Touch Detection System for Various Surfaces Using Shadow of Finger

Abstract

In this paper we try to realize a system that enables users to interact with surrounding surfaces using touch interactions. For this purpose, we propose new touch detection technique which utilizes the shadows of a finger, and developed a prototype system with an infrared (IR) camera and two IR lights. Since the shapes of a finger's shadows vary drastically depending on the distance between the surface and finger, our prototype system can detect touch. To improve the accuracy of the estimated touch position, we also introduce multiple regression analysis into the estimation algorithm of the touch position. We conducted two experiments on the accuracy of estimated touch position, and the results shows that the target accuracy was within an error of less than 5 mm.