A colour image encryption scheme based on Gaussian apertured real-preserving fractional Mellin transform (GARPFrMT) in diffraction domain and chaos permutation is proposed. Real-preserving fractional transform in diffraction domain using Gaussian aperture is constructed to ensure that the output is real, which is convenient for storage and communication. And the Gaussian aperture, as a soft aperture, can improve the intensity distributions of the output light, which contributes to prevent possible attacks for obtaining some useful information from the marginal leakage of light in the optical encryption systems. The colour space rotation transform is first used to convert the colour image from standard space to space. And then, the three new colour components are transformed by GARPFrMT with three different diffraction channels, respectively. A 3D-logistic map is utilized to further scramble the three-colour components. At last, a logistic-sine map is used to perform Xor operation with three components, respectively. Simulation results demonstrate that the proposed algorithm is feasible and robust to noise attack and data loss.

中文翻译：

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在衍射域中使用高斯孔径实数保留分数梅林变换的彩色图像加密

提出了一种基于衍射域和混沌置换的高斯孔径保实分数梅林变换(GARPFrMT)的彩色图像加密方案。采用高斯孔径构造衍射域保实分数阶变换，保证输出为实数，便于存储和通信。而高斯孔径作为一种软孔径，可以改善输出光的强度分布，这有助于防止可能的攻击，从光加密系统中的边际泄漏光中获取一些有用的信息。色彩空间旋转变换首先用于将彩色图像从标准空间转换为空间。然后，三个新的颜色分量分别通过具有三个不同衍射通道的 GARPFrMT 进行转换。3D 物流地图用于进一步打乱三色组件。最后，使用逻辑正弦图分别对三个分量进行异或运算。仿真结果表明，该算法是可行的，并且对噪声攻击和数据丢失具有鲁棒性。