傅里叶变换全息加密数字水印解密实验研究

Experiment Study on Decryption of Fourier Transform Holography Encrypted Watermark

在理论分析傅里叶变换加密全息水印技术的基础上,通过MATLAB软件对加密全息水印的生成和提取进行了模拟仿真,验证了加密全息水印技术的安全性。通过搭建的光学解密再现系统,对经过计算机滤波处理后的含水印载体图像进行了光学解密再现,结果表明,无需原始载体图像的参与,通过正确的密匙就可以提取出原始水印图像,验证了加密全息水印技术的抗攻击性。对不同嵌入强度、位压缩、剪切、嵌入白噪声的载体图像进行了解密实验,计算其PSNR,得到了PSNR>20,即加密全息水印具有较强的抗低通滤波、噪声、剪切性能,具有较强的鲁棒性。傅里叶变换加密全息水印解密光学系统相对于计算机仿真系统,具有高并行性、高处理速度、高信息维度、便捷性等优点,可用于进行版权保护。

The generation and extraction process of holography encrypted watermark was simulated by MATLAB software, based on theoretical analysis of Fourier transform holography encrypted watermark. The securiity of the watermark was proved. The carrier image processed by computer filter and carried the watermark was decrypted by optical decrypted reconstruction system. The original watermark image can be obtained by the right key without the original carrier image. The anti-attack property was tested by the decryption experiment. The original watermark was recovered from the watermarked images distorted by noise added, JPEG compression, part occluded, and low pass filter. The PSNR was computed to be bigger than 20. So the holography encrypted watermark has a good robustness. The optical decrypted reconstruction system has a higher parallelity, processing speed, information dimensions, convenient than the computer simulation system. It can be used for copyright protection.