A Semi-Fragile Reversible Watermarking for 3D Models Based on IQIM with Dual-Strategy Partition Modulation

Aiming at reducing the embedding distortion and improving tamper localization accuracy, a semi-fragile reversible watermarking for 3D models based on IQIM (improved quantization index modulation) with dual-strategy partition modulation is proposed. Firstly, watermark is built based on the position data of vertices and the number of neighboring vertices within the first ring. With IQIM, a dual-strategy partition based on the relationship between the position of quantization coefficients within quantization units and the watermark information is built. It performs single or dual modulation of IQIM to vertices, which is helpful for reducing the distortion induced by watermark embedding in the 3D models. During watermark extraction and data recovery, the watermark is first extracted based on the model vertex information and the original watermark is regenerated. The dual-strategy partition is performed based on the relationship between the position of quantization coefficient within quantization units and the regenerated watermark. Then, the model vertices are respectively recovered. Finally, by comparing the consistency between the extracted and regenerated watermarks, the integrity of the 3D model can be authenticated and the tampered area can be located. The experiments and analysis show that it outperforms several cutting-edge techniques from the aspects of embedding distortion and tamper localization capability.