Inventory of historical polychrome using photogrammetric methods

Abstract

The inventory of a historic monument is carried out to create documentation that provides information on the up-to-date condition of the object. Preserving its original form and materials requires a minimally invasive approach to data acquisition. The implemented research project included an analysis of the possibilities of using photogrammetric methods in the inventory of wall paintings in the historic wooden Greek-Catholic Church of the Protection of the Holy Mother God in Miękisz Stary (Jarosław County, Podkarpackie Voivodeship). The research object is a wooden church from the 17th century with a three-part layout – sanctuary, nave, gallery – and a wide nave in an almost square plan. Inside, the walls and ceilings are decorated by numerous polychromes. Unmanned aerial vehicles (DJI Phantom 4 Pro) and a photographic camera (Canon EOS 1200D) were used for photogrammetric measurements of the polychromes. The results of the photogrammetric measurements were digital photos, which were used for photogrammetric processing. The photographic work involved generating high-resolution images in the Agisoft Metashape Professional software. A point cloud obtained from terrestrial laser scanning was used to render the geometry in the process of creating orthophotoplans. The results of photogrammetric work are orthophotoplans of polychromes with high resolutions. Two orthophotoplans of wall paintings were generated based on drone photos, while ceiling paintings and one of the walls were generated based on high-resolution photos taken with the Canon EOS 1200D camera. The obtained results demonstrated that measurements made using UAVs and digital photos processed with photogrammetric methods enable a comprehensive inventory of wall paintings for historic objects.