基于奇异值分解与小波变换的盲数字水印算法

Blind Digital Watermarking Algorithm Based on Singular Value Decomposition and Discrete Wavelet Transform

提出了一种基于奇异值分解(SVD)和离散小波变换(DWT)的数字图像盲水印算法。对载体图像的二级DWT后的低频子带LL2进行2×2分块,对每一小块进行SVD分解,根据二值水印信息,采用量化步长S量化每小块的最大奇异值,将水印信息嵌入到载体图像。实验结果表明,该算法可以有效地抵抗剪切攻击、噪声攻击、滤波攻击、缩放攻击、JPEG压缩攻击等。

A blind digital image watermarking scheme based on singular value decomposition （SVD） and discrete wavelet transform （DWT） is proposed in this paper. This algorithm executes DWT transform on the original image, and the low - frequency approximation subband （LL2） of the DWT domain is partitioned into non -overlapping blocks with 2 × 2 pixels. For each block, the SVD technique is performed to obtain its singular value decomposition. The quantization step S is used to quantify the max singular value of each block based on the embedded watermark. The experimental results demonstrate that the algorithm has good robustness to the noise, median filtering, cropping, scale, JPEG compression and so on.