Computer-aided design of clustered-dot color screens based on a human visual system model

We address the problem of optimal periodic clustered-dot color-screen design. In traditional clustered-dot color screening, the screen for each colorant is rotated to a different angle relative to the others. If the angles are not carefully chosen, visible moire and rosette artifacts may appear These artifacts primarily result from the interaction of the periodic structures associated with the halftone screens of different colorants. Registration errors can also introduce unwanted artifacts in the screened images. Using lattice theory and a model for the perceived rendered halftone, we present a systematic method for designing moire- and rosette-free clustered-dot color screens for discrete-raster color systems. We also investigate strategies for choosing the periodicities so that the resulting screen is robust to registration errors