Patent ID: 6798539
Filing Date: 2004-09-28
Classification: H04N

Abstract:
A method of generating a plurality of non-orthogonal halftone screens for substantially moirÃ©-free color halftoning, comprising:locating non-orthogonal halftone cells substantially specified by two spatial vectors (xn1, yn1) and (xn2, yn2) that substantially form a non-orthogonal halftone cell, where, xn1, yn1 and xn2, yn2 are substantially integer valued; identifying combinations of the located non-orthogonal halftone cells, suitable for tiling an image plane, of at least three of the located non-orthogonal halftone cells, where the spatial vectors of the identified combinations satisfy: AbAcxa1+AcAaxb1+AaAbxc1â‰…0, AbAcya1+AcAayb1+AaAbyc1â‰…0, AbAcxa2+AcAaxb2+AaAbxc2â‰…0, and AbAcya2+AcAayb2+AaAbyc2â‰…0, where,the subscripts 1 and 2 are arbitrary and interchangeable, n=a, b, c, where, a, b, c are arbitrary color indices; and An=|xn1yn2âˆ’xn2yn1|; selecting one of the identified combinations; and associating each non-orthogonal halftone cell of the selected identified combination with one or more color separations of a color halftone printer.