Method and apparatus for halftone rendering of a gray scale image using a blue noise mask

  • US 5,341,228 A
  • Filed: 12/03/1991
  • Issued: 08/23/1994
  • Est. Priority Date: 12/04/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for the halftoning of color images, comprising the steps of utilizing, in turn, a pixel-by-pixel comparison of each of a plurality of color planes of said color image against a blue noise mask in which the blue noise mask is comprised of a random non-deterministic, non-white noise single valued function which is designed to provide visually pleasing dot profiles when thresholded at any level of said color images, wherein a plurality of blue noise masks are separately utilized to perform said pixel-by-pixel comparison and in which at least one of said blue noise masks has its pixels shifted by at least one pixel prior to performing said pixel-by-pixel comparison.

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