THREE DIMENTIONAL RECONSTRUCTION OF LARGE CULTURAL HERITAGE OBJECTS BASED ON UAV VIDEO AND TLS DATA

This paper investigates the synergetic use of unmanned aerial vehicle (UAV) and terrestrial laser scanner (TLS) in 3D reconstruction of cultural heritage objects. Rather than capturing still images, the UAV that equips a consumer digital camera is used to collect dynamic videos to overcome its limited endurance capacity. Then, a set of 3D point-cloud is generated from video image sequences using the automated structure-from-motion (SfM) and patch-based multi-view stereo (PMVS) methods. The TLS is used to collect the information that beyond the reachability of UAV imaging e.g., partial building facades. A coarse to fine method is introduced to integrate the two sets of point clouds UAV image-reconstruction and TLS scanning for completed 3D reconstruction. For increased reliability, a variant of ICP algorithm is introduced using local terrain invariant regions in the combined designation. The experimental study is conducted in the Tulou culture heritage building in Fujian province, China, which is focused on one of the TuLou clusters built several hundred years ago. Results show a digital 3D model of the Tulou cluster with complete coverage and textural information. This paper demonstrates the usability of the proposed method for efficient 3D reconstruction of heritage object based on UAV video and TLS data.

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Structure from motion (SfM) photogrammetry as alternative to laser scanning for 3D modelling of historical monuments

Open Science Journal ◽

10.23954/osj.v5i2.2327 ◽

2020 ◽

Vol 5 (2) ◽

Cited By ~ 1

Author(s):

Omar Al Khalil

Keyword(s):

Structure From Motion ◽

Laser Scanning ◽

Low Cost ◽

Laser Scanner ◽

Digital Camera ◽

Point Clouds ◽

3D Modelling ◽

3D Point Clouds ◽

Historical Monuments ◽

Culture Heritage

During the past few years, new developments have occurred in the field of 3D photogrammetric modeling of culture heritage. One of these developments is the expansion of 3D photogrammetric modeling open-source software, such as VisualSfM, and cost-effective licensed software, such as Agisoft Metashape into the practical and affordable world. This type of SfM (Structure from Motion) software offers the world of 3D modelling of culture heritage a powerful tool for documentation and visualization. On the other hand, low-cost cameras are now available on the market. These cameras are characterized by high resolution and good quality lens, which makes them suitable for photogrammetric modelling. This paper reports on the results of the application of a SfM photogrammetry system in the 3D modelling of Safita Tower, a medieval structure in Safita, north-western Syria. The applied photogrammetric system consists of the Nikon Coolpix P100 10 MP digital camera and the commercial software Agisoft Metashape. The resulted 3D point clouds were compared with an available dense point cloud acquired by a laser scanner. This comparison proved that the low-cost SfM photogrammetry is an accurate methodology to 3D modeling historical monuments.

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SEE-THROUGH IMAGING OF LASER-SCANNED 3D CULTURAL HERITAGE OBJECTS BASED ON STOCHASTIC RENDERING OF LARGE-SCALE POINT CLOUDS

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsannals-iii-5-73-2016 ◽

2016 ◽

Vol III-5 ◽

pp. 73-80 ◽

Cited By ~ 10

Author(s):

S. Tanaka ◽

K. Hasegawa ◽

N. Okamoto ◽

R. Umegaki ◽

S. Wang ◽

...

Keyword(s):

Cultural Heritage ◽

Laser Scanning ◽

Large Scale ◽

Laser Scanner ◽

Point Clouds ◽

Cultural Value ◽

Stochastic Algorithm ◽

Scale Point ◽

3D Scene ◽

Cultural Heritage Objects

We propose a method for the precise 3D see-through imaging, or transparent visualization, of the large-scale and complex point clouds acquired via the laser scanning of 3D cultural heritage objects. Our method is based on a stochastic algorithm and directly uses the 3D points, which are acquired using a laser scanner, as the rendering primitives. This method achieves the correct depth feel without requiring depth sorting of the rendering primitives along the line of sight. Eliminating this need allows us to avoid long computation times when creating natural and precise 3D see-through views of laser-scanned cultural heritage objects. The opacity of each laser-scanned object is also flexibly controllable. For a laser-scanned point cloud consisting of more than 107 or 108 3D points, the pre-processing requires only a few minutes, and the rendering can be executed at interactive frame rates. Our method enables the creation of cumulative 3D see-through images of time-series laser-scanned data. It also offers the possibility of fused visualization for observing a laser-scanned object behind a transparent high-quality photographic image placed in the 3D scene. We demonstrate the effectiveness of our method by applying it to festival floats of high cultural value. These festival floats have complex outer and inner 3D structures and are suitable for see-through imaging.

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SEE-THROUGH IMAGING OF LASER-SCANNED 3D CULTURAL HERITAGE OBJECTS BASED ON STOCHASTIC RENDERING OF LARGE-SCALE POINT CLOUDS

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-iii-5-73-2016 ◽

2016 ◽

Vol III-5 ◽

pp. 73-80 ◽

Cited By ~ 3

Author(s):

S. Tanaka ◽

K. Hasegawa ◽

N. Okamoto ◽

R. Umegaki ◽

S. Wang ◽

...

Keyword(s):

Cultural Heritage ◽

Laser Scanning ◽

Large Scale ◽

Laser Scanner ◽

Point Clouds ◽

Cultural Value ◽

Stochastic Algorithm ◽

Scale Point ◽

3D Scene ◽

Cultural Heritage Objects

We propose a method for the precise 3D see-through imaging, or transparent visualization, of the large-scale and complex point clouds acquired via the laser scanning of 3D cultural heritage objects. Our method is based on a stochastic algorithm and directly uses the 3D points, which are acquired using a laser scanner, as the rendering primitives. This method achieves the correct depth feel without requiring depth sorting of the rendering primitives along the line of sight. Eliminating this need allows us to avoid long computation times when creating natural and precise 3D see-through views of laser-scanned cultural heritage objects. The opacity of each laser-scanned object is also flexibly controllable. For a laser-scanned point cloud consisting of more than 107 or 108 3D points, the pre-processing requires only a few minutes, and the rendering can be executed at interactive frame rates. Our method enables the creation of cumulative 3D see-through images of time-series laser-scanned data. It also offers the possibility of fused visualization for observing a laser-scanned object behind a transparent high-quality photographic image placed in the 3D scene. We demonstrate the effectiveness of our method by applying it to festival floats of high cultural value. These festival floats have complex outer and inner 3D structures and are suitable for see-through imaging.

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Symmetry Analysis of Oriental Polygonal Pagodas Using 3D Point Clouds for Cultural Heritage

Sensors ◽

10.3390/s21041228 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1228

Author(s):

Ting On Chan ◽

Linyuan Xia ◽

Yimin Chen ◽

Wei Lang ◽

Tingting Chen ◽

...

Keyword(s):

Cultural Heritage ◽

Unmanned Aerial Vehicle ◽

Point Cloud ◽

Geometric Model ◽

Digital Camera ◽

Point Clouds ◽

Symmetry Analysis ◽

3D Point Clouds ◽

Transmission Towers ◽

Aerial Vehicle

Ancient pagodas are usually parts of hot tourist spots in many oriental countries due to their unique historical backgrounds. They are usually polygonal structures comprised by multiple floors, which are separated by eaves. In this paper, we propose a new method to investigate both the rotational and reflectional symmetry of such polygonal pagodas through developing novel geometric models to fit to the 3D point clouds obtained from photogrammetric reconstruction. The geometric model consists of multiple polygonal pyramid/prism models but has a common central axis. The method was verified by four datasets collected by an unmanned aerial vehicle (UAV) and a hand-held digital camera. The results indicate that the models fit accurately to the pagodas’ point clouds. The symmetry was realized by rotating and reflecting the pagodas’ point clouds after a complete leveling of the point cloud was achieved using the estimated central axes. The results show that there are RMSEs of 5.04 cm and 5.20 cm deviated from the perfect (theoretical) rotational and reflectional symmetries, respectively. This concludes that the examined pagodas are highly symmetric, both rotationally and reflectionally. The concept presented in the paper not only work for polygonal pagodas, but it can also be readily transformed and implemented for other applications for other pagoda-like objects such as transmission towers.

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Photo Scanner 3D Survey for Monitoring Historical Monuments. the Case History of Porta Praetoria in Aosta

Geoinformatics FCE CTU ◽

10.14311/gi.6.39 ◽

2011 ◽

Vol 6 ◽

pp. 314-322 ◽

Cited By ~ 3

Author(s):

Paolo Salonia ◽

Tommaso Leti Messina ◽

Andrea Marcolongo ◽

Lorenzo Appolonia

Keyword(s):

Cultural Heritage ◽

New Technology ◽

Digital Camera ◽

Point Clouds ◽

3D Models ◽

Stone Decay ◽

Decay Kinetics ◽

Image Block ◽

Building Site ◽

Historical Monuments

Accessibility to cultural heritage is one of the most important factors in cultural heritage preservation, as it assures knowledge, monitoring, Public Administration management and a wide interest on cultural heritage sites. Nowdays 3D surveys give the geometric basis for an effective artefact reconstruction but most of the times 3D data are not completely and deeply investigated to extract other useful information on historical monuments for their conservation and safeguard. The Cultural Heritage Superintendence of Aosta decided to run a time continual project of monitoring of the Praetorian Roman Gate with the collaboration of the ITABC, CNR of Italy. The Praetorian Roman Gate in Aosta, Italy, of Augustus ages, is one of the most well-known roman monumental gates, it is a double gate with three arches each side, 12 meters high, 20 meters wide, made of pudding stone ashlars, Badoglio, travertine, marble blocks and other stone insertion due to restorations between 1600 and 1950. In years 2000 a final restoration intervention brought the gate at the present state of art, within the frame of a restoration and conservation building site with the purpose of treat the different decay pathologies and conditions. A complete 3D geometric survey campaign has been the first step for the monitoring of the gate morphologic changes and decay progress in time. The main purpose is to collect both quantitative data, related to the geometry of the gate, and the qualitative data, related to the chromatic change on the surface due to the stone decay. The geometric data with colour information permits to associate materials and stone pathologies to chemical or mechanical actions and to understand and analyse superficial decay kinetics. The colours survey will also permit to directly locate on the 3D model areas of different stratigraphic units. The project aims to build a rigorous quantitative-qualitative database so to be uploaded into a GIS. The GIS will become the monitoring main means. Considering the huge dimension of the gate and its urban location a multi-scale approach has been considered. Controlled and free images have been taken from the ground and the top of the gate so to reconstruct all the walls and the upper cover. A topographic survey has been done so to be able to control and relate all the different acquisitions. It has been chosen a Photo Scanner 3D system. It is a photogrammetry-based survey technology for point clouds acquisition and 3D models configuration, from digital images processing. This technology allows to obtain point clouds (xyz coordinates) with RGB information and geometries at different levels of complexity by processing a number of images taken with a limited set of constraints, with the use of a simple acquisition equipment and through an image matching algorithm (ZScan, by Menci Software). Due to the high walls of the arch gates, the higher part has been surveyed with a remote controlled drone (UAV Unmanned Aerial Vehicle) with a digital camera on it, so to take pictures up to the maximum altitude and with different shooting angles ( 90 and 45 degree). This is a new technology which permits to survey inaccessible parts of a high monument with ease and accuracy, by collecting redundant pictures later bound together by an image block algorithm. This paper aims to present the survey experience architectural monuments trough the application of a trifocal quick photogrammetric system, in surveying at different scales and for different purposes.

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An Efficient Probabilistic Registration Based on Shape Descriptor for Heritage Field Inspection

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9120759 ◽

2020 ◽

Vol 9 (12) ◽

pp. 759

Author(s):

Yufu Zang ◽

Bijun Li ◽

Xiongwu Xiao ◽

Jianfeng Zhu ◽

Fancong Meng

Keyword(s):

Cultural Heritage ◽

Solution Space ◽

Point Clouds ◽

Shape Descriptor ◽

Free Form ◽

Registration Method ◽

Field Inspection ◽

3D Point Clouds ◽

Quality Issues ◽

Cultural Heritage Objects

Heritage documentation is implemented by digitally recording historical artifacts for the conservation and protection of these cultural heritage objects. As efficient spatial data acquisition tools, laser scanners have been widely used to collect highly accurate three-dimensional (3D) point clouds without damaging the original structure and the environment. To ensure the integrity and quality of the collected data, field inspection (i.e., on-spot checking the data quality) should be carried out to determine the need for additional measurements (i.e., extra laser scanning for areas with quality issues such as data missing and quality degradation). To facilitate inspection of all collected point clouds, especially checking the quality issues in overlaps between adjacent scans, all scans should be registered together. Thus, a point cloud registration method that is able to register scans fast and robustly is required. To fulfill the aim, this study proposes an efficient probabilistic registration for free-form cultural heritage objects by integrating the proposed principal direction descriptor and curve constraints. We developed a novel shape descriptor based on a local frame of principal directions. Within the frame, its density and distance feature images were generated to describe the shape of the local surface. We then embedded the descriptor into a probabilistic framework to reject ambiguous matches. Spatial curves were integrated as constraints to delimit the solution space. Finally, a multi-view registration was used to refine the position and orientation of each scan for the field inspection. Comprehensive experiments show that the proposed method was able to perform well in terms of rotation error, translation error, robustness, and runtime and outperformed some commonly used approaches.

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Robust external calibration of terrestrial laser scanner and digital camera for structural monitoring

Journal of Applied Geodesy ◽

10.1515/jag-2018-0038 ◽

2019 ◽

Vol 13 (2) ◽

pp. 105-134 ◽

Cited By ~ 2

Author(s):

Mohammad Omidalizarandi ◽

Boris Kargoll ◽

Jens-André Paffenholz ◽

Ingo Neumann

Keyword(s):

Em Algorithm ◽

Laser Scanner ◽

Digital Camera ◽

Point Clouds ◽

Deformation Monitoring ◽

Deformation Analysis ◽

Terrestrial Laser Scanner ◽

External Calibration ◽

3D Point Clouds ◽

Calibration Parameters

Abstract In the last two decades, the integration of a terrestrial laser scanner (TLS) and digital photogrammetry, besides other sensors integration, has received considerable attention for deformation monitoring of natural or man-made structures. Typically, a TLS is used for an area-based deformation analysis. A high-resolution digital camera may be attached on top of the TLS to increase the accuracy and completeness of deformation analysis by optimally combining points or line features extracted both from three-dimensional (3D) point clouds and captured images at different epochs of time. For this purpose, the external calibration parameters between the TLS and digital camera needs to be determined precisely. The camera calibration and internal TLS calibration are commonly carried out in advance in the laboratory environments. The focus of this research is to highly accurately and robustly estimate the external calibration parameters between the fused sensors using signalised target points. The observables are the image measurements, the 3D point clouds, and the horizontal angle reading of a TLS. In addition, laser tracker observations are used for the purpose of validation. The functional models are determined based on the space resection in photogrammetry using the collinearity condition equations, the 3D Helmert transformation and the constraint equation, which are solved in a rigorous bundle adjustment procedure. Three different adjustment procedures are developed and implemented: (1) an expectation maximization (EM) algorithm to solve a Gauss-Helmert model (GHM) with grouped t-distributed random deviations, (2) a novel EM algorithm to solve a corresponding quasi-Gauss-Markov model (qGMM) with t-distributed pseudo-misclosures, and (3) a classical least-squares procedure to solve the GHM with variance components and outlier removal. The comparison of the results demonstrates the precise, reliable, accurate and robust estimation of the parameters in particular by the second and third procedures in comparison to the first one. In addition, the results show that the second procedure is computationally more efficient than the other two.

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Application of Stochastic Point-Based Rendering to Laser-Scanned Point Clouds of Various Cultural Heritage Objects

International Journal of Automation Technology ◽

10.20965/ijat.2018.p0348 ◽

2018 ◽

Vol 12 (3) ◽

pp. 348-355 ◽

Cited By ~ 2

Author(s):

Kyoko Hasegawa ◽

Liang Li ◽

Naoya Okamoto ◽

Shu Yanai ◽

Hiroshi Yamaguchi ◽

...

Keyword(s):

Image Quality ◽

Cultural Heritage ◽

Large Scale ◽

Nearest Neighbor ◽

Point Clouds ◽

Visualization Method ◽

3D Image ◽

Wide Applicability ◽

Internal Structures ◽

Cultural Heritage Objects

Recently, we proposed stochastic point-based rendering, which enables precise and interactive-speed transparent rendering of large-scale laser-scanned point clouds. This transparent visualization method does not suffer from rendering artifact and realizes correct depth feel in the created 3D image.In this paper, we apply the method to several kinds of large-scale laser-scanned point clouds of cultural heritage objects and prove its wide applicability.In addition, we prove better image quality is realized by properly eliminating points to realize better distributional uniformity of points. Here, the distributional uniformity means uniformity of inter-point distances between nearest-neighbor points.We also demonstrate that highlighting feature regions, especially edges, in the transparent visualization helps us understand 3D internal structures of complex laser-scanned objects. The feature regions are highlighted by properly increasing local opacity of the regions.

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A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-5-573-2014 ◽

2014 ◽

Vol XL-5 ◽

pp. 573-580 ◽

Cited By ~ 35

Author(s):

K. Thoeni ◽

A. Giacomini ◽

R. Murtagh ◽

E. Kniest

Keyword(s):

3D Reconstruction ◽

Point Cloud ◽

Laser Scanner ◽

Ground Truth ◽

Point Clouds ◽

Digital Cameras ◽

Rock Wall ◽

Geological Features ◽

Dense Point ◽

Sharp Edges

This work presents a comparative study between multi-view 3D reconstruction using various digital cameras and a terrestrial laser scanner (TLS). Five different digital cameras were used in order to estimate the limits related to the camera type and to establish the minimum camera requirements to obtain comparable results to the ones of the TLS. The cameras used for this study range from commercial grade to professional grade and included a GoPro Hero 1080 (5 Mp), iPhone 4S (8 Mp), Panasonic Lumix LX5 (9.5 Mp), Panasonic Lumix ZS20 (14.1 Mp) and Canon EOS 7D (18 Mp). The TLS used for this work was a FARO Focus 3D laser scanner with a range accuracy of ±2 mm. The study area is a small rock wall of about 6 m height and 20 m length. The wall is partly smooth with some evident geological features, such as non-persistent joints and sharp edges. Eight control points were placed on the wall and their coordinates were measured by using a total station. These coordinates were then used to georeference all models. A similar number of images was acquired from a distance of between approximately 5 to 10 m, depending on field of view of each camera. The commercial software package PhotoScan was used to process the images, georeference and scale the models, and to generate the dense point clouds. Finally, the open-source package CloudCompare was used to assess the accuracy of the multi-view results. Each point cloud obtained from a specific camera was compared to the point cloud obtained with the TLS. The latter is taken as ground truth. The result is a coloured point cloud for each camera showing the deviation in relation to the TLS data. The main goal of this study is to quantify the quality of the multi-view 3D reconstruction results obtained with various cameras as objectively as possible and to evaluate its applicability to geotechnical problems.

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