Method for detecting a true face by a detection device comprising at least one illumination means emitting an infrared flow polarised in a polarisation direction, a camera having a filter polarising orthogonally to the polarisation direction and a camera having a filter polarising parallel to the polarisation direction, a splitter blade placed between the face and the two cameras (108, 110) and intended to divide the light flow coming from the face into a light flow captured by the camera and a light flow captured by the camera, a processing unit and a database containing, for each face region, a truth model based on reference texture characteristic values, on reference coefficient values "b" and on correlations between these elements, said detection method comprising: - a capture step during which a parallel image of the face illuminated by the illumination means is captured by the camera, and an orthogonal image of the face illuminated by the illumination means is captured by the camera, - a difference step during which the processing unit computes a difference image resulting from the difference between the parallel image and the orthogonal image thus captured, - a filtering step during which the processing unit generates a so-called filtered image by filtering said difference image in wavelet packets on 5 levels, eliminating the "low" resolution levels, 1 and 5, - a division step during which the processing unit divides the image thus filtered into three filtered sub-images, the first corresponding to the forehead, the second corresponding to the nose and the third corresponding to the cheeks, - a processing step during which said processing unit subjects the filtered image and each of the filtered sub-images to a process consisting of: ∘ a Fourier transformation or a discreet cosine transformation in radial cumulative projection, by summing the energies belonging to the same frequency ring, for the purpose of defining a frequency decrease profile, and ∘ a modelling during which the frequency decrease profile is modelled in the form of a model of the power type (a.x^b+c), - an extraction step during which the processing unit extracts, from the filtered image and each of the filtered sub-images, texture characteristics relating to the specularities of the surface of the face, - an analysis step during which the processing unit analyses, for each region of the face, the coefficient "b" thus calculated and the texture characteristics thus extracted compared with the truth model corresponding to said region of the face, and - a decision-taking step during which the processing unit takes the decision concerning the veracity of the face from the result of the analysis step. - a capture step during which a parallel image of the face illuminated by the illumination means is captured by the camera, and an orthogonal image of the face illuminated by the illumination means is captured by the camera, - a difference step during which the processing unit computes a difference image resulting from the difference between the parallel image and the orthogonal image thus captured, - a filtering step during which the processing unit generates a so-called filtered image by filtering said difference image in wavelet packets on 5 levels, eliminating the "low" resolution levels, 1 and 5, - a division step during which the processing unit divides the image thus filtered into three filtered sub-images, the first corresponding to the forehead, the second corresponding to the nose and the third corresponding to the cheeks, - a processing step during which said processing unit subjects the filtered image and each of the filtered sub-images to a process consisting of: ∘ a Fourier transformation or a discreet cosine transformation in radial cumulative projection, by summing the energies belonging to the same frequency ring, for the purpose of defining a frequency decrease profile, and ∘ a modelling during which the frequency decrease profile is modelled in the form of a model of the power type (a.x^b+c), ∘ a Fourier transformation or a discreet cosine transformation in radial cumulative projection, by summing the energies belonging to the same frequency ring, for the purpose of defining a frequency decrease profile, and ∘ a modelling during which the frequency decrease profile is modelled in the form of a model of the power type (a.x^b+c), - an extraction step during which the processing unit extracts, from the filtered image and each of the filtered sub-images, texture characteristics relating to the specularities of the surface of the face, - an analysis step during which the processing unit analyses, for each region of the face, the coefficient "b" thus calculated and the texture characteristics thus extracted compared with the truth model corresponding to said region of the face, and - a decision-taking step during which the processing unit takes the decision concerning the veracity of the face from the result of the analysis step.