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Surface Light Fields for 3D Photography. Daniel N. Wood University of Washington SIGGRAPH 2001 Course. Collaborators ( and co-authors on SIGGRAPH 2000 paper ). Daniel Azuma Wyvern Aldinger Brian Curless Tom Duchamp David Salesin Werner Stuetzle University of Washington. Outline.
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Surface Light Fieldsfor 3D Photography Daniel N. Wood University of Washington SIGGRAPH 2001 Course
Collaborators(and co-authors on SIGGRAPH 2000 paper) Daniel Azuma Wyvern Aldinger Brian Curless Tom Duchamp David Salesin Werner Stuetzle University of Washington
Outline • Surface light field representation • Compression primer • Surface light fields for 3D photography • With details of compression • And a preliminary look at a new compression algorithm
Lumisphere-valued “texture” maps Lumisphere
q s Surface light fields in flatland
q s Surface light fields in flatland
q s Surface light fields in flatland
Compression primer • Singular value decomposition(or principal components analysis) • Handling color • Using regions • Reflection parameterization • Vector quantization • Others… (Wavelets, DCT)
Singular value decomposition U VT SLF
SVD in two matrices Eigen Lumispheres Eigen Textures SLF
First eigenvectors Eigen Lumispheres Eigen Textures SLF First eigentexture and corresponding first eigenlumisphere
~ ~ Truncated SVD Eigen-lumisphere = Eigen-texture Outer product of first eigen-texture and first eigen-lumisphere is closest rank 1 (separable) matrix.
Handling color Separate matrices Colors in directions (rows) Colors in surface texture (columns)
Handling color Separate matrices Colors in directions (rows) Colors in surface texture (columns) Chen et al. Wood et al. Nishino et al.
SVD in color Eigen Lumispheres Eigen Textures SLF
Zooming in… Eigen Lumispheres Eigen Textures SLF
Zoom into important vectors ... . . . SLF
Reconstruction using SVD Original Rank 1 Rank 7 (1:20)
Surface light field structure Rows are points on surface What are the columns? And, can they be made more coherent?
Surface light field structure • Rows are points on surface • Increasing column coherence: • Break into regions, and / or • Use reflection parameterization
Separate SVD for regions Eigen Lumispheres Eigen Textures Eigen Lumispheres Eigen Textures
Reconstruction using regions Original One region (Rank 5) Two regions (Rank 5)
Un-reflected Reflected Reflection in flatland* *sort of
q q Reflection doesn’t happenin the plane Un-reflected Reflected
Reflection in 3 space Un-reflected Reflected
Reflection in “flatland” Un-reflected Reflected Original Rank 5 Original Rank 5
Other compression strategies • Discrete cosine transform [ Miller et al. 1999– Eurographics Workshop on Rendering] • Vector quantization [ Wood et al. 2000 - SIGGRAPH ] • Wavelet decomposition [ Magnor and Girod 2000 - SPIE VCIP]
Vector quantization (unreflected) Uncompressed Codebook Vector- quantized
Vector quantization (reflected) Uncompressed Codebook Vector- quantized
Surface light fields for 3D photography(SIGGRAPH 2000) • Goals • Rendering and editing • Inputs • Photographs and geometry • Requirements • Estimation and compression
Overview Data acquisition Estimation and compression Rendering Editing
Overview Data acquisition Estimation and compression Rendering Editing
Scan and reconstruct geometry Range scans (only a few shown . . .) Reconstructed geometry
Take photographs Camera positions Photographs
Register photographs to geometry Photographs Geometry
Register photographs to geometry User selected correspondences (rays)
Parameterizing the geometry Map Scanned geometry Base mesh
Sample base mesh faces Base mesh Detailed geometry
Assembling data lumispheres Data lumisphere
Overview Data acquisition Estimation and compression Rendering Editing
Pointwise fairing Faired lumisphere Data lumisphere
Pointwise fairing results Pointwise faired (177 MB) Input photograph
Pointwise fairing Many faired lumispheres Many input data lumispheres
Compression Small set of prototypes
Compression / Estimation Many input data lumispheres Small set of prototypes
Median removal Reflected Median (“diffuse”) + + Median-removed (“specular”)