At least one kind of image input modality and at least one kind of image information output device are connected to an image processing system. At least one kind of image input modality, which is among connected image input modalities, includes a plurality of image information input apparatuses having different input device characteristics. The image processing system comprises a standardization device for carrying out transform processing on image information such that, in every case where the image information has been received from one image information input apparatus, which is among the plurality of the image information input apparatuses, the received image information may be transformed into standard image information, which does not depend upon the input device characteristics of the one image information input apparatus and depends upon standard device characteristics having been set previously for the image input modality including the one image information input apparatus.