一种DCT变换的三维网格物体盲水印方法

提出了一种基于DCT变换的3D网格物体鲁棒性盲水印方案。首先将3D物体模型转换到仿射不变空间,抽取三维物体重心到顶点的距离生成一个一维的离散信号,将该离散信号进行DCT变换,改变其系数以嵌入水印。然后经过逆DCT变换生成带水印的3D物体模型。在仿射不变空间下,实现了3D物体模型对平移、旋转、比例变换的鲁棒性,采用DCT变换使3D模型具有很强的水印不可见性,而且具有一定的噪声鲁棒性。试验结果也表明该方法不仅对于旋转、平移、比例变换具有很强的鲁棒性,而且具有良好的水印不可见性。

Blind 3D mesh objects watermarking schemes based on DCT

A novel DCT method for blind robust 3D mesh object watermarking applications was proposed.First,a transformation of the model to an affine invariant space was finished prior to watermark embedding.We produced a ID signal through calculating the distance from the object center to tile vertices,and performed a DCT on it,then embedded the watermark by changing the DCT frequency coeffcients,then the 3D object with watermark was produced by reverse DCT.In affine invariant space,the 3D object was not affected by geometric transformations,such as translation,rotation and scalir~g,and realized good visual masking by using the DCT transform,there was also a little robustness to the additive noise.Experimefft~ show that the method is both robust against geometric transformations and good at visual masking.