三维高斯溅射用于航空影像的大规模表面重建方法

A Large-Scale Surface Reconstruction Method for Aerial Imagery Based on 3D Gaussian Splatting

  • 摘要: 三维高斯溅射(3D gaussian splatting, 3DGS)方法在小范围场景的表面重建任务中已展现出优异性能,但在大规模场景中的应用仍面临诸多挑战。针对这一问题,本文提出了一种基于 3DGS 的大规模航拍影像表面重建框架,命名为航拍高斯溅射(aerial gaussian splatting, AGS)。首先,我们设计了一种自适应的场景分块策略,以提升 3DGS 在大范围航拍场景中的适用性。随后,为改善弱纹理与阴影区域的重建质量,引入射线-高斯相交(ray-gaussian intersection, RGI)技术,直接从高斯基元中提取无偏的深度与法向信息。在此基础上,进一步提出深度梯度增强优化(depth-gradient enhanced optimization, DGE)模块,通过引入由单目深度估计模型获得的深度梯度先验来强化几何约束。最后,我们提出多视角深度对齐(multiview depth alignment, MDA)优化策略,以增强多视角条件下的几何一致性。在多个公开数据集上的实验结果表明, AGS 在深度估计精度方面优于现有基于 3DGS 的先进方法,并在新视角生成上保持高质量表现。

     

    Abstract: Objectives: Large-scale surface reconstruction has long been a central topic in both academia and industry, particularly in aerial surveying, 3D urban modeling, and smart-city applications. Although methods based on Neural Radiance Fields (NeRF) have achieved remarkable results in novel view synthesis and shown potential for surface reconstruction, their substantial computational overhead limits their applicability to large-scale scenes. 3D Gaussian Splatting (3DGS) effectively alleviates this limitation by leveraging explicit Gaussian primitives and a rasterization-like forward-splatting pipeline that is highly efficient on modern GPUs. Despite its impressive performance in high-fidelity novel view synthesis, directly applying 3DGS to large-scale aerial imagery—where weak textures, shadows, and massive scene extents are common—remains challenging. This study aims to address these issues and explore the feasibility of employing 3DGS for large-scale aerial surface reconstruction. Methods: We propose Aerial Gaussian Splatting (AGS), a 3DGS-based large-scale surface reconstruction framework specifically designed for aerial scenarios. To overcome memory bottlenecks and computation constraints caused by extensive aerial scenes, AGS introduces an adaptive aerial scene partitioning strategy. This strategy utilizes camera distribution and Structure-from-Motion (SfM) derived visibility relationships to divide the entire region into multiple spatially coherent and independent blocks. Each block can be optimized in parallel and later merged seamlessly, ensuring global geometric consistency while significantly reducing per-block memory consumption. To improve reconstruction in weak-texture and shadowed regions, AGS incorporates the existing Ray-Gaussian Intersection (RGI) technique to extract unbiased depth and normal information directly from Gaussian primitives. Building upon RGI, we further propose a Depth-Gradient Enhanced Optimization (DGE) module, which introduces depth-gradient priors obtained from a monocular depth estimation model. This enhances geometric constraints and improves detail preservation under visually ambiguous conditions. In addition, AGS employs a multi-view depth alignment strategy that enforces geometric consistency between training views and their neighboring viewpoints through a projection-reprojection mechanism, compensating for the geometry-insufficient nature of the original 3DGS pipeline. Results: We evaluated the proposed framework on the WHU-OMVS and Tianjin aerial datasets. Experimental results demonstrate that AGS achieves superior depth estimation accuracy compared with existing state-of-the-art 3DGS-based methods and also outperforms conventional multi-view stereo reconstruction software such as Colmap. Furthermore, AGS achieves high-quality rendering performance on the Mill-19 and UrbanScene3D datasets, consistently surpassing competing approaches in visual quality. Conclusions: This work presents AGS, a dedicated extension of 3DGS for large-scale aerial surface reconstruction. By integrating adaptive scene partitioning, geometry-aware rendering, depth-gradient enhanced optimization, and multi-view depth alignment, AGS effectively addresses the challenges posed by large scene extents, weak textures, and limited geometric supervision. The results validate the feasibility of applying 3DGS to large-scale aerial surface reconstruction and highlight its potential for broader applications in urban mapping, geospatial analysis, and environmental monitoring.

     

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