基于二值化计算鬼成像的盲水印方法

Blind Watermarking Method Based on Binarized Computational Ghost Imaging

提出了一种基于二值化计算鬼成像的盲水印方法.首先将水印图像经计算关联成像加密系统加密,并将加密数据二值化,然后将其隐藏到宿主图像的离散余弦变换域,实现水印信息的嵌入.水印信息的提取和重建是隐藏和加密的逆过程,分别借助提取密钥和解密密钥获取水印信息.仿真实验证明,该方法具有很好的隐蔽性,在嵌入因子α=10时,嵌入水印仍具有较好的不可感知性,含水印图像的峰值信噪比在38 dB以上;另外,该方法也具有一定的容错能力,提取的加密数据错误率达20%时,重建的水印信息仍能分辨和识别;与传统的计算鬼成像相比,加密数据的二值化为水印嵌入提供了方便,但是并未对重建图像带来严重恶化,其相关系数相差不足0.1;水印信息的提取无需借助原始宿主图像,是一种盲提取方法.

A blind watermarking method based on binarization computational ghost imaging was proposed.In this method,a watermark image is firstly encoded by the encryption system based on computational ghost imaging,and then the ciphertext is binarized and embedded in the discrete cosine transform domain of a host image to realize watermark embedding.The process of watermark extraction and reconstruction is the inverse process of embedding and encryption.The watermark is obtained by extraction key and decryption key.Simulation results show that this watermarking technique has good imperceptibility.When α=10,the watermark is also imperceptible and the peak signal-to-niose ratio of the host image containing watermark is above 38 dB.In addition,this method also has some fault tolerance ability.When the error rate of the extracted encrypted data reaches 20%,the reconstructed watermark information can still be distinguished and recognized.Compared with the traditional computational ghost imaging,binarization for the ciphertext data brings convenience for watermark embedding,but does not bring serious deterioration to reconstructed image,and the difference of correlation coefficient is less than 0.1.In the process of watermark extraction,it is unnecessary for the original host image,so it belongs to a blind extraction method.