Patent ID: 7171019

Claim:
An image processing apparatus which embeds predetermined information in an image, comprising: input means for inputting the image; division means for dividing the input image into plural image regions, the respective image regions having a same size; periodicity generation means for generating plural different periodicities, the plural different periodicities being generated in different directions; addition means for adding a positive predetermined value or a negative predetermined value to a pixel value of each pixel in the image region divided by said division means, on the basis of the periodicity; and selection means for selecting the periodicity for the addition from among the plural periodicities, in accordance with the predetermined information, as a result of the addition by said addition means, plural lines which are composed of plural pixels to which the positive predetermined value and the negative predetermined value are added and which are based on the respective directions of periods are formed within the respective image regions divided by said division means.