Virtual Reconstruction of Archaeological Vessels Using Expert Priors & Surface Markings

Abstract

This paper presents a method to assist in the tedious procedure of reconstructing ceramic vessels from unearthed archaeological shards or fragments using 3D computer vision-enabling technologies. The method uses vessels surface markings combined with a generic model to produce a representation of what the original vessel may have looked like. Generic vessel models used are based on a host of factors including expert historical knowledge of the period, provenance of the artifact and site location. The generic model need not be identical to the excavated vessel, but must be within the allowable class, i.e., it is within a geometric transformation of it in most of its parts. The ceramic vessels we worked with have markings, which we exploit under the allowable set of transformations between the generic model and the excavated vessel. We align them using a novel set of weighted curve moments. The morphing transformation (affine or higher order morphing function) is computed from these corresponding curves, and distance error metrics are introduced to access the accuracy of alignment of a fragment to a given vessel. If a vessel has no surface markings, we use curves for alignment these are computed from the intrinsic differential geometry of the surface and are also locally affine preserved. The methods are tested on a subset of Independence National Historical Park (INDE) ceramic artifacts created by 3-D scanning of prospective generic bowls and their pieces.