An X-ray image processing apparatus includes a calculating unit adapted to calculate the noise amount of a sensor on the basis of a difference value of a plurality of dark images acquired at different timings by the sensor when no X-rays are irradiated, a changing unit adapted to change a predetermined parameter for processing an X-ray image acquired by the sensor when X-rays are irradiated, in order to prevent the noise amount from being superposed on the X-ray image, and an image processing unit adapted to perform image processing on the X-ray image on the basis of the changed parameter.
