In xerographic printing, stabilization of the color reproduction function (CRC) or the tone reproduction curve (TRC) for the color separations are critical for achieving color consistency. This problem is challenging because: 1) there exist only a small number of actuators to stabilize a potentially infinite dimensional TRC; 2) only a small number of tone / color test patches can be printed and measured at a time. The first issue is addressed by a curve-fitting TRC stabilization controller based on Linear Quadratic (LQ) control with integral dynamics is proposed. It specifies particular tones or color that to be precisely controlled, while allowing other tones or colors to be close to the desired value. To address the second problem, time-sequential sampling is proposed to enable the time varying TRC or CRC to be reconstructed based on small number of samples. Experimental and simulation results verify the adequacy of the approach.
Teck-Ping Sim, Perry Y. Li, "Stabilization of Color Tone Reproduction Curves Using Time-Sequential Sampling" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP20), 2004, pp 204 - 209, https://doi.org/10.2352/ISSN.2169-4451.2004.20.1.art00048_1