Parametrically controlled stochastically seeded clustered halftones: design strategies and applications

We present a stochastically seeded, clustered halftoning method with parametric control of dot shapes as well as seed placement adaption to local image structure. While the literature on other randomly structured screens (blue noise, green noise, and stochastic halftoning) is quite extensive, there is very little discussion on optimization of dot shape for robustness or preferred tile appearance. The parametric control presented here can enable an imaging engineer to optimize robustness for a given printing system. The halftoning method that we introduce defines dot centers as seeds that are placed typically in a random, high spatial frequency configuration. Spot functions are defined about these randomly placed seeds, where the spot function allows control of dot cluster growth, touch points, cluster angle, and eccentricity. The spot function can also be applied to regular and irregular polygonal halftone tiling. The adaptability of the seed placement provided by the halftoning method allows for better edge rendition than conventional isotropic methods and enables the implementation of data-embedding techniques. The resulting monochromatic screens can be seamlessly integrated with novel successive filling techniques in order to provide dot-off-dot vector halftoning capabilities. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.