The possibility of using close-range photogrammetry in the inventory of historic complex basements - case study

Abstract

In the community, historical objects play the role of witness to past history. Due to that fact, it is necessary to preserve and reconstruct cultural heritage objects and sites for the future generation. Image-based photogrammetric methods have been widely applied for this purpose for many years. Nowadays, Terrestrial Laser Scanning (TLS; range-based method), due to its advantages such as speed of data acquisition, high accuracy and independence from light conditions, is increasingly used in the inventory of complex historic buildings. Despite this, the development of modern image processing methods, i.e. Structure-from-Motion (SfM) and Multi-View Stereo (MVS), has meant that close-range photogrammetric techniques are still competitive with TLS. The article aimed to present the possibility of using close-range photogrammetry to inventory historic complex basements. Laser scanning was performed as part of the measurements (with a Z+F 5006h scanner), and a series of close-range images were taken with a full-frame non-metric Canon 5D Mark II camera. Based on the combined SfM and MVS methods, a dense point cloud was generated, which in a subsequent data processing step served as the basis for generating 3D models and cross-sections. To assess the quality of the generated documentation, the TLS data were used as ground-truth data, and the shape and cross-section mapping quality was compared. It is evident from the investment presented that the use of close-range photogrammetry methods makes it possible to generate documentation that meets the requirements of architectural studies and similar shape accuracy for historic complex basements.