| 摘要 |
PURPOSE:To improve picture quality by eliminating a washboard generated at the time of thinning or adding one line of a dither image comprehensively, by designating a position to be thinned or added in a unit of image element in a main scan direction and also at random. CONSTITUTION:The position where image data is thinned out or added is designated in the unit of image element by a designation means 19 at random, and an image element position for which a thinning or adding processing is completed is stored in a second memory means 17 during one period of the thinning or adding processing. With respect to the image element designated by the designation means 19 and the image element stored in the second memory means 17, the data of the image element before one line or behind one line is selected and outputted instead of the data of present output image element. In such a way, it is possible to reproduce a satisfactory dither image without generating deterioration even when the thinning or addition of a line is performed. |
