【摘要】 为解决当前光学图像加密方法容易遭受各类攻击等安全问题，设计了基于帐篷映射和孔径分数梅林变换的光学图像加密算法。首先，对明文图像作对数极坐标变换，将变换结果图像分解成多个环域子图像；然后利用不同阶数的孔径分数梅林变换分别对子图像进行处理，得到对应的复值图像；为了增强密钥的随机性，借助帐篷映射产生一个辅助相位，并将其融入到加密过程的相位密钥中，并使用重复迭代加密的方法，对幅度和相位信息进行编码。最后，利用帐篷映射生成一个随机矩阵，对迭代加密后的幅度信息进行异或操作，完成最终的加密处理。实验测试结果表明：与当前的光学图像加密方法相比，上述算法具备更好的鲁棒性和稳定性，能够有效地抵抗各类非法攻击。更多还原

【Abstract】 In order to to solve the security problems that the current optical image encryption methods are vulnerable to various attacks, an optical image encryption algorithm based on tent mapping and aperture fractional Merlin transform is designed. Firstly, the log-polar transformation was performed on the plaintext image, and the resulting image was decomposed into multiple cyclic sub-images. Then, in order to prove the random of the key, the apertured fractional mellin transform with different orders was used to transform the sub-images, and N complex images were obtained. Secondly, an auxiliary phase was generated by Tent mapping and incorporated into the phase key of the encryption process. Amplitude encoding and phase encoding were implemented by iterative encryption. Finally, The aim to prove the safety of image, the Tent mapping was used to generate a random matrix to perform the XOR operation with the amplitude information after iterative encryption, and the image encryption was finally completed. Experimental results show that compaed with the current optical image encryption technology, the proposed algorithm has higher security and robustness, stronger anti-noise attack and anti-shear attack capability.更多还原