Patent ID: 7200242

Claim:
An image processing apparatus which multiplexes noise on a multilevel image data to embed visible additional information with a noise-multiplexed distribution, comprising: first noise multiplexing means for multiplexing noise at a first visible intensity; second noise multiplexing means for multiplexing noise at a second visible intensity different from the first visible intensity; input means for inputting, as the additional information for a predetermined pixel region unit, information representing which of the first and second visible intensities is used for multiplexing; determination means for determining on the basis of the additional information which of the first and second visible intensities is used for multiplexing in a pixel region of interest in multilevel image data; and control means for selecting either of said first and second noise multiplexing means for the pixel region of interest on the basis of a determination result of said determination means, and causing selected noise multiplexing means to multiplex noise.