具有自适应校正功能的红外成像系统设计

Design of infrared imaging system with adaptive correction function

针对红外焦平面阵列(IRFPA)响应随温度及时间漂移的特点,及红外成像系统兼备测量和监视的要求,设计了一种能够对环境自适应的长波非制冷红外成像系统。系统采用FPGA单处理器架构,实现系统控制和图像处理等功能,简化了系统架构,降低了功耗。采用ADN8830进行控温,使探测器工作在最佳工作温度点,保证了探测器的成像性能。提出了基于黑体快门的非均匀性校正技术,实现了红外图像的实时校正,并有效补偿了外部环境的影响。视频输出采用模拟和数字双输出方式,模拟视频输出为图像增强后输出,便于人眼观察,数字输出为12 bit量化原始输出,可用于测量,系统可同时满足监视和测量的要求。试验结果表明,系统具有成像质量良好、环境适应性强、功耗低等特点。

In view of the fact that the response of IRFPA will drift with time and temperature and the IR imaging system will be used to measure and watch, an long-wave infrared uncooled imaging system which has adaptive correction function was designed. The system is based on FPGA, in which FPGA performs system control and image processing. Architecture of the system is simple and with less power dissipation. In order to improve the performance of the detector, a temperature control circuit based on ADN8830 was introduced, which could set temperature of the detector to a fixed point. In order to correct non-uniform responses of the detector′s individual elements, an adaptive non-uniformity correction algorithm was proposed based on shutter, which could compensate the response drift according to temperature and time. The system had both analog and digital video output, in which analog video could be used to watch, while digital video with 12 bit precision could be used to measure. The results show that the imaging system has the advantages of good image quality, good environmental adaptability and low power consumption.