Patent ID: 6785332
Filing Date: 2004-08-31
Classification: H04N

Abstract:
Method for marking a compressed digital video signal including a bitstream part encoding a P-type or B-type frame by incorporating a digital signature embedded in the compressed video signal, without computing motion estimation and without computing motion compensation, the said signal representing a series of at least two video images, each of the images being divided into a plurality of regions, the said signal comprising motion vectors representing the movement of the regions between the first and second image, the method comprising the steps of:Selection Selecting from the signal of the bitstream part encoding a P-type or B-type frame; Entropy decoding of the bitstream; Extracting the motion vectors; Selecting a set of the motion vectors according to visual criterion; Selecting a subset of said selected set of motion vectors according to a key; Modifying at least one of the coefficient X or Y on at least one of the motion vectors of said selected set of motion vectors; Inserting the modified motion vectors in the bitstream; Entropy encoding of the bitstream; and Inserting the bitstream in the video signal.