The invention significantly improves operability by automatically discriminating a plurality of image orientations, which are not assured of always being fed in common orientations, and reduces possible burdens to operators by eliminating efforts required to arrange the images in a common orientation before feeding or to correct each orientations into a common orientation after feeding. The invention improves the operability also by enabling modes in which orientation discrimination as well as tilt corrections can be performed before operator's instructions, if the Auto mode has been specified for the orientation recognition function. The invention also improves accuracy of processing by determining whether orientations or tilt recognition is proper and providing the result to the operators.