In setting, by using a format, a non-display region in image data obtained by an image reading unit, a format location information input unit writes in the image data, an image representing information on access to a format storage unit in an external apparatus where a format to be used has been stored. In displaying the image data, a format location information extraction unit extracts the format location information by extracting the image from the image data. A format obtaining unit obtains the format by accessing the format storage unit based on the information. An image modification unit uses the obtained format to modify the image data such that the designated region is displayed in an invisible manner.