Methods for the Epipolarity Analysis of Pushbroom Satellite Images Based on the Rational Function Model

Shuhan Du,Hui Yi,Decheng Wang,Xiangning Chen,Ningbo Guo

doi:10.1109/access.2020.2999393

Abstract

Epipolarity is the foundation of epipolar resampling, which is used to eliminate the vertical disparity between stereo pairs in stereo matching. To analyze the epipolarity of pushbroom satellite images, this paper compares three methods based on the rational function model (RFM): the projection trajectory method (PTM), the piecewise projection trajectory method (PPTM) and our extended projection trajectory method (EPTM). To evaluate the quality of epipolar curves, we defined the deviation coefficient as a metric to evaluate the bending degree of epipolar curves. We also defined the maximum deviation coefficient of an image that can be used to determinate the tile size in multiview satellite image 3D reconstruction based on image dividing. Comparison experiments have been carried out with pushbroom satellite images using these three methods. Experimental results show that our EPTM is more convenient and practical. It only needs the forward form of the RFM to analyze the epipolarity and can be used in the epipolarity analysis of a single image. By projecting straight lines in the ground space into the image space, the EPTM can be used to perform comprehensive epipolarity analysis for pushbroom satellite images. In addition, the EPTM can be used to calculate the maximum deviation coefficient of an image that the PTM and the PPTM cannot calculate, which is important in 3D reconstruction using multiview satellite images.

Highlights

In photogrammetry, epipolarity is the foundation of epipolar resampling [1]–[3], and it is called stereo rectification in computer vision [4]–[6]
To carry out a comprehensive epipolarity analysis of pushbroom satellite images, we summarize the epipolarity analysis methods based on the rational function model (RFM) for pushbroom satellite images in this paper
The main contributions of our work can be summarized in three points: 1) we proposed a novel method to analyze the epipolarity of pushbroom satellite images; 2) we defined the deviation coefficient as a metric to evaluate the bending degree of epipolar curves; and 3) we defined the maximum deviation coefficient of an image to determine the tile size in multiview satellite image 3D reconstruction based on image dividing

Summary

INTRODUCTION

Epipolarity is the foundation of epipolar resampling [1]–[3], and it is called stereo rectification in computer vision [4]–[6]. H. Yi et al.: Methods for the Epipolarity Analysis of Pushbroom Satellite Images Based on the RFM in pushbroom images. To realize the epipolar resampling of pushbroom satellite images more accurately, Oh et al [25], Oh [26] researched the traditional PTM and proposed the piecewise projection trajectory method (PPTM) based on the RFM. The main contributions of our work can be summarized in three points: 1) we proposed a novel method to analyze the epipolarity of pushbroom satellite images; 2) we defined the deviation coefficient as a metric to evaluate the bending degree of epipolar curves; and 3) we defined the maximum deviation coefficient of an image to determine the tile size in multiview satellite image 3D reconstruction based on image dividing

RATIONAL FUNCTION MODEL

METHODS

CONCLUSIONS