| 摘要 |
<p>Method of visual encryption of at least a part of a video stream or of a video sequence at least partially compressed, said stream being able to be decomposed into a first type of objects and a second type of objects, the method being applied to each of the images contained in a video sequence, characterized in that it comprises at least the following steps: ⸠analyzing the sequence in the compressed domain so as to define for a given image N at least one first group of objects to be protected by visual encryption and a second group of objects (2, 3) the transformed coefficients and the motion estimation vectors being transmitted directly to the compression step d), ⸠predicting on the basis of the data emanating from the analysis in the previous step of the compressed image N, the position of the objects for a following image N+1, (4a) ⸠determining the partitioning into portions or into groups of portions of the image N+1, (4b) ⸠compressing (8b) the first group of objects of the image  N+1 and encrypting at least a part (8a) thereof, ⸠transmitting the other types of groups of objects for the image N+1 to a compression step (6).</p> |
