3-D CCTV

09 Apr 2008
by: By John Adams
IN a world of ever contracting margins, the key to success is technological superiority. Users are happy to pay a premium for the latest and the best electronic security devices. Taking this into account, the development of 3-D camera technology that allows full focus scenes with 3-D modeling is interesting news.
Current video surveillance technology produces a 2-dimensional image, while a camera with a pair of lenses is able to deliver 3-D images. Although 3-D offers more detail and better depth of field new research into camera lenses could provide something that’s immeasurably better still.


A Stanford electronics research team is working on an image sensor that not only has more pixels, it also incorporates multiple lenses into the sensor substrate itself creating a sensor comprising multiple sensors. The result of all this is a 3 megapixel image sensor made up of 12,616 individual on-chip cameras, each camera combining 256 0.7 micron pixels topped by a lens. Importantly, the technology can do away with current lens technology and that means cameras will offer more picture for less money.

If this doesn’t sound much chop, consider that a camera with these specifications would be able to measure the exact distance between a subject’s eyes, nose, ears and chin, as well as giving 3-D modeling of all objects in a scene.

According to the researchers, the camera will allow every part of an image stream to be in perfect focus yet the hardware would essentially look exactly the same as current technology.

The way it all works is that the lens of the multi-aperture camera focuses its image about 40 microns (a micron is a millionth of a meter) above the image sensor arrays. What this means is that every point in a scene is being captured by 4 of the tiny cameras on the image sensor and this makes for multiple views that have slightly different perspectives.

According to the researchers, this sort of detail creates a depth map that is electronically stored along with the image that essentially represents a virtual model of the target area. The beauty of this modeling is that it allows image manipulation. Researchers say the technology would allow users to chose to see only objects at a particular distance or from a particular perspective and nothing else.

According to researchers, Professors El Gamal, Fife and Wong, the multi-aperture image sensor has some key advantages. It's small and doesn't require lasers, bulky camera gear, multiple photos or complex calibration. And they say it has excellent color quality. Each of the 256 pixels in a specific array detects the same color. In an ordinary digital camera, red pixels may be arranged next to green pixels, leading to undesirable "crosstalk" between the pixels that degrade color.

The sensor also can take advantage of smaller pixels in a way that an ordinary digital camera cannot, El Gamal explains. This is because current lens technology is getting to the optical limit of the smallest point it’s possible for them to resolve. A pixel smaller than that spot will not give better images but the multi-aperture sensor’s smaller pixels produce far more information.

Another key element of the technology is that it may represent a step forward in the development of the gigapixel camera, a device that looks set to offer 140x the pixels of today’s 7-megapixel systems – that’s upwards of a billion pixels on one sensor.