红外系统小目标成像自动调光方法

提出了一种实时调整红外相机积分时间的方法。针对成像为点目标且灰度值变化剧烈的情况,为保证红外辐射特性测量的精度,标定了相机在不同积分时间下亮度与成像灰度值的对应关系,确定了红外相机响应关系线性度较好的区域;提出了点目标弥散范围的计算方法,并对红外系统的模拟图像和真实图像进行匹配获得最优化估计的目标位置、尺寸以获取目标的所有灰度值,而后根据亮度与灰度的关系对积分时间进行调整。实验结果证明,可同时调整两个不同红外相机的积分时间以保证灰度值处于理想区间内,调整频率可达25Hz,满足高速飞行器试验的实时性要求。

Method of auto light control for small target in infrared system

A measurement method for real-time adjusting integer time of infrared camera is proposed. Since the image of target is a point and the gray value is verified severely, the relationship between light and gray values in different integer times is calibrated for the precision of radiation measurement and the linear curve of response is fitted. Then the algorithm for the diffuse image spot of target in the detector is proposed. Furthermore, the size and central position of the target are estimated accurately by matching the simulated image and the actual image obtained from the IR imaging system. The total gray value is got and the integer time is adjusted based on the relationship between light and gray value. The experiment result shows that the integer time of two different cameras is adjusted, the gray value is in the linear region and the frequency is 25 Hz and the real-time request in the high speed air vehicle is met.