Resolving multipath interference in Kinect: An inverse problem approach

Multipath interference (MPI) is one of the major sources of both depth and amplitude measurement errors in Time-of-Flight (ToF) cameras. This problem has seen a lot of attention recently. In this work, we discuss the MPI problem within the framework spectral estimation theory and multi-frequency measurements. As compared to previous approaches that consider up to two interfering paths, our model considers the general case of K-interfering paths. In the theoretical setting, we show that for the case of K-interfering paths of light, 2K + 1 frequency measurements suffice to recover the depth and amplitude values corresponding to each of the K optical paths. What singles out our method is the that our algorithm is non-iterative in implementation. This leads to a closed-form solution which is computationally attractive. Also, for the first time, we demonstrate the effectiveness of our model on an off-the-shelf Microsoft Kinect for the X-Box one.