Enhanced 3-D Urban Scene Reconstruction and Point Cloud Densification Using Gaussian Splatting and Google Earth Imagery

Three-dimensional urban scene reconstruction and modeling is a crucial research area. From a technical perspective, it is an interdisciplinary research area spanning computer vision, computer graphics, and photogrammetry. Its applications span across multiple disciplines including autonomous navigation with 3-D scene understanding, remote sensing/photogrammetry for the creation of 3-D maps from aerial/drone/satellite images, geographic information systems with urban digital twins, augmented and virtual reality with photorealistic scene reconstructions. Using Google Earth imagery, we create a 3-D Gaussian splatting (3DGS) model of the Waterloo region centered on the University of Waterloo, and are able to achieve view-synthesis results far exceeding previous 3-D view-synthesis results based on neural radiance fields (NeRFs)which we demonstrate in our benchmark. We also retrieve the 3-D geometry of the scene using the 3-D point cloud extracted from the 3DGS model, thereby reconstructing both the 3-D geometry and photorealistic lighting of the large-scale urban scene.