摘要 |
A binary conversion error value as to neighboring pixels stored in an error value storage portion is added to a pixel density of a subject pixel, which is read from an input image storage portion, at a ratio based on an error distribution matrix, so that a modified density is calculated. A determination is made as to whether the modified density is greater than or equal to a threshold value, and an output image is binarized based on the determination, and stored in an output image storage portion. An output density, which is a value of the output image for calculating the binary conversion error value, is set to a value corresponding to a print mode currently set. By subtracting the output density from the modified density, the binary conversion error value generated in the binarization process for the subject pixel is calculated. |