Research And Application Of Digital Watermarking In Static Image

The digital media has become a main way for information communication along with the wide use of network. At the same time, this leads to information security problems emergence. Thus, the protection of intellectual property for digital media becomes an interesting issue. Watermarking, as an important embranchment of information hiding, is the effective means for protect copyrights piracy. It can identify the signal's integrity or property through embedding of additional information into multimedia signal. In general, there should be no perceptible difference between watermarked and original signal, and the watermark should be difficult to remove or alter without damaging the host signal. So, this paper researches systemically image watermarking technology in terms of the following three facts:Firstly, research on robust image watermarking. A digital watermarking scheme based on wavelet transform was proposed. It realizes the watermarking extract without the original image using 64×64×8 bit gray image as the watermark signal. In order to enhancing the security of the watermark, we employ an encryption technology based on chaos and bit plan. Simulation results show that our scheme have good invisibility and can survive low-quality JPEG compression, median filtering and so on. In addition, the analysis of the extracted watermark can help us to detect and localize tampers.Secondly, research on authentication watermarking technology. Here a watermarking scheme for color image authentication is proposed, which operates in the wavelet domain. Firstly, the color image is transformed from the model of RGB to that of YIQ; then three scales wavelet decomposition is followed to the luminance part Y. And one bit plane of the coefficients at the coarse scale is utilized to authenticate the integrity of the image; finally, we embed the watermarks by modulating the 2-scale wavelet coefficients self-adaptively.Thirdly, research on against geometry attacks watermarking technology. A digital watermarking scheme, which is based on combination of simple and reliable harris detector and image normalization, is proposed. The feather points remain holding after geometry attack. Applying image normalization to these non-overlapped circles which centered at the feature points, after that, we can determine area for watermark embedding. Then we embed watermarks in the original circles. In this way, the...