Digital watermarking based on chaotic map and reference register

In this paper, we present a new digital watermarking technique based on chaotic map and reference register (RR). We develop a block-based chaotic map, which outperforms the traditional one by breaking local spatial similarity, to increase the amount of significant coefficients in the transformed image. A RR is then employed to locate specific coefficients of a container efficiently for watermark embedding and extraction. We demonstrate the superiority of the proposed scheme in terms of better embedding capacity and lower message error rate. Furthermore, we show the proposed algorithm works well under some image-processing distortions, such as the JPEG compression, Gaussian noise, and low-pass filter.