Example of imaging in scattering media using our approach. Left: Original scene with objects submerged in water-filled glass tank. Center: 160 ml milk added. Right: Objects that are ''invisible'' due to strong scattering, like the structured object on the top right or parts of the circular object become detectable using our approach.


Correlation image sensors have recently become popular low-cost devices for time-of-flight, or range cameras. They usually operate under the assumption of a single light path contributing to each pixel. We show that a more thorough analysis of the sensor data from correlation sensors can be used can be used to analyze the light transport in much more complex environments, including applications for imaging through scattering and turbid media. The key of our method is a new convolutional sparse coding approach for recovering transient (light-in-flight) images from correlation image sensors. This approach is enabled by an analysis of sparsity in complex transient images, and the derivation of a new physically-motivated model for transient images with drastically improved sparsity.

Paper and Link

Paper [SparseCodingToF_Heide2014.pdf (24MB)]

This paper was published in Optics Express, Vol. 22, Issue 21, pp. 26338-26350 (2014) and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.22.026338. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.