An image processing system comprises: a reading unit configured to optically read a printed material, on which drawing information of an original image is multiplexed, to acquire read image data; an extraction unit configured to extract the drawing information from the read image data acquired by the reading unit; an acquisition unit configured to acquire original image data representing the original image based on the drawing information extracted by the extraction unit; a correction unit configured to compare the read image data with the original image data, and correct the original image data based on a result of the comparison; and a saving unit configured to save, as a result of reading the printed material, the corrected original image data corrected by the correction unit.