| With the widespread application of computer and information technology in hospital and health system, the hospital digitization level has been improved significantly. In the same time, it leads to the accumulation of a large number of medical data information. Along with the consistent reform of national medical and health system, regional health information sharing will be an important development direction of informatization construction in our country’s medical and health area. Medical image information as an important basis for clinical diagnosis, accounted for the whole hospital information about80%, which plays a very important role in clinical, research, teaching and so on, and has become the main part of information sharing. But as the importance of medical imaging in clinical diagnosis and legal ethics, when this sensitive medical information were transmitted through public network, it is very easy to be intercepted or tampered with. Therefore, how to ensure the safety of transmission (authenticity, integrity authentication and privacy protection and so on) is a key problem to be solved.Lossless digital watermarking is a subset of the digital watermarking technology, it has received more and more attention in recent years because of its non-distortion characteristics, and it was widely used in such as medicine, remote sensing and military and so on that the integrity of the data requirements is strict in these scenarios. Reversible digital watermarking technology need the watermarked image can restore to the original state with non-distortion after the watermark is extracted.The main work and contributions of this paper are as follows:1. A more comprehensive overview about Lossless digital watermarking technology was given;2. In order to solve the piracy problem of medical images in shared environment, a lossless robust watermarking algorithm based on image blocks’difference is proposed. The proposed scheme using Huffman algorithm to encode the blocks’marked information of different blocks, therefore, the additional message’s length is reduced observably and the embedding capacity is increased. On the other hand, the K-means clustering method is utilized to extract watermark and the watermark’s extraction accuracy is improved considerably. The experimental results show that the proposed algorithm outperforms the correlation algorithm in terms of embedding capacity and robust;3. Using C#language to achieve a medical image copyright protection system, the proposed method is implemented and demonstrated;4. Finally, based on the summary, the essay gives some suggestion on further research.. |
