Image Watermarking Algorithm based on DCT and Arnold Transform

摘要

At present, to make medical information storage and transmission easily and safely are discussed hotly. According to the safety of the medical image in medical information system, the robust watermarking method is put forward, and it is suitable for medical image authentication and protection. Firstly, the visual feature vectors of medical image are obtained through DCT transformation, which is used to make watermark’s embedding and extraction. Then, chaotic encryption technique is used in watermark to improve the security of watermark information. At last, the zero watermarking concepts are combined to get the watermark with the qualities against conventional watermark attacks and geometric attacks. The experimental results show that the method can effectively extract the watermark information, and has good invisibility and robustness. In addition, compared with the existing watermarking technology, this method can not only reduce the complexity of the watermark embedding, but can improve the capacity of watermark embedding and it has better flexibility and practicability.