The Research Of Mid-infrared Imaging System Compensation And Calibration

The thesis researches on mid-infrared thermal imaging system compensation and calibration, it detailedly introduces the algorithms of blind pixel compensation、 non-uniformity compensation and calibration, it also expatiate on the experiments on compensation and calibration. Infrared thermal imager has a number of advantages, such as directly displaying the temperature field、wide temperature range、rapidly showing the temperature、non-contact temperature measurement and low requirements of work environment, so infrared thermal imager is widely used in many field, such as military、security、fire monitoring、medical diagnostics and industrial inspection. So, study on infrared thermal imager has a great significance.3～5μm mid-infrared band has "atmospheric window" feature, so that in completely lightless night or in battlefield that is full of smoke clouds, people can observe the scene in front of him clearly, so the mid-infrared thermal imager has a wider use of space, the study topic of the thesis is mid-infrared thermal imager. The pixels in focal plane array have disadvantages such as blind pixel and non-uniformity, the shortcomings have an effect on image quality, what’s more, it has a great significance that establishing the relationship between the radiation temperature of target and the gray value of infrared image. So, the compensation and calibration for mid-infrared thermal imager is needed before using it. The study includes the follow three areas:(1) For the processing of blind pixel on the focal plane array, using the blind pixel define method to set the threshold value for pixel detection, and using the neighborhood average method to achieve the blind pixel compensation;(2) For the processing of pixel response non-uniformity, using two point temperature compensation method;(3) For the calibration of the mid-infrared thermal imager, this article uses the method that mid-infrared thermal imager shoots a variety of temperature standard blackbody, and then calculate the relationship between mid-infrared thermal imager output image pixel gray value and the measured target surface radiation temperature.This paper studies the algorithms of compensation and calibration, uses experiments methods to achieve the compensation and calibration of mid-infrared thermal imager. Infrared image processing results show that the compensation algorithms make the image better and enable people observe the measured target better, and the algorithms improve the quality of the mid-infrared thermal imager. Through the calibration, the thesis establishes the relationship between the infrared image pixel gray value and the measured surface radiation temperature. In short, the compensation and calibration of the mid-infrared thermal imager have reached the intended purpose.