基于多角度多光谱相机的相对辐射校正方法分析

Analysis of Relative Radiometric Correction Method Based on Directional Multi-Spectral Camera

多角度多光谱相机(Directional Multi-Spectral Camera,DMC)由5台相机组成,每台相机单独成像,这种成像方式导致其立体成像过程中多相机间辐射响应很难保持一致性。为实现各个视角相机及每片CCD的辐射响应一致,文章提出了多相机全局色差标定法,并与直方图在轨统计法和偏航定标法对DMC影像的辐射校正效果进行了对比。其中几种方法的相机间影像的辐射校正效果比较显示,多相机全局色差标定法校正的5个相机的影像颜色更接近,且均匀地物的相对辐射校正精度更高;CCD片间影像的校正效果比较显示,直方图统计法和多相机全局色差标定法校正的CCD片间影像都呈现颜色均衡,基本无色差,且相对辐射校正精度在3%以内。综上,说明多相机全局色差标定法更适用于校正DMC的辐射一致性问题。

The Directional Multi-Spectral Camera(DMC)consists of five cameras,and the imaging is independent.This imaging method makes it difficult to ensure the consistent radiation response among multiple cameras in the process of realizing stereoscopic imaging.In order to achieve the same radiation response of each camera and each CCD,a multi-camera global chromatic aberration calibration method is proposed in this paper,and the radiation correction effect of histogram on-orbit statistics method and yaw calibration method on the Directional Multi-Spectral Camera images is compared.Compared with the correction effect between cameras,the color of the five cameras corrected by the multi-camera global color difference calibration method is closer,and the relative radiometric correction accuracy of uniform objects is higher.According to the comparison of the correction effect of CCD inter-chip images,the CCD inter-chip images corrected by histogram statistics method and multi-camera global chromatic aberration calibration method show color balance,basically no chromatic aberration,and the relative radiometric correction accuracy is basically less than 3%.In conclusion,the multi-camera global chromatic aberration calibration method is more suitable for correcting the radiation problem between multi-angle and multi-spectral cameras.