本文利用阿贝成像及对称-非对称混合加密原理，实现了基于4f光路的光学图像加密与解密．首先，本文利用Lee型迂回相位编码方法制作了加密函数对应的相位掩膜，作为密钥，并通过空间滤波的方法完成了光学图像的频域加密．其次，本文结合自行编写的程序实现了加密图像的计算机解密，解决了光学图像解密时相位掩膜难以精准对齐的困难，大幅度提升了解密效率和质量．最后，通过一个验证实例直观地揭示了该加密方法具有较高的安全性，并且证明该方案在较低噪声情况下具有较好的鲁棒性． 

Using Abbe^,s imaging principle and symmetric-asymmetric hybrid encryption scheme, the optical image encryption and decryption based on 4f optical system are realized. First, the Lees detour phase encoding method is used to make the phase mask corresponding to the encryption function as the key, and the frequency domain encryption of optical image is completed by spatial filtering method. Secondly, the computer decryption is realized with the program developed by the authors, which gets rid of the difficulty of precise alignment of phase mask during optical image decryption, and greatly improves the efficiency and quality of decryption. Finally, the experiment reveals that the encryption method has high security level, and it also proves this experimental method possesses good robustness under mild noise influence.