Princeton > CS Dept > PIXL > Graphics > Lunch Local Access 


The PIXL lunch meets every Monday during the semester at noon in room 402 of the Computer Science building. To get on the mailing list to receive announcements, sign up for the "pixl-talks" list at lists.cs.princeton.edu.

Upcoming Talks


Monday, February 15, 2010
Symmetry-Guided Texture Synthesis and Manipulation
Vladimir Kim

Abstract
This paper presents a framework for symmetry-guided texture synthesis and processing. It is motivated by the long-standing problem of how to optimize, transfer, and control the spatial patterns in textures. The key idea is that symmetry representations that measure autocorrelations with respect to all transformations of a group are a natural way to describe spatial patterns in many real-world textures. To leverage this idea, we provide methods to transfer symmetry representations from one texture to another, process the symmetries of a texture, and optimize textures with respect to properties of their symmetry representations. These methods are automatic and robust, as they don't require explicit detection of discrete symmetries. Applications are investigated for optimizing, processing and transferring symmetries and textures.


Monday, February 22, 2010
Yaron Lipman


Monday, March 01, 2010
Connelly Barnes


Monday, March 08, 2010
Corey Toler-Franklin


Monday, March 15, 2010
None (Spring Break)


Monday, March 22, 2010
Martin Fuchs


Monday, March 29, 2010
Linjie Luo


Monday, April 05, 2010
Jian Sun


Monday, April 12, 2010
Aleksey Boyko


Monday, April 19, 2010
Xiaobai Chen


Previous Talks


Monday, February 01, 2010
Fundamentals in Computational Conformal Geometry
David Gu, SUNY Stony Brook

Abstract
Conformal mappings preserve angles, the angle structure on a surface is called the conformal structure. Conformal geometry studies the invariants under conformal transformation group. Conformal structure is more rigid than topological structure and more flexible than Riemannian metric structure, therefore it plays important roles in engineering fields.

The fundamental tasks in computational conformal geometry include:

1. Given a Riemannian metric on a surface with an arbitrary topology, determine the corresponding conformal structure.

2. Compute the complete conformal invariants (conformal modules), which are the coordinates of the surface in the Teichmuller shape space.

3. Verify whether there exists a conformal mapping between two metric surfaces. If yes, construct the mapping; otherwise, find the best mapping that is cloest to the conformal mapping.

3. Fix the conformal structure, find the simplest Riemannian metric among all possible Riemannian metrics

4. Given desired Gaussian curvature, compute the corresponding Riemannian metric.

5. Given the distortion between two conformal structures, compute the quasi-conformal mapping.

The methods to tackle these tasks will be introduced. Applications in graphics, vision, medical imaging, geometric modeling and network will be briefly explained.


Monday, February 08, 2010
Dynamic Solid Textures for Real-Time Coherent Stylization
Pierre Bénard

Abstract
Stylized rendering methods, which aim at depicting 3D scenes with 2D marks such as pigments or strokes, are often faced with temporal coherence issues when applied to dynamic scenes. These issues arise from the difficulty of having to satisfy two contrary goals: ensuring that the style marks follow 3D motions while preserving their 2D appearance. In this paper we describe a new texture based method for real-time temporally coherent stylization called dynamic textures. A dynamic texture is a standard texture mapped on the object and enriched with an infinite zoom mechanism. This simple and fast mechanism maintains quasi-constant size and density of texture elements in screen space for any distance from the camera. We show that these dynamic textures can be used in many stylization techniques, enforcing the 2D appearance of the style marks while preserving the accurate 3D motion of the depicted objects.

Although our infinite zoom technique can be used with both 2D or 3D textures, we focus in this paper on the 3D case (dynamic solid textures) which avoids the need for complex parameterizations of 3D surfaces. This makes dynamic textures easy to integrate in existing rendering pipelines with almost no loss in performance, as demonstrated by our implementation in a game rendering engine.

Bio
INRIA, Grenoble. Visiting student at Princeton.