Study Of Uncooled Infrared Thermal Imaging System

The infrared thermal imaging system plays important action in military and civilian affairs. Depending on lower cost, higher dependability, smaller bulk and lower dissipation, the uncooled infrared thermal imaging system holds important position in infrared fields. The uncooled infrared thermal imaging system includes infrared optics, uncooled infrared focal plane array (IRFPA), temperature stabilizer and drive circuit of IRPPA, image signal processor, video synthesis and display drive circuit. In this paper, real-time uncooled infrared thermal imaging system was designed under basic system theory analysing and infrared image processing algorithms discussing. Well processing effect was obtained.Theory analysis is the base of developing uncooled infrared thermal system. In this paper, imaging principle, microbolometer performance, factors affecting system performance, and image processe algorithms were studied.Non-uniformity correction, blind pixel compensation, and image enhancement are basic infrared image processing means. First, infrared image characteristic and factors affecting nonuniformity were discussed. Then, viewing to two-point temperature non-uniformity correction (NUC) algorithm and LMS adaptive non-uniformity correction algorithm, the synthesis algorithm of two-point temperature and LMS adaptive non-uniformity correction was proposed and applied to infrared image NUC in the paper. The synthesis algorithm inherits the advantages of above the two algorithms. It could not only resolving the shift with time of two-point NUC, and simplifying the system structure, but also shorten the time to best output of LMS adaptive.Due to the centralize characteristic of blind pixel, the compensation algorithms of adjacent pixel averaging and adjacent pixel alternation were discussed. As for infrared image enhancement, the general and adaptive linearity gray transfer technology was analyzed. The adaptive algorithm was more flexible and can be realized simply.The miniaturized, real-time image processor was designed in this paper. Which include drive circuit, temperature stabilizer, data sampling circuit, signal-processing circuit, data conversion, and video synthesis circuit. The drive circuit is the base of putouting signals correctly. Temperature stabilizer is designed for stabilizing the temperature of IRFPA. DSP and FPGA are higher speed devices, which are ideal choice of real-time system. Which cooperating with each other, and completing the nonuniformity correction, blind pixel compensation and image enhancement functions. In this system, the higher speed devices were chosen. By optimized designing, real-time image processing was...