Abstract: The invention relates to a method for biometric processing of images of part of the human body comprising at least one finger, said method being performed by a sensor, and wherein an emissive screen (1) displays at least one first display pattern to light said part of the human body and an imager (2) acquires at least one first image of said part of the human body; from this first image, the automated data-processing system determines at least one second display pattern different to the first display pattern; the emissive screen (1) displays at least the second pattern to light said part of the human body and the imager (2) acquires at least one second image of said part of the human body; a biometric processing being performed on a final image constructed from at least the second image.

Abstract: A method for characterizing material in which a surface is formed, by analysis of speckles generated on the surface by a coherent light beam by performing the computation of an autocorrelation function of the light intensity on the image and computation of the value of at least one criterion set up from said function, setting up an autocorrelation matrix of the light intensity of the image, computation of the discrete cosine transform of said matrix, and computation of the value of a characterization criterion such as the average on the image of the matrix trace obtained by the discrete cosine transform of the autocorrelation matrix, and computation of the value of at least one representative criterion of a phase shift distribution of the light beams diffused by the surface, said computation comprising computation of a wavelet transform of the image, and computation of the value of at least one criterion from the following group: average of the phases of the wavelet coefficients on the image, or standard devi

Abstract: The invention relates to a method for biometric processing of images of part of the human body comprising at least one finger, said method being performed by a sensor, and wherein an emissive screen (1) displays at least one first display pattern to light said part of the human body and an imager (2) acquires at least one first image of said part of the human body; from this first image, the automated data-processing system determines at least one second display pattern different to the first display pattern; the emissive screen (1) displays at least the second pattern to light said part of the human body and the imager (2) acquires at least one second image of said part of the human body; a biometric processing being performed on a final image constructed from at least the second image.

Abstract: The invention proposes a method for characterizing material in which a surface is formed, comprising the steps of: projecting a coherent light beam onto the surface to generate on said surface speckles resulting from interferences of the light beams diffused by said surface, acquiring an image of said surface on which the speckles appear, processing said image to compute at least one characterization criterion of the material, and from criteria, determining the material constituting the surface, in which the processing step of the image comprises: computation of an autocorrelation function of the light intensity on the image and computation of the value of at least one criterion set up from said function, and computation of the value of at least one criterion representative of a phase shift distribution of the light beams diffused by the surface.