The invention provides an image process device capable of updating information embedded in a print file in unreadable manner. An image process device (100) processes an image with information embedded by watermark composed of superfine burelage, characterized in that the image process device comprises a watermark detection portion (120) for detecting a first information expressed by watermark; anencoding portion (130) for decoding and correcting the first information, and encoding againg to obtain a second information; and a watermark removing portion (140) for determining the position of the burelage according to the second information. The position of the bureage is determined according to the corrected second information, deformed burelage due to scan is determined and removed, and then information update is realized by embedding the watermark burelage with new information.