基于畸变虚拟相机的海洋一号C型紫外成像仪几何拼接

Geometric stitching of a HaiYang-1C ultra violet imager with a distorted virtual camera.

作者信息

Cao Jinshan, Zhang Zhiqi, Jin Shuying, Chang Xueli

出版信息

Opt Express. 2020 Apr 27;28(9):14109-14126. doi: 10.1364/OE.391418.

Abstract

The HaiYang-1C (HY-1C) ultra violet imager (UVI) consists of five independent cameras with a designed total image swath of approximately 3000 km. In order to obtain a complete seamless image formed by the five sub-images, a feasible geometric stitching method for the HY-1C UVI with a distorted virtual camera is proposed. First, we perform the absolute geometric calibration of camera 3 and the relative geometric calibration of cameras 1, 2, 4, and 5. Then, a distorted virtual camera is assigned. Finally, the five sub-images are stitched together with the distorted virtual camera. Three HY-1C UVI images were tested. The experimental results showed that the georeferencing accuracy of the stitched images was better than 1 pixel. Compared with the conventional stitching method with an undistorted virtual camera, the ground sampling distance differences of the five cameras obtained by the proposed method were reduced from 23%, 37%, 53%, 37%, and 25% to 6%, 6%, 1%, 7%, and 8%, respectively.

摘要

海洋一号C（HY-1C）紫外成像仪（UVI）由五个独立相机组成，设计的总成像宽度约为3000千米。为了获得由五个子图像形成的完整无缝图像，提出了一种适用于具有畸变虚拟相机的HY-1C UVI的可行几何拼接方法。首先，对相机3进行绝对几何校准，对相机1、2、4和5进行相对几何校准。然后，指定一个畸变虚拟相机。最后，用畸变虚拟相机将五个子图像拼接在一起。对三张HY-1C UVI图像进行了测试。实验结果表明，拼接图像的地理配准精度优于1个像素。与使用无畸变虚拟相机的传统拼接方法相比，该方法得到的五个相机的地面采样距离差异分别从23%、37%、53%、37%和25%降低到了6%、6%、1%、7%和8%。