PROBLEM TO BE SOLVED: To generate a sensitivity correction image with no defect, even when photographing is performed by detecting radiation exposure on the basis of a current change inside a radiographic apparatus.SOLUTION: An image processor includes an acquisition part that acquires a plurality of radiation images including a defect photographed without arrangement of a subject and information on the defect included in the radiation image, and a generation part that generates a sensitivity correction image with no defect on the basis of the plurality of radiation images and the information on the defect.
