| 摘要 |
PURPOSE:To prevent the inverse of the gradation of a picture with pseudo halftone at the time of executing a thin OR processing. CONSTITUTION:A pattern '1' detection circuit 12 and a pattern '2' detection circuit 13 monitor a thin signal 16 and check whether the pattern of a picture element is that generating a gradation inverse after it is thinned out by a thinning out OR circuit 15 in a postage. When it is the pattern generating the gradation inverse, an output switch circuit 14 outputs a pattern where gradation inverse is not generated instead of the thinning signal 16 inputted as an output signal 19. Thus, the deterioration of picture quality owing to the inverse of the gradation of the picture with pseudo halftone can be prevented. |
