Optimal parameters based stochastic dot model for tone compensation of dither matrix

The image outputs of a laser printer are accompanied with nonlinear phenomena such as dot gains and losses. As a result, a laser printer model is necessary to suppress such nonlinear distortions. This paper proposes the optimal parameters based stochastic dot model (OPSDM) and applies it to the tone compensation of dither matrices. In the proposed model, Munsell value is taken as intermediate value and a conversion method for the printouts is established at first. Then, no printer model of printout result is measured, and recurrent parameters of model are modified to obtain the optimal parameters of the stochastic dot model of printer by calculating the minimum Munsell value error between the measure result and simulated result of model. Finally, the dither matrix thresholds are modified to make the simulated result of every gray level with dither matrix close to the given level. The results of experimental indicate that the modified dither matrix with proposed model can significantly restrain the influence of the nonlinear characteristics of printer.