实时红外图像非均匀性校正是红外热成像系统的基础。采用Altera公司的NIOSII嵌入式软核CPU技术,提出了一种基于非线性拟合的实时校正方法以及利用FPGA为核心的硬件实现途径。针对校正中耗时的算法用FPGA中模块完成,采用NIOSII处理器的自定制指令,使FPGA的并行性和DSP的灵活性完美结合在一起,极大的提高了系统的性能。该方法动态范围大,系统仅采用一片FPGA芯片,使得系统小型化成为可能。介绍了硬件电路的原理图以及工作过程并给出实验结果。实验证明了这种方法的优越性,并取得了满意的实验结果。

The Infrared Focal Plane Arrays (IRFPA) imaging system is the main technique tendency of infrared imaging,but the inherent nonuniformity of IRFPA limits its imaging quality crucially.Therefore,real-time nonuniformity correction for IRFPA is the base of the infrared thermo-image system.A non-linear curve fitting correction method for IRFPA with real-time realization is proposed using Altera’s NIOSII embedded software CPU.By creating custom instructions for NIOSII embedded processor,time-consuming algorithm is solved in FPGA.As a result,the parallelism of Field Programmable Gate Array (FPGA) and the flexibility of DSP are combined perfectly,and the performance of the system is improved greatly.The block diagram of hardware circuit and the work processes are introduced.The experimental results show that the system has a large dynamic range and utilizes only one FPGA chip.It is possible to minimize the system.