  Light scattered from multiple surfaces can be used to retrieve information of
hidden environments. However, full three-dimensional retrieval of an object
hidden from view by a wall has only been achieved with scanning systems and
requires intensive computational processing of the retrieved data. Here we use
a non-scanning, single-photon single-pixel detector in combination with an
artificial neural network: this allows us to locate the position and to also
simultaneously provide the actual identity of a hidden person, chosen from a
database of people (N=3). Artificial neural networks applied to specific
computational imaging problems can therefore enable novel imaging capabilities
with hugely simplified hardware and processing times
