Review of Time-of-Flight imaging through scattering media technology

Time-of-Flight (ToF) imaging senses the depth information of the scene using the time of light traveling from the target to the camera, with the advantage of compact construction, low cost and real-time imaging. In the scattering scene, the depth measurement of ToF imaging is affected by multipath interference due to the light scattered by the scattering medium, which results in large depth measurement errors, and limits the application of ToF imaging in the scattering scene. ToF imaging through scattering media can effectively correct the multipath interference caused by scattered light via separating the target component from the mixed signal received by a ToF sensor for recovering the depth information of a scattering scene, which is promisingly applied in foggy autonomous driving, underwater surveys, biomedicine, and other fields. Herein, the principle of PL-ToF and CW-ToF imaging is introduced in detail according to the difference of ToF imaging system, and the mechanisms and characteristics of ToF stable and transient imaging in a scattering scene are introduced and analyzed. The researches of ToF imaging through scattering media in stable and transient imaging are reviewed and summarized, respectively. In addition, the potential applications of ToF imaging through scattering media are presented. Finally, the future development trend is prospected according to the advantages and disadvantages of existing ToF imaging through scattering media.