1. An image processing apparatus comprising: an acquirer configured to acquire a blurred image; and a generator configured to acquire a blur estimation area of at least a part of the blurred image to generate an estimated blur based on the blur estimation area, wherein the generator is configured to: generate the estimated blur by performing iterative calculation processing that repeats correction processing and estimation processing, the correction processing correcting a blur included in information relating to a signal in the blur estimation area to generate information relating to a correction signal, and the estimation processing estimating a blur based on the information relating to the signal and the information relating to the correction signal, and generate, as the information relating to the correction signal, information relating to a plurality of correction signals by using a plurality of calculation expressions different from each other in at least one correction processing during the iterative calculation processing.