Underwater 3D reconstruction using a photometric stereo with illuminance estimation

Underwater image sensing is directly affected by the change in illuminance towards a camera caused by the refrac-tion of light in different media. In this study, the convergence of a near-field point light source in water is analyzed using a light propagation model. The photometric stereo (PS) formula is determined based on an accurate esti-mation of the illuminance entering the camera. An underwater PS system is designed to verify the proposed method's feasibility. The experimental results demonstrate improved accuracy in normal calculation. This helps achieve accurate underwater 3D reconstruction of objects that is suitable for underwater surface microdefect detection.(c) 2023 Optica Publishing Group

Automated summary

This study analyzes the convergence of a near-field point light source in water using a light propagation model. The photometric stereo formula is determined based on accurate estimation of illuminance entering the camera. An underwater photometric stereo system is designed to validate the proposed method's feasibility. Experimental results demonstrate improved accuracy in normal calculation, enabling accurate 3D reconstruction for underwater surface microdefect detection.