| 摘要 |
PURPOSE:To obtain a processing circuit where photographs and characters are synthesized very naturally, by switching a dither pattern between a photograph region and a line drawing region on an original including the photograph and the line drawing such as characters. CONSTITUTION:An input video signal 1 is quantized in an A/D converter 2 and is compared with a dither signal 6 in a comparator 4 and resulted in a video signal output. The dither signal 6 is fed from a ROM 18' where dither patterns are written, and the ROM 18' has two kinds of dither pattern in one original, and they are switched in every prescribed region by the control signal from a dither switching control line 19 and are outputted. That is, the dither pattern for the photograph region and the dither pattern for the line drawing region are switched and are applied to the comparator 4. |
