Base models for color halftone reproduction
One of the main challenges for the characterization of printing systems consists, for a given substrate, in establishing the relationship between surface coverages of the selected set of inks and the spectral reflectances of the printed ink halftones. Knowledge of the spectral reflectances of print halftones enables deducing their colors. Models enabling the prediction of spectral reflectances as a function of surface coverages of the inks are helpful in characterizing printers and in creating printer profiles. The presented base models for color halftone reproduction are either surface models such as the Yule-Nielsen modified spectral Neugebauer model or physically inspired models accounting for the interaction of light, inks and substrate such as the Clapper-Yule model. As a complement to reflectance prediction models, we introduce ink spreading models that account for the interaction between superposed ink halftones and the substrate. They help understanding and modeling the dot gain phenomena present in most printing systems. Finally, we compare the prediction accuracies of the different models for different printing technologies, paper types and screen frequencies.