Enhancing Expressiveness in Reference Space

In the broad design space of telepresence systems, we are interested in contexts where users collaborate over a shared workspace. Our work involving connecting distributed touch surfaces (e.g. distributed tabletops) has shed light on the problem of supporting reference space—the ability of collaborators to point at, and refer to objects in the workspace. A promising approach to support this gestural communication has been to capture video of users’ arms as they work over the surface, transmitting and overlaying that video at remote workstations. The problem with this approach is that the video image is a flat projection of users’ 3D bodies, limiting the expressiveness of users’ gestures, and occasionally providing false information. In our most recent work, we have begun exploring ―non-photorealistic‖ visualizations of users’ bodies to support expressiveness in reference space. Introduction We employ Buxton’s three-space conceptual framework for telepresence to ground our research (Buxton, 2009). This framework specifies person-space (where verbal and facial cues are used for expression—typically realized as video and audio connection), task-space (where the work appears—typically realized as a shared workspace application), and reference-space (where remote parties use body language to refer to work). The focus of this position paper is on our investigations into supporting reference space—specifically, enabling gestural communication such as pointing, tracing or workspace gestures that are common to collaborative workspace activity. In designing and building collaborative workspace systems employing touch surfaces such as SMARTBoards or Microsoft Surfaces, we have adopted the design approach realized by Tang & Minneman (1990) to support reference space. This approach captures video of user’s bodies as they interact atop the surface, transmitting the processed video to the remote workstation, where it is then overlaid atop the shared workspace. Figure 1 illustrates such a collaborative system at work (Tang et al., 2010). Remote collaborators are represented with physical surrogates consisting of a screen, webcam, microphone and speaker (facilitating person-space), while the tabletops themselves are running a shared workspace (supporting task-space). Finally, an overhead camera (not visible) captures the arms of collaborators, and we overlay them into remote Anthony Tang University of British Columbia