3 A Method of a Digital Watermarking for 3D Geometric Model STL

摘要

PURPOSE: A digital watermark method of a STL in the 3D geometric shape is provided to simultaneously insert watermarks to normal and vertex domains of a facet for preventing any distortion in the 3D shape and improving the strength against simple attacks of a third party. CONSTITUTION: A digital watermark method of a STL in the 3D geometric shape includes the steps of inserting watermark into normal and vertex areas, wherein the watermark insertion is initiated from the vertex area. The entire facets are aligned according to the size in the ascending power to secure the strength against attacks changing the facet storing sequence. As the facets are aligned, random numbers is generated by a user's key value serving as a seed value. The watermarks are inserted according to the generated numbers. The aligned facets are transmitted to a watermark encoder with the generated random numbers.