| 摘要 |
PROBLEM TO BE SOLVED: To generate a dot pattern, corresponding to number of a plurality of screen lines on request by providing only one dot pattern. SOLUTION: A 6×6 dot pattern is reduced to a half. For example, a coordinate on the 6×6 dot pattern, corresponding to a center point of a picture element of 0-row 0-column of a 3×3 dot pattern, is expressed as x=0.5 and y=0.5. Center points of four picture elements are in existence around the coordinate (x=0.5 and y=0.5) of the 6×6 dot pattern coordinate. A threshold level is given to each center point of the pixels. A threshold level of the 0-th row, 0-th column of the 3×3 dot pattern is calculated, based on each threshold level for each center point of the four pixels and a distance from the coordinate (x=0.5 and y=0.5) to the four pixel points. |
