| 摘要 |
PROBLEM TO BE SOLVED: To prevent a gradation inverted phenomenon and to improve a thinning ratio by generating an effective thinning pattern which is different in the thinning ratio corresponding to the density of the high-density part of an original image based on a specific reference dot so as to vary the thinning ratio of the high-density part of the original image corresponding to the density. SOLUTION: Thinning is executed only to the dot of the high-density part of an original image by a thinning filter algorithm. Then, in order to judge the high-density part of this original image, dots of totally three lines which are a line including an objective dot and two adjacent upper/lower lines are referenced. Then, based on this reference dot, an effective thinning pattern different in a thinning ratio corresponding to the density of the high-density part of the original image are generated to vary the density of the high-density part of the original image corresponding to the density. In this ink jet printer, a CPU 5 executes thinning and successively sends raster data converted to CMYK data to a head 10 via a head driving device 9 to execute forming of an image. |
