In a radiation image processing apparatus, method, and program, performing image processing based on scattered radiation, such as scattered radiation elimination processing, accurately by taking into account the influence of scattered radiation from an area adjacent to a processing target area. For this purpose, performing image processing on a radiation image captured by applying radiation to a subject based on scattered radiation generated by the subject. In this case, a processing target area which is the processing target in the radiation image is added with another area different from the processing target area in the radiation image. Then, the image processing based on scattered radiation is performed on the processing target area using the another area and the processing target area.