Paper Info
Title
Coded time of flight cameras: sparse deconvolution to address multipath interference and recover time profiles
Abstract
Time of flight cameras produce real-time range maps at a relatively low cost using continuous wave amplitude modulation and demodulation. However, they are geared to measure range (or phase) for a single reflected bounce of light and suffer from systematic errors due to multipath interference. We re-purpose the conventional time of flight device for a new goal: to recover per-pixel sparse time profiles expressed as a sequence of impulses. With this modification, we show that we can not only address multipath interference but also enable new applications such as recovering depth of near-transparent surfaces, looking through diffusers and creating time-profile movies of sweeping light. Our key idea is to formulate the forward amplitude modulated light propagation as a convolution with custom codes, record samples by introducing a simple sequence of electronic time delays, and perform sparse deconvolution to recover sequences of Diracs that correspond to multipath returns. Applications to computer vision include ranging of near-transparent objects and subsurface imaging through diffusers. Our low cost prototype may lead to new insights regarding forward and inverse problems in light transport.
Year
DOI
Venue
2013
10.1145/2508363.2508428
ACM Transactions on Graphics
Keywords
DocType
Volume
new application,electronic time delay,coded time,conventional time,flight camera,per-pixel sparse time profile,light transport,sparse deconvolution,light propagation,new goal,multipath interference,new insight,sweeping light
Journal
32
Issue
ISSN
Citations 
6
0730-0301
54
PageRank 
References 
Authors
1.87
14
7
Name
Order
Citations
PageRank
Achuta Kadambi111211.32
Refael Whyte2603.75
Ayush Bhandari3655.52
Lee Streeter4897.59
Christopher Barsi51358.65
Adrian A. Dorrington613613.61
Ramesh Raskar75305422.69