Reflectance and transmittance model for recto-verso halftone prints

Abstract

We propose a spectral prediction model for predicting the reflectance and transmittance of recto-verso halftone prints. A recto-verso halftone print is modeled as a diffusing substrate surrounded by two inked interfaces in contact with air (or with another medium). The interaction of light with the print comprises three components: (a) the attenuation of the incident light penetrating the print across the inked interface, (b) the internal reflectance and internal transmittance that accounts for the substrate's intrinsic reflectance and transmittance and for the multiple Fresnel internal reflections at the inked interfaces, and (c) the attenuation of light exiting the print across the inked interfaces. Both the classical Williams-Clapper and Clapper-Yule spectral prediction models are special cases of the proposed recto-verso reflectance and transmittance model. We also extend the Kubelka-Munk model to predict the reflectance and transmittance of recto-verso halftone prints. The extended Kubelka-Munk model is compatible with the proposed recto-verso reflectance and transmittance model. In the case of a homogeneous substrate, the recto-verso model's internal reflectance and transmittance can be expressed as a function Kubelka-Munk's scattering and absorption parameters, or the Kubelka-Munk's scattering and absorption parameters can be inferred from the recto-verso model's internal reflectance and transmittance, deduced from spectral measurements. The proposed model offers new perspectives both for spectral transmission and reflection predictions and for characterizing the properties of printed diffuse substrates.

Yule–Nielsen based recto–verso color halftone transmittance prediction model

“…If the print is flipped, i.e., the verso face takes the place of the recto face, its transmittance may be modified especially when the light source and the capturing device have different angular geometries [6].…”

“…The prediction of the resulting colors requires a transmittance model. Recently, we developed a first reflectance and transmittance prediction model as an extension of the Clapper-Yule model, also valid for recto-verso prints [6,7]. It describes the multiple reflections of light between the paper and the print-air interfaces (Fig.…”

Predicting the Reflectance of Paper Dyed with Ink Mixtures by Describing Light Scattering as a Function of Ink Absorbance

“…We account for these interfaces, by modeling them using Kubelka's 16 layering model. 17 Using this model, we bound the paper with two paper-air interfaces. The characteristics of these two interfaces (surface reflection, internal reflection and transmittance) are identical and given by Snell's and Fresnel's formulae.…”

Deducing ink-transmittance spectra from reflectance and transmittance measurements of prints

“…The ink layer and the ink-air interface may be grouped together, forming a single element called a colored interface 5 . If the paper is not printed, the colored interface corresponds to the paper-air interface alone.…”