Patent ID: 9113104
Filing Date: 2015-08-18
Classification: H04N

Abstract:
1. An image processing apparatus to perform screen processing for image data, and to form an image based on the image data which has been performed with the screen processing, comprising a screen processing unit to perform the screen processing by using a subcell which corresponds to a plurality of pixels, and in which a first threshold value and a second threshold value are determined according to each position of the pixels, so as to satisfy a relationship of the first threshold value<the second threshold value in a case where a beam spot diameter of a laser light which is used at a time of an exposure exceeds a controllable size of one pixel, wherein the screen processing unit obtains the first threshold value and the second threshold value from the subcell, which correspond to the position of each pixel in an image, to output: an invariable value D and wherein the subcell is a pixel group which configures one halftone dot, and a pixel among the subcell is determined so that the first threshold value of the pixel is larger than the first threshold value of at least 2 prior pixels among the subcell and is smaller than the second threshold value of each of at least 3 prior pixels for a whole range of the pixel value.