1. A face tracking system for predicting the future position of a face comprising: multiple cameras for observing a user, each camera carrying out the steps of: (a) providing a current prediction of the face position using facial features detected in a previous and current input image frame; (b) deriving a first covariance matrix from the current prediction and a previous covariance matrix; (c) utilizing said current prediction of the face position from step (a) and a Kalman filter to determine a corresponding projected point of the facial feature on the plane of at least one camera; (d) deriving a Jacobian of the projected points in said step (c); (e) deriving a residual covariance of the projected points in said step (c); (f) deriving a suitable filter gain for said Kalman filter; (g) deriving a suitable update coefficients for said first covariance matrix; (h) updating said Kalman filter utilizing said filter gain.