Image processing method and device using dither matrixes with size and density being inversely related to a unit images distance to the center of the dither matrix
An image processor includes: memory storing data including pixel values; memory storing dither matrixes corresponding to dot size and having cells with individual threshold values; a generator generating quantized data including dots corresponding to cells by comparing the data with a dither matrix, and showing that a given sized dot is formed; a calculator calculating a duty ratio of first sized dots to second sized dots based on quantized data; a determining unit determining whether the duty ratio satisfies a predetermined condition; and a threshold updater updating the dither matrixes if the condition is satisfied, at least one update being based on duty ratio; the threshold values being to: form larger dots around the dither matrix center; decrease dot size as a distance between a cell and the dither matrix center increases; and decrease dot density as the distance between a cell and the dither matrix center increases.
