When a plurality of objects having RFID tags attached are to be read, an image sensing unit performs image sensing, and at the same time an RFID reader reads an RFID tag within the image sensing range. A characteristic quantity (external appearance model) of an object obtained from a database on the basis of ID data of the RFID tag is compared with a characteristic quantity obtained by image processing of the sensed image, thereby acquiring information unique to the object. The object is discriminably specified by superimposing the acquired unique information on the object in the sensed image.