关键词: 数字水印, 仿射变换, DCT变换, 3D模型

Abstract:

In order to protect the 3D（Three Dimensions）models-originality and security of weaponaries effectively, we take fighter's 3D model as an example, and adopt digital watermark technique to embed the copyright information. A multiple watermark plan on 3D mesh model based on DCT（Discrete Cosine Transform） is proposed. Firstly, put 3D model to affined transform, and consider the center of gravity of 3D model as the base point of three-dimensional Cartesian coordinate, extract the vertex's coordinate data of 3D model after principal elements’ analysis projected on three 2D （Two Dimensions）planes of  XOY、XOZ、YOZ. Take these three sets of two-dimensional discrete signal into DCT transform and embed two-dimensional digital watermark into three sets- middle-frequency coefficients after transform. Multiple watermark embedding achieves 3D model's robustness to simplification, noise and cut and so on under fixed-affine space. Experiments prove that this approach has strong robustness and fine watermark invisibility. Thus, this way avoids unlawful second-hand exploitation or application availably.

Key words: digital watermark, affined transform, discrete cosine tranform (DCT), 3D model