scholarly journals POINT CLOUD GENERATION OF A BUILDING FROM CLOSE RANGE THERMAL IMAGES

2019 ◽  
Vol XLII-5/W2 ◽  
pp. 29-33 ◽  
Author(s):  
A. Dlesk ◽  
K. Vach
Keyword(s):  
Point Cloud ◽  
Laser Scanner ◽  
Facility Management ◽  
Thermal Images ◽  
Check Points ◽  
Close Range ◽  
Photogrammetric Method ◽  
Family House ◽  
Valuable Result ◽  
Thermal Inspection

<p><strong>Abstract.</strong> Thermal inspection of a building is a very important part of facility management. This paper presents the methodology how to capture thermal images on a case of a family house, how to process thermal images using current photogrammetric method and how to achieve point cloud where each point is enhanced by information about temperature. This enhanced point cloud could be data for BIM or GIS and could be a valuable result for facility managers where they can detect thermal leaks or anomalies. Due to the point cloud, the thermal leaks or anomalies could be easily located and described. The accuracy of the point cloud is tested by check points and the resulted point cloud is compared with point cloud gathered by a laser scanner. The last part of the paper is devoted to a discussion about the results and outputs of the photogrammetric processing of thermal images.</p>

scholarly journals 3D MODELING FOR ROCK ART DOCUMENTATION USING LIGHTWEIGHT MULTISPECTRAL CAMERA

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 787-793 ◽  
Author(s):  
K. Zainuddin ◽  
Z. Majid ◽  
M. F. M. Ariff ◽  
K. M. Idris ◽  
M. A. Abbas ◽  
...  
Keyword(s):  
Point Cloud ◽  
3D Model ◽  
Rock Art ◽  
Three Dimensional ◽  
Laser Scanner ◽  
3D Point Cloud ◽  
Short Period ◽  
Dense Point ◽  
Close Range ◽  
Multispectral Camera

<p><strong>Abstract.</strong> This paper discusses the use of the lightweight multispectral camera to acquire three-dimensional data for rock art documentation application. The camera consists of five discrete bands, used for taking the motifs of the rock art paintings on a big structure of a cave based on the close-range photogrammetry technique. The captured images then processed using commercial structure-from-motion photogrammetry software, which automatically extracts the tie point. The extracted tie points were then used as input to generate a dense point cloud based on the multi-view stereo (MVS) and produced the multispectral 3D model, and orthophotos in a different wavelength. For comparison, the paintings and the wall surface also observed by using terrestrial laser scanner which capable of recording thousands of points in a short period of time with high accuracy. The cloud-to-cloud comparison between multispectral and TLS 3D point cloud show a sub-cm discrepancy, considering the used of the natural features as control target during 3D construction. Nevertheless, the processing also provides photorealistic orthophoto, indicates the advantages of the multispectral camera in generating dense 3D point cloud as TLS, photorealistic 3D model as RGB optic camera, and also with the multiwavelength output.</p>

scholarly journals DIGITAL DOCUMENTATION, BRIDGE DECK LINEARITY DEFORMATION AND DECK THICKNESS MEASUREMENT USING TERRESTRIAL LASER SCANNER (TLS) AND CLOSE RANGE PHOTOGRAMMETRY (CRP)

2018 ◽  
Vol IV-5 ◽  
pp. 47-51 ◽  
Author(s):  
S. K. P. Kushwaha ◽  
H. Pande ◽  
S. Raghavendra
Keyword(s):  
Point Cloud ◽  
Bridge Deck ◽  
Laser Scanner ◽  
Bottom Layer ◽  
Thickness Measurement ◽  
Terrestrial Laser Scanner ◽  
Road Transportation ◽  
The Road ◽  
Close Range Photogrammetry ◽  
Close Range

<p><strong>Abstract.</strong> Bridges are one of the vital and valuable engineer structure from decades. As they play a major role in the road transportation sector. Few old bridges lacks its documents about the measurements of the structure. The study has been carried out on three different types of bridges like Truss, Beam and Cable bridges. Documenting these bridges can be utilised to reconstruct or renovate the bridge in case of any disaster or damage. 3D documentation is made from the point cloud Dataset acquired from Terrestrial Laser Scanner – TLS (Riegl VZ 400) and Close Range photogrammetry – CRP (Nikon DSLR 5300). TLS and CRP point cloud are merged together to increase the density of points. Over the duration of time the bridge gets older and due to the load on the bridge deck, linearity in the deck effects and this linearity deformation measurement is important to know the present deformation in the deck. To know exactly at which part there is more linearity deformation, deflection is calculated at sample intervals between the present linearity conditions of the deck to the idle linearity conditions of the deck. The bridge deck thickness is also measured with the point cloud dataset. A slice is cut through the deck of point cloud dataset, the difference between the top and bottom layer of the deck gives us the thickness of the deck including the road. This thickness can be used to measure when a new deck layer is constructed or during filling up of any potholes. This study is mainly focused to help the construction and maintenance authority, bridge monitoring department and researchers.</p>

scholarly journals THE SEGMENTATION OF POINT CLOUDS WITH K-MEANS AND ANN (ARTIFICAL NEURAL NETWORK)

2017 ◽  
Vol XLII-1/W1 ◽  
pp. 595-598 ◽  
Author(s):  
R. A. Kuçak ◽  
E. Özdemir ◽  
S. Erol
Keyword(s):  
Neural Network ◽  
Urban Areas ◽  
Point Cloud ◽  
Laser Scanner ◽  
Digital Terrain Model ◽  
Point Clouds ◽  
Self Organizing Map ◽  
Terrestrial Lidar ◽  
The Road ◽  
Photogrammetric Method

Segmentation of point clouds is recently used in many Geomatics Engineering applications such as the building extraction in urban areas, Digital Terrain Model (DTM) generation and the road or urban furniture extraction. Segmentation is a process of dividing point clouds according to their special characteristic layers. The present paper discusses K-means and self-organizing map (SOM) which is a type of ANN (Artificial Neural Network) segmentation algorithm which treats the segmentation of point cloud. The point clouds which generate with photogrammetric method and Terrestrial Lidar System (TLS) were segmented according to surface normal, intensity and curvature. Thus, the results were evaluated.<br><br> LIDAR (Light Detection and Ranging) and Photogrammetry are commonly used to obtain point clouds in many remote sensing and geodesy applications. By photogrammetric method or LIDAR method, it is possible to obtain point cloud from terrestrial or airborne systems. In this study, the measurements were made with a Leica C10 laser scanner in LIDAR method. In photogrammetric method, the point cloud was obtained from photographs taken from the ground with a 13 MP non-metric camera.

scholarly journals USAGE OF PHOTOGRAMMETRIC PROCESSING OF THERMAL IMAGES FOR CIVIL ENGINEERS

2018 ◽  
Vol XLII-5 ◽  
pp. 99-103 ◽  
Author(s):  
A. Dlesk ◽  
K. Vach ◽  
P. Holubec
Keyword(s):  
Thermal Imaging ◽  
Facility Management ◽  
Image Resolution ◽  
The Czech Republic ◽  
Thermal Images ◽  
Climate Conditions ◽  
2D And 3D ◽  
Thermal Inspection ◽  
Test Objects ◽  
Civil Engineers

<p><strong>Abstract.</strong> In climate conditions of the Czech Republic is getting more important to carry out thermal inspection during documentation and inventory of buildings. Capturing and photogrammetric processing of thermal images requires special photogrammetric approaches especially because of low thermal image resolution. Part of this paper is focused on photogrammetric processing of thermal images using different methods with different 2D and 3D results which help civil engineers and architects better interpretation of thermal imaging. Those results are presented on chosen test objects. Photogrammetric results are also analysed in terms of geometric accuracy. The importance of integration of 2D and 3D results to GIS and BIM for facility management is discussed in final part of the paper.</p>

scholarly journals QUALITY ASSESSMENT OF 3D RECONSTRUCTION USING FISHEYE AND PERSPECTIVE SENSORS

2015 ◽  
Vol II-3/W4 ◽  
pp. 215-222 ◽  
Author(s):  
C. Strecha ◽  
R. Zoller ◽  
S. Rutishauser ◽  
B. Brot ◽  
K. Schneider-Zapp ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Quality Assessment ◽  
Unmanned Aerial Vehicles ◽  
Point Cloud ◽  
Laser Scanner ◽  
3D Modelling ◽  
Sensor Selection ◽  
Aerial Vehicles ◽  
Photogrammetric Method ◽  
Fisheye Lenses

Recent mathematical advances, growing alongside the use of unmanned aerial vehicles, have not only overcome the restriction of roll and pitch angles during flight but also enabled us to apply non-metric cameras in photogrammetric method, providing more flexibility for sensor selection. Fisheye cameras, for example, advantageously provide images with wide coverage; however, these images are extremely distorted and their non-uniform resolutions make them more difficult to use for mapping or terrestrial 3D modelling. In this paper, we compare the usability of different camera-lens combinations, using the complete workflow implemented in Pix4Dmapper to achieve the final terrestrial reconstruction result of a well-known historical site in Switzerland: the Chillon Castle. We assess the accuracy of the outcome acquired by consumer cameras with perspective and fisheye lenses, comparing the results to a laser scanner point cloud.

scholarly journals Smartphone-Based Photogrammetry for the 3D Modeling of a Geomorphological Structure

2019 ◽  
Vol 9 (18) ◽  
pp. 3884 ◽  
Author(s):  
Dabove ◽  
Grasso ◽  
Piras
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Smartphone Application ◽  
Computational Time ◽  
Detailed Knowledge ◽  
Operator Experience ◽  
Dense Point ◽  
Close Range ◽  
Three Dimensional Models

The geomatic survey in the speleological field is one of the main activities that allows for the adding of both a scientific and popular value to cave exploration, and it is of fundamental importance for a detailed knowledge of the hypogean cavity. Today, the available instruments, such as laser scanners and metric cameras, allow us to quickly acquire data and obtain accurate three-dimensional models, but they are still expensive, require a careful planning phase of the survey, as well as some operator experience for their management. This work analyzes the performance of a smartphone device for a close-range photogrammetry approach for the extraction of accurate three-dimensional information of an underground cave. The image datasets that were acquired with a high-end smartphone were processed using the Structure from Motion (SfM)-based approach for dense point cloud generation: different image-matching algorithms implemented in a commercial and an open source software and in a smartphone application were tested. In order to assess the reachable accuracy of the proposed procedure, the achieved results were compared with a reference dense point cloud obtained with a professional camera or a terrestrial laser scanner. The approach has shown a good performance in terms of geometrical accuracies, computational time and applicability.

Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

scholarly journals Fitting Terrestrial Laser Scanner Point Clouds with T-Splines: Local Refinement Strategy for Rigid Body Motion

2021 ◽  
Vol 13 (13) ◽  
pp. 2494
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann
Keyword(s):  
Point Cloud ◽  
Goodness Of Fit ◽  
Laser Scanner ◽  
Point Clouds ◽  
Statistical Testing ◽  
Computational Time ◽  
Terrestrial Laser Scanner ◽  
Reference Surface ◽  
Local Refinement ◽  
Surface Approximation

T-splines have recently been introduced to represent objects of arbitrary shapes using a smaller number of control points than the conventional non-uniform rational B-splines (NURBS) or B-spline representatizons in computer-aided design, computer graphics and reverse engineering. They are flexible in representing complex surface shapes and economic in terms of parameters as they enable local refinement. This property is a great advantage when dense, scattered and noisy point clouds are approximated using least squares fitting, such as those from a terrestrial laser scanner (TLS). Unfortunately, when it comes to assessing the goodness of fit of the surface approximation with a real dataset, only a noisy point cloud can be approximated: (i) a low root mean squared error (RMSE) can be linked with an overfitting, i.e., a fitting of the noise, and should be correspondingly avoided, and (ii) a high RMSE is synonymous with a lack of details. To address the challenge of judging the approximation, the reference surface should be entirely known: this can be solved by printing a mathematically defined T-splines reference surface in three dimensions (3D) and modeling the artefacts induced by the 3D printing. Once scanned under different configurations, it is possible to assess the goodness of fit of the approximation for a noisy and potentially gappy point cloud and compare it with the traditional but less flexible NURBS. The advantages of T-splines local refinement open the door for further applications within a geodetic context such as rigorous statistical testing of deformation. Two different scans from a slightly deformed object were approximated; we found that more than 40% of the computational time could be saved without affecting the goodness of fit of the surface approximation by using the same mesh for the two epochs.

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