Three-dimensional grid watermark embedding and detecting method based on local roughness analysis

Abstract

The invention discloses a three-dimensional grid watermark embedding and detecting method based on local roughness analysis. The method comprises a watermark information embedding process and a watermark information detecting process. The watermark information embedding process comprises the steps of conducting sub-grid dividing on a three-dimensional grid model according to the roughness of vertexes, and then achieving multi-watermark embedding by adjusting the vertex norm distribution of sub-grids; the watermark information detecting process comprises the steps of extracting one watermark sequence from each sub-grid, and then determining the extracted final watermark information through a majority vote mechanism.

Description

technical field [0001] The invention relates to a digital watermark technology for copyright protection of a three-dimensional model, which belongs to the technical field of computer graphics and multimedia information security, in particular to a three-dimensional grid watermark embedding and detection method based on local roughness analysis. Background technique [0002] Robust digital watermarking technology can be effectively applied to the copyright protection of digital content. Using this watermarking technology to embed watermark information in the data of multimedia content, when copyright disputes occur, the copyright can be confirmed through the extracted watermark information. Digital watermarking for copyright protection requires strong robustness and security. Watermarking should be able to resist malicious attacks in addition to existing in general routine processing operations. In recent years, 3D models have been widely used in virtual reality, video games,...

AI Technical Summary

Problems solved by technology

However, these methods have limited embedding capacity and limited improvement in robustness, and are still sensitive to some common attacks

Moreover, the dihedral angle and average curvature actually only describe the curvature of the model, and cannot reflect the surface roughness well, so the improvement effect on visual distortion is still limited

Chinese patent 201310126150.2 3D model digital watermark embedding and blind detection method based on vertex curvature, uses the distribution of vertex curvature to embed watermark, this method has good robustness to various attacks, but it is not suitable for subdivision and shear attacks For evaluation, and the geometric distortion caused by the watermark is relatively high

Chinese patent 201310167803.1 non-blind watermarking method based on mesh segmentation for 3D mesh models adopts this idea. The segmentation algorithm based on the shape-diameter function performs meaningful segmentation of the model, and then embeds watermarks for each segmented block. This method can resist attacks such as simplification, clipping, and noise, but it does not improve the geometric distortion caused by watermarks much, and it still causes the degradation of the visual quality of the model.

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