A small dual-band (LWIR/VIS) color video camera with common optical path and its real-time fusion method

The small video camera of the video life detector, which can go into the narrow space that the rescuers can hardly reach, is used to get color video of the trapped people in the ruins after the disasters such as earthquake. Due to the covering of rubble and dust, it is difficult to detect the position of the trapped persons effectively and judge their physical condition from the video, which affects the search efficiency during the golden time of 72 hours for rescue. In this paper, a small dual-band (LWIR/VIS) video camera with common optical path is designed. The dual-band video camera contains a micro color video camera for details of the scene and a miniaturized thermal imaging component which has a micro uncooled infrared focal plane array (IRFPA) as the detector for capturing the location and vitality of trapped people. The field of view (FOV) of the color video camera, is partly matched with the FOV of the IRFPA component through a hot mirror as the visible and infrared optical splitter. In other words, the FOV of the dual-band imaging system is designed in common path. Then a real-time fusion algorithm of dual-band video is implemented on a DSP hardware image processing platform. As a result, the people and other hot targets in the scene are highlighted in the fused video, which can provide a basis for target detection and decision-making in the rescue process.