| 摘要 |
In case of an erasure of dots that reduce the ink density by thinning on dots of a bit map data, disappearance of thin lines, and a loss of low density picture and a gradation reversal are prevented. For this reason, mask patterns for thinning processing with different thinning rates according to densities of an original picture beforehand. A conjunction operation of the picture data of the original picture with the mask pattern according to the density of the picture data is carried out, and the on dots of the bit map data are thinned out to turn off thereby decreasing the ink density, and changing the thinning rate of the original picture. As the mask pattern, the thinning pattern is prepared against the original picture with 100% density, and the thinning rate is changed by changing the bit of 0 of the thinning pattern to 1 according to the density of the original picture. In case the density of the original picture is less than 50%, the thinning processing is not carried out.
|
