A network transparent, retained mode multimedia processing framework for the Linux operating system environment

Die Arbeit präsentiert ein Multimedia-Framework für Linux, das im Unterschied zu früheren Arbeiten auf den Ideen "retained-mode processing" und "lazy evaluation" basiert: Statt Transformationen unmittelbar auszuführen, wird eine abstrakte Repräsentation aller Medienelemente aufgebaut. "renderer"-Treiber fungieren als Übersetzer, die diese Darstellung zur Laufzeit in konkrete Operationen umsetzen, wobei das Datenmodell zahlreiche Optimierungen zur Reduktion der Anzahl der Schritte oder der Minimierung von Kommunikation erlaubt. Dies erlaubt ein stark vereinfachtes Programmiermodell bei gleichzeitiger Effizienzsteigerung. "renderer"-Treiber können zur Ausführung von Transformationen den lokalen Prozessor verwenden, oder können die Operationen delegieren. In der Arbeit wird eine Erweiterung des X Window Systems um Mechanismen zur Medienverarbeitung vorgestellt, sowie ein "renderer"-Treiber, der diese zur Delegation der Verarbeitung nutzt

Enhancing a Neurosurgical Imaging System with a PC-based Video Processing Solution

This work presents a PC-based prototype video processing application developed to be used with a specific neurosurgical imaging device, the OPMI® PenteroTM operating microscope, in the Department of Neurosurgery of Helsinki University Central Hospital at Töölö, Helsinki. The motivation for implementing the software was the lack of some clinically important features in the imaging system provided by the microscope. The imaging system is used as an online diagnostic aid during surgery. The microscope has two internal video cameras; one for regular white light imaging and one for near-infrared fluorescence imaging, used for indocyanine green videoangiography. The footage of the microscope’s current imaging mode is accessed via the composite auxiliary output of the device. The microscope also has an external high resolution white light video camera, accessed via a composite output of a separate video hub. The PC was chosen as the video processing platform for its unparalleled combination of prototyping and high-throughput video processing capabilities. A thorough analysis of the platform and efficient video processing methods was conducted in the thesis and the results were used in the design of the imaging station. The features found feasible during the project were incorporated into a video processing application running on a GNU/Linux distribution Ubuntu. The clinical usefulness of the implemented features was ensured beforehand by consulting the neurosurgeons using the original system. The most significant shortcomings of the original imaging system were mended in this work. The key features of the developed application include: live streaming, simultaneous streaming and recording, and playing back of upto two video streams. The playback mode provides full media player controls, with a frame-by-frame precision rewinding, in an intuitive and responsive interface. A single view and a side-by-side comparison mode are provided for the streams. The former gives more detail, while the latter can be used, for example, for before-after and anatomic-angiographic comparisons.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

A survey of techniques and technologies for web-based real-time interactive rendering

When exploring a virtual environment, realism depends mainly on two factors: realistic images and real-time feedback (motions, behaviour etc.). In this context, photo realism and physical validity of computer generated images required by emerging applications, such as advanced e-commerce, still impose major challenges in the area of rendering research whereas the complexity of lighting phenomena further requires powerful and predictable computing if time constraints must be attained. In this technical report we address the state-of-the-art on rendering, trying to put the focus on approaches, techniques and technologies that might enable real-time interactive web-based clientserver rendering systems. The focus is on the end-systems and not the networking technologies used to interconnect client(s) and server(s).Siemens; Bertelsmann mediaSystems GmbH; Eptron Multimedia; Instituto Politécnico do Porto - ISEP-IPP; Institute Laboratory for Mixed Realities at the Academy of Media Arts Cologne, LMR; Mälardalen Real-Time Research Centre (MRTC) at Mälardalen University in Västerås; Q-Systems

An Internet based multimedia infrastructure for collaborative engineering

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.Includes bibliographical references (leaves 129-131).The evolution of computer based collaborative environments has resulted in easier and more economical design efforts among geographically distributed design teams. Most of today's internet based collaborative applications allow people that are geographically dispersed to meet with each other using their computers and work together without actually having to travel. A prototype system was developed by taking two tactical planning applications and incorporating them into the collaboration model employed by CAIRO (Collaborative Agent Interaction control and synchROnization). This system was developed based on the collaboration infrastructure that was developed as a part of the Da-Vinci Society Initiative at MIT. The main focus of this research lies in the formalization of a multi-media based architecture that supplements the existing collaboration infrastructure. This architecture lays the groundwork for development of a robust collaboration system that incorporates audio/video conferencing, speech recognition and synthesis and three-dimensional virtual meeting environments in order to facilitate efficient collaboration.by Padmanabha N. Vedam.S.M

Time-varying volume visualization

Volume rendering is a very active research field in Computer Graphics because of its wide range of applications in various sciences, from medicine to flow mechanics. In this report, we survey a state-of-the-art on time-varying volume rendering. We state several basic concepts and then we establish several criteria to classify the studied works: IVR versus DVR, 4D versus 3D+time, compression techniques, involved architectures, use of parallelism and image-space versus object-space coherence. We also address other related problems as transfer functions and 2D cross-sections computation of time-varying volume data. All the papers reviewed are classified into several tables based on the mentioned classification and, finally, several conclusions are presented.Preprin

Real-time structured video decoding and display

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1995.Includes bibliographical references (leaves 57-59).by Brett Dawson Granger.M.S

Real-time decoding and display of layered structured video

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (leaves 72-73).by Tzu-Yun Teresa Chang.M.Eng

Report of the discussion on Free and Open Source Software (FOSS) for OER

Appendix: FOSS tools for OER development, management and dissemination

Parametrization, auralization, and authoring of room acoustics for virtual reality applications

The primary goal of this work has been to develop means to represent acoustic properties of an environment with a set of spatial sound related parameters. These parameters are used for creating virtual environments, where the sounds are expected to be perceived by the user as if they were listened to in a corresponding real space. The virtual world may consist of both visual and audio components. Ideally in such an application, the sound and the visual parts of the virtual scene are in coherence with each other, which should improve the user immersion in the virtual environment. The second aim was to verify the feasibility of the created sound environment parameter set in practice. A virtual acoustic modeling system was implemented, where any spatial sound scene, defined by using the developed parameters, can be rendered audible in real time. In other words the user can listen to the auralized sound according to the defined sound scene parameters. Thirdly, the authoring of creating such parametric sound scene representations was addressed. In this authoring framework, sound scenes and an associated visual scene can be created to be further encoded and transmitted in real time to a remotely located renderer. The visual scene counterpart was created as a part of the multimedia scene acting simultaneously as a user interface for renderer-side interaction.reviewe