基于图像自准直自动调焦技术

Based on Image Autocollimation Automatic Focus Technology

根据航空相机调焦准确度要求及CCD相机成像特点,提出了一种基于图像处理技术的航空相机自动调焦系统.该系统基于自制分辨率靶标,图像清晰度函数及优化的爬山算法,利用自准直离焦补偿法实现由温度、大气压力引起航空相机离焦量的校正;通过引入飞机高度数据进行离焦量计算,并通过自准直调焦技术实现离焦校正.对本系统进行了自动调焦测试实验,结果表明,该系统对相机的离焦校正误差小于相机的1/2焦深,能够满足航空相机快速、高准确度调焦要求.

According to the requirements of focusing accuracy and the imaging characteristics of the CCD camera,an automatic focusing system of aerial camera which is based on image processing technology was proposed.It was based on the self-made resolution target,the image sharpness function and the optimized mountain climbing algorithm.The calibration of the aerial camera’s defocusing amount caused by temperature and atmospheric pressure were realized by using the self collimation and the defocusing compensation method.Through the introduction of aircraft altitude data to calculate the defocusing amount and the correction were achieved by using the self collimation focusing technology.The automatic focusing test experiment was carried out and the results show that,the system can satisfy the requirements of fast and high precision focusing of the aerial camera,the calibration error is less than 1/2depth of the camera.