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