1. An image processing system, comprising: an image acquisition unit for acquiring a scanned image; a non-volatile storage medium that stores correction information prior to the acquiring of the scanned image, said correction information corresponding to a known object having a planar shape specified by a standard; and when an object of the scanned image is the known object, a correction unit that corrects distortion of an aspect ratio of the scanned image on the basis of the correction information and that resizes the scanned image with different factors in longitudinal and cross directions.