Imaging for archaeology: an instrument of reading and interpretation complex architecture

Photography is an essential instrument of knowledge in the archaeological field, both for historical source analysis and state of conservation mapping. This article aims to highlight the multifaceted role of this instrument, tracing known historical paths and reconstructing detailed 3D reality-based mould. The case study is the Arch of Drusus in Rome. Located at the beginning of the Via Appia, dating and interpretation activities result particularly complex. It presents several structures superimposed and stratified over time: a first original one in pre-imperial age, a second one as an aqueduct arch in the 3rd century A.D., and a third one decorated with some architectural elements around 1800. The method of analysis of the case study will move around the use of images. It will start from a historical/stylistic analysis, going to the construction of a complex image-based 3D model of the entire archaeological system. The data collected will serve as the basis for the definition of a semantic model, useful both for asset management and to prepare the Scan-to-BIM phase. The results obtained will ratify the role of photography as a basic tool for archaeology reading and interpretation, producing complex 3D models useful for virtual reconstruction. The case study's complexity will highlight some bottleneck in the process of data acquisition and restitution, which will be addressed to obtain reliable data. The comparison with active methodologies results will validate the result achieved. Refining an image-based research path for a semantically structured model opens new research scenarios related to the archeo-bim field.