本文分析比较了多种实现光学图象相位加密的方法，发现不同方法获得的加密图象有不同类型的噪音分布．无论加密相位是随机相位模板、浑沌序列的相位列阵，还是用相位重构迭代算法计算的结果，它们都能起到加密图象的功能．解密图象的质量或被相关识别的能力与解密过程中所使用正确解密相位的不同部分以及高低频分量多少有关，且其依赖程度是由不同的加密方法自身决定 This paper analyzes and compares a number of methods to realize optical image phase encryption, and finds that different methods obtain different types of noise distribution in the encrypted image. Whether the encryption phase is a random phase template, a phase array of chaotic sequences, or the result of an iterative algorithm of phase reconstruction, they both serve to encrypt the image. The quality of the decrypted image or its ability to be correlated is related to the different parts of the correct decryption phase and the high and low frequency components used in the decryption process, and their dependence is determined by the different encryption methods themselves