An image processing system for performing image processing on a plurality of images including overlapping image regions as overlapping regions, the image processing system comprising: a section divider configured to divide each of the plurality of images into a plurality of evaluation sections; an average calculator configured to calculate average values of pixel values of a plurality of pixels in each of the evaluation sections, wherein each of the pixel values includes the amounts of signals in colors of RGB when RGB color space is employed and wherein each of the pixel values includes values of brightness, hue and intensity of blue color, and hue and intensity of red color when YCbCr color space is employed; a section detector configured to detect a plurality of evaluation sections included in said overlapping regions, a calculator configured to calculate an evaluation value for evaluating each of the plurality of images using pixel values of one or more pixels in said overlapping regions by averaging the average values calculated for each of the plurality of images, each calculated by the average calculator, for the plurality of evaluation sections detected by the section detector; a determination controller configured to determine whether there is an image to be corrected in the plurality of images if the calculated evaluation value of the image is larger than a threshold; an image determiner configured to, when the determination controller determines that there is the image to be corrected, determine, out of the plurality of images, an image with a smallest evaluation value as a correction reference image as a reference for correction and to determine, as the image to be corrected, one or more images out of the plurality of images except for the correction reference image; and an image corrector configured to calculate, by using the calculated evaluation value of the correction reference image and the calculated evaluation value of the image to be corrected, amounts of correction to the plurality of evaluation sections included in the overlapping regions of the image to be corrected to quantify the degree to which the brightness and color of an image has to be reduced, to calculate, by using the amounts of correction to the plurality of evaluation sections, amounts of correction to evaluation sections other than the plurality of evaluation sections included in the overlapping regions, and to correct the image to be corrected by using the calculated amounts of correction. a section divider configured to divide each of the plurality of images into a plurality of evaluation sections; an average calculator configured to calculate average values of pixel values of a plurality of pixels in each of the evaluation sections, wherein each of the pixel values includes the amounts of signals in colors of RGB when RGB color space is employed and wherein each of the pixel values includes values of brightness, hue and intensity of blue color, and hue and intensity of red color when YCbCr color space is employed; a section detector configured to detect a plurality of evaluation sections included in said overlapping regions, a calculator configured to calculate an evaluation value for evaluating each of the plurality of images using pixel values of one or more pixels in said overlapping regions by averaging the average values calculated for each of the plurality of images, each calculated by the average calculator, for the plurality of evaluation sections detected by the section detector; a determination controller configured to determine whether there is an image to be corrected in the plurality of images if the calculated evaluation value of the image is larger than a threshold; an image determiner configured to, when the determination controller determines that there is the image to be corrected, determine, out of the plurality of images, an image with a smallest evaluation value as a correction reference image as a reference for correction and to determine, as the image to be corrected, one or more images out of the plurality of images except for the correction reference image; and an image corrector configured to calculate, by using the calculated evaluation value of the correction reference image and the calculated evaluation value of the image to be corrected, amounts of correction to the plurality of evaluation sections included in the overlapping regions of the image to be corrected to quantify the degree to which the brightness and color of an image has to be reduced, to calculate, by using the amounts of correction to the plurality of evaluation sections, amounts of correction to evaluation sections other than the plurality of evaluation sections included in the overlapping regions, and to correct the image to be corrected by using the calculated amounts of correction.