In this paper, a wavelet packets watermarking algorithm based on chaos encryption for still digital images is presented. The watermarking is changed into bit sequence by modular arithmetic, at the same time, a random sequence is gotten by using a chaos map and deal with it also by modular arithmetic. After getting these two sequences, we do XOR arithmetic, then getting a new encrypted watermarking sequence. At the embedding stage, wavelet packets decomposition is used for original image, then embedding encrypted watermarking sequence into some frequency bands of original image by repeatedly em...
