Abstract
We describe a unified representation of occluders in light transport and photography using shield fields: the 4D attenuation function which acts on any light field incident on an occluder. Our key theoretical result is that shield fields can be used to decouple the effects of occluders and incident illumination. We first describe the properties of shield fields in the frequency-domain and briefly analyze the "forward" problem of efficiently computing cast shadows. Afterwards, we apply the shield field signal-processing framework to make several new observations regarding the "inverse" problem of reconstructing 3D occluders from cast shadows -- extending previous work on shape-from-silhouette and visual hull methods. From this analysis we develop the first single-camera, single-shot approach to capture visual hulls without requiring moving or programmable illumination. We analyze several competing camera designs, ultimately leading to the development of a new large-format, mask-based light field camera that exploits optimal tiled-broadband codes for light-efficient shield field capture. We conclude by presenting a detailed experimental analysis of shield field capture and 3D occluder reconstruction.
Supplemental Material
- Accorsia, R., Gasparini, F., and Lanza, R. C. 2001. Optimal coded aperture patterns for improved SNR in nuclear medicine imaging. Nuclear Instruments and Methods in Physics Research A 474, 3, 273--284.Google ScholarCross Ref
- Adelson, T., and Wang, J. 1992. Single lens stereo with a plenoptic camera. IEEE TPAMI 14, 2, 99--106. Google ScholarDigital Library
- BowHaus, Inc., 2007. BowHaus LVT specs and resolutions. http://www.bowhaus.com/services/lvtspecs.php4.Google Scholar
- Chai, J.-X., Tong, X., Chan, S.-C., and Shum, H.-Y. 2000. Plenoptic sampling. In SIGGRAPH, 307--318. Google Scholar
- Debevec, P., Hawkins, T., Tchou, C., Duiker, H.-P., Sarokin, W., and Sagar, M. 2000. Acquiring the reflectance field of a human face. In SIGGRAPH, 145--156. Google Scholar
- Durand, F., Holzschuch, N., Soler, C., Chan, E., and Sillion, F. X. 2005. A frequency analysis of light transport. ACM Trans. Graph. 24, 3, 1115--1126. Google ScholarDigital Library
- Farid, H. 1997. Range Estimation by Optical Differentiation. PhD thesis, University of Pennsylvania. Google Scholar
- Fenimore, E., and Cannon, T. 1978. Coded aperture imaging with uniformly redundant arrays. Appl. Optics 17, 3, 337--347.Google ScholarCross Ref
- Georgiev, T., Zheng, K. C., Curless, B., Salesin, D., Na-yar, S., and Intwala, C. 2006. Spatio-angular resolution tradeoffs in integral photography. In EGSR, 263--272. Google Scholar
- Goodman, J. W. 1996. Introduction to Fourier Optics.Google Scholar
- Gortler, S. J., Grzeszczuk, R., Szeliski, R., and Cohen, M. F. 1996. The lumigraph. In SIGGRAPH, 43--54. Google Scholar
- Gross, M., Würmlin, S., Naef, M., Lamboray, E., Spagno, C., Kunz, A., Koller-Meier, E., Svoboda, T., Gool, L. V., Lang, S., Strehlke, K., Moere, A. V., and Staadt, O. 2003. blue-c: a spatially immersive display and 3d video portal for telepresence. ACM Trans. Graph. 22, 3, 819--827. Google ScholarDigital Library
- Isaksen, A., McMillan, L., and Gortler, S. J. 2000. Dynamically reparameterized light fields. In SIGGRAPH, 297--306. Google Scholar
- Ives, H. E. 1928. Camera for making parallax panoramagrams. J. Opt. Soc. of America 17, 435--439.Google ScholarCross Ref
- Levin, A., Fergus, R., Durand, F., and Freeman, W. T. 2007. Image and depth from a conventional camera with a coded aperture. ACM Trans. Graph. 26, 3, 70. Google ScholarDigital Library
- Levoy, M., and Hanrahan, P. 1996. Light field rendering. In SIGGRAPH, 31--42. Google Scholar
- Lippmann, G. 1908. Epreuves reversible donnant la sensation du relief. Journal of Physics 7, 4, 821--825.Google Scholar
- Matusik, W., Buehler, C., and McMillan, L. 2001. Polyhedral visual hulls for real-time rendering. In EGSR, 115--126. Google Scholar
- Nayar, S. K., Krishnan, G., Grossberg, M. D., and Raskar, R. 2006. Fast separation of direct and global components of a scene using high frequency illumination. ACM Trans. Graph. 25, 3, 935--944. Google ScholarDigital Library
- Ng, R., Levoy, M., Brédif, M., Duval, G., Horowitz, M., and Hanrahan, P. 2005. Light field photography with a hand-held plenoptic camera. Tech. rep., Stanford University.Google Scholar
- Ng, R. 2005. Fourier slice photography. ACM Trans. Graph. 24, 735--744. Google ScholarDigital Library
- Ramamoorthi, R., Koudelka, M., and Belhumeur, P. 2005. A fourier theory for cast shadows. IEEE TPAMI 27, 2, 288--295. Google ScholarDigital Library
- Ramamoorthi, R., Mahajan, D., and Belhumeur, P. 2007. A first-order analysis of lighting, shading, and shadows. ACM Trans. Graph. 26, 1, 2. Google ScholarDigital Library
- Raskar, R., Agrawal, A., and Tumblin, J. 2006. Coded exposure photography: motion deblurring using fluttered shutter. ACM Trans. Graph. 25, 3, 795--804. Google ScholarDigital Library
- Savarese, S., Rushmeier, H., Bernardini, F., and Per-ona, P. 2001. Shadow carving. In ICCV, 190--197.Google Scholar
- Soler, C., and Sillion, F. X. 1998. Fast calculation of soft shadow textures using convolution. In SIGGRAPH, 321--332. Google Scholar
- Talvala, E.-V., Adams, A., Horowitz, M., and Levoy, M. 2007. Veiling glare in high dynamic range imaging. ACM Trans. Graph. 26, 3, 37. Google ScholarDigital Library
- Thornber, K., and Jacobs, D. 2001. Cast shadows and linear subspaces. Tech. rep. TR-2001-100, NEC.Google Scholar
- Veeraraghavan, A., Raskar, R., Agrawal, A., Mohan, A., and Tumblin, J. 2007. Dappled photography: Mask enhanced cameras for heterodyned light fields and coded aperture refocusing. ACM Trans. Graph. 26, 3, 69. Google ScholarDigital Library
- Vlasic, D., Pfister, H., Molinov, S., Grzeszczuk, R., and Matusik, W. 2003. Opacity light fields: Interactive rendering of surface light fields with view-dependent opacity. In Symposium on Interactive 3D Graphics (i3D), 65--74. Google Scholar
- Wilburn, B., Joshi, N., Vaish, V., Talvala, E.-V., An-tunez, E., Barth, A., Adams, A., Horowitz, M., and Levoy, M. 2005. High performance imaging using large camera arrays. ACM Trans. Graph. 24, 3, 765--776. Google ScholarDigital Library
- Wood, D., Azuma, D., Aldinger, K., Curless, B., Duchamp, T., Salesin, D., and Stuetzle, W. 2000. Surface light fields for 3d photography. In SIGGRAPH, 287--296. Google Scholar
- Yamazaki, S., Narasimhan, S. G., Baker, S., and Kanade, T. 2007. Coplanar shadowgrams for acquiring visual hulls of intricate objects. In ICCV, 1--8.Google Scholar
- Zhou, K., Hu, Y., Lin, S., Guo, B., and Shum, H.-Y. 2005. Precomputed shadow fields for dynamic scenes. ACM Trans. Graph. 24, 3, 1196--1201. Google ScholarDigital Library
- Zwicker, M., Matusik, W., Durand, F., and Pfister, H. 2006. Antialiasing for automultiscopic displays. In EGSR, 1--10. Google Scholar
Index Terms
- Shield fields: modeling and capturing 3D occluders
Recommendations
Shield fields: modeling and capturing 3D occluders
SIGGRAPH Asia '08: ACM SIGGRAPH Asia 2008 papersWe describe a unified representation of occluders in light transport and photography using shield fields: the 4D attenuation function which acts on any light field incident on an occluder. Our key theoretical result is that shield fields can be used to ...
Phasor Imaging: A Generalization of Correlation-Based Time-of-Flight Imaging
In correlation-based time-of-flight (C-ToF) imaging systems, light sources with temporally varying intensities illuminate the scene. Due to global illumination, the temporally varying radiance received at the sensor is a combination of light received ...
Glare aware photography: 4D ray sampling for reducing glare effects of camera lenses
Glare arises due to multiple scattering of light inside the camera's body and lens optics and reduces image contrast. While previous approaches have analyzed glare in 2D image space, we show that glare is inherently a 4D ray-space phenomenon. By ...
Comments