Patent ID: 6281924
Filing Date: 2001-08-28
Classification: H04N

Abstract:
A method for forming an image, comprising the steps of:receiving an input image density value for each of a plurality of pixel positions, the plurality of pixel positions being defined two-dimensionally in first and second predetermined directions which are perpendicular to each other; andconverting the input image density value for each pixel position into output data for indicating whether to turn ON or OFF a pixel dot on the corresponding pixel position, by repeatedly locating a dither matrix along the first and second predetermined directions, the dither matrix including a plurality of threshold values which are arranged two-dimensionally in the first and second predetermined directions in a manner that pixel dots will be turned ON in a predetermined order when the input image density value changes uniformly successively, the predetermined order being defined so that as the input image density gradually increases, a linear pattern is first generated to extend parallel to the first direction and then grows in both of opposite two directions along the second direction, comparing the input image density value at each pixel position with a threshold value at a corresponding location of the dither matrix, and producing, based on the compared result, the output data for each pixel location.