Computational and Mathematical Methods in Medicine
Volume 2012 (2012), Article ID 839161, 8 pages
Research Article

Nested Quantization Index Modulation for Reversible Watermarking and Its Application to Healthcare Information Management Systems

1Department of Electrical Engineering, National Central University, Chungli 320-01, Taiwan
2Department of Electronics Engineering, Chung Hua University, Hsinchu 300-12, Taiwan
3Department of Computer Science and Information Engineering, National United University, Miaoli 360-03, Taiwan

Received 25 August 2011; Accepted 15 September 2011

Academic Editor: Shengyong Chen

Copyright © 2012 Lu-Ting Ko et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Digital watermarking has attracted lots of researches to healthcare information management systems for access control, patients' data protection, and information retrieval. The well-known quantization index modulation-(QIM-) based watermarking has its limitations as the host image will be destroyed; however, the recovery of medical images is essential to avoid misdiagnosis. In this paper, we propose the nested QIM-based watermarking, which is preferable to the QIM-based watermarking for the medical image applications. As the host image can be exactly reconstructed by the nested QIM-based watermarking. The capacity of the embedded watermark can be increased by taking advantage of the proposed nest structure. The algorithm and mathematical model of the nested QIM-based watermarking including forward and inverse model is presented. Due to algorithms and architectures of forward and inverse nested QIM, the concurrent programs and special processors for the nested QIM-based watermarking are easily implemented.