Farinella, Giovanni MariaRustico, EugenioVittorio Scarano and Rosario De Chiara and Ugo Erra2014-01-272014-01-272008978-3-905673-68-5https://doi.org/10.2312/LocalChapterEvents/ItalChap/ItalianChapConf2008/043-048We present a flexible system to track the movements of a bare finger on a flat surface. The proposed system is able to discriminate whether the user is touching or just pointing at the surface. The system works using two webcams and a fast scanline-based algorithm. The initial setup of the two webcams is easy and fast. No markers, gloves, or other hand-held devices are required. Since the system is independent from the nature of the pointing surface, it is possible to use a screen or a projected wall as a virtual touchscreen. The complexity of the algorithms used by the system grows less than linearly with resolution, making the software layer very lightweight and suitable also for low-powered devices like embedded controllers.Categories and Subject Descriptors (according to ACM CCS): H.5.2 [User Interfaces]: Input Devices and Strategies; General Terms: Low Cost Input Devices, Human Computer Interaction, Computer Vision