Emerging single-photon-sensitive sensors combined with advanced inverse
methods to process picosecond-accurate time-stamped photon counts have given
rise to unprecedented imaging capabilities. Rather than imaging photons that
travel along direct paths from a source to an object and back to the detector,
non-line-of-sight (NLOS) imaging approaches analyse photons {scattered from
multiple surfaces that travel} along indirect light paths to estimate 3D images
of scenes outside the direct line of sight of a camera, hidden by a wall or
other obstacles. Here we review recent advances in the field of NLOS imaging,
discussing how to see around corners and future prospects for the field
