1. A radiographic image generation method comprising: dividing a first radiation exposure dose of a first energy to be emitted to an object into a plurality of first radiation dose portions and dividing a second radiation exposure dose of a second energy into a plurality of second radiation dose portions; emitting the plurality of first radiation dose portions and the plurality of second radiation dose portions to the object a number of times corresponding to a number of the plurality of first radiation dose portions and a number of the plurality of second radiation dose portions with varying an irradiation time of each radiation dose portion; acquiring a plurality of radiographic images corresponding to the plurality of first radiation dose portions and the plurality of second radiation dose portions by detecting the plurality of first radiation dose portions and the plurality of second radiation dose portions that have been passed through the object; and aligning the acquired plurality of radiographic images by correcting a position of at least one of the acquired plurality of radiographic images such that an image region of an article displayed by each of the plurality of radiographic images is positioned at a same relative position in each of the plurality of radiographic images as a result of the correcting.