An image processing apparatus comprising: a data selection unit for selecting an electronic document based on a user instruction; object data processing means configured to extract, from a plurality of object data included in the selected electronic document, object data that is associated with tag information which satisfies a condition specified by the user; pattern generation means configured to generate an encoded image pattern which includes both of object ID information for identifying the object data extracted by the object data processing means and electronic document specifying information for specifying the selected electronic document; print data generation means configured to generate print data which includes both of the object data extracted by the object data processing means and the encoded image pattern generated by the pattern generation means; printing means configured to execute print processing of the print data generated by the print data generation means; input means configured to input an image obtained by scanning a printed product printed by the print processing performed by the printing means; decoding means configured to detect the encoded image pattern from the image input by the input means, and to decode the object ID information and the electronic document specifying information from the detected encoded image pattern; characterized by comprising: difference extraction means configured to extract a difference by comparing object data included in the image input by the input means and object data extracted from the electronic document based on the decoded object ID information and the decoded electronic document specifying information; tag information addition means configured to, based on the difference extracted by the difference extraction means, add tag information for extraction by the object data processing means to the new object data; and storage control means configured to store the new object data to which the tag information is added by the tag information addition means in the electronic document specified by the electronic document specifying information. a data selection unit for selecting an electronic document based on a user instruction; object data processing means configured to extract, from a plurality of object data included in the selected electronic document, object data that is associated with tag information which satisfies a condition specified by the user; pattern generation means configured to generate an encoded image pattern which includes both of object ID information for identifying the object data extracted by the object data processing means and electronic document specifying information for specifying the selected electronic document; print data generation means configured to generate print data which includes both of the object data extracted by the object data processing means and the encoded image pattern generated by the pattern generation means; printing means configured to execute print processing of the print data generated by the print data generation means; input means configured to input an image obtained by scanning a printed product printed by the print processing performed by the printing means; decoding means configured to detect the encoded image pattern from the image input by the input means, and to decode the object ID information and the electronic document specifying information from the detected encoded image pattern; characterized by comprising: difference extraction means configured to extract a difference by comparing object data included in the image input by the input means and object data extracted from the electronic document based on the decoded object ID information and the decoded electronic document specifying information; tag information addition means configured to, based on the difference extracted by the difference extraction means, add tag information for extraction by the object data processing means to the new object data; and storage control means configured to store the new object data to which the tag information is added by the tag information addition means in the electronic document specified by the electronic document specifying information. difference extraction means configured to extract a difference by comparing object data included in the image input by the input means and object data extracted from the electronic document based on the decoded object ID information and the decoded electronic document specifying information; tag information addition means configured to, based on the difference extracted by the difference extraction means, add tag information for extraction by the object data processing means to the new object data; and storage control means configured to store the new object data to which the tag information is added by the tag information addition means in the electronic document specified by the electronic document specifying information.