Being able to see inside a closed room was a skill once reserved for superheroes. But researchers at the Stanford Computational Imaging Lab have expanded on a technique called non-line-of-sight imaging so that just a single point of laser light entering a room can be used to see what physical objects might be inside.
Non-line-of-sight (NLOS, for short) imaging is by no means a new idea. It’s a clever technique that’s been refined in research labs over the years to create cameras that can remarkably see around corners and generate images of objects that otherwise aren’t in the camera’s field of view, or are blocked by a series of obstacles.
Previously, the technique has leveraged flat surfaces like floors or walls that are in the line of sight of both the camera and the obstructed object. A series of light pulses originating from the camera, usually from lasers, bounce off these surfaces and then bounce off the hidden object before eventually making their way back to the camera’s sensors. Algorithms then use the information about how long it took these reflections to return to generate an image of what the camera can’t see. The results aren’t high resolution, but they’re usually detailed enough to easily determine what the object in question is.