3D Reconstruction of Ancient Bronze Mirrors

Contact: Simon Brenner

With over 3000 known examples, Etruscan mirrors form one of the largest object groups in Etruscan art. The majority are metal (mostly bronze) discs with handles whose polished obverse served as a mirror while the reverse was often embellished with engraved and/or chased figures. The old-fashioned way of documenting these objects is to draw their features by hand. We want to improve that.

Within a new research project, the bronze missors located in Austria will be scanned in different modalities and analysed. This involves the following tasks, which are available as thesis or practica topics:

3D Acquisition

(Practica only)
Assist in acquiring/processing 3D scans of the bronze mirrors. Focus on Photometric Stereo: test/implement methods that are promising for our application and determine the best approach.

3D Fusion

Structured light scanning produces geometrically correct models, but the resulution can be insufficient for tiny details (like engravings on a mirror). Photometric Stereo captures tiny details but suffers from geometric distortions. Evaluate/improve existing approaches to combine both types of reconstruction in a single high precision 3D model and apply it to scans of the bronze mirrors.

Extraction of Drawings

The engraved drawings on the back side of the bronze mirrors are probably their most interesting features. Your job is to extract those drawings from 3D models, color images and (in rare cases) x-ray images. This is challenging because in the wide range of conditions the mirrors can be in.

Extraction of Reliefs and Cross-Sections

Other interesting features of those reliefs are their cross-sections and relif ornaments. While extracting cross sections of a 3D model is trivial, creating illustrational drawings of the reliefs is in fact a computer graphics problem. Your task will be to research on rendering methods that can produce results like shown below, apply them to the bronze mirror scans and evaluate.