To enable storage of image data while preventing a shadow of a scale from being read by setting a non-effective image area of an area at a predetermined distance from an outer frame of an original and storing only image data in an inside area of the non-effective image area and to increase the number of stored image data by reducing amount of data to be encoded.

A page memory control part 125 stores the image data within a range of image area discrimination setting for one page which is preliminarily set when the image data from an image correcting device 105 is stored in page memory 121. The number of main scanning pixels and lines as the range of image area discrimination setting is set in a counter of the page memory control part 125. This setting is capable of being changed by an instruction from an operation panel 80 and contents of the change is supplied to the page memory control part 125 with a main CPU 91 and an interface 97. When the image data stored in the page memory 121 is filed further, the image data is stored in memory 122 after it is encoded by an encoding/decoding part 123.