Patent ID: 7301676

Claim:
A method of printing a given multivalue image in a binary-form out put pattern, said method comprising the steps of: (a) providing a binary-form dither matrix pattern which is used to obtain the binary-form output pattern, said binary-form dither matrix pattern having a rectangular pattern in which a plurality of pattern elements that are numbered to be successively turned on are arranged in matrix, the sequence of turning on of said plural pattern which groups are substantially identical in shape, grow successively from a plurality of local points associated with the respective groups and successively from a center dot element in each group; (b) expanding the given multivalue image in a memory area of a storage device; and (c) forming a binary image of said output dot elements in accordance with said binary-form output pattern obtained by turning on the individual pattern elements of said binary-form dither matrix pattern, based on the given multivalue image which has been expanded in the memory area, in such a manner that said output dot elements of an individual print dot of the binary image which correspond to said pattern elements of said binary-form dither matrix pattern grow successively from said center dot element at the associated local point in each group in the sequence the corresponding pattern elements of said binary-form dither matrix pattern are numbered.