It is well known that the chromaticity coordinate points of a single ink halftone ramp are in a curve on the CIE xy chromaticity diagram. This non-linear behavior is caused by a color component, which is neither the color of paper nor the color of ink. This third component can result from both variation of ink layer thickness and light scattering in paper.In the current study, we used a halftone dot structure model to simulate the variation of ink layer thickness and then estimated the colorimetric characteristics of single ink halftone print.Our model assumes that a halftone dot consists of two regions. One region is a central area of the dot that has the same thickness of ink layer as that of the solid print, and is referred as “core”. The other region is the marginal area of the dot that has thinner ink layer than that of the solid print, and is referred as “fringe”. Using this model, we calculated the reflectance spectra and chromaticity coordinates for single ink halftone ramps and then compared them with the measured values. Consequently, the model could describe the non-linear behavior of single ink halftone prints as well as predict the reflectance spectra more precisely than the Murray-Davies model.
Yoshihiko Azuma, Hiromi Uomoto, Shunsuke Takahashi, Masao Inui, "Prediction of Color in Halftone Prints using Core-Fringe Model" in Proc. IS&T CGIV 2002 First European Conf. on Colour in Graphics, Imaging, and Vision, 2002, pp 594 - 597, https://doi.org/10.2352/CGIV.2002.1.1.art00124