In a digital multifunction peripheral having a function of preventing unauthorized duplication, a situation is prevented in which a document to which encoded images having contradictory contents are added is created. An apparatus having a control unit configured to perform detection processing of an encoded image for a document image and add a different encoded image to a document image form which an encoded image is detected by the detection processing and output the document image, characterized in that the control unit does not perform output of a document image to which the different encoded image is added upon receipt of an instruction not to perform the detection processing from a user.