The positional offset of an image is corrected without performing any processing
for the setting of a reference position with respect to a document image, e.g.,
the setting of markings. Pieces of information about a reference image, including
a reference position, are stored in a predetermined storage unit. Information about
the input image is extracted from the input image, and a target position on the
input image is calculated on the basis of the extracted information. In addition,
a reference image with respect to the input image is specified on the basis of
the information about the input image from the predetermined storage unit. The
positional offset of the target position with respect to the reference position
of the specified reference image is calculated. The positional offset of the input
image with respect to the reference image is corrected on the basis of the calculated
positional offset amount.
