MIT Proposes to Use Polarization to Improve 3D Imaging

Optics.org: Researchers from MIT media lab (Prof. Ramesh Raskar) claim that exploiting the polarization of light allows them increasing the resolution of conventional 3-D imaging devices by as much as 1,000 times. The new 3D imaging system, which they call Polarized 3D, in a paper they are presenting at the International Conference on Computer Vision in Santiago, Chile, on December 11-18, 2015:

"Today, 3-D cameras can be miniaturized to fit on cellphones,” said Achuta Kadambi, a PhD student in the MIT Media Lab and one of the system’s developers. “But this involves making compromises to the 3-D sensing, leading to very coarse recovery of observed geometry. That is a natural application for polarization, because you can still use a low-quality sensor, but by adding a polarizing filter gives a result quality that is better than from many machine-shop laser scanners.”

Polarization affects the way in which light bounces off of physical objects. Light within a certain range of polarizations is more likely to be reflected. So the polarization of reflected light carries information about the geometry of the objects it has struck. Microsoft Kinect is used for a coarse depth estimation, while polarization helps to interpolate and improve its depth accuracy.

“The work fuses two 3-D sensing principles, each having pros and cons,” commented Yoav Schechner, an associate professor of electrical engineering at Technion — Israel Institute of Technology. “One principle provides the range for each scene pixel: This is the state of the art of most 3-D imaging systems. The second principle does not provide range. On the other hand, it derives the object slope, locally. In other words, per scene pixel, it tells how flat or oblique the object is.”

Thanks to AG for the link!