| 摘要 |
PROBLEM TO BE SOLVED: To prevent inversion of color component ratio before and after quantization in quantizing processing of a multi-level color image. SOLUTION: When quantizing the color image, depending on an input pixel value, threshold is varied so as to make average quantization error cancelled, using a varied threshold table 202. In the varied threshold table 202, the average value of the average quantization error for each color component, when all the values in the varied threshold table set to zeroes are registered as indices for the sum of each color component. The varied threshold table 202 outputs the registered value, depending on the sum of magenta and cyan to be input, to which a random noise is added properly. This resultant value is added to each color component of the pixel after error diffusion, and quantization is performed. COPYRIGHT: (C)2004,JPO
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