the invention concerns a method which consists in processing in a central unit the digitized image obtained by sensing noisy radiation . the image is considered as a table of pixel intensity values , which is broken down into p elementary tables of n pixels so as to subsequently order them into a processing table with p lines of n columns ; applying to said table a factorial analysis method , to deduce therefrom the n significant factors ; then reconstituting a reconstructed processing table taking into account the most significant factors , and in deducing therefrom a reconstituted image wherein the high - frequency noise is reduced , maintaining a satisfactory contrast .