Abstract:For the problem of color deviation caused by mixing near-infrared light into the images taken in the visible light range, the traditional monitoring system uses the mechanically switched infrared cut-off filter to achieve the switching of day and night shooting mode, which is prone to produce mechanical faults and affect the imaging. On the basis of not changing the original CCD or CMOS sensor, this study adopts visible light and 850 nm dual-peak filter to replace the traditional mechanical switching filter, but there is still the 850 nm infrared crosstalk problem. In order to solve the infrared interference, this study abandons the traditional color deviation correction analysis method of infrared interference image, starts with the analysis of the influence of near-infrared light on the sensor, and corrects the spectral characteristics of the camera by ridge regression color calibration method. This process simulates the state of using the infrared cut-off filter when the camera takes the three-band image. First, in the dark environment of the laboratory, use the D65 standard light source box, and use the 850 nm near-infrared light source to directly shoot the camera that has removed the infrared cut-off filter, and shoot the four-band image of the Pantone color card in the shed (RGB three-band and IR near Infrared band); then close the near-infrared light source, taking the three-band image of the Pantone color card with the same position. Color calibration is performed according to the ridge regression algorithm, and a correction matrix between the three-band image and the four-band image is obtained, which is used for color correction of the four-band image to obtain a natural color image.