Research Of Digital Image Watermarking Algorithms With Blind Detection In Wavelet Domain

With the development of computer and network, digital media can be copied easily. At the same time, digital copyright protection has become a serious problem. Watermarking is considered as a new means to solve this problem. Information is embedded to host media to protect the integrity and the ownership.Compared with DCT that was applied in traditional image coding standard,wavelet transform has more advantages. Embedding watermark in wavelet domain has been researched in resent years. This thesis focuses on image watermarking, providing some meaning watermark algorithms based on DWT.My work in this paper is mainly about:1. For rise watermark security, the algorithm unites Arnold varies and random varies before the waterwark embeding, so the tow keys make the watermarking sequence much more steady.2.The algorithm researchs the bilevel image watermark to insert in the image of gradation. The algorithm of inserting in three level of wavelet is odd-even quantization for gradation. Experimental results show that the proposed algorithm ensured the high quality of the image and robustness against some common image processing, such as cut, JPEG compress, strain wave , noise attack, etc.3. The algorithm researchs the gradation image watermark to insert in the color image, and has improved two kinds algorithms. Namely: an algorithm based on the place flat surface breaks up and an algorithm based on relation. And I develops out an algorithm of a piece disperses to embed Watermark information. All of watermarking sequence inserts in three level of wavelet coefficient by the carrier image .And the extract is blind. The experimental result indicates the three algorithms are all invisible and robust Finally, I compare the attack experiment result of the three kinds of algorithm.