Patent ID: 8335020
Filing Date: 2012-12-18
Classification: H04N

Abstract:
1. An image forming apparatus which forms a visible image by exposure scanning and development on an image carrier and transfers the visible image to a print medium, the apparatus comprising: an averaging unit configured to average H adjacent pixels in a subscanning direction serving as a conveyance direction of the print medium in an input image, thereby reducing a size of the input image to 1/H in the subscanning direction, wherein H is not smaller than 2; a multi-level error diffusion unit configured to perform multi-level error diffusion processing for each averaged pixel in an output image from the averaging unit; an H-pixel reconstruction unit configured to replace each averaged pixel that has been multi-level error-diffusion processed in an output image from the multi-level error diffusion unit with H reconstructed adjacent pixels, which have been expanded from the corresponding averaged pixel that has been multi-level error-diffusion processed, in the subscanning direction; an exchange unit configured to exchange pixel values of the H reconstructed adjacent pixels in an output image from the H-pixel reconstruction unit; and a generator configured to generate an exposure control signal for performing the exposure scanning, based on an output image from the exchange unit.