Virtual Vessel Reconstruction from a Fragment?s Profile

Every archaeological excavation must deal with a vast number of ceramic fragments. The documentation, administration and scientific processing of these fragments represent a temporal, personnel, and financial problem. Up to now documentation and classification have been done manually which means a lot of routine work for archaeologists and a very inconsistent representation of the real object. First, there may be errors in the measuring process (diameter or height may be inaccurate). Second, the drawing of the fragment should be in a consistent style, which is not possible since a drawing of an object without interpreting it is very hard to do. We are developing a documentation system for archaeological fragments based on their profile, which is the cross-section of the fragment in the direction of the rotational axis of symmetry. Hence the position of a fragment (orientation) on a vessel is important, since it allows a good profile to be obtained. This paper presents two different approaches to the estimation of the orientation of archaeological fragments and the profile extraction. One method is based on a Hough inspired approach and the other is based on genetic algorithms and expert interaction. We compare the methods and show results with respect to robustness, applicability, and accuracy.