Identifying the lights position in photometric stereo under unknown lighting

TL;DR

This paper presents a Matlab implementation for solving the photometric stereo problem with unknown lighting conditions and introduces a simple shooting technique to address the bas-relief ambiguity, enhancing 3D shape reconstruction accuracy.

Contribution

It provides a practical implementation of an algorithm to estimate light source positions in photometric stereo without prior lighting information, along with a novel shooting technique.

Findings

Successful estimation of light positions from data

Effective solution to the bas-relief ambiguity

Improved 3D shape reconstruction accuracy

Abstract

Reconstructing the 3D shape of an object from a set of images is a classical problem in Computer Vision. Photometric stereo is one of the possible approaches. It stands on the assumption that the object is observed from a fixed point of view under different lighting conditions. The traditional approach requires that the position of the light sources is accurately known. It has been proved that the lights position can be estimated directly from the data, when at least 6 images of the observed object are available. In this paper, we give a Matlab implementation of the algorithm for solving the photometric stereo problem under unknown lighting, and propose a simple shooting technique to solve the bas-relief ambiguity.