Haptic Interaction with Depth Video Media

Abstract

In this paper we propose a touch enabled video player system. A conventional video player only allows viewers to passively experience visual and audio media. In virtual environment, touch or haptic interaction has been shown to convey a powerful illusion of the tangible nature – the reality – of the displayed environments and we feel the same benefits may be conferred to a broadcast, viewing domain. To this end, this paper describes a system that uses a video representation based on depth images to add a haptic component to an audio-visual stream. We generate this stream through the combination of a regular RGB image and a synchronized depth image composed of per-pixel depth-from-camera information. The depth video, a unified stream of the color and depth images, can be synthesized from a computer graphics animation by rendering with commercial packages or captured from a real environment by using a active depth camera such as the Zcam^TM. In order to provide a haptic representation of this data, we propose a modified proxy graph algorithm for depth video streams. The modified proxy graph algorithm can (i) detect collisions between a moving virtual proxy and time-varying video scenes, (ii) generates smooth touch sensation by handling the implications of the radically different display update rates required by visual (30Hz) and haptic systems (in the order of 1000Hz), (iii) avoid sudden change of contact forces. A sample experiment shows the effectiveness of the proposed system.