| 摘要 |
PROBLEM TO BE SOLVED: To prevent delays in dot forming, caused by accumulated quantization error at the time of quantization processing of a multi-level image. SOLUTION: The method includes: (1) obtaining a reference threshold (C-threshold) for use in error diffusion of a cyan (C) component, based on a concentration value M of the magenta (M) component; (2) referring a threshold modulation amount table as shown in the Fig., using a combination of the concentration value C of the C component and the concentration value M of the M component; (3) determining a corrected threshold modulation amount (C-threshold'), by adding the threshold modulation amount obtained in the step (2) to the reference threshold (C-threshold) used in the error diffusion of the C component; and (4) comparing the concentration value Ct of the C component after the error diffusion with the corrected threshold modulation amount (C-threshold'); and if the concentration value Ct is larger, the quantized value binDatC of the pixel of interest is set to 255, while if the concentration value Ct is smaller, the quantized value binDatC is set to 0. A similar procedure for cyan is also conducted. COPYRIGHT: (C)2004,JPO
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