Research Of Video Watermarking Technique Based On H.264 Standard

In recent years, with popularity of digital video in social life, the issue of video works by malicious attacks and illegal use has become increasingly serious. How to protect the copyright of digital video effectively has become an urgent and realistic issue in the development of multimedia technique. Video watermarking technique to solve this problem is paid more and more attention by researchers and has emerged to a flourishing research topic in current academic domain.The basis for the existence of watermarking technique is the advanced nature of its technology, which uses redundant information to carry watermarking. And video compression aims to remove redundant, so a good watermarking scheme should take full account of the new video compression coding trends in close connection with the current and future standards for research. H.264, as the latest generation of video coding standard, has an urgent requirement of integration watermarking technique with it to enhance and improve the existing video watermarking algorithms to adapt to the new application environment.This paper proposes a robust video watermarking scheme aiming at H.264 low bit rate stream based on the analysis and research of video watermarking technique and H.264 standard. This scheme scans a binary watermark image into sequences firstly and processes them with spread-spectrum, and then embeds watermark sequences into certain median-frequency or high-frequency transform coefficients selected bit-by-bit by judgment under certain conditions in all 4×4 sub-blocks of each macroblock of I frames in H.264 intra prediction coding stage. The embedding process has certain adaptability, and introduces the coding control model based on the algorithm of Lagrangian optimization to enhance the rate-distortion performance of the watermarking video bitstream. Finally, experiments are performed to simulate the embedding and extraction scheme.Experimental results show that this algorithm obtains better rate-distortion performance of video bitstream, and has certain robustness against some common attacks such as requantization coding, filtering, adding noise, frame editing and so on. Watermark extraction does not need to decode compressed bitstream completely, which realizes the blind extraction; this algorithm which has a low complexity can meet the requirement of real-time random detecting, and has certain practicality.