| 摘要 |
PROBLEM TO BE SOLVED: To perform edge processing of upper and lower edges in subscanning direction. SOLUTION: An edge discrimination part 109 discriminates the upper and lower edges of character or drawing in the subscanning direction. A gradation processing part 104 outputs image information while keeping 8 bits, for example, as it is in order to improve the image quality of edges of drawing and selects that image information in the pixel block discriminated as the upper and lower edges by the edge discrimination part 109. A gradation processing part 105 performs multilevel error diffusion double dot processing in order to improve the picture quality of picture pattern or photograph, and the output of the gradation processing part 105 is selected in any block excepting for the pixel block discriminated as upper and lower edges by the edge discrimination part 109. |
