An image processing system which 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 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 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 via a public switched network. A repair material compound ratio calculation database is searched and compound data for a material that matches the hue of the patient's teeth is retrieved, so that a crown repair or denture or the like that very closely matches the color of the patient's teeth can be produced.