Digital Watermark of 3D CAD Product Model

This paper proposes a novel watermarking algorithm of 3D CAD product model, which is able to keep strictly geometrical shape around embedding watermark and make watermarked model have function transparency. Firstly, the isolated geometrical entities are selected as watermark carriers. Secondly, the watermark is embedded into the isolated geometrical entities with a geometric entity substitution algorithm. When extracting the watermark, the original product model and pre-process (registration or re-sampling) need not be provided. The experimental results have shown that the proposed watermarking algorithm is robustness against some common attacks, such as transformation, rotation, scaling and entity deletion.