An image processing apparatus includes a storage unit and a converting unit. The storage unit stores a dither matrix including a plurality of sub-matrices. Each sub-matrix has a group of dot regions and each dot region has a threshold value. The dot regions are arranged in N rows and N columns in which N is an integer greater than or equal to 4 and the dot regions define a first diagonal line and a second diagonal line. Each sub-matrix has 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 are contained in the group of dot regions. Only one of N dot regions is contained in each row and each column. At most one of N dot regions is contained in each first orthogonal line and each second orthogonal line. The converting unit is configured to convert print data into binary data by using the dither matrix.