Patent ID: 7079620

Claim:
A method of determining a magnification factor in a radiography apparatus comprising means for providing an X-ray source and means for acquiring images, the means for providing an X-ray source and the means for acquiring images being mounted so as to rotate about at least one axis with respect to a support on which an object to be X-rayed is intended to be positioned, comprising: acquiring at least two images corresponding to two different angular positions separated by an angle greater than 15° of the means for providing an X-ray source and of the means for acquiring images with respect to the support; identifying on these images projections of at least one point of the X-rayed object; the identification of the projections implements automatic tracking of at least one point of the object from one image to another, on the plurality of images acquired; and determining the magnification factor of at least one of the images, first, as a function of the angular displacement of the means for providing an X-ray source and of the means for acquiring images between the acquisitions of the images in question and, secondly, as a function of the positions on these images of the identified projections.