Thursday, October 30, 2008

Insects eye an inspiration for BugEye, six times better than regular cameras

A prototype of a tiny bug-eyed camera that provides a field of view six times that of the conventional camera it’s designed to replace has been tested for the first time. The new system, called BugEye, is intended for use on missiles to keep track of targets but is also small enough to be used on endoscopes, giving an improved field of view in keyhole surgery. An insect’s eye provides a wide field of view as it contains many lenses, each angled in a slightly different direction. The insect’s brain pieces together images from each lens into one big picture, covering a wide angle.

To gain a similarly wide field of view, cameras have had to be either mounted on a moving platform that scans the scene, or fitted with fisheye lenses that focus details from a wide area. “Both systems are very large, and take up most of the weight and volume of the camera,” says Leslie Laycock of defence company BAE Systems at Great Baddow in the UK. Various teams have attempted to build smaller, lighter wide-angle cameras by copying the design of an insect’s eye. Previous attempts had one lens for each pixel of the camera’s sensor, but this limited the resolution, Laycock says. Instead, Laycock’s team has whittled the array of lenses down to just nine, each looking at a different part of the scene. The lenses are polished on to the end of a bundle of millions of glass fibres that have been fused together.

The fibres direct the images onto separate areas of a flat light-sensitive chip, and image-processing software is used to stitch them together. Size of a sugar cubeThe resulting wide-angle assembly can be made smaller and lighter than an equivalent fisheye lens because it uses less glass. The BugEye is roughly the size of a sugar cube and one-tenth the weight of systems using fish-eye lenses or moving platforms, Laycock says. Although the camera was designed to sit on missiles to track targets, Laycock believes it could also provide surgeons with a better view during keyhole surgery. Endoscopes presently use movable mirrors to change the direction of view, but these systems are relatively bulky and the moving parts prone to failure. BugEye could also provide CCTV cameras with a wider field of surveillance.

Emma Johnson, a biomimetics expert from the University of Reading in the UK, agrees the new system will provide a “significant improvement”, allowing the field of view of cameras to approach that of human vision. She points out that having several “lenses” makes the new camera more robust, since it should still be able to capture a good image if one lens is obstructed.
Credits: New Scientist.

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