摘要
针对打印扫描过程对硬拷贝水印图像的攻击,提出一种抗打印扫描的全息水印改进算法。改进的算法将双水印的数字全息图隐藏在载体图像的离散傅里叶变换(DFT)中频系数的幅度谱中,并在中心对称的相应块做同样的替换,通过控制图像纹理的峰值信噪比(PSNR)自适应地控制水印嵌入强度,并实现最佳的水印嵌入。改进的算法不可见性明显提高,嵌入有意义水印容量大,具有抗剪切、噪声、JPEG压缩等攻击的优势,且通过打印扫描校正,可从打印扫描图像中清晰提取水印。
A print-scan resilient watermarking algorithm based on digital hologram was studied in this paper. A hologram image of two watermark was embedded into the amplitude of middle spectral magnitude of the host image, and the same replacement was done in the central semmetry block. A Peak Signal-to-Noise Ratio （PSNR） threshold adapted to the texture of the host image was set to adjust the watermark shrength. The proposed approach shows advantages in invisibility, robustness, embedding capacity, resistance against the attack of scaling, noise, and JPEG compression. The watermark can be extracted from the watermarked image after print-scan.
出处
《计算机应用》
CSCD
北大核心
2013年第3期752-755,共4页
journal of Computer Applications
关键词
数字全息
打印扫描
数字水印
digital hologram
print-scan
digital watermarking
