| 摘要 |
PROBLEM TO BE SOLVED: To improve the gradation stability of an output image by suppressing the dullness of an edge due to error propagation delays and clustering output dots.SOLUTION: A first product-sum computing element 103 calculates the weighted average of multi-valued pixel data in an original image, and a second product sum computing element 104 calculates the weighted average of binary pixel data outputted by a quantizer 102, by performing band-pass filter processing. A subtractor 101 calculates a difference value for which the weighted average calculated by the second product sum computing element 104 is subtracted from the weighted average calculated by the first product-sum computing element 103, and the quantizer 102 outputs 1 when the difference value calculated by the subtractor 101 is ≥0 and outputs 0 as the binary pixel data, when it is <0. |
