抗几何攻击的量化鲁棒视频水印技术研究

Research on Quantization-Based Robust Video Watermarking Technique Against Geometrical Attacks

能有效抵抗信号处理又能抵抗几何攻击是当今数字水印研究的热点和难点之一,提出一种能够抵抗信号处理、旋转、缩放和平移的鲁棒视频水印.嵌入方案中,提出几何不变量——基于圆区域内的统计特征不变性;再依据离散余弦变换域(DCT)系数特性,自适应地在DCT域量化嵌入有意义的水印.提取方案中,利用同步信息定位,若发生几何形变则先矫正形变,然后在DCT域中盲提取水印.结果表明,该方案具有较好的透明性,同时具有较强的抗几何形变能力,对MPEG压缩和去帧等攻击具有很强的鲁棒性.

The watermarking technique robust to both signal processing attacks and geometrical attacks is one of the hotspots and difficulties in the digital watermarking research. Proposed in this paper is a video watermarking scheme efficiently robust to many kinds of signal processing attacks and rotation, scaling and translation （RST） attacks. In the embedding scheme, a geometrical invariable is proposed, which is based on the invariability of statistical feature in the circular image area. Using this invariability, the geometrical distortion is first retrieved. And then a significant watermarking and synchronization information is adaptively embedded into the discrete cosine transform （DCT） domain according to the characteristics of DCT coefficients. Moreover, in the algorithm a novel embedding method is adopted, which can embed multi-bit information in a selected position. In the extraction scheme, the embedded watermarking is located by the synchronization information and the geometrical distortion is retrieved making use of circular feature area if geometrical attacks are encountered, and finally the watermarking is obliviously extracted in the DCT domain. The experimental results show the proposed scheme can achieve good transparency and better resistance against RST attacks and excellent robustness to common attacks such as MPEG compression, frame loss, etc.