A radiography system includes a radiography apparatus including two radiation detectors and a console that corrects a ratio of pixel values in a region, which corresponds to a soft tissue of a subject and is a corresponding region of radiographic images generated by the two radiation detectors irradiated with radiations having different energy levels, on the basis of correction data corresponding to a body thickness, and derives the bone density of the subject on the basis of a difference between a ratio of pixel values in a region corresponding to a bone tissue of the subject and the corrected ratio of the pixel values.
