Theory and practice for an object-based approach in archaeological remote sensing

Object-based image analysis (OBIA) is rapidly emerging as a valuable method for integrating the data processing techniques and GIS approaches classically employed in archaeology. OBIA is intended to replicate human perception by using a protocol of (semi)automated image segmentation and classification. However, the lack of a theoretical background adapted to the specificities of the archaeological discipline is still preventing researchers from finding a shared language and a common protocol of investigation necessary to allow the comparability of the results. This article discusses a series of crucial theoretical issues linked to the incompleteness and the equi-/multifinality of the archaeological record and introduces the core concept of Diachronic Semantic Models (DhSM) as a means to integrate the long-term evolution of the archaeological landscape in the conceptual, digital and real world frameworks of the object-based approach. We also present an assessment of the limits and potential of this method, built from a set of case studies from published and unpublished research. Finally, we propose a general workflow of an Archaeological Object-Based Image Analysis (ArchaeOBIA) project, designed for stimulating the development of an operational routine for object-based applications in archaeology.