Integrating discrete events and continuous head movements for video-based interaction techniques.

Human head gestures can potentially trigger different commands from the list of available options in graphical user interfaces or in virtual and smart environments. However, continuous tracking techniques are limited in generating discrete events which could be used to execute a predefined set of commands. In this article, we discuss a possibility to encode a set of discrete events by integrating continuous head movements and crossing-based interaction paradigm. A set of commands can be encoded through specific sequences of crossing points when a head-mouse cursor such as a scaled pointer interacts with a graphical object. The goal of the present experiment was testing the perceptual-motor performance of novices in target acquisition tasks using a subset of round head gestures and symbolic icons designating eight types of directional head movements. We have demonstrated that the novices can equally well execute round head gestures in clockwise and counter-clockwise directions by making two crossings for about 2 s or three crossings for about 3 s. None of the participants reported neck strain or other problems after 360 trials performed during a 40-min test in each of 5 days.