A perceptual user interface for recognizing head gesture acknowledgements

We present the design and implementation of a perceptual user interface for a responsive dialog-box agent that employs real-time computer vision to recognize user acknowledgements from head gestures (e.g., nod = yes). IBM Pupil-Cam technology together with anthropometric head and face measures are used to first detect the location of the user's face. Salient facial features are then identi ed and tracked to compute the global 2-D motion direction of the head. For recognition, timings of natural gesture motion are incorporated into a state-space model. The interface is presented in the context of an enhanced text editor employing a perceptual dialog-box agent.