Toward a tongue-based task triggering interface for computer interaction

A system able to detect the existence of the tongue and locate its relative position within the surface of the mouth by using video information obtained from a web camera is proposed in this paper. The system consists of an offline phase, prior to the the operation by the final user, in which a 3-layer cascade of SVM learning classifiers are trained using a database of 'tongue vs. not-tongue' images, that correspond to segmented images containing our region of interest, the mouth with the tongue in three possible positions: center, left or right. The first training stage discerns whether the tongue is present or not, giving the output data to the next stage, in which the presence of the tongue in the center of the mouth is evaluated; finally, in the last stage, a left vs. right position detection is assessed. Due to the novelty of the proposed system, a database needed to be created by using information gathered from different people of distinct ethnic backgrounds. While the system has yet to be tested in an online stage, results obtained from the offline phase show that it is feasible to achieve a real-time performance in the near future. Finally, diverse applications to this prototype system are introduced, demonstrating that the tongue can be effectively used as an alternative input device by a broad range of users, including people with some physical disability condition.