Digital watermarking in transform-domain based on Cellular Automata Transform

This paper proposes a novel algorithm of digital watermarking based on Cellular Automata Transform (CAT). In this research, the carrier image is first disassembled by CAT method according to the gateway values, and then the CAT coefficients c_kl fall into four distinct groups. The group I is further transformed by level-1 CAT and this domain is called “low-low frequency”. At last, the watermark is embedded into this group (low-low Frequency) of the CAT coefficients c_kl. The experimental result shows that this proposed method is more robust against different watermarking attacks. In addition, the quality of watermarked images is also evaluated.