[en] Defects detection in radiography can be done by a pixel by pixel comparison with a reference radiography made on a fault-less part. However, because of the parts complexness, an a priori knowledge is necessary which must be supplied by several reference radiographies and different image processing methods. This presentation emphasizes the adequation of the different existing methods with the characteristics of the problems under study and analyzes several methods developed and tested at the laboratory for precise industrial purposes. Abstract only. (J.S.)