Patent ID: 7436550
Filing Date: 2008-10-14
Classification: H04N

Abstract:
1. An image processing method to mark out a multi-gradation original image into two regions on a boundary along one scanning line set at an arbitrary position, and to synthesize all of the regions after error diffusion processing is applied to each of the marked-out regions, the image processing method comprising: performing the error diffusion processing after the scanning line is determined, for errors of respective pixels on a scanning line to be diffused to two regions sandwiching the scanning line to be diffused, the scanning line including one or more pixels; and applying the error diffusion processing in each of the two regions to each of the two regions sequentially in parallel with the scanning line to be diffused, using, of a pixel sequence including pixels present at positions adjacent to the scanning line to be diffused, an unprocessed pixel positioned at an end portion of the pixel sequence as a start point, wherein if the scanning line to be diffused is a first scanning line, then one or both of the two regions are marked out further into two regions on a boundary along one second scanning line set at an arbitrary position to extend in a direction that intersects with the first scanning line, and after the second scanning line is determined, performing the error diffusion processing for errors of respective pixels on the second scanning line to be diffused to two regions sandwiching the second scanning line, the first scanning line including one or more pixels and the second scanning line including one or more pixels, and when the error diffusion processing is applied to each of the two regions sandwiching the second scanning line, performing the error diffusion processing sequentially in parallel with either scanning line, using an unprocessed pixel positioned at an intersection of the first scanning line and the second scanning line as a start point.