1. An image processing apparatus, for correcting a blur due to an optical system of an image capturing apparatus, the image processing apparatus comprising: an obtaining unit configured to obtain a plurality of representative filters; a selection unit configured to select a subset of representative filters from the plurality of representative filters based on a pixel position of a pixel of interest in an image; and a correction unit configured to correct the pixel value of the pixel of interest based on (a) the selected representative filter and (b) the pixel position of the pixel of interest.