Microsoft's Kinect and the soon-to-be-released Leap Motion have thrust 3D gesture-recognition technology into the mainstream. Touchless phones, however, are still a rarity.

of the 1.6 billion mobile devices shipped in 2012, just 27 million (about 0.2 per cent) were equipped with gesture-sensing technology, according to ABI Research, a market research firm based in New York.

Korean company Pantech released a smartphone in 2011 that could use it's camera to recognise simple gestures.

But across the industry the capability has yet to catch on:

Nowadays, there is a device that enables a smartphone's camera to recognise gestures without gobbling up precious battery life.

One reason may be that existing techniques infer gestures based on 2D images captured by a phone's camera.

This is problematic because visually cluttered backgrounds can confuse the software.

Now Andrea Colaco at the Massachusetts Institute of Technology Media Lab in Cambridge and colleagues have developed a system called 3dim.

Kinect and Leap Motion illuminate an area with either an infrared laser or intense infrared light to capture depth information about a scene.

Tobias Hollerer at the University of California, Santa Barbara, sees more promise for 3dim as a Google Glass system because he thinks it's awkward to make gestures while you're holding a phone.

3dim's software then looks for mathematical structures in the 2D image data in order to simplify the scene.