Sensitive sensor

Eastman Kodak has introduced a new type of image sensor that will help make dark, blurry digital photos a thing of the past.

When the new sensor is built into a camera, users will realize a 2x to 4x increase in sensitivity (from one to two photographic stops), which will improve performance when taking pictures under low light and reduce motion blur when imaging moving subjects.

The new design advances an existing Kodak technology that has become a standard in digital imaging. Today, the design of almost all colour 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 colour signal for each pixel in the final image.

Kodak’s new proprietary technology builds on the existing Bayer Pattern by adding panchromatic, or ‘clear’ pixels to the red, green, and blue pixels already on the sensor. Since these pixels are sensitive to all wavelengths of visible light, they collect a significantly higher proportion of the light striking the sensor. The remaining red, green, and blue pixels are then used to record the colour information of the scene.

To reconstruct a full colour image, Kodak has also developed new software algorithms specifically designed to work with the raw data generated from these new image sensors. These algorithms use the more sensitive panchromatic pixels to act as the luminance channel of the final image, and derive chrominance information from the colour pixels on the sensor. The algorithms support the increased sensitivity provided by these new pixel patterns, while retaining the overall image quality and colour fidelity.

‘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.

Initially, Kodak expects to develop CMOS sensors using the new technology consumer markets such as digital still cameras and camera phones. As the technology is appropriate for use with both CCD and CMOS image sensors, however, its use can be expanded across Kodak’s full portfolio of image sensors, including products targeted to applied imaging markets such as 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.