The present invention comprises: creating imaged document data, whose entire page is made up of one image object, based on document data including text objects within a page; determining whether each of the text objects is a text object that is displayed in a state where a user can visually recognize it; and embedding, based on results of the determination, data of a character string corresponding to the text object, that is displayed in a state where a user can visually recognize it, in the imaged document data.