scholarly journals MULTI-WAVELENGTHS 3D LASER SCANNING FOR PIGMENT AND STRUCTURAL STUDIES ON THE FRESCOED CEILING <q>THE TRIUMPH OF DIVINE PROVIDENCE</q>

Author(s):  
M. Guarneri ◽  
S. Ceccarelli ◽  
M. Ferri De Collibus ◽  
M. Francucci ◽  
M. Ciaffi

<p><strong>Abstract.</strong> The modern 3D digitalization techniques open new scenarios on how to transmit to the next generations the state of health of Cultural Heritage (CH) buildings, paintings, frescos or statues. The final goal of the 3D digitalization is an exact replica of the acquired target, but a standard and unique technique able to digitalize artworks of different size and in different ambient light conditions is still far from being successfully ready for the CH field. Even if both laser scanning and photogrammetry can be considered mature techniques, applied with success in most of the Cultural Heritage study cases, they are limited in terms of colour digitalization and image quality in all the cases where ambient light and big sensor-target distances are crucial factors: differently to standard laser scanners, which collect colour information by the use of a coaxial camera and the distance by an IR laser source, the RGB-ITR (Red, Green and Blue Imaging Topological Radar) scanner, developed in ENEA, is equipped with three different laser sources for the simultaneous colour and distance estimation. The present work shows the results obtained applying the above-mentioned multi-wavelengths laser scanner for collecting a complete high-quality 3D colour model of “The Triumph of Divine Providence” vault, painted by Pietro da Cortona on the ceiling of the noble hall inside Palazzo Barberini in Rome.</p>

Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.


2019 ◽  
pp. 275-303
Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.


2018 ◽  
Vol 4 (11) ◽  
pp. 130 ◽  
Author(s):  
Sofia Ceccarelli ◽  
Massimiliano Guarneri ◽  
Mario Ferri de Collibus ◽  
Massimo Francucci ◽  
Massimiliano Ciaffi ◽  
...  

Digital tools as 3D (three-dimensional) modelling and imaging techniques are having an increasing role in many applicative fields, thanks to some significative features, such as their powerful communicative capacity, versatility of the results and non-invasiveness. These properties are very important in cultural heritage, and modern methodologies provide an efficient means for analyzing deeply and virtually rendering artworks without contact or damage. In this paper, we present two laser scanner prototypes based on the Imaging Topological Radar (ITR) technology developed at the ENEA Research Center of Frascati (RM, Italy) to obtain 3D models and IR images of medium/large targets with the use of laser sources without the need for scaffolding and independently from illumination conditions. The RGB-ITR (Red Green Blue-ITR) scanner employs three wavelengths in the visible range for three-dimensional color digitalization up to 30 m, while the IR-ITR (Infrared-ITR) system allows for layering inspection using one IR source for analyses. The functionalities and operability of the two systems are presented by showing the results of several case studies and laboratory tests.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Xiaoquan Shi ◽  
Yazhou Sun ◽  
Haitao Liu ◽  
Linqi Bai ◽  
Chonghao Lin

AbstractThis study presents laser stripe center extraction algorithm for desktop-level 3D laser scanners. The laser stripe center extraction accuracy is an important factor affecting 3D scanning result. Desktop-level devices should have adaptability of a wide range of scanning objects. In this paper, laser stripe energy distribution characteristics with different laser stripe width, ambient light, materials and colors are obtained by experiments. Experiment results show that waveforms of bright spot, low brightness stripe and stripe with large width are complex or easily disturbed, so the center extraction algorithm of them are studied. The extraction effects of extremum method, gradient method and gray centroid method under different conditions are compared. Based on traditional grayscale value, a weighted grayscale value is proposed to extract laser stripe center. Standard deviations of extracted pixel position and fitting pixel position are calculated by different method with different weighted grayscale value. For different conditions, especially for different ambient light intensity, weight matrix plays an important role to extraction result.


Author(s):  
J.-F. Hullo

We propose a complete methodology for the fine registration and referencing of kilo-station networks of terrestrial laser scanner data currently used for many valuable purposes such as 3D as-built reconstruction of Building Information Models (BIM) or industrial asbuilt mock-ups. This comprehensive target-based process aims to achieve the global tolerance below a few centimetres across a 3D network including more than 1,000 laser stations spread over 10 floors. This procedure is particularly valuable for 3D networks of indoor congested environments. In situ, the use of terrestrial laser scanners, the layout of the targets and the set-up of a topographic control network should comply with the expert methods specific to surveyors. Using parametric and reduced Gauss-Helmert models, the network is expressed as a set of functional constraints with a related stochastic model. During the post-processing phase inspired by geodesy methods, a robust cost function is minimised. At the scale of such a data set, the complexity of the 3D network is beyond comprehension. The surveyor, even an expert, must be supported, in his analysis, by digital and visual indicators. In addition to the standard indicators used for the adjustment methods, including Baarda’s reliability, we introduce spectral analysis tools of graph theory for identifying different types of errors or a lack of robustness of the system as well as <i>in fine</i> documenting the quality of the registration.


2020 ◽  
Vol 1 (2) ◽  
Author(s):  
TOMASZ Lipecki ◽  
Kim THI THU HUONG

Laser scanners are used more and more as surveying instruments for various applications. With the advance of high precisions systems, laser scanner devices can work in most real-world environments under many different conditions. In the field of mining surveying open up a new method with data capturing. Mining industry requires precise data in order to be able to have a as-built documentation of the facility. Nowadays, the mines are increasingly deepened. For the safe operation of the underground mine, special attention is paid to vertical transport and a set of devices supporting it, mounted in mining shafts. All components must meet stringent criteria for proper operation. The classic geodetic measurements and mechanical tests are long-lasting and do not always provide the full range of information needed about the condition of the object. This paper reports about terrestrial laser scanning method and system mobile terrestrial laser scanning, which has been applied at many vertical shafts in mines of Poland for determining geometric deformation of vertical shaft elements. This system gives high precision 1-3 mm in every horizontal cross – section. Processing time is very quickly and need only few staff to implement all system.


Author(s):  
C. Altuntas

Abstract. This study aims to introduce triangulation and ToF measurement techniques used in three-dimensional modelling of cultural heritages. These measurement techniques are traditional photogrammetry, SfM approach, laser scanning and time-of-flight camera. The computer based approach to photogrammetric measurement that is named SfM creates dense point cloud data in a short time. It is low-cost and very easy to application. However traditional photogrammetry needs a huge effort for creating 3D wire-frame model. On the other hand active measurement techniques such as terrestrial laser scanner and time-of-flight camera have also been used in three-dimensional modelling for more than twenty years. Each one has specific accuracy and measurement effectiveness. The large or small structures have different characters, and require proper measurement configurations. In this study, after these methods are introduced, their superior and weak properties in cultural heritage modelling to make high accuracy, high density and labour and cost effective measurement.


Author(s):  
R. A. Kuçak ◽  
F. Kiliç ◽  
A. Kisa

Historical artifacts living from the past until today exposed to many destructions non-naturally or naturally. For this reason, The protection and documentation studies of Cultural Heritage to inform the next generations are accelerating day by day in the whole world. The preservation of historical artifacts using advanced 3D measurement technologies becomes an efficient tool for mapping solutions. There are many methods for documentation and restoration of historic structures. In addition to traditional methods such as simple hand measurement and tachometry, terrestrial laser scanning is rapidly becoming one of the most commonly used techniques due to its completeness, accuracy and fastness characteristics. This study evaluates terrestrial laser scanning(TLS) technology and photogrammetry for documenting the historical artifacts facade data in 3D Environment. PhotoModeler software developed by Eos System was preferred for Photogrammetric method. Leica HDS 6000 laser scanner developed by Leica Geosystems and Cyclone software which is the laser data evaluation software belonging to the company is preferred for Terrestrial Laser Scanning method. Taking into account the results obtained with this software product is intended to provide a contribution to the studies for the documentation of cultural heritage.


Author(s):  
V. E. Oniga ◽  
A. I. Breaban ◽  
E. I. Alexe ◽  
C. Văsii

Abstract. Indoor mapping and modelling is an important research subject with application in a wide range of domains including interior design, real estate, cultural heritage conservation and restoration. There are multiple sensors applicable for 3D indoor modelling, but the laser scanning technique is frequently used because of the acquisition time, detailed information and accuracy. In this paper, the efficiency of the Maptek I-Site 8820 terrestrial scanner, which is a long-range laser scanner and the accuracy of a HMLS point cloud acquired with a mobile scanner, namely GeoSlam Zeb Horizon were tested for indoor mapping. Aula Magna “Carmen Silva” of the “Gheorghe Asachi” Technical University of Iasi is studied in the current paper since the auditorium interior creates a distinct environment that combines complex geometric structures with architectural lighting and for preserving its great cultural value, the monument has a national historical significance. The registration process of the TLS point clouds was done using two methods: a semi-automatic one with artificial targets and a completely automatic one, based on Iterative Closest Point (ICP) algorithm. The resulted TLS point cloud was analysed in relation to the HMLS point cloud by computing the M3C2 (Multiscale Model to Model Cloud Comparison), obtaining a standard deviation of 2.1 cm and by investigating the Hausdorff distances from which resulted a standard deviation (σ) of 1.6 cm. Cross-sections have been extracted from the HMLS and TLS point clouds and after comparing the sections, 80% of the sigma values are less or equal to 1 cm. The results show high potential of using HMLS and also a long-range laser scanner for 3D modelling of complex scenes, the occlusion effect in the case of TLS being only 5% of the scanned area.


Author(s):  
Avar Almukhtar ◽  
Henry Abanda ◽  
Zaid O. Saeed ◽  
Joseph H.M. Tah

The urgent need to improve performance in the construction industry has led to the adoption of many innovative technologies. 3D laser scanners are amongst the leading technologies being used to capture and process assets or construction project data for use in various applications. Due to its nascent nature, many questions are still unanswered about 3D laser scanning, which in turn contribute to the slow adaptation of the technology. Some of these include the role of 3D laser scanners in capturing and processing raw construction project data. How accurate is the 3D laser scanner or point cloud data? How does laser scanning fit with other wider emerging technologies such as Building Information Modelling (BIM)? This study adopts a proof-of-concept approach, which in addition to answering the afore-mentioned questions, illustrates the application of the technology in practice. The study finds that the quality of the data, commonly referred to as point cloud data is still a major issue as it depends on the distance between the target object and 3D laser scanner’s station. Additionally, the quality of the data is still very dependent on data file sizes and the computational power of the processing machine. Lastly, the connection between laser scanning and BIM approaches is still weak as what can be done with a point cloud data model in a BIM environment is still very limited. The aforementioned findings reinforce existing views on the use of 3D laser scanners in capturing and processing construction project data.


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