Depth from phasor distortions in fog

This paper presents a time-of-flight (ToF) measurement method for use in foggy weather. The depth measured by a ToF camera is greatly distorted in fog because the light scattered in the fog reaches the camera much faster than the target reflection. We reveal that the multi-frequency measurements contain a cue whether two arbitrary pixels have the same depth. After clustering the same depth pixels using this cue, the original depth can be recovered for each cluster by line fitting in the Cartesian coordinate frame. The effectiveness of this method is evaluated numerically via real-world and road-scale experiments.