摘要 |
<p>A halftone image is formed from a contone image with one of a hardware dot generator and a software dot generator. Halftone dots in simpler shapes used in usual reproduction or printing are formed with the hardware dot generator; thus high-speed dot generation is accomplished. Halftone dots in special shapes or of special conditions are formed with the software dot generator; thus flexible dot generation is accomplished. A dot shape, a screen ruling, and a screen angle are input as halftone dot information. When the halftone dot information corresponds to a basic pattern stored in a screen pattern memory in the hardware dot generator, the hardware dot generator is activated to produce binary halftone-dot image data. When the halftone dot information corresponds to a basic pattern stored in a memory in the software dot generator, the software dot generator is activated to produce binary halftone-dot image data according to a dot generation program. <IMAGE></p> |