Thermal imaging for interactive surfaces

Abstract

Thermal camera operating in Far Infrared (FIR) is considered to be un- derexplored in elds other than security and law enforcement. Nevertheless, recently it drawn the attention of Human Computer Interaction (HCI) re- searchers as a new sensory system enabling novel interactive systems. They are robust to illumination changes and using it with well-known computer vi- sion techniques, the complexity of the interaction detection is highly reduced as compared to RGB and depth cameras. FIR radiation, however, has an- other undiscovered characteristic that distinguishes thermal cameras from their RGB or depth counterparts, namely thermal re ection. Commonly, surfaces re ect thermal radiation differently than visual light and can be- come a perfect thermal mirror. In this thesis, we show that through thermal re ection, thermal cameras can sense the space beyond their direct eld of view (areas besides and even behind the camera' eld of view). We investi- gate how thermal re ection can potentially increase the interaction space of projected surfaces using camera-projection systems. We moreover discuss the re ection characteristics of common surfaces in our vicinity in both the visual and thermal radiation bands. Using a proof-of-concept prototype, we demonstrate the increased interaction space for hand-held camera-projection system. Furthermore, we depict a number of other promising application examples that can largely bene t from the thermal re ection characteristic of surfaces