Documentation and interpretation of an archeological excavation: an experience with dense stereo reconstruction tools

An archeological excavation is usually a rapidly evolving environment: several factors (weather, costs, permissions) force the work to be concentrated in a few weeks. Moreover, excavating is essentially a mono-directional operation, which constantly modifies the state of the site. Since most of the interpretation is performed in a second stage, it is necessary to collect a massive amount of documentation (images, sketches, notes, measurements). In this paper we present an experiment of monitoring of an excavation in Uppåkra, South Sweden, using dense stereo matching techniques. The archeologists were trained to collect a set of images every day; the set was used to produce a 3D model depicting the state of the excavation. In this way, it was possible to obtain a reliable geometric representation of the evolution of the excavation. The obtained model were also used by the archeologists, by the means of an open-source tool, to perform a site study and interpretation stage directly on the geometric data. The results of the experimentation show that dense stereo matching can be easily integrated with the daily work of archeologists in the context of an excavation, and it can provide a valuable source of data for interpretation, archival and integration of acquired material.