Parallax estimation for push-frame satellite imagery: application to super-resolution and 3D surface modeling from Skysat products

Abstract

Recent constellations of satellites, including the Skysat constellation, are able to acquire burst of images. This new acquisition mode allows for modern image restoration techniques, including multiframe super-resolution. As the satellite moves during the acquisition of the burst, elevation changes in the scene translate into noticeable parallax. This parallax hinders the results of the restoration. To cope with this issue, we propose a novel parallax estimation method. The method is composed of a linear Plane+Parallax decomposition of the apparent motion and a multi-frame optical flow algorithm that exploits all frames simultaneously. Using SkySat L1A images, we show that the estimated perpixel displacements are important for applying multiframe super-resolution on scenes containing elevation changes and that can also be used to estimate a coarse 3D surface model.