| 摘要 |
PROBLEM TO BE SOLVED: To improve image stability, to prevent an increase of image processing time and to suppress the increase of memory capacity.SOLUTION: An image forming apparatus includes a storage section for storing a first dither pattern group including a plurality of dither patterns formed by a line screen whose line width increases as a gradation value in a first range increases, a second dither pattern group including a plurality of dither patterns formed by a void dot screen in which dots increase and void parts surrounded by the dots decrease as a gradation value in a second range, which is higher than the gradation value in the first range, increases, a third dither pattern group including a plurality of dither patterns which are for shift from the line screen to the void dot screen and which are formed of patterns to which adjacent lines are connected by an increase of the line width, whose connection parts are formed to be narrower toward tips and which are gradually connected from the tips as the gradation value increases from a reference gradation value.SELECTED DRAWING: Figure 2 |
