1. A system for compositing various images using a clustering technique, the system comprising: an image inputting unit receiving two or more input images; an image compositing unit compositing the two or more input images into one composite image; a brightness information analyzing unit calculating a brightness distribution degree of each input image in the composite image and a representative brightness values of one or more increase/decrease curves (modal) in the brightness distribution degree; a representative brightness value clustering unit determining clustering of each input image or not and a clustering type of each input image through the representative brightness value and grouping the respective increase/decrease curves; a brightness correction value calculating unit calculating a correction target value of each group through the representative brightness values of the grouped increase/decrease curves and subtracting the representative brightness value of each increase/decrease curve of a corresponding group from the correction target value of each group to calculate a correction value of each increase/decrease curve; and a brightness correction value controlling unit correcting brightness by adding the correction value corresponding to the pixel value of each input image.