Clustering-based 3D Point Cloud Watermarking In Discrete Cosine Domain

With the rapid development of digital information technology and three-dimensional imaging technology,three-dimensional digital model plays an irreplaceable role in many fields.With the development of technology,new problems are emerging.Through simple operation,digital data can be illegally copied,tampered with and counterfeited,which affects its authenticity,and even infringes on the intellectual property rights of digital data owners.The copyright protection of digital data has become an urgent problem to be solved.How to effectively protect the copyright and value of three-dimensional digital products has become a new research topic.This paper mainly focuses on the research of three-digit watermarking,including the following aspects:A clustering-based three-dimensional point cloud watermarking algorithm in discrete cosine domain is proposed.The algorithm combines the idea of clustering,transformation of spherical coordinate system and transformation domain.The encrypted watermarking with double random phase encoding is embedded in the feature area of the three-dimensional model after hierarchical clustering filtering.In the embedding process,spherical coordinates are transformed from the data of the three-dimensional point cloud model,and then the encrypted information is embedded into the low-frequency part of the embedded carrier in the discrete cosine transform domain of the modular two-dimensional matrix sorted according to the spherical coordinate angle.After the embedding is completed,the inverse spherical coordinate transformation is carried out to restore the data to the original coordinate system,so that the encrypted information is embedded into most points in the specific area of the three-dimensional model.Based on the proposed watermarking algorithm,a corresponding software system is developed.The system can easily implement the embedding and testing of watermarking.Its main functions include: reading in watermarking and model,embedding watermarking,storing watermarking and model,attack model,extracting watermarking and detecting.The test results show that the algorithm has good anti-attack performance and can resist geometric attack,shear attack,signal attack and simplified attack.It is a compromise between security,robustness and concealment.