GMLight: Lighting Estimation via Geometric Distribution Approximation

TL;DR

GMLight introduces a novel framework combining regression and generative models to accurately estimate scene illumination from a single image, improving realism and detail in relighting applications.

Contribution

The paper proposes GMLight, a new method that uses geometric distribution approximation and a geometric mover's loss for better illumination estimation.

Findings

Achieves state-of-the-art accuracy in illumination estimation

Produces high-fidelity panoramic illumination maps

Enhances relighting realism for 3D object insertion

Abstract

Inferring the scene illumination from a single image is an essential yet challenging task in computer vision and computer graphics. Existing works estimate lighting by regressing representative illumination parameters or generating illumination maps directly. However, these methods often suffer from poor accuracy and generalization. This paper presents Geometric Mover's Light (GMLight), a lighting estimation framework that employs a regression network and a generative projector for effective illumination estimation. We parameterize illumination scenes in terms of the geometric light distribution, light intensity, ambient term, and auxiliary depth, which can be estimated by a regression network. Inspired by the earth mover's distance, we design a novel geometric mover's loss to guide the accurate regression of light distribution parameters. With the estimated light parameters, the generative projector synthesizes panoramic illumination maps with realistic appearance and high-frequency details. Extensive experiments show that GMLight achieves accurate illumination estimation and superior fidelity in relighting for 3D object insertion. The codes are available at \href{https://github.com/fnzhan/Illumination-Estimation}{https://github.com/fnzhan/Illumination-Estimation}.