摘要 |
The invention provides a method of burying additional information in an image, which can suppress deterioration of image quality and reduce an extraction error rate when extracting the additional information. For implementing the method, in an image processing apparatus for burying predetermined information in a color image, the apparatus comprises an input unit for inputting a color image; a quantizing unit for quantizing the input color image with an error diffusion process for each of predetermined color components; and a quantizing condition control unit for controlling, in accordance with the predetermined information, periodicity at which an amplitude of a quantizing threshold is modulated by the quantizing unit. The quantizing condition control unit controls a phase in the amplitude modulation of the quantizing threshold to be different between at least one of the color components and the other color components.
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