Spies can now eavesdrop on you using a bag of potato chips
Like something straight out of a Hollywood spy movie, high-tech researchers have figured out how to spy on conversations - through soundproof glass - using an empty bag of potato chips.
In experiments the team were able to use the technology to eavesdrop by filming the empty chip bag through a sheet of soundproof glass from almost 5 metres away.
The scientists created an algorithm in order to read minute vibrations in objects that are invisible to the naked eye - from video footage - and then reconstruct this into audio.
Some of the experiments required high-speed cameras capturing up to 6000 frames per second, far exceeding the 25-60 frames per second in films and television.
However, in other tests they were able to use an ordinary digital camera at a standard frame rate.
The technique has obvious applications in forensics and law enforcement but will also enable the everyday public to exploit the technology.
The collaborators from the Massachusetts Institute of Technology (MIT), Microsoft and Adobe were also able to extract useful audio information from videos of tin foil, the surface of water or even the leaves of a pot plant.
“When sound hits an object, it causes the object to vibrate,” said graduate student Abe Davis in an MIT press release.
“The motion of this vibration creates a very subtle visual signal that’s usually invisible to the naked eye.”
“People didn’t realise that this information was there.“
The researchers were able to measure tiny deviations in visual information invisible to the human eye and even smaller than a pixel’s width.
By monitoring the colour value of a pixel over time, it’s possible to infer motions smaller than one pixel.
“We’re scientists, and sometimes we watch these movies, like James Bond, and we think, ‘This is Hollywood theatrics. It’s not possible to do that. This is ridiculous.’ And suddenly, there you have it. This is totally out of some Hollywood thriller. You know that the killer has admitted his guilt because there’s surveillance footage of his potato chip bag vibrating.”
News break – August 6
