Analysis of misregistration-induced color shifts in the superposition of periodic screens

Abstract

We present an analysis and model for evaluation of color shifts in halftone printing caused by inter-separation misregistration for periodic clustered dot halftones. Using a lattice framework, we present intuitive analysis that demonstrates conditions under which the average color is asymptotically invariant under inter-separation misregistration. Combining the framework with an analytic representation for the halftone dots, we develop a hybrid analytical-numerical model for quantitatively estimating color shifts as a function of inter-separation misregistration. The model is compared against experimental data for a xerographic printer.

Uniform-rosette color halftoning for <inline-formula><math display="inline" overflow="scroll"><mrow><mi>N</mi></mrow></math></inline-formula>-color moiré-free printing

“…These area types are the Neugebauer primaries. 12 The Neugebauer model would predict a significant color shift 13 due to the significant change in the fractional areas of the primaries.…”

Misregistration sensitivity in clustered-dot color halftones

“…We define a metric k 1 k 2 indicating denseness of U ⌳ k 1 +⌳ k 2 in U k 1 k 2 as the total number of unit cells U ⌳ k 1 +⌳ k 2 of the sum lattice that are needed to tile a unit cell U k 1 k 2 of the intersection lattice. The metric k 1 k 2 can be computed as the ratio between the areas of U k 1 k 2 and U ⌳ k 1 +⌳ k 2 and is referred to as the index of…”