Research And Implementation Of Digital Watermark Technology For Digital Museum

With the development of digital multimedia technology, digital watermark has become a popular topic in the field of digital copyright protection. Digital watermark serves as protecting the securities of digital multimedia by embedding special information into it. When accomplishing the project of "University's Digital Museum", which sponsored by the ministry of education, I focus on the digital watermark technology and try to protect the copyright and securities of 2d and 3d images. In order to prevent the 2D or 3D images shared in Internet from being illegally copied or used with some other purpose, this paper demonstrates how to embed 2d true color images as watermark information into them. This paper developed mainly in the follow aspects:1. This paper improved the spatial digital watermark algorithm of 2D true color images. At first, by using texture autocorrelation function I got the texture information of different block, then embedded different degree watermark based on human visual sensitization to different texture. This algorithm is more robust than the old spatial domain algorithm.2. This paper analyzed the frequency domain watermark algorithm. Embedded the watermark information into intermediate frequency in the DCT-based watermark algorithm. Improved the DCT transform speed by using FDCT instead of DCT. Quantized the frequency coefficients by using quantized table made from mentality visual threshold. This paper chose lifting scheme and Daubechies9/7 function to finish wavelet transform.3. This paper studied the structure of 3D data model, presented a new algorithm to 3D images, which embedded watermark by altering the coordinates of the 3D polygonal.4. As for evaluation, this paper listed some criterions of evaluating the robust of the watermark algorithm, assessed the above three algorithms of 2D images,Compared them and Chose DCT-based watermark algorithm which perform best to digital museum system.