Study On Low Frequency Watermarking Algorithm Based On Image Wavelet Transform

With the rapid development of computer network technology and multimedia technology, multimedia data is becoming the main source which people get information from. At the same time to protect the copyright of the digital product owner is becoming more and more important. Watermarking technology, as an important method of protecting copyright, are under abroad research and application at present. The wavelet technology has been improved rapidly since 1980s, and now it has been used widely in image processing. Wavelet transform is the key technologies in the new image compressed standard-JPEG2000, now more and more people focus on the watermarking based on the DWT.In this thesis, main investigate the basic principles and characteristic of information hiding technique, introduced the applications aeries ,researching backgrounds, principles and recent development of the digital watermarking technology. Analyze wavelet transform, lifting scheme and lifting factorization of 9/7 wavelet, then point out the advantages of using wavelet transform in digital watermarking. Put forward a kind of watermarking schemes in DWT domain, which is superior to Wang's algorithm . we can inspect watermark without original image and original watermarking.Simulation results of two methods show that although image quality of our algorithm is lower, but is superior to a algorithm in Kundur's algorithm in resistance attacks to JPEG and JPEG2000.