Patent ID: 7457004
Filing Date: 2008-11-25
Classification: H04N

Abstract:
1. A halftone dot formation method for forming halftone dots used to represent an original image of gray scale, comprising the steps of: a) arranging a plurality of halftone cells in irregular shapes at random and dividing said plurality of halftone cells into a plurality of groups each consisting of halftone cells which are distributed uniformly; and b) forming halftone dots on the basis of an original image with said plurality of groups having different dot growth speeds each of which corresponds to the amount of variation of a dot area in a halftone cell with respect to the amount of variation in gray level of said original image, wherein halftone cells belonging to one of said plurality of groups which consists of a minimum number of halftone cells are so arranged as not to be adjacent to one another, each having a larger area and a higher dot growth speed as compared with halftone cells belonging to other groups.