IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD FOR DETECTING DISPLACEMENT AMOUNT BETWEEN IMAGES HAVING DIFFERENT IN-FOCUS POSITIONS

An image processing apparatus comprises an image capturing unit which captures a plurality of images having different in-focus positions; a defocus amount calculating unit which calculates a defocus amount of an image captured by the image capturing unit; a filtering unit which performs filtering on an original image according to the defocus amount calculated by the defocus amount calculating unit; and a displacement amount detecting unit which detects a displacement amount between the images having different in-focus positions using the image on which filtering was performed by the filtering unit.