August 24, 2PM, ICS 432

Advancement to Candidacy for Yan Huang

Committee members

• Prof. M. Gopi (Chair)
• Prof. Jim Arvo
• Prof. Aditi Majumder
• Prof. Tony Givargis
• Prof. Joerg Meyer

Title: Progressive Compression of Point-Based 3D Models

Point-based 3D models represent objects by a large number of points sampled from an object' surface. The point cloud describes the 3D geometry, normal, diffuse colors and other attributes of an object. Compared to polygon models, point-based 3D models illustrate highly detailed objects more readily and can be rendered more efficiently. However, millions of points are typically needed to achieve satisfactory visual quality and huge amount of model data makes a raw point-based 3D model inappropriate for Internet applications. To solve this problem, progressive model compression and transmission have been investigated by researchers. When progressively compressed and transmitted, a 3D model can be reconstructed continuously from coarse to fine levels of detail (LODs) by the decoder while the bit stream is being received.

In this talk, two different schemes are proposed, namely Progressive Compression for Arbitary Point-Based 3D Models and Progressive Compression of Point-Based 2-Manifolds. The first scheme uses an octree structure to organize a point cloud hierachically and encodes the difference between each two continuous octree levels progressively. The second scheme explores a hybrid (triangular mesh + point) representation of 3D models in order to achieve a high compression ratio for 2 manifolds. In this talk, both schemes will be discussed in detail and preliminary results of scheme 1 will be provided, demonstrating the high coding efficiency of the proposed octree-based coder.

August 24, 12PM, ICS 432

Pablo Diaz-Gutierrez will be giving practice talks for the following papers:

• Pablo Diaz-Gutierrez, M. Gopi, Renato Pajarola, Hierarchyless Simplification, Stripification and Compression of Triangulated Two-Manifolds, in Computer Graphics Forum (EUROGRAPHICS 2005).
• Koel Das, Pablo Diaz-Gutierrez and M.Gopi Sketching Free-form Surfaces Using Network of Curves, in Eurographics Workshop on Sketch Based Interfaces and Modeling, 2005.

August 19, 3PM, ICS 432

Masaki Kitago will give a talk. He suggests reading the following papers before the talk is given:

• J.C.Carr, R.K.Beatson, J.B.Cherrie, T.J.Mitchell, W.R.Fright, B.C.McCallum, and T.R.Evans: "Reconstruction and Representation of 3D Objects with Radial Basis Functions", In Proceedings of ACM SIGGRAPH 2001.
• Yutaka Ohtake, Alexander Belyaev, Marc Alexa, Greg Turk, and Hans-Peter Seidel: "Multi-level Partition of Unity Implicits", In Proceedings of ACM SIGGRAPH 2003.
• Chen Shen, James F. O'Brien, and Jonathan R. Shewchuk: "Interpolating and Approximating Implicit Surfaces from Polygon Soup" In Proceedings of ACM SIGGRAPH 2004.