Abstract
Projectors are increasingly being used as light-sources in computer vision applications. In several applications, they are modeled as point light sources, thus ignoring the effects of illumination defocus. In addition, most active vision techniques assume that a scene point is illuminated only directly by the light source, thus ignoring global light transport effects. Since both defocus and global illumination co-occur in virtually all scenes illuminated by projectors, ignoring them can result in strong, systematic biases in the recovered scene properties. To make computer vision techniques work for general real world scenes, it is thus important to account for both these effects.
In this paper, we study the interplay between defocused illumination and global light transport. We show that both these seemingly disparate effects can be expressed as low pass filters on the incident illumination. Using this observation, we derive an invariant between the two effects, which can be used to separate the two. This is directly useful in scenarios where limited depth-of-field devices (such as projectors) are used to illuminate scenes with global light transport and significant depth variations. We show applications in two scenarios: (a) accurate depth recovery in the presence of global light transport, and (b) factoring out the effects of illumination defocus for correct direct-global component separation. We demonstrate our approach using scenes with complex shapes, reflectance properties, textures and translucencies.
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Atcheson, B., Ihrke, I., Heidrich, W., Tevs, A., Bradley, D., Magnor, M., & Seidel, H. (2008). Time-resolved 3d capture of non-stationary gas flows. In SIGGRAPH.
Bai, J., Chandraker, M., Ng, T.-T., & Ramamoorthi, R. (2010). A dual theory of inverse and forward light transport. In ECCV.
Bouguet, J.-Y., & Perona, P. (1998). 3d photography on your desk. In Proc. IEEE ICCV.
Chen, T., Lensch, H. P. A., Fuchs, C., & Seidel, H.-P. (2007). Polarization and phase-shifting for 3d scanning of translucent objects. In CVPR.
Chen, T., Seidel, H.-P., & Lensch, H. P. A. (2008). Modulated phase-shifting for 3d scanning. In CVPR.
Fuchs, C., Heinz, M., Levoy, M., Seidel, H.-P., & Lensch, H. P. A. (2008). Combining confocal imaging and descattering. Computer Graphics Forum, 27(4), 1245–1253.
Garg, G., Talvala, E.-V., Levoy, M., & Lensch, H. P. A. (2006). Symmetric photography: Exploiting data-sparseness in reflectance fields. In EGSR.
Godin, G., Beraldin, J.-A., Rioux, M., Levoy, M., Cournoyer, L., & Blais, F. (2001). An assessment of laser range measurement of marble surfaces. In Fifth conference on optical 3-D measurement techniques.
Gu, J., Nayar, S. K., Grinspun, E., Belhumeur, P. N., & Ramamoorthi, R. (2008). Compressive structured light for recovering inhomogeneous participating media. In ECCV.
Gupta, M., Tian, Y., Narasimhan, S. G., & Zhang, L. (2009). (De) focusing on global light transport for active scene recovery. In Proc. IEEE CVPR.
Hardy, A. (1967). How large is a point source? Journal of Optical Society of America, 57(1), 44–47.
Hasinoff, S. W., & Kutulakos, K. N. (2006). Confocal stereo. In ECCV (1).
Hawkins, T., Einarsson, P., & Debevec, P. (2005). Acquisition of time-varying participating media. In SIGGRAPH.
Horn, B. (1975). Obtaining shape from shading information. The Psychology of Computer Vision19(1), 115–155.
Hullin, M. B., Fuchs, M., Ihrke, I., Seidel, H.-P., & Lensch, H. P. A. (2008). Fluorescent immersion range scanning. In SIGGRAPH.
Kutulakos, K. N., & Steger, E. (2008). A theory of refractive and specular 3d shape by light-path triangulation. IJCV, 76(1), 13–29.
Levin, A., Fergus, R., Durand, F., & Freeman, B. (2007). Image and depth from a conventional camera with a coded aperture. In SIGGRAPH.
Levoy, M., Chen, B., Vaish, V., Horowitz, M., McDowall, I., & Bolas, M. (2004). Synthetic aperture confocal imaging. In SIGGRAPH.
Liu, S., Ng, T.-T., & Matsushita, Y. (2010). Shape from second-bounce of light transport. In ECCV.
Morris, N. J. W., & Kutulakos, K. N. (2007). Reconstructing the surface of inhomogeneous transparent scenes by scatter-trace photography. In ICCV.
Mukaigawa, Y., Yagi, Y., & Raskar, R. (2010). Analysis of light transport in scattering media. In CVPR.
Narasimhan, S. G., Gupta, M., Donner, C., Ramamoorthi, R., Nayar, S. K., & Jensen, H. W. (2006). Acquiring scattering properties of participating media by dilution. ACM Transactions on Graphics, 25(3), 1003–1012.
Narasimhan, S. G., & Nayar, S. K. (2002). Vision and the atmosphere. IJCV, 48(3), 233–254.
Narasimhan, S. G., Nayar, S. K., Sun, B., & Koppal, S. J. (2005). Structured light in scattering media. In Proc. IEEE ICCV (pp. 420–427).
Nayar, S., Ikeuchi, K., & Kanade, T. (1991). Shape from Interreflections. IJCV, 6(3), 173–195.
Nayar, S. K., Krishnan, G., Grossberg, M. D., & Raskar, R. (2006). Fast separation of direct and global components of a scene using high frequency illumination. In SIGGRAPH.
Nayar, S. K., & Nakagawa, Y. (1994). Shape from focus. PAMI, 16(8), 824–831.
O’Toole, M., & Kutulakos, K. N. (2010). Optical computing for fast light transport analysis. In Proc. SIGGRAPH Asia.
Schechner, Y. Y., & Kiryati, N. (2000). Depth from defocus vs. stereo: How different really are they? IJCV, 39(2), 141–162.
Seitz, S. M., Matsushita, Y., & Kutulakos, K. N. (2005). A theory of inverse light transport. In ICCV.
Sen, P., Chen, B., Garg, G., Marschner, S. R., Horowitz, M., Levoy, M., & Lensch, H. P. A. (2005). Dual photography. In SIGGRAPH.
Subbarao, M., & Lu, M.-C. (1992). Computer modeling and simulation of camera defocus. In Machine vision and applications (pp. 277–289).
Treibitz, T., & Schechner, Y. Y. (2006). Instant 3Descatter. In Proc. IEEE CVPR (Vol. 2, pp. 1861–1868).
Watanabe, M., & Nayar, S. (1998). Rational filters for passive depth from defocus. IJCV, 27(3), 203–225.
Woodham, R. (1980). Photometric method for determining surface orientation from multiple images. OptEng, 19(1), 139–144.
Zhang, L., & Nayar, S. K. (2006). Projection defocus analysis for scene capture and image display. In SIGGRAPH.
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Gupta, M., Tian, Y., Narasimhan, S.G. et al. A Combined Theory of Defocused Illumination and Global Light Transport. Int J Comput Vis 98, 146–167 (2012). https://doi.org/10.1007/s11263-011-0500-9
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DOI: https://doi.org/10.1007/s11263-011-0500-9