Reconstructing Archeological Vessels from Fragments using Anchor Points Residing on Shard Fragment Borders

This paper presents a method to assist in the tedious process of reconstructing ceramic vessels from excavated fragments. The method models the fragment borders as 3D curves and uses intrinsic differential anchor points on the curves. Corresponding anchors on different fragments are identified using absolute invariants and a longest string search technique. A rigid transformation is computed from the corresponding anchors, allowing the fragments to be virtually mended. A global constraint induced by the surface of revolution (basis shape) to decide on how all pairs of mended fragments are coming together as one global mended vessel is used. The accuracy of mending is measured using a distance error map metric. The method is tested on a set of 3D scanned fragments (313 pieces) coming from 19 broken vessels. 80% of the pieces were properly mended and resulted into alignment error at the scanner-resolution-level. The method took 59 seconds for mending pieces plus 60 minutes for 3D scans as compared to 12 hours for stitching manually.