| 摘要 |
A method is provided for visually encrypting at least one part of an at least partially compressed video stream or video sequence, it being possible for said stream to be decomposed into a first type of objects and a second type of objects, the method being applied on each of the images contained in a video sequence, including 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, the transformed coefficients and the motion estimation vectors being transmitted directly to step d) of compression, predicting on the basis of the data arising from the analysis in the previous step of the compressed image N, the position of the objects for a following image N+1, determining the splitting into slices or into groups of slices of the image N+1, compressing the first group of objects of the image N+1 and ciphering at least one part thereof, transmitting the other types of groups of objects for the image N+1 to a compression step.
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