Misregistration sensitivity in clustered-dot color halftones

bstract. Halftoned separations of individual colorants, typically yan, magenta, yellow, and black, are overlaid on a print substrate n typical color printing systems. Displacements between these eparations, commonly referred to as “interseparation misregistraion”, can cause objectionable color shifts in the prints. We study this isregistration-induced color shift for periodic clustered-dot halfones using a spatiospectral model for the printed output that comines the Neugebauer model with a periodic lattice representation or the individual halftones. Using Fourier analysis in the framework f this model, we obtain an analytic characterization for the condiions for misregistration invariance in terms of colorant spectra, peiodicity of the individual separation halftones, dot shapes, and misegistration displacements. We further exploit the framework in a ybrid analytical-numerical simulation that allows us to obtain quanitative estimates of the color shifts due to misregistration, thereby roviding a characterization for these shifts as a function of the opical dot gain, halftone periodicities, spot shapes, and interseparaion misregistration amounts. We present simulation results that emonstrate the impact of each of these parameters on the color hift and demonstrate qualitative agreement between our approxiation and experimental data. © 2008 SPIE and IS&T. DOI: 10.1117/1.2917517