Engineers in the United States have built a prototype gigapixel camera the size of a bedside cabinet that can capture an image in a single snapshot with 1,000 times more detail than today's devices.

It is not the world's first gigapixel camera, but it is the smallest and fastest and opens up prospects for improving airport security, military surveillance and even online sports coverage, its developers say.

A pixel is a small light point in a digital image, concentrations of which together form a picture.

Today's cameras capture images measured in megapixels -- a million pixels -- normally between eight and 40 for an average consumer device. A thousand megapixels make a gigapixel, which is thus comprised of a billion pixels.

Most of today's gigapixel images are made by digitally merging several megapixel pictures.

"Our camera records a one gigapixel image in less than a 10th of a second," project member David Brady told AFP of the project reported in the journal Nature.

Gigapixel imaging captures details that are invisible to the human eye and can later be examined by zooming in without losing clarity.

Dubbed AWARE-2, the device is housed in a box of 75 cm X 50 cm X 50 cm -- most of which comprises electronic processing and communication equipment.

The optical system consists of a six-centimeter (2.4-inch) ball-shaped lens surrounded by an array of 98 micro-cameras each with a 14-megapixel sensor.

Brady said the optical system on its own weighs about 10 kilograms (22 pounds), but with the case about 45 kg.

"The electronic system shrinks by a factor of four in the next generation, however."

In use today are highly specialized gigapixel astronomical telescopes and airborne surveillance systems, which are comparatively large and have a narrow field of view, said Brady of Duke University in North Carolina.

There are also some film-based gigapixel cameras.

"Our technology is most interesting as the first demonstration of high pixel count and wide field of view imaging at finite focal ranges," said Brady.

The cost of such a camera today would be similar to that of a high-resolution digital movie camera, he said -- about $100,000 to $250,000 (80,000 to 200,000 euros).

But as the electronics improve, the price should become affordable for professional and serious amateur photographers within about five years, followed soon thereafter by hand-held gigapixel cameras entering into widespread use.

Brady said the technology could be used, for example, to stream sporting events over the Internet -- enabling viewers to zoom in and watch the game from whatever perspective and resolution they choose.

Similarly, cameras mounted in game parks or at scenic lookouts would allow online tourists to examine a scene in much more detail than if they were actually there.

"Ubiquitous gigapixel cameras may transform the central challenge of photography from the question of where to point the camera to that of how to mine the data," said the Nature report.