Research And Implementation On Image Watermarking Algorithms Based On Discrete Wavelet Transform

With the rapid development of Information Technology and the emergence of electronic commerce and commercial multimedia service, copyright protection technology of multimedia data is the hot spot of the current research. Digital watermarking technique is an effective method to solve the problem of digital copyright protection. And digital watermarking technique based on color image is the research hotspot in this field. This dissertation makes a research on the algorithm of image watermarking based on DWT (Discrete Wavelet Transform). The emphases is image watermarking algorithm based on color image, two kinds basic algorithms was improved which gray image watermarking was embed in to color image, based on the two methods, this dissertation makes a wide and deep research on an improved algorithm of a piece disperses to embed watermarking information based on DWT. The experimental results show the superiority of design algorithm.The main contributions of this dissertation are recapitulated as follows:1. Much more attention has been paid in the domestic and oversea development process and trend, existing problems and research hotspot of the information hiding and digital watermarking. On the basis of thorough research on information hiding theory and its relating techniques, this dissertation analyzes the problem in digital watermarking, discusses the main topic and the solutions of this subject, and also explained the basic theory of digital watermarking technology which is including watermarking wavelet generic embedding model and the typical algorithm. Then compares DWT to other transform domain algorithm, discusses the main reason to choose the algorithm based on DWT.2. For rise watermarking security, the algorithm unites Arnold varies and random varies before the watermarking embedding, so the tow keys make the Watermarking sequence much more steady.3. The algorithm researches the bilevel image watermarking 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.4. The paper researches two basis algorithm that gray image watermarking is embed in to color image. Namely: an algorithm based on the place fiat surface breaks up and an algorithm based on relation. On this basis it focused on the research of the algorithm of a piece disperses to embed watermarking information. All of watermarking sequence inserts in three level of wavelet coefficient by the Carrier image. And the extract is blind. Three experimental result indicates the three algorithms are all invisible and robust Finally, It compare the attack experiment result of the three kinds of algorithm. The experimental results indicate that, the design algorithm has better ability of anti attacks than the former two algorithms.