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Monday, May 6, 2013

Scientists make 'bug-eye' camera

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A digital camera that functions like an insect's compound eye is reported in the journal Nature this week.
It comprises an array of 180 small lenses, which, along with their associated electronics, are stretched across a curved mounting.

The prototype currently has few pixels, so its images are low-resolution.

But the device displays an immense depth of field, and a very wide-angle view that avoids the distortion seen in standard camera lenses.

The development team, led from the University of Illinois at Urbana-Champaign, US, believes its new imaging system could eventually find uses in surveillance and for endoscopic investigations of the human body.

In their report, the researchers also suggest such cameras could be fitted to tiny aerial vehicles one day that behaved like robotic insects.

At the moment, the "bug-eye" system's vision is comparable to that enjoyed by some ants and beetles.

The expectation, however, is that the array can be greatly enlarged.

"The compound design of the fly's eye incorporates perhaps 28,000 small eyes, or ommatidia," explained team-member Dr Jianliang Xiao from the University of Colorado at Boulder, US. "That's the direction we want to move in," he told BBC News.

In an insect, each ommatidium in the compound eye has a corneal lens, a crystalline cone and a light-sensitive organ at its base. The ommatidia work in unison to build a picture of the world.

In the artificial version, microlenses sit above photodetectors and other electronics, and software stitches together the individual signals.

This whole arrangement is fabricated flat and then moulded to a hemispherical shape to give a 160-degree view. The latest generation of stretchable electronics was key to achieving the desired geometry.

Scientists are keen to exploit the advantages of compound eyes.

For one, they show remarkable depth of field - they can focus on objects at different distances at the same time. They also do not suffer from the aberrations seen in single lens systems when viewing off-axis objects. A good example is the huge distortion observed in wide-angle camera lenses such as the fish-eye.

For an insect, their compound system capabilities make them very sensitive to movement.

"Our system could eventually be used in surveillance cameras. One device of this kind could see 180 degrees. If you had two, you could then conceivably see the whole field of view," said Dr Xiao.

Alexander Borst and Johannes Plett are from the Max-Planck-Institute of Neurobiology in Martinsried, Germany. They are not connected with the research but speculated for Nature on other possible future applications.

"Picture the following: a palm-sized micro aerial vehicle uses an artificial faceted eye to navigate autonomously through a collapsed building while other sensors onboard scan the environment for smoke, radioactivity or even people trapped beneath rubble and debris,"
This News is copy from bbc technology news 1 May 2013 

Facebook grows up


Facebook's results last night painted a somewhat mixed picture - advertising revenues growing, with mobile really taking off, but profits lower than analysts had forecast.
One thing was, however, clear. This company is growing in all sorts of ways, and with that comes growing pains.

After all those anecdotal reports that "none of my friends use it anymore", and various research firms hinting at falling user figures, the hard numbers say Facebook is still expanding. Monthly active users rose to 1.1 billion, meaning 100 million new users had arrived in the last six months.

Now many of them will be in developing countries - after all so many people have already joined in places like the US and UK that Facebook is reaching saturation point. But the company insists, that contrary to reports, it is still growing in both of those countries.

In the UK, user numbers hit 33 million in December, and I'm told there has been a modest increase since then. In the US, there has also been a rise from December's 174 million monthly users, though it looks like the growth story there is nearing its end.

There has been a decline in use of the network on the desktop but that was more than made up for by the growth in mobile use, where advertising returns have proved higher. And that rapid transformation of the firm into a mobile advertising business will be the most encouraging aspect of the figures for anyone who was brave enough to buy Facebook shares at their sky-high IPO valuation last year.

Mind you, there's growth too in the cost of running the business, as more staff are taken on. The UK operation is among those expanding rapidly, as I found out this week when I met the engineer in charge of one of the firm's most important ventures, Graph Search.

Lars Rasmussen has moved to London to head up an expanded engineering operation, and he is in the process of recruiting another couple of dozen people to work mainly on the search project. (How easy that process proves will be an interesting test of the computer science skills available in the UK.)

Each of the recruits will then spend four to six weeks at a boot camp in California, learning how Facebook writes code and attending lectures by its top executives.

That sounds like an expensive process and a contrast to the early days of a business where Mark Zuckerberg just called up a few friends for all-night coding sessions fuelled by pizza.

But if the London team can then help take Graph Search to the next stage, where users will be able to comb the network's newsfeed for all kinds of information, then it will have been a worthwhile investment. So far, Facebook's limited search bar has not done anything to worry its rivals. But if it becomes a conduit to breaking news, then the likes of Twitter may have to sit up and take notice.

Like an awkward teenager, however, Facebook is finding that growing up can be painful. Yesterday's story about its refusal to remove horrifying decapitation videos, followed by a rapid U-turn, is a case in point.

Like so many other web giants, Facebook just wants to be seen as a technology platform enabling its users to do all sorts of cool stuff without any interference. But it has grown into a massive media player, where more than a billion people - many of them under 18 - come in search of entertainment.

That means a constant spotlight is being shone on the firm's policies, with parents and regulators increasingly worried about an environment where young people now spend so much time. Welcome to adulthood, Mr Zuckerberg.
This News is copy from bbc technology news 2 May 2013