Although a copying machine which has finally output a forged print can be specified by the forgery tracking function, a copying machine which has output an original used for copying or a scanner used to read the images of bills or securities cannot be specified. For this purpose, history information embedded in input image data is extracted. When the history information is extracted, information unique to the apparatus is added to the history information. When no history information is extracted, history information containing information unique to the apparatus is generated. The generated or updated history information is embedded in the image data.