An object of the present invention is to solve dissatisfaction of the user who cannot take out the source data in a case where a code image in the original can not be decoded. In order to accomplish the above object, the invention provides an image processing apparatus comprising code image detection unit that determines whether or not an code image is included in the original image data, code image decoding unit that decodes the code image to extract source data if it is determined that the code image is included by the code image detection unit, and synthesizing unit that encodes information obtained by decoding a partial area of the code image and overlaying encoded information on the area where the code image is included, if the code image decoding unit is successful in decoding only the partial area of the code image.