A novel high accuracy 3D scanning device for rock-art sites

Abstract

ABSTRACT:We are currently developing a novel 3D scanning device for rock-art. Within the European project 3D-Pitoti, this scanner shall be used to acquire 3D structure and radiometric surface properties of ancient rock-art sites in Valcamonica. Overall design goals include high spatial accuracy and precision, as well as radiometric quality beyond phototexture. This paper is devoted to the geometric measurement principle of the new scanner. We present a novel scanning scheme based on various constraints to Structure from Motion, that guarantees high accuracy of the resulting scans by combining tachymeter-based tracking of the scanner, stereo, and structure-from-motion. This method provides scale information (by calibrated stereo), and does not require ground control points, because outside-in tracking avoids the typical issues of drift in structure-from-motion. The system is designed for flexibility, high throughput, approx. 0.1mm precision, and an overall accuracy of the reconstructed 3D structure that conforms with the specifications of the tachymeter.

Digital Documentation and Conservation of Architectural Heritage Information: An Application in Modern Chinese Architecture

“…Soler-Estrela (2018) [15] used 3D laser scanning to collect first-hand on-site data based on the surveying and mapping of the relocation project of a historical building. Höll et al, (2014) [16] investigated a high-accuracy 3D scanning device designed for ancient rock art sites in the European 3D-Pitoti project. This device captured the 3D structure and radiometric surface properties with high accuracy and precision beyond photo texture.…”

Multi-scale 3D rock-art recording

“…For T-shape rig calibra-250 tion, we combine measurements by a total station (prism position and position of a 2D calibration target placed on the floor) with measurements of a calibration target obtained by the previously calibrated stereo rig. For a more technical explanation of the geometric calibration procedure, we refer the reader to Höll et al (2014).…”

“…the stereo rig). More technical details on this approach and a detailed comparison of various algorithmic solutions including experimental validation of the geometry acquisition process are provided in(Höll et al, 2014). In summary, 200 our novel method can recover 3D model scale without needing any external measurements (through its use of stereo), it can avoid well-known problems of large-scale drift in standard SfM, and it can provide georeferencing without needing ground control points (by means of total station measurements of prism positions).…”

Using Structure from Motion Mapping to Record and Analyze Details of the Colossal Hats (Pukao) of Monumental Statues on Rapa Nui (Easter Island)

“…SfM is well-suited for identifying petroglyphs on uneven surfaces, such as those often found in caves (Caninas et al 2016; Fritz et al 2016), and SfM models give spatial context to petroglyphs that is helpful for interpretation (Alexander et al 2015; Janik et al 2007). Because of the value of SfM for the interpretation of rock art, archaeologists have recently explored methods of digitally enhancing model visualization (e.g., Carrero-Pazos et al 2016; Vilas-Estevez et al 2016), have developed specialized tools for efficiently collecting rock art photographs (e.g., Höll et al 2014), and have segmented rock art models to effectively store and query models in databases (e.g., Poier et al 2016; Zeppelzauer et al 2015; Zeppelzauer et al 2016). Significantly, SfM mapping has a substantially lower impact on rock art than tracing, and monitoring of archaeological features through SfM mapping can be used to identify conservation priorities (Plets et al 2012).…”