【摘要】 以离散余弦变换(DCT)和矩阵奇异值分解(SVD)为基础,结合Quick Response(QR)码的高容量、高纠错特性,提出了一种适合QR码的强鲁棒性数字水印算法。首先,提取QR码图像中的寻像和分隔符图形,并进行高斯加噪模糊化处理,把得到的QR码灰度图像作为载体图像,同时对水印图像进行Arnold置乱处理。然后,对载体图像进行8×8的分块DCT变换,取每块的直流系数得到矩阵A(64×64),对A进行SVD分解,并在A的奇异值处嵌入水印信息。实验结果表明:该算法在不影响QR码正确识别的基础上,不仅具有较好的不可见性,而且对如叠加高斯噪声、椒盐噪声、泊松噪声和中值滤波等攻击均具有很好的鲁棒性。更多还原

【Abstract】 The proposes a new robust digital watermarking method for Quick Response(QR) code images, which was based on Discrete Cosine Transformation(DCT) and singular value decomposition(SVD). The new method fully takes advantage of the high-capacity property and a good error-correction ability of QR code. Firstly, position detection was performed to extract pattern positions and separators in a given QR image and then fuzzify the image with Gaussian noise to form a carrier image. At the meanwhile, the watermarking image was scrambled with Arnold transform. Next, transformation with DCT were done on the basis of 8′ 8 blocks and whose DC coefficients were put together to form a matrix A with a dimension of 64′64. Finally, watermarking image can be embedded in singular values of matrix A after applying SVD to it. Experimental results show that the algorithm was robust in resisting attacks such as Gaussian noise, salt & pepper noise, speckle noise and median filter without affecting the correct identification of QR code.更多还原