3D Imaging of Complex Specular Surfaces by Fusing Polarimetric and Deflectometric Information

TL;DR

This paper presents a novel 3D imaging method for complex specular surfaces that fuses polarimetric and deflectometric data, overcoming limitations of existing techniques and achieving high accuracy in surface normal estimation.

Contribution

The paper introduces a new measurement principle combining polarization and geometric cues to resolve ambiguities in 3D specular surface imaging, removing orthographic assumptions.

Findings

Achieved surface normal accuracy below 0.6 degrees.

Demonstrated effective single-shot and multi-shot measurements on complex surfaces.

Improved generalizability over traditional methods.

Abstract

Accurate and fast 3D imaging of specular surfaces still poses major challenges for state-of-the-art optical measurement principles. Frequently used methods, such as phase-measuring deflectometry (PMD) or shape-from-polarization (SfP), rely on strong assumptions about the measured objects, limiting their generalizability in broader application areas like medical imaging, industrial inspection, virtual reality, or cultural heritage analysis. In this paper, we introduce a measurement principle that utilizes a novel technique to effectively encode and decode the information contained in a light field reflected off a specular surface. We combine polarization cues from SfP with geometric information obtained from PMD to resolve all arising ambiguities in the 3D measurement. Moreover, our approach removes the unrealistic orthographic imaging assumption for SfP, which significantly improves the respective results. We showcase our new technique by demonstrating single-shot and multi-shot measurements on complex-shaped specular surfaces, displaying an evaluated accuracy of surface normals below $0.6^\circ$.