Eastman
Kodak Company today announced what it considers a “groundbreaking advancement”
in image sensor technology that will help reduce the accidental taking of dark and
blurry digital photos. Kodak claims its new sensor technology provides a two-
to four-fold increase in sensitivity to light (from one to two photographic
stops) compared to current sensor designs.
“This
represents a new generation of image sensor technology and addresses one of the
great challenges facing our industry – how to capture crisp, clear digital
images in a poorly lit environment,” said Chris McNiffe, General Manager of
Kodak’s Image Sensor Solutions group. “This is a truly innovative approach to
improving digital photography in all forms, and it highlights Kodak’s unique
ability to differentiate its products by delivering advanced digital
technologies that really make a difference to the consumer.”
Image
sensors convert light into electric charge to capture images. Today, the design
of almost all color image sensors is based on the Bayer Pattern, an
arrangement of red, green, and blue pixels that was first developed by Kodak
scientist Dr. Bryce Bayer in 1976. In this design, half of the pixels on the
sensor are used to collect green light, with the remaining pixels split evenly
between sensitivity to red and blue light. After exposure, software
reconstructs a full color signal for each pixel in the final image.
Kodak’s
new proprietary technology, invented by John Compton and John Hamilton, adds
panchromatic, or clear pixels to the red, green, and blue elements that form
the image sensor array. Since these pixels are sensitive to all wavelengths of
visible light, they collect a significantly higher proportion of the light
striking the sensor. By matching these pixel arrangements with advanced
software algorithms from Kodak that are optimized for these new patterns, users
can realize an increase in photographic speed, directly improving performance
when taking pictures under low light.
Inventor
John Hamilton explains in the Kodak blog,
“One way that helps to think about this is to look at it in terms of luminance
and chrominance. In the original Bayer design, the green pixels are used to
recover most of the luminance information from the image. Now, we are using
panchromatic pixels - which are more sensitive than green pixels, because none
of the photons get filtered out or wasted - to act as the luminance. This gives
us a more sensitive luminance channel in the final image, which raises the
sensitivity of the entire sensor.”
John
Compton adds, “The real advantage is that the panchromatic pixels are more
sensitive, since they detect all wavelengths of visible light (rather than
filtering light to detect color information).” Hamilton points out that the
improved images don’t come from using panchromatic pixels, but rather the more
accurate luminance data.
Kodak’s
new technology also enables faster shutter speeds (to reduce motion blur when
imaging moving subjects), as well as the design of smaller pixels (leading to
higher resolutions in a given optical format) while retaining performance.
As
for which situations benefit most from the improved sensor, Hamilton says, “In
situations where you want more sensitivity to light. In a low-light situation,
these new patterns will produce a lot less color noise than a Bayer pattern
sensor. You can run the shutter faster, which gets rid of a lot of motion
artifacts. It will cut down on camera shake or, if you're taking a picture of a
moving object there will be less blur.”
“Another
way to think of this is that you have the same number of photons coming into
the new sensor as you would with the Bayer pattern,” adds Compton. “It's just
that the new filter arrays waste fewer of the photons since fewer of them end
up absorbed in a color filter.”
The
inventors say that the technology is appropriate for use with both CCD and CMOS
image sensors, and that Kodak is developing this technology for consumer
markets such as digital still cameras and camera phones. The technology may
also be applied to other image sensor devices for industrial and scientific
imaging. The first Kodak sensor to use this technology is expected to be
available for sampling in the first quarter of 2008.
Kodak’s announcement comes on the heels of advancements in
low-light photography made by South Korea's Electronic Technology Institute.
The institute announced in late May that it had developed an image sensor for
use in extreme low-light conditions and would be suitable for use in tunnels,
night clubs and bars.
