Revisited Yule–Nielsen model without fitting of the n parameter

Abstract

We introduce a so-called "mean-path-defined Yule-Nielsen" (MPD-YN) model for predicting the color of halftone prints in reflectance or transmittance modes, inspired by the Yule-Nielsen modified spectral Neugebauer model, where the empirical n value is replaced with a spectral parameter different for each halftone, directly calculated thanks to a closed-form formula, a function of the measured spectral reflectances (or accordingly transmittances) of full-tone calibration patches and the surface coverages of the Neugebauer primaries in the halftone. This parameter is based on the average number of internal reflections undergone by light between two half layers of the print, whose expression derives from a flux transfer model between the two half layers. According to the tests carried out in this study with paper printed in inkjet, the predictive performances of the MPD-YN model are rather good and very close to those obtained with the Yule-Nielsen model.

Study on spectral reflectance model for color printing dot

“…The earliest prediction model used is the Murray-Davies model 2,3 , which simplifies the light propagation path, and considers the reflectance to be determined only by the graphic and non-graphic portions, ignoring other light propagation characteristics such as light scattering. The Yule-Nielsen model takes into account light scattering characteristics 4 , and introduces a correction parameter N, which improves the accuracy of the reflectance model, but the parameter N is an empirical value, which is difficult to be determined by objective measurement.Clapper-Yule model 5 is an improved version of the Yule-Nielsen model, which focuses on the phenomenon of multiple internal reflection. A reflection prediction model based on the Kubelka-Munk theory further improves the accuracy 6,7 .…”