基于压缩感知及光学理论的图像信息加密

Image Information Encryption by Compressed Sensing and Optical Theory

针对信息加密系统中信息安全性不理想的问题,提出一种基于压缩感知的光学图像信息加密方法.在发送端,自然图像经稀疏表示、随机投影实现图像信息加密;然后将降维后的观测值通过4F双随机相位编码光学系统进行二次加密并将其融入宿主图像,实现信息加密及隐藏.在接收端,图像信息经双随机相位编码技术解码,通过正交匹配追踪算法实现原始图像信息重构.该系统能有效降低数据传输量、减小随机相位板大小.且收发方只需按照规则生成密钥而不需传输密钥,保证了密钥的安全性.仿真结果表明:解密恢复图像质量理想,峰值信噪比为30.899 1dB,且系统能较好地抵抗裁剪、噪音污染、高通滤波、旋转等攻击,鲁棒性强,安全性高.

Due to the problem of security for information encryption system, an image information encryption scheme combined compressed sensing with optical theory was proposed. At the transmitted terminal, image information encryption based on compressive sensing was realized by sparse representation and random projection firstly. Then, the measured values with low data volume after dimensional reduction were re-encrypted by double random-phase encoding technique and then dispersed and embedded into the host image. At the received terminal, original image information was reconstructed approximately via Orthogonal Matching Pursuit algorithm after the inverse process of double random-phase encoding technique. Not only the security of information was ensured under the premise of decreasing the amount of data transmission and reducing the size of the random phase masks but also the privacy of keys were assured which were gained by rules rather than transmitted from transmitter to receiver. Numerical experiments showed that the quality of decryption image was ideal with the corresponding peak signal to noise ratio of 30. 899 1 dB and this system had the advantages of good performance of anti-cropping, anti-noising, anti-rotating and anti-filtering, strong robustness and high security.