Visual Privacy in the Collaborative Cyber-infrastructure Environment:
A Case Study of Public Dance Performance in Physical and Cyber-Space
Ruzena Bajcsy and Lisa Wymore, UC Berkeley
Klara Nahrstedt, University of Illinois, Urbana-Champaign ,IL
Katherine Mezure , Mills College
Abstract
We are engaged in a collaborative effort, partially sponsored by the NSF, CITRIS-HP and the Department of Theater, Dance, and Performance Studies at the University of California, Berkeley , to investigate the technical, social and privacy issues that stem from the use of Internet and video capture. We are creating an immersive environment in which dancers in geographically remote areas (in this case California and Illinois) dance synchronously in real time. We are planning a real live performance in December 8, 2006, in which in addition to the dancers performing in cyberspace we will have real live dancers merging in and out from the virtual space.
In this abstract we shall briefly describe the system that generates the immersive environment, show some preliminary experiments and layout the privacy issues.
System Overview
The tele-immersive system consists of three components: Image capture, reconstruction, transmission and display.
In the first image processing component, multiple camera clusters, consisting of three black-and-white cameras and a colour camera, are processed independently to compute 3D information of the scene from different viewpoints. The partial 3D information from each viewpoint is combined later in the display component at the rendering machine to produce a full representation of the scene.
The second component of the system is the network transmission of the 3D data. To achieve immersive virtual environments that allow realistic interactions, it is required that multiple 3D stream be transmitted to a rendering system synchronously with minimal delay. A simple compression and encoding algorithm as well as an application-level reliable and semantic-aware adaptive protocol are used to shape the traffic and adjust bandwidth according to available resources and user demands
In the rendering machine resides the third component, where the received 3D streams are combined together and visualized/displayed so that users can feel relative depths in the scene. The diagram of the system is shown in Figure 1.
Preliminary Experiment
We have performed with one, two and 3 dancers several dance pieces first locally. It means the dancers were collocated in the same room, they danced and saw themselves on the display. The second step was to have the dancers in distributed locations. In this case, two dancers one in Illinois and one Berkeley were dancing together synchronously in the cyber-space. We shall show these via DVD.
Intellectual Property and Privacy Issues
First, we will address the intellectual property issue. In the art world the fundamental question is who owns the content? In our case, since the dancers are digitized, their performance is instantly available in digital form, hence can be easily copied, distributed, and changed. The technical questions are as follows. How do we protect this data? During the experimentation (such as rehearsals), can we store the data or should the data be discarded immediately? There are various protective mechanisms such watermarking, crypto-coding. When should these techniques be applied? What are the appropriate real-time watermarking techniques for 3D multi-camera streams?
Second, we have to consider the network security issue, and the following questions must be answered. Since we are using a public network such as Internet2, how should the dancers’ multi-view content be protected over the network? What are the appropriate real-time encryption algorithms? Since we have firewalls along the end-to-end network path, how do we map content copyright and access protection into the firewall policies? Who should have access to this data?
Third, we must consider the identity theft issue. Should the dancers be camouflaged so that they are not recognizable? What should be the ethical code for performance in the 3D multi-view media?
Finally, the privacy issue must be dealt with. When the dancers are interacting with the public, what should be the rules, policies of such interaction? Do we need any protections from undesired law suits? What type of liability issues surround this technology and what steps should be taken to avoid litigation?
Biography
* Image Caption, Source, Info.