1. A method for calibrating an X-ray inspection system for a tire, which includes an X-ray tube, a linear X-ray detector, and a manipulator for the tire, wherein the manipulator is arranged such that the tire is arranged with its tread between the X-ray tube and the X-ray detector, the method comprising: moving one of the X-ray tube, the linear X-ray detector, and the manipulator along a travel path from a set starting position to a set end position; capturing, at a preset reading rate during the movement of one of the X-ray tube, the linear X-ray detector, and the manipulator, a continuous capture of X-ray radiography images of a cord within the tire; tracking the cord using successive X-ray radiography images; and deducing an absolute position of the cord using a total shift of the cord in the X-ray radiography images between the starting position and the end position and using known geometric data.