A frequency decomposition unit performs frequency decomposition for a first radiographic image to acquire a plurality of band images. A scattered radiation removal unit calculates a scattered radiation component that is caused by a subject and is included in a second radiographic image which has a linear relationship with the amount of radiation, using the second radiographic image, and removes the scattered radiation component from the second radiographic image to acquire a scattered-radiation-removed radiographic image. A conversion function determination unit determines a conversion function for converting at least one of the band images according to the scattered radiation component included in the second radiographic image. A reconstruction unit converts the band image, using the conversion function, and generates a converted band image. The reconstruction unit reconstructs the scattered-radiation-removed radiographic image and the converted band image to acquire a processed radiographic image.