| 摘要 |
PURPOSE:To reproduce a picture of high precision and of high quality by binarizing a picture data by an error diffusion method after giving a weight to it periodically, when the picture data is detected to be in the non-edge part of the picture. CONSTITUTION:When an edge detection circuit 13 detects that the picture data is in the non-edge part, the data 108 from a multilevel dither processing part is sent to a binarization circuit 17. A multilevel dither circuit 14 converts the data of 8 bits into the data of 3 bits by using, for instance, 7-number of dither matrixes of 3X3, and performs a requantization. When the data is binarized by a binarization circuit 17 by using a concentrated dot type for the dither matrix and by using the error diffusion method, a pseudo net dot is formed. This is because by using the concentrated dot type matrix, the data to be processed at the center of the matrix is more weighted than the data to be processed at a periphery. Thus, a pattern stripe and a granular noise at a highlight or a dark part can be reduced, and the reproduced picture of high quality is obtained.
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