抗亮度调整攻击的小波域图像数字水印方法

Image Watermarking Method for Resisting Lightness-adjusting Attack in DWT Domain

现有的许多小波变换域图像数字水印方法无法抵抗亮度调整攻击,为此,本文提出了一个抗亮度调整攻击的小波变换域图像数字水印新方法。该方法在原始图像小波变换域的低频系数中嵌入水印,而在含水印图像小波变换域低频系数抗亮度调整修正后的值中提取水印。该方法简单、快速、有效,在提取水印时无需原始图像。实验结果表明:该方法具有很好的水印透明性,对亮度调整攻击非常稳健,并且对常见的其他图像处理攻击(如重采样、颜色抖动、平滑、加噪声和有损压缩等)具有很强的稳健性。

Lots of existing image watermarking methods in Discrete Wavelet Transform （DWT） domain cannot resist lightness-adjusting attack. Therefore, a novel image watermarking method for resisting lightness-adjusting attack in DWT domain is proposed in this paper. In the method, watermark bits are embedded into DWT low frequency coefficients of original image and are extracted from the revised DWT low frequency coefficients that resist lightness adjustment of watermarked image. The method is simple and is executed rapidly and effectively. Moreover, original image is not needed when extracting watermark. Experimental results show that the method has a fine transparence of embedded watermark and is very robust to brightness-adjusting attack. Furthermore, it is strongly robust to other ordinary attacks such as re-sampling, color dithering, smoothing, noise adding, and lossy compression.