1. A method, comprising: providing an x-ray generator for radiographic imaging; providing a beam shaping assembly; providing an x-ray grating interferometer comprising a phase grating G1, and an analyzer grating G2; offsetting a pitch of the analyzer grating G2 relative to a pitch of an interference pattern produced by the phase grating G1 at a prescribed distance from the phase grating G1 to generate a repeatable fringe pattern; repeatedly exposing an object using an x-ray source while moving the object relative to at least one cycle of the fringe pattern to generate a set of image data; and taking a plurality of reference images by an x-ray detector.