Spectral prediction model for variable dot-size printers

TLDR: In the p contribution, the possibility of producing accu rate spectral reflectance predictions at all pixel dot-sizes is explored, using a Clapper-Yule model, extended according to Beer’s la w, which accounts for ink thickness variations.

Abstract: By printing a variable number of droplets onto the same pixel location, ink jet printers produce pixels at variable dot-s izes yielding several darkness levels. Varying the number of printed d roplets affects the ink volume deposited onto the substrate. In the p contribution, we explore the possibility of producing accu rate spectral reflectance predictions at all pixel dot-sizes. For this purpose, we use a Clapper-Yule model, extended according to Beer’s la w, which accounts for ink thickness variations. This model exp resses each colorant transmittance as a function of its constituen t ink transmittances and their respective relative thicknesses. Thes e relative thicknesses are initially computed when calibrating the mo del, at a given pixel dot-size, and can then be dynamically scaled ac cording to the printed pixel dot-size. We first study the effect ofvarying pixel dot-sizes on the halftone’s physical (mechanical) do t-gain. We then express the ink volume variations as a function of pixeldotsizes. Lastly, we show how, using the thickness extended Cla pperYule model, we can effectively predict reflectances for diff erent configurations of ink pixel dot-sizes.