Abstract
Abstract. In recent years, handheld laser scanning systems have been developed for documenting architectural heritage, among other applications. In this article we present a new alternative for the 3D documentation of historical heritage based on videogrammetry. For this purpose, a prototype has been designed with two cameras, a high resolution camera and a VGA camera which, when connected to a tablet, allow the user to establish a guidance system to ensure that the trajectory is not lost and enables highly flexible and long-lasting movements over time. This paper unveils the operation of the filtering and image selection system to finally proceed to an evaluation of the prototype in three areas of an archaeological site, called “Casa del Mitreo” in the city of Mérida (Spain). The results are compared to the Faro Focus 3D X330 laser scanner, yielding very similar accuracies and a capture time about 17 times faster than the 3D laser scanner. The article therefore proposes a real alternative to 3D data acquisition systems in applications for the graphic documentation of architectural and archaeological heritage.
Highlights
Terrestrial photogrammetry has evolved a lot in recent years, allowing more flexibility in data acquisition and better results
Due to the results of previous experiments carried out with our prototype, we have observed that the three-dimensional models generated after applying our image selection algorithm increase the accuracy with respect to those that have used only those suggested by the initial process; we have even observed that in complex paths, the initial selection of keyframes is frankly deficient, causing breaks in the trajectory
Once all the data had been processed with both systems, the average resolution of the point clouds generated with both methods was calculated in the three study areas, including overlap areas, resulting in an average point-to-point distance of 0.4mm for the Faro Focus 3D X330 laser scanner and 1.4mm for the proposed prototype
Summary
Terrestrial photogrammetry has evolved a lot in recent years, allowing more flexibility in data acquisition and better results. With self-calibration or improvements in bundle adjustment (Triggs et al, 2000), where very positive and exciting results can be observed for the present and future of this field of knowledge. These scientific and technical improvements in photogrammetry have provided a further advance in the democratisation of the technology, which can be used by people without a deep knowledge of the technique, using commercial sensors, even mobile phones, without the need for calibration or special care during data acquisition.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have