A 3D grid model copyright authentication method

Abstract

The invention provides a three-dimensional grid model copyright authentication method. Including: S1: Generating optical holographic encrypted copyright watermark information; S2: Preprocessing the 3D mesh model; S3: Constructing the geometric feature matrix of the model in the cylindrical coordinate system; S4: Embedding copyright watermark information on the geometric feature matrix through QR decomposition; S5 : Publish the 3D grid model embedded with copyright watermark information on public information platforms such as the Internet; S6: After preprocessing the 3D grid model to be detected, perform QR decomposition on the geometric feature matrix to extract the grayscale image of copyright encrypted information. The inverse Fourier transform and the second-order Butterworth high-pass filter are used to obtain the copyright binary watermark image, which can be recognized by human eyes to determine the copyright ownership of the 3D grid model. This method is a blind watermarking algorithm in airspace, which has high robustness, and overcomes the prominent problem that the existing 3D model copyright authentication method is easy to be decrypted and imitated, and cannot be conveniently and effectively authenticated for copyright anti-counterfeiting.

Description

technical field [0001] The invention relates to the field of three-dimensional technology, in particular to a copyright authentication method for a three-dimensional grid model. Background technique [0002] In recent years, with the improvement of computer processing capabilities, 3D models have been widely used in many fields such as computer-aided design, computer animation, virtual reality, cultural relics and archaeology, medical visualization, film and television games, etc. Compared with traditional media data (text, audio, image), the acquisition and processing of 3D models are more complicated, more human, material and financial resources are invested, and more intellectual factors are condensed, which has higher value. Today, with the increasing popularity of network communication and the rapid development of e-commerce, the copyright certification of 3D models is the key content of the research on the production and supervision of socialized content in digital pub...

AI Technical Summary

Problems solved by technology

Kai wang also performed wavelet decomposition on the 3D grid model, and embedded the robust watermark, fragile watermark, and high-capacity watermark into the appropriate wavelet resolution level to realize the blind watermarking algorithm, but the robustness is not high

In 2008, Liu and Y proposed to use the manifold harmonic transformation to transform the original grid into the frequency domain for watermark embedding, but it is easy to lose serious shape information during shear attacks

In 2009, Konstantinides proposed to embed the watermark information in the spherical harmonic coefficient, but this method completely relies on the global registration of the grid so it cannot withstand shearing attacks

In 2005, Zafeiriou proposed to embed watermark information by changing the vertex coordinates in the spherical coordinate system, but it cannot resist affine transformation.

In 2009, Wang Yuping, Hu Shimin and others of Tsinghua University proposed a spatial semi-fragile busy watermarking algorithm based on integral invariance, which can resist attacks such as vertex disorder, RST transformation, slight noise, etc., but it is easy to cause the overall deformation of the original 3D model

In 2009, Qingsongai of Wuhan University of Technology proposed to divide the 3D model into multiple Voronoi patches according to the feature points of the 3D model and then embed the watermark information in it, which has good anti-cropping performance, but the pre-processing of dividing the Voronoi patch according to the selected feature points The process will take a lot of time, and the operation is difficult to implement

In 2011, Ho L proposed to use the vertex information intersecting the surface of the 3D model and the center of the particle to embed the watermark and combine it with progressive mesh compression for watermark protection of the 3D LOD model, but the technology based on the movement of the histogram bins changed the vertex geometric information

In addition, due to the lack of natural parameterization methods for 3D models, it is difficult to achieve direct frequency domain decomposition of 3D models.

Compared with the frequency domain algorithm, the air domain algorithm has the advantages of simple embedding method and large embedding amount, and has important practical application value, but blind watermarking is difficult to implement, and its robustness is often poor, and its practical application has certain limitations.

In addition, in the above-mentioned existing 3D grid digital watermarking algorithms, pseudo-random sequences or Amold transforms are often used to scramble and encrypt the watermark image as embedded watermark information. Due to the low linear complexity of pseudo-random sequences, Amold transform encryption is vulnerable to exhaustive attacks. , the above algorithm has the outstanding problem that it is easy to be decrypted and imitated, and cannot be accurately authenticated for anti-counterfeiting

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