1. An image processing system comprising: an image capturing unit; and an image processing unit, the image capturing unit comprising: an image pick-up optical system which picks-up an image of a subject; an image pick-up device unit which obtains a subject signal from the subject; a plurality of illuminating light sources with different characteristics of spectroscopic distributions; and a photographing operating unit which performs an image photographing operation, the image capturing unit interlocking the plurality of illuminating light sources with an exposure timing of the image pick-up device unit, selectively lighting-on the plurality of illuminating light sources, and thus obtaining a plurality of subject spectroscopic images, and the image processing unit comprising: an image memory unit which stores the subject spectroscopic images photographed by the image pick-up unit; and the image processing unit calculates a desired image based on the image signal stored in the image memory unit.