1. A method for the processing of images produced by an X-ray device, the method comprising: computing, from a radiography projection of a body, a raw image of the body; computing, for each element of the raw image, a mean grey level characterizing the raw image wherein the step of computing for each element of the raw image further comprises: a) associating elements of the raw image in regions of elements as a function of the size of the opacity to be detected, b) determining a sliding window of a size and shape similar to those of the region of elements, c) determining for each region of elements, an immediate environment, d) applying the sliding window to each immediate environment of each region of elements, and e) computing at each position of the sliding window on each immediate environment, a mean value of grey levels, wherein f) the mean value of grey levels to be considered for each region of elements as the background intensity I b is the lowest mean value of grey levels among the set of mean values of grey levels computed in the corresponding immediate environment.