Abstract: A novel image encryption scheme based on chaos-sorting technique is proposed. The chaos-sorting map is generated by sorting the chaotic matrix in order; The permutation module and the substitution module are designed; Encryption algorithms in spatial domain and frequency domain are proposed. For the encryption algorithm in frequency domain, the cipher-image can be lossy compressed, and low-distortion plain image can be obtained after decrypting the compressed cipher-image. Simulation results and analysis demonstrate that the proposed scheme is of favorable security and efficiency.

Key words: Image processing, Image encryption, chaos-sorting map, cipher-image compression

摘要： 提出一种新的基于混沌有序化映射的数字图像加密方法。把混沌矩阵映射成有序矩阵同时得到混沌有序化映射；给出了加密算法的置乱模块和替代模块；设计了空间域和频率域加密算法。频率域加密密文图像能根据传输率要求随时进行相应压缩比的有损压缩，并能解密得到较低失真率的解密图像。实验结果表明所提图像加密方法安全、高效。

关键词: 图像处理, 图像加密, 混沌有序化映射, 密文图像压缩