Simultaneously acquire colour & near-infrared images

Commercially available compact and low-cost colour digital cameras acquire single-sensor colour images with a Colour Filter Array (CFA) - an array of R, G, and B filters and overlaid on the image sensor (Figure 1). Therefore, the data acquired by CFA based image sensors are mosaic. A set of image processing algorithms such as an interpolation process of the mosaic data called demosaicking and colour correction is performed to acquire a full-colour image. In this way, current colour cameras realise low-cost and easy-to-use colour image acquisition.

Figure 1 - colour image acquisition using a single image sensor with a CFA

In recent years, many applications using a pair of RGB and NIR images have been proposed by computer vision and image processing communities. With this background, the group of Masatoshi Okutomi at Tokyo Institute of Technology and researchers at Olympus R&D have developed a prototype of a new imaging system for the simultaneous acquisition of RGB and NIR images using a single image sensor. Figure 2 is an overview of a prototype of this system consisting of a novel CFA that contains both RGB and NIR filters. The arrangement of the new CFA is shown in the Figure 2, where “N” represents the NIR filter.

The researchers have also developed an image processing system that can execute sets of image processing algorithms, such as demosaicking and colour correction, in real time. The new system can acquire and display high-quality RGB and NIR images simultaneously at 60fps. Since the new system can provide users with a practical solution for simultaneously acquiring both the RGB and the NIR images, it is expected to open up a new range of applications in many fields such as remote sensing, security, robotics, agriculture and medical imaging, where the NIR information is useful.

Figure 2 - overview of the developed prototype system

This research was partly supported by the MIC/SCOPE #141203024 funding.