PURPOSE: To enable the correction processing of read errors on the side of a device which received drawing information in the case of outputting raster information as the drawing information to an external device and to correct the accompanying read errors in the lump even when coexisting raster information from the plural external devices with scanners being different is received.

CONSTITUTION: Correction information for correcting the proper read errors for the scanner 11 used for reading the drawing is added to the raster information and let it be input drawing information. Also, at the time of obtaining an input drawing from the input drawing information or the input drawing information from the external device 19, a processor 13 is provided for performing the correction processing by using the correction information in the input drawing information and thereafter preserving obtained vector information as a normal input drawing.