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Structure of light fields in natural scenes.
Alexander A Mury1, Sylvia C Pont, Jan J Koenderink
1Delft University of Technology, Faculty of Industrial Design Engineering, Landbergstraat 15, 2628 CE Delft, The Netherlands.
Applied Optics
|October 3, 2009
Summary
Natural scene light fields exhibit structural similarities based on geometry. Low-order approximations, like the light vector and squash tensor, capture essential properties, enabling efficient light field measurement and interpolation.
Area of Science:
- Optics and Photonics
- Computer Vision
- Computational Geometry
Background:
- Light fields in natural scenes are complex and spatially variable.
- Low-order approximations of light fields are often sufficient for applications.
- Understanding light field structure is crucial for scene analysis and rendering.
Purpose of the Study:
- To investigate the structure of light fields in natural scenes.
- To analyze the spatial variation and properties of light fields using spherical harmonics.
- To study the behavior of first- and second-order light field approximations.
Main Methods:
- Describing light field structure using spherical harmonics.
- Analyzing spatial variations and qualitative properties over different scene geometries.
- Empirical measurements and modeling of local light fields using a novel device, the Plenopter.
- Measuring light fields in terms of spherical harmonics up to the second order.
Main Results:
- Structurally similar light fields were found in scenes with similar geometries, suggesting a link between light fields and geometry.
- The first-order term (light vector) and the second-order quadrupole component (squash tensor) effectively approximate local light fields.
- Smooth spatial variation of low-order light field components was observed.
Conclusions:
- Light fields can be considered a property of scene geometry.
- Measuring light fields at a few points and using interpolation can be sufficient to reconstruct the light field across a scene.
- The Plenopter device enables accurate measurement of second-order light field approximations.
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