Robust stabilization of tone reproduction curves for the xerographic process

The stabilization of a single color tone reproduction curve (TRC) is critical for high fidelity color printing. A TRC controller uses a small number of actuators and a small number of measurements to stabilize the potentially high dimensional TRC. The overall least squares deviation of the TRC from the ideal nominal TRC is minimized in the face of the many disturbances and uncertainty in the system description. The control design consists of the steps of: 1) determining a robust optimally performing static controller, and 2) realizing a causal controller. Simulations and experiments showed that the proposed controllers perform superiorly, in terms of robustness, disturbance and noise rejection, compared to integral controllers.