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debevec

Discover the techniques for capturing the human face's reflectance field, relighting faces and objects with any illumination, and extrapolating human reflectance for new viewpoints. Explore the methodology developed by Paul Debevec, Tim Hawkins, and others at UC Berkeley and USC Institute for Creative Technologies. This study delves into advanced concepts such as in-plane reflectometry measurements, separating reflectance components, and transforming reflectance functions. Learn about the lighting through image recombination, specular and subsurface components, color space techniques, and ongoing work to animate faces and capture spectral samples. Experience the innovative technology behind the Light Stage apparatus and the Interactive Lighting Demo at SIGGRAPH 2000. This research represents a significant contribution to digital media innovation and interactive pictures. Join us in the exploration of lighting reflectance functions and the potential for creative applications in rendering realistic facial expressions. Stay informed about updates and future developments in the field of digital media and computer graphics.

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debevec

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  1. Acquiring the Reflectance Fieldof a Human Face www.debevec.org UC Berkeley / USC Institute for Creative Technologies / LifeF/X Paul Debevec, Tim Hawkins, Chris Tchou, H.P. Duiker, Westley Sarokin, and Mark Sagar

  2. Rendering with Natural Light Fiat Lux

  3. Related Work Hanrahan and Krueger. Reflection from Layered Surfaces due to Subsurface Scattering. SIGGRAPH 93 Bregler et al. Video Rewrite. SIGGRAPH 97 Guenter et al. Making Faces. SIGGRAPH 98 Pighin et al. Synthesizing Realistic Facial Expressions from Photographs. SIGGRAPH 98 Sagar et al. The Jester. SIGGRAPH 99 ET Marschner et al. Reflectance Measurements of Human Skin. 1999

  4. The Reflectance Field

  5. The Reflectance Field

  6. The Reflectance Field

  7. The Reflectance Field Ri( ui ,vi ,qi ,fi ) incident light field

  8. The Reflectance Field Ri( ui ,vi ,qi ,fi ) Rr ( ur ,vr ,qr ,fr ) incident light field radiant light field

  9. The Reflectance Field Ri( ui ,vi ,qi ,fi ; ur ,vr ,qr ,fr) 8D reflectance field

  10. 4D Slices of the 8D Reflectance Field Ri( ui ,vi ,qi ,fi ; ur ,vr ,qr ,fr)

  11. The Light Stage

  12. The Light Stage:60-second exposure

  13. Original Resolution: 6432 Light Stage Data Lighting through image recombination: Haeberli ‘92, Nimeroff ‘94, Wong ‘97

  14. Light Stage Results Environments from the Light Probe Image Gallery www.debevec.org

  15. Reflectance Functions

  16. 1 1 DCT Basis Smith and Rowe. Compressed domain processing of JPEG-encoded images. 1996 Lighting Reflectance Functions normalized light map reflectance function lighting product rendered pixel

  17. Interactive Lighting DemoSIGGRAPH 2000 Creative Applications Laboratory

  18. Interactive Lighting DemoSIGGRAPH 2000 Creative Applications Laboratory

  19. Changing the Viewpoint

  20. Reflection of Light from Skin • Specular Component:Color of light, shiny, brighter near grazing, maintains polarization • Subsurface Component:Color of skin, diffuse, desaturated near grazing, scrambles polarization After Hanrahan ‘93 (After Hanrahan and Krueger 93)

  21. Separating Reflectance Components using Crossed Polarizers Normal Image Subsurface Component Specular Component Colorspace techniques - Sato ‘94, Nayar ‘97

  22. Original RF Specular Component Shifted and ScaledSpecular Subsurface Component Surface Normal Estimate Final RF Comparison RF Transforming a Reflectance Function => Torrance-Sparrow microfacet distribution

  23. Point-Source Comparison Original Image Novel Viewpoint

  24. Spatially-VaryingReflectance Parameters Surface Normalsn Diffuse Albedord SpecularIntensityks Specular Roughnessa

  25. Original Image Light Probe Rendered Face Composite Compositing Test

  26. 4. Ongoing Work • Animate the faces • Capture more spectral samples • Use high-speed cameras to achieve real-time capture

  27. 5. Conclusion • We have presented: • The light stage apparatus for capturing slices of the reflectance field of the human face • A technique for correctly relighting faces and objects with arbitrary illumination • A technique for extrapolating human reflectance to novel viewpoints

  28. Thanks Digital Media Innovation Program Interactive Pictures Corporation Alias|Wavefront UCB Digital Digital Media/New Genre Program ONR/BMDO Cornell Program of Computer Graphics Berkeley Millennium Project and Shawn Brixey, Bill Buxton, Larry Rowe, Jessica Vallot, Patrick Wilson, Melanie Levine, Eric Paulos, Christine Waggoner, Holly Cim, Eliza Ra, Bryan Musson, David Altenau, Marc Levoy, Maryann Simmons, Henrik Wann Jensen, Don Greenberg, Pat Hanrahan, Randal Kleiser, Chris Bregler, Michael Naimark, Dan Maas, Steve Marschner, and Kevin Binkert.

  29. qi qi qr qr In-plane Reflectometry Measurements • Subsurface exhibits chromaticity falloff • Specular is monochromatic with Torrance-Sparrow microfacet behavior Subsurface Subsurface + Specular

  30. Reflectometry Experiment

  31. The JesterSIGGRAPH 99 Electronic TheaterMark Sagar et al. - LifeF/X, Inc.Performance and Text: Jessica Vallot

  32. Changing the Viewpoint Model from Structured Lighting

  33. Traditional Approach • Derive reflectance parameters for each point on the face’s surface • Map the parameters onto a geometric model of the face • Render using traditional methods

  34. Reflectance Function Mosaic

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