Precision Controllable Reversible Watermarking Algorithm for Oblique Photography 3D Models.

Area of Science:

• Computer Vision
• Digital Image Processing
• 3D Modeling

Background:

• Existing 3D model watermarking methods for oblique photography lack sufficient data recovery capabilities.
• Current algorithms often fail to restore the original 3D model, limiting their practical application.

Purpose of the Study:

• To develop a novel reversible watermarking scheme for oblique photography 3D models.
• To enable adjustable and precise control over model recovery accuracy.

Main Methods:

• Feature points extracted using the mean angle between vertex normals for global stability.
• A mapping based on feature and non-feature point distances establishes vertex groups.
• Watermark embedding via radius modification in a spherical coordinate system constructed around feature points.

Main Results:

• The proposed scheme offers superior reversibility and controllable restoration accuracy.
• Error-free watermark extraction achieved under translation and rotation attacks.
• Demonstrated average improvements of 0.121 and 0.298 under cropping and simplification attacks, respectively, indicating enhanced robustness.

Conclusions:

• The novel watermarking scheme effectively meets diverse user demands for watermarking and model restoration in oblique photography 3D models.
• The method provides a robust and flexible solution for protecting 3D model data while allowing controlled recovery.