To reduce the time required for surrounding darkening correction processing.

A limb darkening correction means (32d) modifies the position of a surrounding darkening component for each image, by using the positional offset modification amounts of position offset modification means (32a, 32b), with respect to n images captured for exposure times T1(1) to T1(n) which are obtained, by dividing a single exposure time T1 by n, composites the surrounding darkening components for the respective images subjected to position modification, generates a surrounding darkening component for correction, and uses the generated component to correct the surrounding darkening with respect to a composited image.