针对网格环境中图像信息资源的版权保护问题,提出了一种可应用于网格环境下的基于离散小波变换DWT和扩频技术的有意义数字水印算法。该算法在传统的基于DWT和扩频技术的有意义数字水印算法中,利用小波变换的多分辨率特性来进行图像的小波分解和重构,利用数字扩频技术来实现嵌入和检测水印。实验证明选择频域嵌入水印可以获得更好的图像保真度,并且比在空域中的水印算法更稳健,可实现在网格环境下的版权保护。
Aiming at the problem of copyright protection of digital muhimedia documents in the gird environments, author proposed a meaningful digital watermarking algorithm which could be used in the gird environments. It decomposed and reconstructed a digital image using multi-resolution ratio of wavelet transform based on the discrete wavelet transform and digital spread spectrum technology. Experiments show that choosing frequency domain to embed watermarking can gain image fidelity better and have more robustness than watermarking embedded algorithm in space domain.