Patent ID: 6356360
Filing Date: 2002-03-12
Classification: H04N

Abstract:
A method of reproducing an image with a series of patterns of halftone dots, each halftone dot being comprised of plural pixels arranged in a halftone cell, the image being derived from unrendered image data represented by pixels each having an unrendered pixel value density assignment of one of M grey levels, the method comprising:generating rendered pixels by comparing for each of at least some pixels to be rendered a corresponding unrendered pixel value with threshold values associated with the corresponding position of the pixel to be rendered in a halftone cell, the rendered pixels being generated with at least R+1 levels of density including background, wherein R is a whole number greater than two and less than M; and forming halftone dots each of plural rendered pixels wherein at least some halftone dots are of a first density D1 and other halftone dots are of a second density D2 and wherein D2>D1, a halftone dot of density D1 having a rendered pixel at a respective pixel location with an assigned density d1 and a halftone dot of density D2 having a rendered pixel at the same respective pixel location with an assigned density d2 and wherein d21, and wherein d2 is assigned a background density.