Research Of Robust Video Watermarking Technology

Video Watermarking will be widely used in lots of application areas, such as Video On Demand(VOD), Digital Versatile Disk(DVD) copyright protection, Satellite Digital Video transmission and so on.But the technology of video watermarking hasn't been developed enough.There are still lots of problems to be solved which brings chances and challenges for study.As to many video watermarking algorithms, it's hard to extract watermark once lose the synchronized relations between frames of video. As a series of stationaries pictures set, video sequence may be faced with some specific attacks (such as Frame average, Frame removement, Frame inserting, Frame reconstruct and so on). Besides, to present an rubost realtime watermark algorithm with the ability to resist geometric attacks is the most important problem to be solved. If embeded in the compression video bit streams, the watermark should be compounded with the compression standard. However, the advanced video compression standard emerges one after another incessantly, and lots of new technologies were brought into the standard. An alogrithm based on these new standards needs to be proposed. Finally, large capacity video watermarking is also needed in lots of applications.Based on the invariant regions in the image, a localized image watermarking algorithm against geometrical attacks is proposed. Salient regions detected by Saliency detector are used to synchronize the watermark. How to use the salient regions to construct the invariant regions to attain the translation, scaling and rotation invariance and how to select the embedding regions out of the invariant regions are key problems to be resolved in our paper. The watermark is first geometrically transformed to match the shape of each embedding region and then imperceptibly embedded into corresponding embedding regions. The watermark detection process is blindly done based on the normalized correlation.Another geometrically robust watermarking scheme was proposed based on image local content, which could resist both image cropping and RST attacks and can be used in video because of the low computation quantity. It first extracts the robust feature points, and then partitions the image into multi circular area. Each area is transformed into PM sub-images, then 2-D DFT is performed and the magnitudes are used as the watermark-embedding domain. Finally the watermark is embedded by modifying the DFT magnitudes using energy modulation. Comparing with Fourier-Mellin transform-based watermarking, its computational cost is reduced as only one 2-D DFT is performed. Moreover, the method can overcome the interpolation problem by using PM in the spatial domain because images have a similar scale between neighboring pixels.Based on the Chinese video compression standard AVS, a new watermark algorithm named AVS-BW is proposed. By embedding an additional watermark bit between two regions and using three differential embedding cut-off indexes, the watermark capacity and robustness are successfully improved. And a new method is also proposed in this paper to remove the high frequency components in AVS video sequence.A real-time watermarking scheme with high robustness and security has been proposed based on modulating the log-scaling magnitudes of DCT coefficients, which is most suitable for JPEG images and MPEG streams. The watermark bit is encoded as the sign of the difference between the individual log-scaling magnitude of a group-region and the average one of all group-regions. The log-scaling magnitude can be modulated by modifying the low and middle frequency DCT coefficients imperceptibly. The robustness of scheme is not only dependent on those largest coefficients, but also on the other coefficients with the same proportion. It can embed 512 bits into an image with a size of 512×512, which can satisfy the payload requirement of most video watermarking applications. Moreover, the watermark embedding process only requires one-sixth of the time consumed during normal playing of video, and the watermark detection only requires one-twelfth of that, which can meet the real-time requirements of most video watermarking applications.