A device that uses a grating to carry out high sensitivity radiographic image shooting using the wave nature of x-rays or the like can shoot a sample that moves relative to a device. A pixel value computation section determines, using a plurality of intensity distribution images of a sample that moves in a direction that traverses the path of radiation, whether or not a point (p, q) on the sample belongs in a region (Ak) on each intensity distribution image. Further, the pixel value computation section obtains a sum pixel value (Jk) for each region (Ak) by summing pixel values on the each intensity distribution image for point (p, q) that belongs to each region (Ak). An image computation section creates a required radiographic image using the sum pixel values (Jk) of the region (Ak).