Research Of Digital Watermarking Algorithm Based On Discrete Wavelet Transform

With the rapid development of computer and network technology, the information of digital multimedia becoming more easily to acquire, while at the same time, it also more easily suffer the illegal copying, fabricating, tamperring, infringement etc. attack, the conventional safety precautions which based the cryptology have the ability not equal to their ambition. In order to protect the digital product itself security as well as the owner's benefits, people put forward the digital watermarking technique. Digital watermarking is a technology which with the precondition of has no affection to the using of the digital product, to make use of embed in digital product the secret information which can't be seen to attain the protection of digital product; generally, it demands three basic characters of imperceptibility, robustness and security. The paper carry on the systemic comparatively research of the algorithm of digital watermarking which based wavelet transform. At first the background and the actuality of digital watermarking is introduced, dissertate the digital watermarking about the basic concept and character, generic model, typical algorithms, attack analysis and evaluation of performance. Then the theory and application of wavelet transform, the human vision system, the principle of image permutation are introduced.Based on the analysis of the research in existence of the digital watermarking algorithm, we put forward an adaptively robustness digital watermarking algorithm which based on discrete wavelet transform. The paper mainly carried on three aspects work of the following:(1) Put forward using the two-value image which has special meaning as watermark information, and pretreatment the watermark with image permutation before it be embedded, make it become disorderly information and then embed the watermark, in this way the watermark's security and imperceptibility was strengthened.(2) Combine the HVS(human vision system) models, according to the characters of wavelet transform, adopt multiresolution analysis technology, carry on corresponding multiresolution embed after the watermark and the original image were disassembled with wavelet, thus the algorithm's imperceptibility and robustness request was contented better.(3) For strengthenning the steadiness of the watermark algorithm, the paper put forward to the thought of the watermark was repeat embedding. taxis and grouping the...