【摘要】 在实际应用中 ,加有水印的数字图像不可避免会遭到一些有意或无意的攻击 .针对一些常用的攻击方法 ,提出了一种反攻击方法和相应的水印算法 ;算法自适应地选择水印嵌入位置和确定水印序列长度 ;水印嵌入在 DWT域进行 ;根据人眼视觉掩蔽特性确定水印嵌入强度 .实验结果表明该方法具有较好的图像自适应性和水印不可见性 ;对JPEG压缩、图像加噪声和图像滤波等常见的攻击方法具有极强的鲁棒性更多还原

【Abstract】 In real application situation, the watermarked images are unavoidably manipulated by malicious attackers (such as collusion attackers, removal attackers) or those who are unintentional to distort the watermark using various manipulation tools. A counterattack method and a counterattack based watermarking algorithm are presented in this paper. The watermarking algorithm can select the position where the watermark is embedded and determine the length of the watermark adaptively with different images. The watermark is embedded into the coefficients of discrete wavelet transform (DWT) of the original images and the watermark strength is determined with human visual masking. The experiments show that the algorithm has good adaptivety and that the quality of watermarked images is guaranteed. The algorithm is very robust against attacks such as JPEG compression, the image filtering and the noise addition.更多还原