE), impairment of glial “Excitatory Amino Acid Transporters” (EAATs) together with an excess glutamate-release by invading immune cells causes excitotoxic damage of the central nervous system (CNS). In order to identify pathways to dampen excitotoxic inflammatory CNS damage, we assessed the effects of a β-lactam antibiotic, ceftriaxone, reported to enhance expression of glial EAAT2, in “Myelin Oligodendrocyte Glycoprotein” (MOG)-induced EAE. Ceftriaxone profoundly ameliorated the clinical course of murine MOG-induced EAE both under preventive and therapeutic regimens. However, ceftriaxone had impact neither on EAAT2 protein expression levels in several brain areas, nor on the radioactive glutamate uptake capacity in a mixed primary glial cell-culture and the glutamate-induced uptake currents in a mammalian cell line mediated by EAAT2. Moreover, the clinical effect of ceftriaxone was preserved in the presence of the EAAT2-specific transport inhibitor, dihydrokainate, while dihydrokainate alone caused an aggravated EAE course. This demonstrates the need for sufficient glial glutamate uptake upon an excitotoxic autoimmune inflammatory challenge of the CNS and a molecular target of ceftriaxone other than the glutamate transporter. Ceftriaxone treatment indirectly hampered T cell proliferation and proinflammatory INFγ and IL17 secretion through modulation of myelin-antigen presentation by antigen-presenting cells (APCs) e.g. dendritic cells (DCs) and reduced T cell migration into the CNS in vivo. Taken together, we demonstrate, that a β-lactam antibiotic attenuates disease course and severity in a model of autoimmune CNS inflammation. The mechanisms are reduction of T cell activation by modulation of cellular antigen-presentation and impairment of antigen-specific T cell migration into the CNS rather than or modulation of central glutamate homeostasis