1. A method for determining the change in position of an object in an item of luggage by means of two X-ray images, points being allocated to individual features in each X-ray image and the features being extracted such that a set of points results in each case; a search for clusters being carried out in each set of points; the proximity being determined in each X-ray image by means of a valuation function that displays different values when points are very close than when points are less close; an analysis of the movement of the object being carried out by observation of the proximities of the clusters.