Patent ID: 8094968

Claim:
An image creating method for creating a halftone image of an original image of a tone number P, where P is a given integer, the image creating method comprising the steps of: acquiring an output condition of the halftone image; generating a basic array of pixels meeting the output condition, the basic array consisting of (N−1) pixels, where N is an integer not exceeding a reproducible tone number under the output condition; letting the basic array be a sub-array, setting a super-array of Q sub-arrays, where Q is an integer, such that (N−1)Q≦P; setting a set of (N−1)R thresholds parting P tones, where R is an integer not exceeding Q; distributing the set of (N−1)R thresholds to pixels of R sub-arrays of the super-array, allotting lowest and near-lowest thresholds to central pixels of the R sub-arrays, to generate a dither array of thresholds parting P tones; and dithering a grayscale data of the original image by the dither array.