| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image without sense of incongruity in a part where image characteristics change by controlling a signal obtained from the image characteristics so as to change the signal in multi-steps and smoothly and also widening the area of the part where the image characteristics change. SOLUTION: The changeover of the image characteristics is detected on the basis of separation information (character/halftone dot and photograph) (11), and a dither matrix switch signal is given to a dither threshold switching part 12. The switching part 12 switches dither thresholds in accordance with the image characteristics, and a quantizing part 13 quantizes input data by using a selected threshold. |
