Abstract: A process and an apparatus for treatment of an analog electric signal, in particular the image signal of bar codes, for obtaining a parametrable binary signal, the process comprising storing certain non-linear filtering parameters (MP) and, after having converted the analog signal into a digital signal (CAN), detecting sequentially the successive extremums of said digital signal (PIC) by an iterative treatment while considering said parameters, and then carrying out in each sequence a sigmentation treatment (BIN) by the detection of each extremum, for extracting and storing (RAM) the length of the representative segments of the succession of extremums.