The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 2017
Filed:
Sep. 06, 2016
Safran Identity & Security, Issy-les-Moulineaux, FR;
Aldo Maalouf, Issy les Moulineaux, FR;
Florence Guillemot, Issy les Moulineaux, FR;
Remy Chiu, Issy les Moulineaux, FR;
SAFRAN IDENTITY & SECURITY, Issy les Moulineaux, FR;
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 deviation of the phases of the wavelet coefficients on the image.