Near-light Photometric Stereo with Symmetric Lights

TL;DR

This paper introduces a linear, closed-form solution for near-light photometric stereo that leverages symmetric light source arrangements, enabling accurate shape recovery without extensive calibration or initialization.

Contribution

It presents a novel symmetric light-based approach that simplifies near-light photometric stereo by avoiding non-convex optimization and calibration.

Findings

Achieves shape recovery comparable to state-of-the-art methods.

Reduces the need for careful depth initialization and light calibration.

Works with uncalibrated, symmetrically arranged light sources.

Abstract

This paper describes a linear solution method for near-light photometric stereo by exploiting symmetric light source arrangements. Unlike conventional non-convex optimization approaches, by arranging multiple sets of symmetric nearby light source pairs, our method derives a closed-form solution for surface normal and depth without requiring initialization. In addition, our method works as long as the light sources are symmetrically distributed about an arbitrary point even when the entire spatial offset is uncalibrated. Experiments showcase the accuracy of shape recovery accuracy of our method, achieving comparable results to the state-of-the-art calibrated near-light photometric stereo method while significantly reducing requirements of careful depth initialization and light calibration.