filename     : Lamboray05.pdf
entry        : article
conference   :
pages        : 637-648
year         : 2005
month        : November/December
title        : Data Streaming in Telepresence Environments
subtitle     :
author       : Edouard Lamboray, Stephan Würmlin, Markus Gross
booktitle    : IEEE Transactions on Visualization and Computer Graphics, Special Issue-Haptics, Virtual and Augmented Reality
ISSN/ISBN    :
editor       : Grigore C. Burdea, Ming C. Lin, Susumu Tachi
publisher    :
publ.place   :
volume       : 11
issue        : 6
language     : English
keywords     :  H.4.3 [Communications Applications]: Computer conferencing, teleconferencing, and videoconferencing. I.3.2 [Graphics Systems]: Distributed/network graphics. I.3.7 [Computer Graphics]: Three-dimensional graphics and realism
abstract     : In this paper, we discuss data transmission in telepresence environments for collaborative virtual reality applications. We analyze data streams in the context of networked virtual environments and classify them according to their traffic characteristics. Special emphasis is put on geometry-enhanced (3D) video. We review architectures for real-time 3D video pipelines and derive theoretical bounds on the minimal system latency as a function of the transmission and processing delays. Furthermore, we discuss bandwidth issues of differential update coding for 3D video. In our telepresence system – the blue-c – we use a point-based 3D video technology which allows for differentially encoded 3D representations of human users. While we discuss the considerations which lead to the design of our three-stage 3D video pipeline, we also elucidate some critical implementation details regarding decoupling of acquisition, processing and rendering frame rates and audio/video synchronization. Finally, we demonstrate the communication and networking features of the blue-c system in its full deployment. We show how the system can possibly be controlled to face processing or networking bottlenecks by adapting the multiple system components like audio, application data and 3D video.