Physics-informed Active Polarimetric 3D Imaging for Specular Surfaces

TL;DR

This paper introduces a physics-informed deep learning method for single-shot 3D imaging of complex specular surfaces, combining polarization cues and structured illumination to improve accuracy and robustness.

Contribution

It presents a novel dual-encoder neural network that integrates polarization and geometric cues for accurate surface normal estimation in single-shot 3D imaging.

Findings

Achieves accurate normal estimation on complex surfaces.

Provides robust performance in single-shot 3D imaging.

Enables practical, fast 3D measurement of specular surfaces.

Abstract

3D imaging of specular surfaces remains challenging in real-world scenarios, such as in-line inspection or hand-held scanning, requiring fast and accurate measurement of complex geometries. Optical metrology techniques such as deflectometry achieve high accuracy but typically rely on multi-shot acquisition, making them unsuitable for dynamic environments. Fourier-based single-shot approaches alleviate this constraint, yet their performance deteriorates when measuring surfaces with high spatial frequency structure or large curvature. Alternatively, polarimetric 3D imaging in computer vision operates in a single-shot fashion and exhibits robustness to geometric complexity. However, its accuracy is fundamentally limited by the orthographic imaging assumption. In this paper, we propose a physics-informed deep learning framework for single-shot 3D imaging of complex specular surfaces. Polarization cues provide orientation priors that assist in interpreting geometric information encoded by structured illumination. These complementary cues are processed through a dual-encoder architecture with mutual feature modulation, allowing the network to resolve their nonlinear coupling and directly infer surface normals. The proposed method achieves accurate and robust normal estimation in single-shot with fast inference, enabling practical 3D imaging of complex specular surfaces.