一种基于图像特征点的数字水印嵌入方法

A Feature-Based Digital Image Watermarking Algorithm

如何有效抵抗去同步攻击是数字图像水印研究领域的热点问题之一.本文提出了一种可有效抵抗去同步攻击的图像水印新算法.该算法首先利用Harris-Laplace算子从载体图像中提取尺度空间特征点;再结合特征尺度自适应确定局部特征区域;最后,采纳DFT中频幅值量化策略将水印重复嵌入到多个不相交的局部特征区域中.检测时,利用特征点实现水印的重同步,无须求助于原始图像.仿真结果表明,本文算法不仅具有较好的透明性,而且对常规信号处理和去同步攻击均具有较好的鲁棒性.

Watermark synchronization is very crucial to design robust image watermarking scheme.In this paper, a new robust image watermarking scheme against desynchronization attacks is proposed. Firstly,the Harris-Laplace detector is utilized to extract feature points, which can survive a variety of attacks. Then,the local characteristic regions are adaptively constructed according to the characteristic scale theory.Finally, several copies of the digital watermark are embedded into the nonovedappped local characteristic regions by quantizing the DFT mid-frequency magnitudes. By binding the watermark and image features, the resynchronization between the embedding and detection can be accomplished. Experimental results show that the proposed scheme is not only invisible but also robust against common signals processing and desynchronizafion attacks.