Image processing apparatus

An image processing apparatus comprising:

• an image reading unit that reads a document to obtain electronic image data;
• an image writing unit that prints the image data on a recording medium;
• a storing unit that stores therein the image data and supplemental information of the image data;
• an external interface unit that exchanges the image data and the supplemental information with an external device;
• a first image-data processing unit that processes first image data input from the image reading unit;
• and
• a second image-data processing unit that processes second image data stored in the storing unit, wherein
• the first image-data processing unit unifies characteristics of the first image data in such a manner that the first image data is usable in both the image writing unit and the external device, stores characteristic-unified image data in the storing unit, and changes an attribute of the supplemental information to be stored together with the image data according to an image input condition in the image reading unit, and
• when converting target image data to be processed into image data with characteristics suitable for outputting to the image writing unit and the external interface unit, the second image-data processing unit makes the first image data stored in the storing unit be reusable in both the image writing unit and the external device by performing an image processing on the target image data based on the supplemental information stored in the storing unit.