1. An image processing system comprising: an image capturing unit; and an image processing unit, the image capturing unit comprising: an illuminating light source including a plurality of light-emitting devices which respectively emit illumination lights having a plurality of different characteristics of spectroscopic distributions; an image pick-up optical system which forms an image of a subject illuminated by the illuminating light source; an image pick-up device which picks up the subject image formed by the image pick-up optical system and obtains a subject signal; and a control unit which controls light emission by the plurality of light-emitting devices and image pick-up by the image pick-up device and which switches the image capturing unit between a spectroscopic image capturing mode in which it obtains a still image of a subject spectroscopic image and a moving image capturing mode in which it obtains a moving image thereof; wherein, in the spectroscopic image capturing mode, the control unit controls the plurality of light-emitting devices to sequentially emit light according to the different characteristics of spectroscopic distributions by a plurality of times interlocking the light emission with an exposure timing of the image pick-up device thereby causing the image pick-up device to obtain a plurality of subject spectroscopic images; and wherein, in the moving image capturing mode, the control unit is arranged to cause light emission of a light-emitting device for a single specific primary color or cause light emission of light-emitting devices for a plurality of specific primary colors selected from the plurality of light-emitting devices, or cause sequential light emission of a group of R devices, a group of G devices, and a group of B devices selected from the plurality of light-emitting devices, group by group, and to cause the image pick-up device to obtain a moving image; and the image processing unit comprising: an image identification calculating unit which calculates grade data to be used to determine a grade of a color of the subject based on one or more of the subject spectroscopic images captured by the image capturing unit when operating in the spectroscopic image capturing mode.