一种解密图像无背景噪声的加密全息数字水印技术

Encrypted Holographic Watermarking Technology with Decrypted Image Superposed No Noise

提出了一种新的加密计算全息技术,原始水印图像经过双随机相位编码,所得复数图像经过共轭对称延拓和傅里叶变换后得到全息图,所得全息图解密图像上没有视觉可见噪声污染。将快速识别矩阵(QR)码作为原始水印图像,进行加密得到全息图水印,并嵌入在原始图像的Haar小波对角线中频系数中,在较高的水印信息不可见性的情况下,含水印图像经过打印过程获得的印刷品再扫描后,提取出的全息图水印经解密后依然能够得到可解码的QR码,QR码的使用使得算法可以准确定位版权人。所提的数字水印技术有很好的实用价值。

A new encrypted computer-generated holographic technique is presented. The watermark image is encoded with double-random-phase encoding. The encrypted image with complex value is transformed to hologram by conjugate symmetric extension and Fourier transform. The decrypted image is not superimposed by perceptual noise. The original watermark is quick response （QR） code. The hologram generated from the preprocessed QR code is embedded in the intermediate frequency coefficients of original image. The extracted QR code from the watermarked image under print-scan attack can be decoded correctly. The QR code represents not only a picture, but also text message. So the message decoded from the QR code makes authority verification more precisely. The proposed algorithm is of high practical value.