Liansheng Sui, Jiahao Wang, Ailing Tian, Asundi Anand
Opt Express. 2019 Mar 4;27(5):7213-7225. doi: 10.1364/OE.27.007213.
A novel optical image hiding scheme based on an expansion strategy is presented under the framework of computational ghost imaging. The image to be hidden is concealed into an expanded interim with the same size as the host image. This is implemented by rearranging the measured intensities of the original object after the process of ghost imaging. An initial Hadamard matrix is used to generate additional matrices by shifting it circularly along the column direction, so that enough 2D patterns are engendered to retrieve phase-only profiles for imaging. Next, the frequency coefficients of the host image are modified with that of the expanded interim by controlling a small weighting factor. After an inverse transform, the host image carrying the hidden information can be obtained with high imperceptibility. Security is assured by considering optical parameters, such as wavelength and axial distance, as secret keys due to their high sensitivity to tiny change. Importantly, differing from other computational ghost imaging based schemes, many phase-only profiles are used to collect the measured intensities to enhance the resistance against noise and occlusion attacks. The simulated experiments illustrate the feasibility and effectiveness of the proposed scheme.
在计算鬼成像框架下，提出了一种基于扩展策略的新型光学图像隐藏方案。待隐藏图像被隐藏到一个与宿主图像大小相同的扩展中间图像中。这是通过在鬼成像过程后重新排列原始物体的测量强度来实现的。使用初始哈达玛矩阵通过沿列方向循环移位来生成额外的矩阵，从而产生足够的二维图案以检索仅相位轮廓用于成像。接下来，通过控制一个小的加权因子，用扩展中间图像的频率系数修改宿主图像的频率系数。经过逆变换后，可以获得携带隐藏信息且具有高不可感知性的宿主图像。由于光学参数（如波长和轴向距离）对微小变化高度敏感，将其作为秘密密钥可确保安全性。重要的是，与其他基于计算鬼成像的方案不同，该方案使用许多仅相位轮廓来收集测量强度，以增强对噪声和遮挡攻击的抵抗力。模拟实验说明了该方案的可行性和有效性。
