A Robust Video Watermarking Algorithm Resistant to Geometry Transformation Attacks Based on Background

How to resist geometry transformation attacks effectively has become a focus of digital watermarking. In this paper a video blind watermarking algorithm resistant to geometry transformation attacks is proposed. In the scheme of watermark embedding, video shot segmentation is used first. Then, background of a video segment in the video shot is extracted by independent component analysis(ICA). Finally, the background image is decomposed by nonsubsampled Contourlet transform(NSCT) and meaningful watermark is embedded into the lowpass subband. In the scheme of watermark extraction, video segment embedded with watermark in the video shot is analyzed by ICA and the background image with watermark information is extracted first. Then, video segment embedded with watermark and other frames in the video shot are analyzed by ICA, and the background image without watermark information is extracted. Finally, the two background images are decomposed by NSCT, and the watermark is extracted though detecting the distinction of the lowpass subbands of the two background images. Experimental results show that, this algorithm can make the watermark resist geometry transformation attacks effectively and keep the visual quality of the video. In addition, it also has enough robustness to resist other attacks.