Carver Mead wins Dickson Prize in Science

Carver Mead showed no trace of exaggeration last Tuesday when he said that his digital camera technology will usher in a "whole new paradigm for photography." And Mead is no novice to setting off breakthroughs in technology-related fields. He invented Very Large Scale Integration (VLSI), which revolutionized computers by allowing many more transistors to be packed onto a microchip. Mead also founded Synaptics, the company that invented the computer touch pad which is used in many laptops.

Mead was presented with the Carnegie Mellon Dickson Prize in Science last Tuesday. The prize is awarded each year to the candidate who is judged to have made outstanding contributions to science. The award, which carries a monetary sum of $47,000, was presented by Carnegie Mellon President Jared Cohon in McConomy Auditorium. The packed auditorium, with people standing along the sides, showed the high degree of interest in Mead and his work.

Following presentation of the award, Mead gave a lecture on his current work in digital photography.

Mead is the founder and chairman of Foveon Inc., a company which recently announced they have developed a new image sensor, named the Foveon X3, which triples the color capture capabilities of a digital camera.

Current digital cameras use a method called mosaic filtering, in which each image sensor in the camera's chip detects only one color (red, green, or blue). For every four pixels in the sensor array, two of them are for green, one for red, and one for blue. After image data is recorded, the camera uses an averaging algorithm to assemble the color measurements into a usable image. However, pixel averaging can cause artifacts and distortions to appear in a photo.

Foveon's new sensor is the world's first color image sensor that captures all three light wavelengths in each pixel. Using concepts similar to the way film captures light, the Foveon chip detects all three colors in one sensor by detecting different wavelengths of light at different levels in the silicon of the chip.

For years it has been known that a method of capturing all three colors in one pixel would be far superior, but no one had been able to figure out how to accomplish this feat. Mead and the engineers at Foveon have succeeded in solving this problem and believe that it will have an enormous impact on digital photography.

"I think this technology is literally a really large historic breakthrough," said Mead. The X3 image chip they invented has many advantages over current digital camera chips. It effectively gathers three times as much image data from the same number of pixels. So a three megapixel Foveon camera is equivalent to a nine megapixel camera using mosaic filtering. The mosaic filtering in current digital cameras throws away about two-thirds of the light in an image because each pixel only captures one color.

According to Mead, the new X3 technology has "all the advantages of Kodachrome film, but it's electronic." Besides just capturing all three colors in each pixel, the Foveon chip provides other advantages. Because the camera no longer needs to use a pixel averaging algorithm to combine the colors, this eliminates the possibility of moiré patterns and other artifacts.

In addition, since the camera no longer needs to carry out the computationally expensive averaging operations, cameras using the Foveon chip will require less processing power and in turn preserve battery life. The Foveon chip is also capable of recording video that is superior to video produced by current digital cameras.

The first camera utilizing X3 technology will be available from Sigma Corporation in the near future. "It makes much better images than 35 mm film," said Mead about the Sigma camera. The camera, which will sell for about $2,500, uses a 3.5 megapixel Foveon sensor, equivalent to about a nine megapixel digital camera.

Mead pointed out that the Sigma camera is priced considerably lower than other cameras in the high-end nine megapixel range. However, Foveon is working to appeal to a broader consumer market by developing a X3 camera in the $300 to $400 range.

Mead sees a great deal of potential for further improvements to digital camera technology and dubs the new image sensor array an "intelligent image plane." He says that the methods for doing autofocus, flash, and autoexposure in current digital cameras could all be improved.

The present techniques for doing these adjustments are "pretty brain-dead" because they are based entirely on film photography and do not take advantage of the different nature of digital image capture, explained Mead. Autofocus, for example, could be done directly on the camera microchip, instead of in other processing steps.

Mead asserts that the Foveon technology will enable digital cameras to eventually replace film cameras, with film cameras remaining only as vintage or hobbyist items. Mead envisions a future where digital cameras provide improved ease-of-use and quality and thereby mostly replace film photography.

However, not everyone thinks that digital cameras serve all of a photographer's needs. One criticism of digital cameras is that they allow a user to instantly delete photos and lose them forever.

"I think there's also something to be said for keeping the rejects," said Charlee Brodsky, a professor of design who teaches several photography classes. Sometimes a photo that is deemed garbage at first may later turn out to be useful.

Another concern with digital cameras is that as technology changes, images stored on computers may get lost on obsolete media. For example, some current digital cameras use floppy disks to store images. Since the floppy drive is nearly relegated to the realm of the dinosaurs, people may lose access to images stored on floppy disks. They may forget or not make the effort to transfer the images to a new storage medium.

"I am concerned with technology that changes so much," said Brodsky. "That is a downside." In addition, it is possible that hard drive failure could cause someone to lose large collections of digital images (assuming they were not backed up).

Nevertheless, there is no question that the Foveon chip is far superior to current digital camera technology and will likely deliver photos of impressively-high quality.