User awareness for collaborative multi-touch interaction

Multi-touch enables direct manipulation of graphical computer interfaces. This intuitive interaction paradigm rapidly became popular, particularly in the domain of individual mobile devices. Collaborative work on large scale multi-touch devices, instead, suffers from mutual interferences if many simultaneous touch events cannot be attributed to individual users. On the example of a large, adjustable, high-resolution (4K) multi-touch device, we describe a lightweight and robust method to solve this issue. An additional depth camera above the tabletop device tracks the users around the table and their respective hands. This environment tracking and the multi-touch sensor are automatically calibrated to the same coordinate system. We discuss relevant implementation details to help practitione rs building similar systems. Besides improved multi-user coordination we reveal general usability benefits including the reduction of false positives. Exploiting the developed system, we implemented several novel test applications to analyze the capabilities of such a system with regard to different interaction metaphors. Finally, we combined several of the analyzed metaphors to a novel application serving as an intuitive multi-touch application and environment for seismic interpretation.