| 摘要 |
PURPOSE:To perform high speed processing by a simple control system and to achieve faithful reproduction with sufficient resolving power and the sufficient number of gradations, by distributing the output dots in two square matrices in the so called dot concn. type. CONSTITUTION:When a rectangular matrix is divided into two square matrices K1, K2 each composed of a four-line/four-row array, the setting of a threshold value is performed so that a threshold value level becomes high toward the peripheral part of each of the square matrices K1, K2 and mutual threshold values are alternately set largely. When certain density X is reproduced, an output dot is distributed to a pixel having a threshold value S<X smaller than the value X and, for example, when an image having density of 8 is reproduced, output dots are distributed to pixels S=0-7 having the threshold values of up to 7. Threshold values are set like a Fattening type being a dot concn. type but, since they are related to each other to alternately distribute output dots, this type is one mode of a dot dispersion types wherein output dots are dispersed if attention is paid to the whole of the rectangular matrix. |
