1. A method of providing a three-dimensional radiographic image of an object, comprising: (a) acquiring a first series of projected two-dimensional mask images of the object obtained for different positions around the object; (b) acquiring a second series of opacified projected two-dimensional images of the object obtained at the same positions around the object; (c) an elaborating a third series of subtracted projected two-dimensional images respectively obtained from the first and second series of images; (d) reconstruction of a three-dimensional image subtracted from the third series of images and from an analytical algorithm of image reconstruction; (e) reconstruction of a three-dimensional mask image from a first series of images and from an analytical algorithm of image reconstruction; (f) identification of defects in the three-dimensional mask image; and (g) elimination of corresponding voxels in the three-dimensional image subtracted.