Uncalibrated Deflectometry on a Mobile Device for the 3D Measurement of Stained Glass Artwork

We introduce a deflectometry system for the three-dimensional (3D) surface acquisition of extended specular objects using only a mobile device such as a phone or tablet. The system targets a specific application: The 3D measurement and analysis of stained glass artworks, commonly found in church windows and glass reliefs. These artworks are challenging objects to measure because of their extended size and high surface frequencies. In this contribution, we demonstrate high-quality deflectometric measurements without the need for an offline calibration procedure. In addition, we present a technique that registers measurements acquired from multiple views to compensate for the small screen of a mobile device and to capture the object in its entirety. Our introduced framework is a first step towards a self-calibrating deflectometry system that is accessible to users with little to no technical imaging experience. We hope that our technique will enable crowd-sourced aggregation of "3D-fingerprints" for stained glass artwork across the globe, helping to establish provenance and authentication of unattributed works.