航空交错TDI红外影像复原

Restoration of Infrared Images Captured by Aerial Staggered TDI Cameras

针对航空交错延时积分(Time delay and integration,TDI)红外影像奇数行和偶数行之间灰度差异、错动以及影像降晰问题,提出了一种交错TDI红外影像复原方法.首先采用对影像灰度差异不敏感的基于相位相关(Phase-only correlation,POC)的位移估计方法估计奇数行影像和偶数行影像之间的亚像素精度位移场.其次以奇数行影像为参考,根据位移估计结果对偶数行影像做点对点灰度校正,并对齐奇数行影像和灰度校正后的偶数行影像.最后采用BTV(Bilateral total variation)正则化超分辨率重建方法反降晰,得到复原影像.实验结果表明复原影像中奇偶行的错动得到有效补偿,地物的边缘和纹理结构更加清晰,影像质量显著提高.

The infrared images captured by aerial staggered time delay and integration （TDI） cameras suffer from gray difference and stagger displacement between the odd field and even field, as well as blur owing to the long integrated exposure time. In order to restore the images, a POC （Phase-only correlation）-based motion estimation method is employed to estimate the motion field between the odd and even fields, because the POC is independent of gray differences between image pairs and can achieve sub-pixel accuracy. The motion field is then used for pixel-to-pixel gray correction of the even field with the odd field as the reference, and the odd field and the corrected even field are aligned. Finally, a BTV- based super-resolution algorithm is used for debluring. Experimental results show that the displacement is effectively compensated, texture and edges are sharper and clearer, and the quality of the restored image is improved obviously.