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Proxy Plane Fitting for Line Light Field Rendering. Presented by Luv Kohli COMP238 December 17, 2002. Group Teleimmersion. Project in UNC’s Office of the Future group Goal: create a system for many-to-many video teleconferencing
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Proxy Plane Fitting for Line Light Field Rendering Presented by Luv Kohli COMP238 December 17, 2002
Group Teleimmersion • Project in UNC’s Office of the Future group • Goal: create a system for many-to-many video teleconferencing • Attempt to provide best approximate view for all participants while maintaining sense of presence
Approach • Use light field rendering techniques to create novel views of participants • Participant’s viewpoint tends to be limited to eye level with small lateral motions • Motivation for using a 1D linear array of cameras instead of a full 2D setup
Line Light Field • Less data required, so real-time capture, transmission, and rendering possible
Multiple focal planes • Current system only allows one focal plane • Background out of focus • Participants out of focus if they move away from focal plane • Use plane fitting and multiple focal planes instead
(u,v) C1 C2 Plane fitting • Determine a focal plane for each participant using stereo correlation of silhouette points • Epipolar constraint:
Plane fitting (2) • Segment foreground objects out • Find silhouette points • Use stereo correlation of silhouette points to find approximate plane • Silhouette point in one image corresponds to epipolar line in second image
Multiple focal planes • Use techniques described in Dynamically Reparameterized Light Fields (Isaksen, McMillan, Gortler) paper • Conceptually, shoot a ray through light field and determine which focal planes it intersects • Choose focal plane closest to geometry in scene – use scoring function σ
Issues and future work • Implementation issues • Will plane-fitting and multiple focal planes be viable in a real-time networking environment? • Work can be done in parallel • Will this enhance the feeling of immersion?
References • "Creating Adaptive Views for Group Video Teleconferencing -- An Image-Based Approach " Ruigang Yang, Celso Kurashima, Andrew Nashel, Herman Towles, Anselmo Lastra, Henry Fuchs. Presented at International Workshop on Immersive Telepresence, December 6, 2002, Juan Les Pins, France. • S. J. Gortler, R. Grzeszczuk, R. Szeliski, and M.F. Cohen. The Lumigraph. In Proceedings of SIGGRAPH 1996, pages 43-54, New Orleans, August 1996.
References • M. Levoy and P. Hanrahan. Light Field Rendering. In Proceedings of SIGGRAPH 1996, pages 31-42, New Orleans, August 1996. • A. Isaksen, L. McMillan, and S. J. Gortler. Dynamically reparameterized light fields. Technical Report LCS-TR-778, Massachusetts Institute of Technology, May 1999.
References • C. Kurashima, R. Yang, A. Lastra. Combining Approximate Geometry with View-Dependent Texture Mapping – A Hybrid Approach to 3D Video Teleconferencing. Presented at SIBGRAPI 2002, XV Brazilian Symposium on Computer Graphics and Image Processing (07 – 10 October 2002, Fortaleza, CE, Brazil). • L. McMillan and Gary Bishop. Plenoptic Modeling: An Image-Based Rendering System. In Proceedings of SIGGRAPH 1995, pages 39-46, 1995.