On visual gaze tracking based on a single low cost camera

• Uses only a single camera, offering convenience and minimal intrusiveness.
• Positions of upper eyelids contribute in ameliorating vertical gaze accuracy.
• Calibration points arranged at a ‘cross pattern’ demonstrate better performance.
• Gaze is estimated with high accuracy, suitable for most gaze tracking applications.

Gaze tracking technologies provide an unconventional way of human–computer interaction, envisaged to advance practical applications and industrial products in a multitude of fields. The success of such systems depends on selecting the best calibration setup and image features that correspond to a person׳s line of sight. The purpose of this study is to estimate eye gaze from a single, low cost web-cam, under natural lighting. Facial traits are extracted from the sensory data, from which distance vectors related to gaze are derived. Different experimental setups are studied to evaluate the robustness of the proposed method with respect to various calibration setups, camera position and head movements. The use of new additional features improves the modeling of the subtle eye movements in the vertical direction, while a new calibration setup is proposed that further enhances the performance. The results demonstrate that the proposed framework is able to track gaze with good accuracy, consolidating the use of inexpensive equipment and techniques towards an ever-expanding range of gaze tracking applications.