Patent ID: 8447034
Filing Date: 2013-05-21
Classification: H04L,H04N

Abstract:
1. A method for protecting at least part of an at least partially compressed video stream against a violation of the information contained in said video stream, images of said video stream capable of being decomposed into a first type of objects and a second type of objects, the method being applied on each of the images contained in the video stream, comprising at least the following steps: a) analyzing the video stream in a compressed domain to define, for a given image N, at least one or more groups of objects to be protected by ciphering, and designating a first group of objects and a second group of objects, the analysis in the compression domain generating transformed coefficients and motion estimation vectors; b) subsequent to step a), tracking, using a historical log of the position of the one or more groups of objects over a previous predetermined number of images based on the analysis data, the position of mobile objects of a foreground plane in a next image N+1 that has not yet been compressed, and splitting the next image N+1 into groups of slices, by: c) compressing the areas of the next image N+1 comprising the second group of slices corresponding with the foreground plane and then encrypting at least part of the second group of slices; d) compressing the first group of slices for the next image N+1; and e) adding, to the first group of objects and the second group of objects of the next image N+1, information identifying whether the groups of objects are encrypted or not encrypted, wherein the added information indicates which objects have been encrypted, and wherein at least one processor performs the functions of steps a), b), c), d), and e).