Narrow band, anisotropic stochastic halftone patterns and methods of creating and using the same
Assignee3M Innovative Properties Company
InventorRichard L. Rylander
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Abstract
A stochastic halftone pattern has been invented which has a narrow band power spectrum due to the incorporation of a dot growth process. The narrow band power spectrum may be matched to the resolution characteristics of specific printers, resulting in smoother printed halftone textures. The spectrum of a halftone pattern may be made anisotropic (angularly dependent), helping to de-couple sets of patterns for color printing with reduced color noise or mottle.
Claims6
A halftone pattern having a power spectrum which has a low spectral energy level at low frequencies, a high spectral energy level at frequencies corresponding to mid-tone ranges, and a low to moderate spectral energy level at high frequencies, and wherein the peak energy level of the spectrum corresponds to a mean dot-to-dot distance just above the minimum spot size of the imaging engine with which the halftone pattern is to be used.
A set of halftone patterns having a power spectrum that has a low spectral energy level at low frequencies, a high spectral energy level at frequencies corresponding to mid-tone and a low to moderate spectral energy level at high frequencies, and wherein the halftone patterns are anisotropic.
Dependencies are inferred from the claim text.