Patent ID: 8922827
Filing Date: 2014-12-30
Classification: H04N

Abstract:
1. An image processing apparatus comprising: a storage unit that stores a dither matrix including a plurality of sub-matrices, each sub-matrix having a group of dot regions and each dot region having a threshold value, the dot regions being arranged in N rows and N columns in which N is an integer greater than or equal to 4 and the dot regions defining a first diagonal line and a second diagonal line, each sub-matrix having a plurality of first orthogonal lines extending in a direction parallel to the first diagonal line and a plurality of second orthogonal lines extending in a direction parallel to the second diagonal line, N dot regions whose threshold value is smaller than a prescribed value being contained in the group of dot regions, only one of N dot regions being contained in each row and each column, at most one of N dot regions being contained in each first orthogonal line and each second orthogonal line; and a converting unit that is configured to convert print data into binary data by using the dither matrix, wherein a dot region is turned on when a threshold value of the dot region is smaller than an input value, wherein the threshold values are set in each sub-matrix such that, while the input value increases after N dot regions have been turned on in all sub-matrices, a dot region meeting the following conditions (a) and (b) is turned on in sequence: (a) the dot region is adjacent to a turned-on-dot region that has been already turned on; and (b) the dot region is positioned in one of row and column in which the turned-on-dot region is positioned.