1. An image processing method of embedding orientation detection information for detecting an image orientation in an image, the image processing method comprising: embedding, using a processor, the orientation detection information in at least two positions that are symmetric with respect to a center of the image so that, when the orientation detection information embedded in a first position moves to a second position in which the orientation detection information is embedded as a result of a rotation of the image around a center of the image, a pattern of the orientation detection information embedded in the first position becomes an inverted pattern of a pattern of the orientation detection information embedded in the second position.