A Semi-Fragile Reversible Watermarking for Authenticating 3D Models Based on Virtual Polygon Projection and Double Modulation Strategy

Aiming to reduce the embedding distortion and improve tampering location precision of reversible watermarking for authenticating three-dimensional(3D) models, a semi-fragile reversible watermarking based on virtual polygon projection and double modulation strategy is proposed. During the embedding, it first constructs virtual adjacent vertices for each vertex and obtains a corresponding virtual polygon, and then a watermark is generated according to the projection value of the current vertex on the corresponding polygon. For each vertex, double modulation is used to move the vertex to realize watermark embedding. For the verification, it first obtains the vertex position and extracts the watermark, and then regenerates a watermark according to the restored vertex. If the extracted watermark is consistent with the regenerated one, it means that the vertex has not been tampered, and the 3D model can be lossless recovered; otherwise, the vertex is tampered. Experimental results and analysis show that the proposed scheme outperforms the existing methods in embedding distortion and tampering location precision. It has potential application in the integrity authentication of 3D models.