The Nonuniformity Correction Of Infrared Image Based On DSP

The infrared image of object is taken by detecting it using infrared radiation. The figure, temperature distribution and inner configuration of object can be observed from its thermal image. Now, infrared thermal image technology is applied widely in many relative fields from civil products to national defenses, and it is noticed by people more and more.With the development of microelectronic technology, LSI circuits technology and signal processing, the infrared focus plane array (IRFPA) developed by thermal effect and CMOS techonology have been attracted much attention in the field of infrared thermal imaging. But every detector on the IRFPA can have different responses under the same simulus, what is considered as the nonuniformity problem, influencing the detection sensitivity and spatial resolution of detector, so nonuniformity correction is a necessary and unavoidable task to be performed in order to achieve higher-quality infrared image. This paper gives the hardware and software design of an infrared image nonuniformity correction system based on DSP.At first, domestic and foreign development situation of infrared focal imaging technology is introdued in this paper, and the development prospect of the infrared thermal imager is analyzed. Then several common method of nonuniformity correction of infrared image is summarized and compared, and the principles of two-point nonuniformity correction and integration time correction are described in detail. On these bases, using a CMOS image sensor to stimulate the IRFPA, employing the TMS320VC5509A DSP as the core processor, completed the design and manufacture of the infrared image nonuniformity correction system. The hardware circuit of the system includes the function modules as image acquisition circuit, the memory extension circuit, image output circuit, the internal logic circuit of CPLD, the power circuit and so on. In this paper, some key technologies of the hardware design of the system were explained, and realizion process of the circuit's function module of the system was introduced in detail.In this paper, the software design of the system was also discussed. In the CCS software develop environment, the image acquisition, processing, storage and display program, and the configure program of the image sensor were designed. In the VC environment, run the programmed non-uniformity correction algorithms and contrast enhancement algorithm program of C language on a 128×128 infrared image, results show that made a very good effect.