1. An image processing apparatus comprising: a detection unit adapted to detect a positional shift of a main object in each of the images; a coordinate converting unit adapted to convert coordinates of each of the images using a detection result of said detection unit; and a correcting unit adapted to correct image exposure by combining the images after coordinate conversion, wherein in combination of the images, images that have fewer positional shifts are selected among images that have been sensed in a number larger than the number of images with correct the exposure and the selected images is combined.