To overcome the drawback of the existing immunity watermarking algorithm that the original image cannot be recovered exactly, a new reversible watermarking algorithm in wavelet domain based on immune watermarking framework was proposed. The algorithm has large embedding capacity and can recover the original image exactly. Meanwhile, the algorithm used histogram shifting method of reversible watermarking to embed recovery vector for recovering the original image precisely. By using the block size in the wavelet transform, the amount of the peak-zero point pair and the round amount in the histogram shifting, 〖JP2〗the control factor in the algorithm could be selected to decide the embedding depth. Then the algorithm could generate publishing image which has large distortion but also kept the main information of the original image. The scrambling and encryption methods were used in the algorithm so that the invaders could not recover the original image correctly by brute-force method without authorized file. The experimental results show that the algorithm can not only obtain the publishing image which has big differences with the original one, but also can recover the exact image when security permission is released.

In this paper, a novel image blocks encryption algorithm based on Coupled Map Lattice (CML) system was presented to solve the parallel problem of the common image encryption algorithm. The basic idea is to divide the image into blocks，and then used the block number as the spatial parameter of CML to iterate the chaos system. The chaotic stream was used to conduct confusion operations with part of the image，the result of which was applied to encrypt the other part. The proposed method can encrypt image in parallel and can also satisfy color image encryption. The simulation process indicates that the algorithm is easy to realize with low computation complexity，high sensitivity，high speed，high security and other properties simultaneously.