NeRF2Points: Large-Scale Point Cloud Generation From Street Views' Radiance Field Optimization

TL;DR

NeRF2Points introduces a novel NeRF variant tailored for urban point cloud generation from street-view images, employing advanced pose optimization and layered modeling to improve accuracy and coherence in large-scale city environments.

Contribution

The paper presents NeRF2Points, a new method combining WIGO, SfM, and LPiM to generate high-quality urban point clouds from RGB images, addressing pose inaccuracies and data challenges.

Findings

High-quality point clouds achieved from RGB data alone.

Enhanced camera pose accuracy through WIGO and SfM integration.

Coherent urban point clouds demonstrated on a 20 km dataset.

Abstract

Neural Radiance Fields (NeRF) have emerged as a paradigm-shifting methodology for the photorealistic rendering of objects and environments, enabling the synthesis of novel viewpoints with remarkable fidelity. This is accomplished through the strategic utilization of object-centric camera poses characterized by significant inter-frame overlap. This paper explores a compelling, alternative utility of NeRF: the derivation of point clouds from aggregated urban landscape imagery. The transmutation of street-view data into point clouds is fraught with complexities, attributable to a nexus of interdependent variables. First, high-quality point cloud generation hinges on precise camera poses, yet many datasets suffer from inaccuracies in pose metadata. Also, the standard approach of NeRF is ill-suited for the distinct characteristics of street-view data from autonomous vehicles in vast, open settings. Autonomous vehicle cameras often record with limited overlap, leading to blurring, artifacts, and compromised pavement representation in NeRF-based point clouds. In this paper, we present NeRF2Points, a tailored NeRF variant for urban point cloud synthesis, notable for its high-quality output from RGB inputs alone. Our paper is supported by a bespoke, high-resolution 20-kilometer urban street dataset, designed for point cloud generation and evaluation. NeRF2Points adeptly navigates the inherent challenges of NeRF-based point cloud synthesis through the implementation of the following strategic innovations: (1) Integration of Weighted Iterative Geometric Optimization (WIGO) and Structure from Motion (SfM) for enhanced camera pose accuracy, elevating street-view data precision. (2) Layered Perception and Integrated Modeling (LPiM) is designed for distinct radiance field modeling in urban environments, resulting in coherent point cloud representations.