Diffuse Mirrors: 3D Reconstruction from Diffuse Indirect Illumination Using Inexpensive Time-of-Flight Sensors

Felix Heide, Lei Xiao, Wolfgang Heidrich, and Matthias B. Hullin
In proceedings of IEEE Conference on Computer Vision and Pattern Recognition (CVPR), pages to appear, June 2014
 

Abstract

The functional difference between a diffuse wall and a mirror is well understood: one scatters back into all directions, and the other one preserves the directionality of reflected light. The temporal structure of the light, however, is left intact by both: assuming simple surface reflection, photons that arrive first are reflected first. In this paper, we exploit this insight to recover objects outside the line of sight from second-order diffuse reflections, effectively turn- ing walls into mirrors. We formulate the reconstruction task as a linear inverse problem on the transient response of a scene, which we acquire using an affordable setup consisting of a modulated light source and a time-of-flight image sensor. By exploiting sparsity in the reconstruction domain, we achieve resolutions in the order of a few centimeters for object shape (depth and laterally) and albedo. Our method is robust to ambient light and works for large room-sized scenes. It is drastically faster and less expensive than previous approaches using femtosecond lasers and streak cameras, and does not require any moving parts.

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Bibtex

@INPROCEEDINGS{HeideCVPR2014,
     author = {Heide, Felix and Xiao, Lei and Heidrich, Wolfgang and Hullin, Matthias B.},
      pages = {to appear},
      title = {Diffuse Mirrors: {3D} Reconstruction from Diffuse Indirect Illumination Using Inexpensive
               Time-of-Flight Sensors},
  booktitle = {IEEE Conference on Computer Vision and Pattern Recognition (CVPR)},
       year = {2014},
      month = jun,
   abstract = {The functional difference between a diffuse wall and a mirror is well understood: one scatters back
               into all directions, and the other one preserves the directionality of reflected light. The temporal
               structure of the light, however, is left intact by both: assuming simple surface reflection, photons
               that arrive first are reflected first. In this paper, we exploit this insight to recover objects
               outside the line of sight from second-order diffuse reflections, effectively turn-
               ing walls into mirrors. We formulate the reconstruction task as a linear inverse problem on the
               transient response of a scene, which we acquire using an affordable setup consisting of a modulated
               light source and a time-of-flight image sensor. By exploiting sparsity in the reconstruction domain,
               we achieve resolutions in the order of a few centimeters for object shape (depth and laterally) and
               albedo. Our method is robust to ambient light and works for large room-sized scenes. It is
               drastically faster and less expensive than previous approaches using femtosecond lasers and streak
               cameras, and does not require any moving parts.}
}