This reminds me of dual photography, where one can recover hidden images from diffuse-diffuse light transfer.
This should be used to save people's lives. Many of the marines on the ground that have to go into buildings expect a 50% casualty rate.
Originally I thought they were detecting diffracted light around the edge of the wall but it turna out they are just annalzying the light on the floor, which seems to have been done before https://phys.org/news/2015-12-amazing-camera-corners-video.h...
Very cool! I'm always interested by clever uses of perception technology. I wonder if this can be combined with video magnification[1] to remove some of the noise?
Not related but I once saw this effect where your shades/curtain gap sometimes if the light goes through it correctly you see the image coming in from the window projected onto your wall... I think this is related to how pinhole cameras were discovered/made but anyway that's pretty sweet.
Fascinating and counter-intuitive that so much information is 'leaked' in light patterns that can't be discerned by the eye. There's a color-amplified visualization in the first embedded video of TFA (starts at 1:40) that shows this really well.
Paper is available here: http://people.csail.mit.edu/klbouman/pw/papers_and_presentat...
Abstract:
We show that walls, and other obstructions with edges, can be exploited as naturally-occurring “cameras” that reveal the hidden scenes beyond them. In particular, we demonstrate methods for using the subtle spatio-temporal radiance variations that arise on the ground at the base of a wall’s edge to construct a one-dimensional video of the hidden scene behind the wall. The resulting technique can be used for a variety of applications in diverse physical settings. From standard RGB video recordings, we use edge cameras to recover 1-D videos that reveal the number and trajectories of people moving in an occluded scene. We further show that adjacent wall edges, such as those that arise in the case of an open doorway, yield a stereo camera from which the 2-D location of hidden, moving objects can be recovered. We demonstrate our technique in a number of indoor and outdoor environments involving varied floor surfaces and illumination conditions.