Suprisingly you can get alot of information from a system, that seems "lost" at first. https://www.csail.mit.edu/news/imaging-method-uses-shadows-reconstruct-v

Suprisingly you can get alot of information from a system, that seems "lost" at first. https://www.csail.mit.edu/news/imaging-method-uses-shadows-reconstruct-video-projected-unseen-part-room https://www.csail.mit.edu/news/imaging-method-uses-shadows-r... The problem here is the complexity of the room in between and the background. As in- light deformed by gravity lenses etc. - but in theory alot more can be extracted from the "noise" in the neighbouring pixels.