Image Scrambling and Gray-level Diffusion Algorithm Based on Wavelet Transform
Yin De-hui, Yan Mei Tang · Journal of Sichuan University · 2005
Based on image hierarchy, all sub-images generated by wavelet transform are scrambled. When the scrambled sub-images are combined to form a complete image through reverse wavelet transform, both pixel locations and gray-levels are changed. Therefore, the algorithm achieves good scrambling effects. By using randomly selected scrambling matrix and the number of iterations as secret keys, the algorithm's security is improved. Expriments have proved that the recovery of scambled imgaes is hidh-fidelity and the algorithm is strong in resisting attackes. The proposed algorithm can be used as an image encryption algorithm, or can be used to hide images during pre-processing.