基于四阶迂回相位编码的计算全息水印技术

Computer-Generated Holographic Watermark Technology Based on Four Detour Phases Encoding Scheme

利用四阶迂回相位计算全息原理实现原始图像计算全息图的制作,并将其作为水印信号嵌入到载体图像。在水印嵌入过程中选择载体图像离散余弦变换(DCT)域中频系数作为嵌入点,以提高抗JPEG压缩能力,而对全息水印数据的Arnold置乱处理可明显提高水印信息的抗剪切能力。仿真实验结果表明,基于迂回相位编码方法的计算全息水印技术在透明性和稳健性方面具有一定优势,特别在抗剪切方面具有优良性能。计算全息术及置乱的引入使所嵌入的水印具有较高的安全性。

The formation of computer-generated hologram（CGH）based on four detour phases encoding scheme for the original image has been proposed and the CGH is used as watermark signal to be embedded into the carrier image.Medium frequency parameters in discrete cosine transform（DCT）domain are selected as the embedded positions to get better ability of anti-JPEG compression and the Arnold scrambling can obviously improve anti-cropping ability.The experimental simulation results show that the holographic watermark technology based on the detour encoding method discussed has certain advantages in invisibility and robustness.And especially it has high performance of anti-cropping.Holography and scrambling technology can bring higher safety of the embedded watermark.