An image processing apparatus prints a mark-sensing sheet containing a plurality of entry fields. The image processing apparatus reads the mark-sensing sheet, determines a marked entry field entered by a user among the plurality of entry fields of the mark-sensing sheet, and stores information indicating the determined result. When the image processing apparatus rereads the mark-sensing sheet, the image processing apparatus compares the marked entry field entered by the user and information stored in a memory, thereby detecting the marked entry field that the user additionally enters for revision before rereading.