| 摘要 |
An image processing method of creating synthetic image information in which sub-information is embedded in main image information, characterized by comprises: assigning specific information in accordance with a level of gradation of an attention area in the main image information to the attention area; performing color difference modulation processing of key information selected in accordance with a value of the sub-information based on a predetermined color difference amount; creating enlarged main image information obtained by enlarging the main image information constituted by pixels having multi-valued pixel values in a predetermined enlargement ratio; dividing the enlarged main image information into small blocks; setting the attention block to the divided small blocks; and making the attention block multi-valued by a block error diffusion method; and superposing the key information, for which the color difference modulation processing has been performed, on an area to which the specific information in the main image information is assigned, wherein assigning specific information to the attention area is to assign a specific image as the specific information corresponding to a level of gradation of the multi-valued attention block, and superposing is to superpose the key information, for which the color difference modulation processing has been performed, on the block to which the specific image is assigned in the main image information. |
