Abstract：In order to improve the security of the image, and to enhance the effect of encryption, an image encryption algorithm based on discrete wavelet and fractional Fourier transform（FRFT）is proposed. Firstly, the discrete wavelet transform is used to make the image signal sparse, then the discrete fractional Fourier transform is used to deal with the image of sparse processing, and the final image is obtained. The MATLAB simulation results show that compared with the single wavelet transform, the algorithm has better encryption and decryption effect, and can hide the information of the image better.
