This invention provides an image free from camera shake by using a plurality of images captured by a camera array image capturing apparatus. A determination unit determines whether to execute a camera shake correction processing. A memory unit temporarily stores only a group of images determined by a determination unit to be camera shake corrected. A camera shake correcting unit synthesizes images to correct blurs in the images. A matching point searching unit determines matching pixels by checking pixel value similarity between images. A moving amount calculating unit, based on the result acquired by the matching point searching unit, calculates a moving amount of each pixel between images. A position correcting unit, based on the moving amount of each pixel calculated by the moving amount calculating unit, corrects the positions of the images. An image synthesizing unit synthesizes a group of images that are position-corrected by the position correcting unit.