基于DCT的三维网格模型数字水印算法

Digital Watermarking Algorithm for Three-Dimensional Mesh Model Based on DCT

基于离散余弦变换(DCT)技术和扩频通信技术提出三维模型稳健水印嵌入算法.算法将原始的一维二值水印序列利用扩频通信技术生成可以直接嵌入的水印信息;利用主成分分析(PCA)方法,将原始模型变换到仿射(旋转、平移和均匀缩放)不变空间中,选取模型顶点到其中心距离作为水印嵌入单元,基于双极性量化嵌入单元离散余弦变换系数的方法嵌入水印并实现水印的盲提取.该算法嵌入的水印信息具有不可见性,能够抵抗模型的旋转、平移、均匀缩放等常见攻击.仿真实验验证了算法的有效性.

A novel watermark embedding algorithm for three-dimensional （3D） mesh model based on Discrete Cosine Transform （DCT） and spread-spectrum communication technique is proposed. The original one-dimensional （1D） binary watermark sequence is mapped to the watermark information, which can be directly embedded into host, with spread-spectrum communication technique. With the principal component analysis （PCA）, a transformation of the model to invariant space is proposed prior to watermark embedding. The lengths between the vertices and the centroid of the model are chosen as watermark embedding primitives. The watermark information is embedded into the host with modifying the discrete cosine transform （DCT） coefficients of embedding primitives with the bi-polar quantization technique to achieve the blind watermark extraction. The embedded watermark is invisible and can withstand the affine transform （rotation, translation and uniform scaling） attack. The validity of the proposed algorithm has been confirmed with experiments.