Reseach On Image Processing Of Infrared Imaging System

With the rapid development of infrared imaging technology in recent years,infrared imaging systems have been widely used and playing a key role in military,civil,and many other fields.However,because of the manufacturing and technical limits which may induce the problems like non-uniformity,bad-pixels,low contrast to infrared images,how to properly process the infrared images is the critical and difficult part of constructing an infrared imaging system.In this thesis,according to the overall design requirement of a certain infrared product,and based on the fundamental theories of infrared imaging system and the review of the research status of the infrared images processing algorithms,the image processing methods for the infrared product are studies in detail,and our work is shown as follows:(1)The common non-uniformity correction(NUC)algorithms are systemically analyzed.By investigating the advantages and disadvantages of the Calibration-based and Scene-based NUC algorithms,we present a combined NUC algorithm based on the two points NUC and temporal high-pass filter(THPF)NUC algorithm.Initially,the algorithm corrects the raw output of the infrared imaging system by the two points NUC algorithm;afterwards,the offsets of the calibration coefficients are revised in real,and the design of the classic THPF NUC algorithm is modified.(2)The performance of the common bad-pixel detection methods are evaluated and a new method is proposed.By analyzing the drawbacks of the common methods,we present a bad pixel detection method based on the median filter,and a blinking pixel detection method based on the histogram statistics,which show the effectiveness in solving the detection problems of the dead pixels and the blinking pixels.(3)The existing image enhancement algorithms for infrared imaging system are studied.The algorithm based on the spatial-stretch to enhance the grey-level of an image is employed,so as to enhance the intensity of a small target and contrast in the image and improve the image contrast.(4)The existing infrared image filter algorithms are studied.The enhance high-pass filter algorithm is employed in the step of image filtering.By using the high-pass filer to filter the low-frequency spatial background,and the median filter to remove the high-frequency spatial noise,the algorithm improves the image signal-noise ratio obviously.(5)The aforementioned methods are simulated respectively with the infrared image data.Accordingly,the design of the image processing algorithm based on the image processing hardware platform of a certain infrared product is completed,and its performance is verified on the imaging system of the product.The experimental results show the effectiveness and the superiority of the proposed imaging processing methods in thesis,and also their high reliability and practicality in engineering.