# FluoNeRF: Fluorescent Novel-View Synthesis Under Novel Light Source Colors and Spectra

## TL;DR

This paper introduces FluoNeRF, a method to create realistic images of fluorescent objects under different lighting conditions and viewpoints.

## Contribution

The novel contribution is a view synthesis method that accurately reproduces fluorescent object colors under arbitrary lighting using neural radiance fields.

## Key findings

- FluoNeRF outperforms existing methods in synthesizing fluorescent object colors under novel lighting.
- Using more than three primary colors improves reproduction of fluorescent colors under common light sources.

## Abstract

Synthesizing photo-realistic images of a scene from arbitrary viewpoints and under arbitrary lighting environments is one of the important research topics in computer vision and graphics. In this paper, we propose a method for synthesizing photo-realistic images of a scene with fluorescent objects from novel viewpoints and under novel lighting colors and spectra. In general, fluorescent materials absorb light with certain wavelengths and then emit light with longer wavelengths than the absorbed ones, in contrast to reflective materials, which preserve wavelengths of light. Therefore, we cannot reproduce the colors of fluorescent objects under arbitrary lighting colors by combining conventional view synthesis techniques with the white balance adjustment of the RGB channels. Accordingly, we extend the novel-view synthesis based on the neural radiance fields by incorporating the superposition principle of light; our proposed method captures a sparse set of images of a scene from varying viewpoints and under varying lighting colors or spectra with active lighting systems such as a color display or a multi-spectral light stage and then synthesizes photo-realistic images of the scene without explicitly modeling its geometric and photometric models. We conducted a number of experiments using real images captured with an LCD and confirmed that our method works better than the existing methods. Moreover, we showed that the extension of our method using more than three primary colors with a light stage enables us to reproduce the colors of fluorescent objects under common light sources.