Friday, November 19, 2010

Laser camera takes photos around corners

Image captured with camera

A camera that can shoot around corners has been developed by US scientists.

The prototype uses an ultra-short high-intensity burst of laser light to illuminate a scene.

The device constructs a basic image of its surroundings - including objects hidden around the corner - by collecting the tiny amounts of light that bounce around the scene.

The Massachusetts Institute of Technology team believe it has uses in search and rescue and robot vision.

"It's like having x-ray vision without the x-rays," said Professor Ramesh Raskar, head of the Camera Culture group at the MIT Media Lab and one of the team behind the system.

"But we're going around the problem rather than going through it."

Professor Shree Nayar of Columbia University, an expert in light scattering and computer vision, was very complimentary about the work and said it was a new and "very interesting research direction".

"What is not entirely clear is what complexities of invisible scenes are computable at this point," he told BBC News.

"They have not yet shown recovery of an entire [real-world] scene, for instance." ...

If there is a corner, some of the light will be reflected around it. It will then continue to bounce around the scene, reflecting off objects - or people - hidden around the bend.

Some of these particles will again be reflected back around the corner to the camera's sensor. ... Following the initial pulse of laser light, its shutter remains closed to stop the precise sensors being overwhelmed with the first high-intensity reflections.

This method - known as "time-gating" - is commonly used by cameras in military surveillance aircraft to peer through dense foliage.

In these systems, the shutter remains closed until after the first reflections off the tops of the trees. It then opens to collect resections of hidden vehicles or machinery beneath the canopy.

Similarly, the experimental camera shutter opens once the first reflected light has passed, allowing it to mop up the ever-decreasing amounts of reflected light - or "echoes" as Prof Raskar calls them - from the scene. ...

via BBC News - Laser camera takes photos around corners.

The images produce so far are very basic, but give them time...

No comments: