| 摘要 |
PURPOSE: To attain print-out with high resolution and less required quantity of ink and less quantity of required calculation in the halftone process by the error diffusion method or the dither method to convert a gray scale image having continuous tone into a halftone image suitable for binary printer. CONSTITUTION: Let the resolution of print be dpi, when the radius of a dot corresponding to one picture element formed by a printer 28 is 1/dpi<=r<=√2/dpi, the halftone process device adopting the error diffusion method or the dither method executes half tone processing selectively only to picture elements at an interval of one on each line while processing one by one line of image data (26). For example, only picture elements in odd-numbered columns are processed in an odd-numbered row and only picture elements in even-numbered columns are processed in an even-numbered row. The printer prints out only processed picture elements at an interval of one. |
