Modeling coverage-dependent ink thickness in ink-jet printing

We propose a simple extension of the Murray-Davis halftone reflectance model that accounts for the change of ink dot reflectance due to ink spreading. Significant improvement of the prediction accuracy is obtained for a range of paper substrates and printer combinations compared to the classical Yule-Nielsen and Clapper-Yule models. The results show that ink dot thickness dependency is the main factor limiting the validity of the Murray-Davis model and that optical dot gain can be neglected when the model is calibrated for one specific printer, ink, and substrate combination. The proposed model provides a better understanding of the reflectance from halftone prints that contributes to the development of physical models for simpler and faster printer calibration to different substrates. (C) 2016 Optical Society of America