The image processing system is applied to dentistry, for example, and performs photography of the teeth of a patient while causing a plurality of illumination light LEDs of different wavelengths to emit light by means of a photography device(1A) when producing a crown repair or denture of the patient, whereby image data are acquired. The image data are transmitted to a dental filing system (2A) constituting a processing device where color reproduction data are determined through computation. In addition, color reproduction data are transmitted to the dental technician's office (55) via a public switched network. Therefore, a repair material compound ratio calculation database (56) is searched and the compound data for a material that matches the hue of the patient's teeth are found, whereby a crown repair or denture or the like that very closely matches the color of the patient's teeth is produced.