Abstract—Digital watermarking has been proposed to increase medical image security, confidentiality and integrity. This paper proposes a secure watermarking system using Arnold scrambling and 2-D Cellular Automata Transform (CAT). In the first step, the original image is decomposed into two levels by CAT transform. Then the watermark is scrambled using Arnold‟s scrambling algorithm and decomposed into one level by CAT transform. At last, the LL, HL, LH and HH sub bands of the watermark are embedded into the „low-low frequency‟ and „middle frequency‟ of the original image respectively. This algorithm is tested on medical images “BODY” and “VESSEL” (512x512, gray scale) with binary watermark of size 256x256. Experiment results show that our CAT-based watermarking system can simultaneously improve security, robustness and image quality of the watermarked image.
Index Terms—Arnold scrambling, cellular automata transform, digital watermarking.
X. W. Li and S. T. Kim are with the Department of Information and Communications Engineering, Pukyong National University, 599-1, Busan, Republic of Korea (e-mail: setakim@pknu.ac.kr).
S. J. Cho is with the Department of Applied Mathematics, Pukyong National University, 599-1, Daeyeon 3-Dong, Nam-Gu, Busan, Republic of Korea.
Cite: Xiao-Wei Li, Sung-Jin Cho, and Seok-Tae Kim, "2-D CAT-Based Medical Image Watermarking Algorithm," International Journal of Computer Theory and Engineering vol. 4, no. 5, pp. 722-725, 2012.