3维网格数据是不规则采样的数据集,传统的图像变换域水印算法不能直接应用到网格上.提出了一种小波变换域的鲁棒网格水印算法.该算法对半规则的多分辨率网格进行小波变换,得到一个基网格和一系列小波系数.在对小波系数的统计特性进行实验分析的基础上,选择在低频子带的小波系数中嵌入水印,并对小波系数的切向和法向分量设计了不同的嵌入强度,以减小几何失真.实验结果表明,该水印算法满足不可见性,并具有较强的鲁棒性.
Traditional watermarking methods in the transformed domain for images can' t be applied on meshes directly because meshes are generally irregular sampled data sets. This paper proposes a robust mesh watermarking algorithm using wavelet transform for semi-regular meshes obtained by remeshing. The original mesh with multiresolution representation is decomposed into a base mesh and a set of wavelet coefficient vectors by applying the wavelet transform. Based on the statistical analysis of wavelet coefficients, the watermarks are embedded by perturbing the wavelet coeffieient vectors in low resolution subband, and the embedding strengths for different components of the wavelet coefficient vectors are designed differently in order to decrease the geometric distortion. Experimental results show that this algorithm satisfies imperceptibility and is robust to various attacks.