Chaos-based color image encryption scheme in the wavelet domain

Chaos-based dynamics system is typical of the properties of randomness, determinacy and sensitivity to the initial parameters, which makes it suitable for the application of image encryption. In this paper, a wavelet domain color image encryption algorithm based on chaos is proposed. The color plain image is firstly decomposed into R, G, B components. Then an improved 3D chaotic cat map is proposed to confuse the wavelet coefficients of R, G, B components to make these three components affect each other and mixed randomly. The coupled map lattice model is employed to the diffusion process in the spatial domain to improve the performance of the cryptosystem. The effectiveness and capability of the proposed method are tested by a series of simulations and the results show that it is validity for color image and robustness to various attacks.