PICTURE ENHANCEMENT METHOD

摘要

PURPOSE: To smooth a jagged edge of an oblique line or a curved line by enhancing an area of an image in a three-level printer. CONSTITUTION: The method is constituted by changing selected video data in a sub-set by converting a series of video data into a series of composite analog video pulses corresponding to plural pixel cycles, discriminating the sub-set of the video data to be changed to improve appearance of a charge area development(CAD) region of an output image and correcting the video pulse corresponding to the selected video data. Each pixel period is provided with a composite video pulse representing a charge area, a discharge area and an intermediate discharge area which are formed on a surface of a photosensitive member and the composite video pulse is added to an acoustooptical modulator 82 to modulate a laser beam.