| 摘要 |
<p>PURPOSE:To attain high quality halftone print and halftone display or the like by expressing the density of picture elements of nearly square shape in terms of area ratio of a flat dark color portion and non-dark color portion provided in the picture element and selecting the picture element corresponding to the density discriminated from plural patterns with same expressed density. CONSTITUTION:A black color portion 9 being a dark color portion is selected to have a width being 1/4 of a picture element 10 of nearly square form and 0-4 portions are provided in one picture element 10 to attain 5 stages of gradation expression for density level of L=0-4. Then in the picture element 10 width No.2-No.15 whose density level corresponds to L=1-3 being the intermediate density, the arrangement of the black portion 9 in the picture element 10 is changed to set patterns of 4-6 kinds. Thus, even when the density level of the picture to be expressed is uniform, the picture element with different pattern is displayed or printed out.</p> |
