Analysis of the Photogrammetric Use of 360-Degree Cameras in Complex Heritage-Related Scenes: Case of the Necropolis of Qubbet el-Hawa (Aswan Egypt)

Abstract

This study shows the results of the analysis of the photogrammetric use of 360-degree cameras in complex heritage-related scenes. The goal is to take advantage of the large field of view provided by these sensors and reduce the number of images used to cover the entire scene compared to those needed using conventional cameras. We also try to minimize problems derived from camera geometry and lens characteristics. In this regard, we used a multi-sensor camera composed of six fisheye lenses, applying photogrammetric procedures to several funerary structures. The methodology includes the analysis of several types of spherical images obtained using different stitching techniques and the comparison of the results of image orientation processes considering these images and the original fisheye images. Subsequently, we analyze the possible use of the fisheye images to model complex scenes by reducing the use of ground control points, thus minimizing the need to apply surveying techniques to determine their coordinates. In this regard, we applied distance constraints based on a previous extrinsic calibration of the camera, obtaining results similar to those obtained using a traditional schema based on points. The results have allowed us to determine the advantages and disadvantages of each type of image and configuration, providing several recommendations regarding their use in complex scenes.

Multi-Sensor Geomatic Techniques for the 3D Documentation and Virtual Repositioning of Elements of the Church of S. Miguel (Jaén, Spain)

“…We included a cameramounted 360-degree illumination system to guarantee lighting conditions in indoor areas. In addition, we minimized the need of GCPs for the orientation procedure by using some known constraints (used as scale bars) after the extrinsic calibration of the 360-degree camera (see the example in [7]). The camera was mounted both on a tripod to cover narrow spaces and on the mast to reach elevated zones (Figure 4d).…”

“…The advantages of this integration have been described in several studies [1][2][3][4][5][6], for example, to facilitate the acquisition of data, to obtain a full coverage of the object, even in complex scenes, and to improve the geometric and radiometric quality of the products. Most of the scenes studied in heritage sites can commonly be considered as complex, due to, among other environmental circumstances, their geometrical characteristics and location and accessibility [7].…”

“…Regarding geometrical characteristics, the presence of narrow spaces [8,9] makes simple data acquisition difficult or impossible in specific cases [7]. Therefore, in complex scenes, the integration of techniques plays a fundamental role in achieving the requirements of the study, taking into account the efficiency in data acquisition and processing.…”