A novel image watermarking algorithm based on two-dimensional cellular automata transform

Generally CAT is used in image compression and encryption. In this paper a novel watermarking algorithm based on cellular automata transform (CAT) is proposed. A binary watermark is embedded in a certain sub-band, which is further subdivided into non-overlapped blocks, after the original image is disassembled with two-dimensional CAT. Then choose one coefficient of each block, and embed a bit of watermark. Neither the original host image nor the binary image watermark is needed in extraction of the algorithm. The experiments show that the proposed method is robust to the common watermark attacks. Due to limited space, we only list the results of the rotation attack and JPEG attack experiments.