A Novel Multi-Camera Global Calibration Method for Gaze Tracking System

In a 3-D gaze tracking system, the system calibration is used to determine the positions of the light sources and the screen in the camera coordinate system, which plays an important role in the estimation of the 3-D gaze and the point of regard (PoR). The traditional way for the system calibration is the mirror-based method, in which a mirror is used to make the light sources and the screen can be captured by the camera through specular reflection. However, the mirror-based method is imprecise and complex. In this paper, a novel system-calibration method for the 3-D gaze tracking system is proposed. On the basis of the system camera, a calibration camera is placed on the opposite of the screen to constitute a multi-camera system. The images are captured by the two cameras to estimate the light sources and the screen of the system camera coordinate frame. Simulations and experiments were carried out to illustrate the validation of the method. This method solves the problem that the light sources and the screen are not in view of the system camera. In addition, it is easy to implement while ensuring high accuracy and providing a new method for other similar calibration systems.