A robust watermarking scheme for 3D triangular mesh models

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A robust watermarking scheme for 3D triangular
mesh models

• Pattern Recognition Volume 36, Issue 11,
  November, 2003, pp. 2603-2614
• Yu, Zhiqiang Ip, Horace H.S. Kwok, L.F.
• University of Hong Kong
• Northwestern Polytechnical University
• Speaker Jen-Bang Feng

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Outline

• Introduction
• Attacks on watermarks for 3D models
• The proposed scheme
• Controlling parameters
• Experimental results
• Conclusion
• Future works (Feng's)

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Introduction

• Previously methods
• Triangle similarity quadruple (TSQ)
• Tetrahedral volume ratio (TVR)
• Mesh density pattern
• Modifying the surface normals
• Extend 2D to 3D surface
• Multi-resolution methods
• Designed issues
• Robust against variety of attacks
• Imperceptibly with possible strength
• Extract watermarks
• This paper proposed a new watermarking scheme for
  triangle meshes and focuses on robustness.

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Attacks on watermarks for 3D models

• Rotation, translation, and uniform scaling
• Polygon simplification
• Mesh smoothing
• Re-meshing
• Reordering of points
• Topology changing
• Adding white noise
• Local deformation
• Cropping

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Block diagram for watermark embedding
Divided the vertices into N sections
Original Mesh
Scramble the vertices
Modify the length from vertex to center
Secure key
Pseudorandom generator
Watermarked mesh
Recover the original order of the vertices
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Block diagram for watermark detection
Scramble and divide the vertices into N sections
Compute the length from vertex to center of
each section
Mesh For detection
Registration
Re-sampling
Divided the vertices into N sections
Compute the length from vertex to center of
each section
Original Mesh
Scramble the vertices
Extract watermark
Compute correlation value
Secure key
Pseudorandom generator
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Controlling parameters for watermarking strength

• Controlling the locally adaptive watermarking
  strength
• Weighted process for watermarking detection

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Experimental results
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Experimental results
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Experimental results
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Experimental results
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Conclusion

• A robust watermarking scheme by modifying the
  local geometry of the model.
• Develop a weighting process for watermarking
  detect.
• Robust against
• Polygon mesh simplification
• Addition of random noise ?
• Model cropping
• And combination of these attacks
• Mesh smoothing, re-meshing, and topology changing
  are not discussed.

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Future works (Feng's)

• Store secrets in
• Sequence of polygons by size
• Characteristic of polygons
• Special polygons
• Sequence of points
• Special relation between points
• Special set of points
• Textures
• Relation between sub-models
• Attack methods
• Random vibrations (shake)
• Detect methods