基于联合变换的旋转不变光学图像加密

利用两个彼此独立的编码脉冲相位掩模在联合变换相关器中对需要保护的图像进行编码，实现对原始图像的加密。该方法的特点是解密时加密图像的旋转不会影响解密效果，相位分布是密钥的合法持有者唯一掌握的确定性函数，可以重构，便于实际应用。计算机模拟的结果证明了方法的可行性。

关 键 词 光学图像; 加密; 联合变换; 旋转不变; 编码脉冲信号; 相位掩模板

Two phase mask plate with independent chirp signals are used to encode image in the joint transform correlator,so as to make encrypt the original image.The characteristic of this method is when decoding,the rotation of encrypted image can not affected decoding effect,and moreover,owing to the fact that phase distribution is a decisive function only grasped by owner of secure key and the secure key can be regenerated.It makes the practical use convenient.The results of computer simulation shows the feasibility of this method.