In a method for the processing of radiological images for the detection of opacities in a radiography image, an algorithm is proposed for detecting opacities according to their contrasts. To determine a contrast that is not over-estimated in each element, an algorithm is proposed for computing the background intensity by means of a sliding-window filtering. This type of sliding-window filtering computes the set of mean values of grey levels about an immediate environment of a region of elements whose size depends on the size of the opacity to be detected. The algorithm considers a background intensity of the region of elements to be the lowest mean value grey levels among the set of mean values of grey levels.