Algorithm And Realization Of Infrared Image Pre-processing System

With the development of infrared imaging technology and infrared focal plane array (IRFPA) solid image detectors, IRFPA has been widely used in various imaging system in the military, industrial and commercial fields. Typical applications include missile guidance, aerial measurement, infrared hunting and tracing system, custom suppress smuggling, salvage equipment and forest fire control etc. The requirements of the quality of infrared imaging is becoming higher and higher. The research of infrared image pre-processing technology is necessary.The main research of this dissertation includes:A review of the development history of the infrared focal plane array (IRFPA ) detectors and the current level of international technology of infrared image pre-processing are given in this thesis. The dissertation also includes the main characteristics of the real-time infrared image processing and some comparisons of different types of infrared image pre-processing system.Study the key algorithm of the infrared image pre-processing technology, such as BPR (Bad Pixel Replacement), NUC (Non-Uniformity Correction) and AGC (Auto Gain Control):Bad pixels severely influence the imaging quality of the IRFPA devices. The definition of BPR is introduced, the reason of bad pixel is studied and the detection method is given. The DSP(Digital Signal Processor)software code for bad pixel auto-detection and correction is presented.NUC algorithm is necessary because of the limitation of IRFPA production. Almost every kind of NUC algorithm is studied in this dissertation. The approach of one-temperature point correction and two-temperature points correction is realized in the DSP system, and the software code is presented.The reason and necessity of the AGC is studied in this thesis. Different approaches of AGC are compared. The software used in DSP-based system is given. The feasibility of infrared image pre-processing system based on FPGA(Field Programmable Gate Array)is discussed. The hardware diagram of NUC, AGC and BPR based on FPGA is proposed.According to the practical measurement of this system, the performance of both hardware and software all meet with such requirements as stability, reliability and real time etc.This research lay the foundation for the system based on FPGA .