PROBLEM TO BE SOLVED: To detect degradation of image quality due to a change in relative positions of a radiographic apparatus and a subject from image data without using any special device such as a marker.SOLUTION: The control unit 51 of the controller 5 in a radiographic system performs regression analysis on signal values (image data) of at least two of a differential phase image, a differential absorption image, and a differential small-angle scattering image to calculate an index value indicative of a relationship between the images, and then detects degradation of image quality due to a change in relative positions of the radiographic apparatus 1 and a subject, based on the calculated index value.SELECTED DRAWING: Figure 15COPYRIGHT: (C)2017,JPO&INPIT
