Patent ID: 8208176
Filing Date: 2012-06-26
Classification: G06K

Abstract:
1. A printing method of printing on a printing medium, comprising: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and generating the print image by forming dots on each of the print pixels according to the dot data, wherein the halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value; the dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range; and the predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements, and wherein the dither matrix is generated by storing multiple threshold values according to a rank order in each element for each print pixel group, based on a predetermined dither matrix generation method, and when storing the threshold values, a subsequent threshold value in the rank order is stored in a candidate storage element that is included in at least one of certain lines and columns which have values smaller than a predetermined value, the values being represented by a counted number of threshold values already stored in the print pixel group and the counted number being counted for each line and each column in the print pixel group.