Naoya Takao

Tele-Graffiti: A Camera-Projector Based Remote Sketching System with Hand-Based User Interface and Automatic Session Summarization

One way to build a remote sketching system is to use a video camera to image what each user draws at their site, transmit the video to the other sites, and display it there using an LCD projector. Such camera-projector based remote sketching systems date back to Paul Wellners (largely unimplemented) Xerox Double DigitalDesk. To make such a system usable, however, the users have to be able to move the paper on which they are drawing, they have to be able to interact with the system using a convenient interface, and sketching sessions must be stored in a compact format so that they can be replayed later. We have recently developed Tele-Graffiti, a remote sketching system with the following three features: (1) real-time paper tracking to allow the users to move their paper during system operation, (2) a hand based user interface, and (3) automatic session summarization and playback. In this paper, we describe the design, implementation, and performance of Tele-Graffiti.

Extended Digital Video Broadcasting with Time-Lined Hypermedia

In recent years, digital broadcasting services have started up and spread all over the world. Digital broadcasting is one of the most promising infrastructures to provide interactive services aimed at consumers. However, the broadcast bandwidth has an upper bound limitation. This paper describes our proposition, a hypermedia model, called Time-lined Hypermedia, which is designed to provide a large hypermedia navigation space in a limited broadcast bandwidth. We also describe an implementation for time-lined hypermedia called Digital Video eXtension system.