| 摘要 |
A method and system is provided of protecting at least one part of a video stream or of a compressed video sequence against a violation of the information contained in said stream, said stream being able to be broken down into at least one first type of objects and one second type of objects, the method being applied to a selection of images contained in said video sequence, characterized in that it comprises at least the following steps: analyzing the video sequence in the compressed domain so as to define for a given image N at least one first type of objects to be protected by encryption and one second type of objects, the analysis module which identifies the portions of the image belonging to the first type of objects to be protected sends the motion estimation vectors and the transformed coefficients to the encryption step; determining, according to the breakdown into portions or into groups of portions of the existing image N, those corresponding respectively to the first type of objects to be protected and to the other types; encrypting at least a part of the first type of objects; reconstructing, on the basis of the outputs of the preceding steps, a stream consisting of at least one first type of encrypted objects and other types of objects, to which is added information indicating which objects are the ones that have been encrypted. |
