Robust Video Watermarking Using Normalized Zernike Moments

Digital video watermarking has become a hot research topic in recent years due to the increasing demand of protecting the intellectual property of video data. Even though many conventional video watermarking methods have been reported in past years, few of them are resistant to high-intensity geometric attacks, which motivates the authors in this paper to propose a video watermarking technique that is robust against high-intensity geometric distortion. To this purpose, the proposed method embeds the watermark information into the normalized Zernike moments of the target frames of the cover video sequence. The advantage is that the normalized Zernike moment preserves a strong invariance to geometric distortions such as rotation and scaling attacks. During data embedding, secret bits are embedded into adaptively selected moments with slight modifications to provide good robustness while maintaining the imperceptibility. The chrominance channel of the video data rather than the luminance one is used in our algorithm, as distortion in the former channel is less sensitive to the human visual system. Experimental results show that, compared with the existing scheme, the PSNR values of the proposed method gain about 7 dB averagely, meaning that the proposed method achieves high imperceptibility. Moreover, it is demonstrated that the proposed method is more robust against geometric distortions such as rotation and upscaling, which has verified the applicability and superiority of the proposed work.