scholarly journals Shrinking tube mesh: combined mesh generation and smoothing for pathologic vessels

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Annika Niemann ◽  
Bernhard Preim ◽  
Sylvia Saalfeld
Keyword(s):  
Mesh Generation ◽  
Point Cloud ◽  
3D Model ◽  
Point Clouds ◽  
Model Generation ◽  
Outer Contour ◽  
Generation Algorithm ◽  
Tissue Deformations

AbstractWe present a mesh generation algorithm which is able to produce smooth meshes from point clouds derived from histological slices. In this work, the shrinking tube mesh generation is used on histologic images depicting pathologic vessels. Our mesh generation is modeled after the behaviour of a shrinking tube. A start shape is fitted iteratively to the point cloud. The presented algorithm was successfully used to generate meshes of the inner and outer contour from vessels in histologic images. While histologic slices have a high in-plane resolution, the large slice distance and deformations during tissue deformations are challenging for 3D model generation.

scholarly journals An Efficient Pipeline to Obtain 3D Model for HBIM and Structural Analysis Purposes from 3D Point Clouds

2020 ◽  
Vol 10 (4) ◽  
pp. 1235 ◽  
Author(s):  
Massimiliano Pepe ◽  
Domenica Costantino ◽  
Alfredo Restuccia Garofalo
Keyword(s):  
Structural Analysis ◽  
Case Studies ◽  
Point Cloud ◽  
3D Model ◽  
Point Clouds ◽  
Single Element ◽  
Building Information Modelling ◽  
Information Modelling ◽  
3D Point Clouds ◽  
Building Information

The aim of this work is to identify an efficient pipeline in order to build HBIM (heritage building information modelling) and create digital models to be used in structural analysis. To build accurate 3D models it is first necessary to perform a geomatics survey. This means performing a survey with active or passive sensors and, subsequently, accomplishing adequate post-processing of the data. In this way, it is possible to obtain a 3D point cloud of the structure under investigation. The next step, known as “scan-to-BIM (building information modelling)”, has led to the creation of an appropriate methodology that involved the use of Rhinoceros software and a few tools developed within this environment. Once the 3D model is obtained, the last step is the implementation of the structure in FEM (finite element method) and/or in HBIM software. In this paper, two case studies involving structures belonging to the cultural heritage (CH) environment are analysed: a historical church and a masonry bridge. In particular, for both case studies, the different phases were described involving the construction of the point cloud and, subsequently, the construction of a 3D model. This model is suitable both for structural analysis and for the parameterization of rheological and geometric information of each single element of the structure.

Converting Point Cloud to Revolved Solids

2013 ◽  
Vol 371 ◽  
pp. 468-472
Author(s):  
Mircea Viorel Drăgoi ◽  
Slobodan Navalušić
Keyword(s):  
Reverse Engineering ◽  
Cross Section ◽  
Software Package ◽  
Point Cloud ◽  
3D Model ◽  
Point Clouds ◽  
3D Scanning ◽  
Main Drawback ◽  
Mass Properties

3D scanning is one of the basic methods to gather data for reverse engineering. The main drawback of 3D scanning is that its output - the point cloud - can never be used directly to define surfaces or solids useful to reconstruct the electronic 3D model of the scanned part.The paper presents a piece of software designed in VisualLISP for AutoCAD, software that acts as a point cloud to 3D primitives converter. The novelty consists of the method used to find the parameters of the primitive that best fits to the point cloud: the mass properties of regions are used to find the center of a cones cross section. Parts have been scanned and the point clouds processed. The results obtained prove the correctness of the algorithm and of the method applied. A piece of software that processes the point cloud in order to find the 3D primitive that it fits the best has been developed. The output is the 3D primitive that successfully and accurate replaces the point cloud. Some adjacent tools were designed, so the entire software package becomes a useful tool for the reverse engineering user. The ways the researches can be continued and developed are foreseen, as well

scholarly journals GUIDELINES FOR AUTHORS PREPARING A FULL PAPER TO BE SUBMITTED TO ISPRS EVENTS

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 613-618
Author(s):  
P. Ortiz-Coder ◽  
R. Cabecera
Keyword(s):  
Case Studies ◽  
3D Model ◽  
Laser Scanner ◽  
Point Clouds ◽  
Model Generation ◽  
Selection Algorithm ◽  
Full Paper ◽  
Historical Heritage ◽  
The Moment ◽  
New Generation

Abstract. In recent years, a new generation of instruments has appeared that are motion-based capture. These systems are based on a combination of techniques, among which LIDAR stands out. In this article we present a new proposal for a 3D model generation instrument based on videogrammetry. The prototype designed consists of two cameras connected to a computer system. One of the cameras is in charge of running VisualSLAM and guiding the user in real time at the moment of data acquisition; the other camera, with a higher resolution, saves the images and, thanks to a refined 3D-Based frame selection algorithm, processes them using automatic photogrammetric procedures, generating one or more point-clouds that are integrated to give way to a high-density and high-precision 3D colour point-cloud.The paper evaluates the proposal with four case studies: two of an urban nature and two related to historical heritage. The resulting models are confronted with the Faro Focus3D X330 laser scanner, classic photogrammetric procedures with reflex camera and Agisoft metashape software and are also confronted with precision points measured with a total station. The case studies show that the proposed system has a high capture speed, and that the accuracy of the models can be competitive in many areas of professional surveying and can be a viable alternative for the creation of instruments based on videogrammetry.

scholarly journals A PROJECTION-BASED RECONSTRUCTION ALGORITHM FOR 3D MODELING OF BRIDGE STRUCTURES FROM DRONE-BASED POINT CLOUD

2021 ◽  
Vol XLVI-4/W1-2021 ◽  
pp. 77-83
Author(s):  
M. Mehranfar ◽  
H. Arefi ◽  
F. Alidoost
Keyword(s):  
Point Cloud ◽  
Clustering Algorithm ◽  
3D Model ◽  
Reconstruction Algorithm ◽  
Point Clouds ◽  
3D Models ◽  
Reconstruction Technique ◽  
Reconstruction Process ◽  
Median Error ◽  
Bridge Structures

Abstract. This paper presents a projection-based method for 3D bridge modeling using dense point clouds generated from drone-based images. The proposed workflow consists of hierarchical steps including point cloud segmentation, modeling of individual elements, and merging of individual models to generate the final 3D model. First, a fuzzy clustering algorithm including the height values and geometrical-spectral features is employed to segment the input point cloud into the main bridge elements. In the next step, a 2D projection-based reconstruction technique is developed to generate a 2D model for each element. Next, the 3D models are reconstructed by extruding the 2D models orthogonally to the projection plane. Finally, the reconstruction process is completed by merging individual 3D models and forming an integrated 3D model of the bridge structure in a CAD format. The results demonstrate the effectiveness of the proposed method to generate 3D models automatically with a median error of about 0.025 m between the elements’ dimensions in the reference and reconstructed models for two different bridge datasets.

scholarly journals POINT CLOUD DERIVED FROMVIDEO FRAMES: ACCURACY ASSESSMENT IN RELATION TO TERRESTRIAL LASER SCANNINGAND DIGITAL CAMERA DATA

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 217-223 ◽  
Author(s):  
P. Delis ◽  
M. Zacharek ◽  
D. Wierzbicki ◽  
A. Grochala
Keyword(s):  
Data Storage ◽  
Point Cloud ◽  
Laser Scanning ◽  
3D Model ◽  
Accuracy Assessment ◽  
Point Clouds ◽  
Histogram Equalization ◽  
Video Data ◽  
Video Frame ◽  
Video Frames

The use of image sequences in the form of video frames recorded on data storage is very useful in especially when working with large and complex structures. Two cameras were used in this study: Sony NEX-5N (for the test object) and Sony NEX-VG10 E (for the historic building). In both cases, a Sony α f = 16 mm fixed focus wide-angle lens was used. Single frames with sufficient overlap were selected from the video sequence using an equation for automatic frame selection. In order to improve the quality of the generated point clouds, each video frame underwent histogram equalization and image sharpening. Point clouds were generated from the video frames using the SGM-like image matching algorithm. The accuracy assessment was based on two reference point clouds: the first from terrestrial laser scanning and the second generated based on images acquired using a high resolution camera, the NIKON D800. The performed research has shown, that highest accuracies are obtained for point clouds generated from video frames, for which a high pass filtration and histogram equalization had been performed. Studies have shown that to obtain a point cloud density comparable to TLS, an overlap between subsequent video frames must be 85 % or more. Based on the point cloud generated from video data, a parametric 3D model can be generated. This type of the 3D model can be used in HBIM construction.

scholarly journals 3D DATA ACQUISITION BASED ON OPENCV FOR CLOSE-RANGE PHOTOGRAMMETRY APPLICATIONS

2017 ◽  
Vol XLII-1/W1 ◽  
pp. 377-382 ◽  
Author(s):  
L. Jurjević ◽  
M. Gašparović
Keyword(s):  
Traffic Management ◽  
Point Cloud ◽  
3D Model ◽  
Point Clouds ◽  
Model Reconstruction ◽  
Close Range Photogrammetry ◽  
3D Data ◽  
3D Model Reconstruction ◽  
Close Range ◽  
Real Time Application

Development of the technology in the area of the cameras, computers and algorithms for 3D the reconstruction of the objects from the images resulted in the increased popularity of the photogrammetry. Algorithms for the 3D model reconstruction are so advanced that almost anyone can make a 3D model of photographed object. The main goal of this paper is to examine the possibility of obtaining 3D data for the purposes of the close-range photogrammetry applications, based on the open source technologies. All steps of obtaining 3D point cloud are covered in this paper. Special attention is given to the camera calibration, for which two-step process of calibration is used. Both, presented algorithm and accuracy of the point cloud are tested by calculating the spatial difference between referent and produced point clouds. During algorithm testing, robustness and swiftness of obtaining 3D data is noted, and certainly usage of this and similar algorithms has a lot of potential in the real-time application. That is the reason why this research can find its application in the architecture, spatial planning, protection of cultural heritage, forensic, mechanical engineering, traffic management, medicine and other sciences.

Rapid and Adaptive Quadrilateral Mesh Generation Algorithm from Dense Point Cloud

2019 ◽  
Vol 31 (1) ◽  
pp. 39
Author(s):  
Yongchuan Zheng ◽  
Boliang Guan ◽  
Shujin Lin ◽  
Xiaonan Luo ◽  
Ruomei Wang
Keyword(s):  
Mesh Generation ◽  
Point Cloud ◽  
Quadrilateral Mesh ◽  
Generation Algorithm ◽  
Dense Point

scholarly journals THE TESTING OF PHOTOSCAN 3D OBJECT MODELLING SOFTWARE

2014 ◽  
Vol 40 (2) ◽  
pp. 68-74 ◽  
Author(s):  
Tomáš Jiroušek ◽  
Roman Kapica ◽  
Dana Vrublová
Keyword(s):  
Point Cloud ◽  
3D Model ◽  
3D Models ◽  
3D Modelling ◽  
Model Generation ◽  
Model Accuracy ◽  
Test Procedures ◽  
Accuracy Test ◽  
Object Modelling ◽  
Calibration Techniques

The paper presents triangulation-based accuracy test procedures for PhotoScan 3D modelling software with automatic features including camera station identification, point cloud construction and the generation of polygon networks and polygon net textures. The process starts with establishing the camera resolutions. Then, internal orientation elements of the cameras are established by means of different calibration techniques and comparisons between them are made. 3D models are then tested using diverse model generation parameters and different configurations of sets of images including how each type of calibration affects the resulting 3D model accuracy. To conclude, 3D model accuracy is compared with geodesic surveying results.

scholarly journals Rail Track Detection and Projection-Based 3D Modeling from UAV Point Cloud

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5220
Author(s):  
Shima Sahebdivani ◽  
Hossein Arefi ◽  
Mehdi Maboudi
Keyword(s):  
3D Modeling ◽  
Point Cloud ◽  
3D Model ◽  
Three Dimensional ◽  
Point Clouds ◽  
Rail Track ◽  
Three Dimensional Modeling ◽  
Railway Industry ◽  
Dense Point ◽  
Uav Images

The expansion of the railway industry has increased the demand for the three-dimensional modeling of railway tracks. Due to the increasing development of UAV technology and its application advantages, in this research, the detection and 3D modeling of rail tracks are investigated using dense point clouds obtained from UAV images. Accordingly, a projection-based approach based on the overall direction of the rail track is proposed in order to generate a 3D model of the railway. In order to extract the railway lines, the height jump of points is evaluated in the neighborhood to select the candidate points of rail tracks. Then, using the RANSAC algorithm, line fitting on these candidate points is performed, and the final points related to the rail are identified. In the next step, the pre-specified rail piece model is fitted to the rail points through a projection-based process, and the orientation parameters of the model are determined. These parameters are later improved by fitting the Fourier curve, and finally a continuous 3D model for all of the rail tracks is created. The geometric distance of the final model from rail points is calculated in order to evaluate the modeling accuracy. Moreover, the performance of the proposed method is compared with another approach. A median distance of about 3 cm between the produced model and corresponding point cloud proves the high quality of the proposed 3D modeling algorithm in this study.

scholarly journals MODELOWANIE HAŁDY KRUSZYWA NATURALNEGO Z WYKORZYSTANIEM TECHNOLOGII UAV WRAZ Z ANALIZĄ DOKŁADNOŚCI

1970 ◽  
pp. 103-117
Author(s):  
MACIEJ SMACZYŃSKI
Keyword(s):  
Point Cloud ◽  
3D Model ◽  
Point Clouds ◽  
Digital Model ◽  
Control Points ◽  
Independent Control ◽  
Model Accuracy ◽  
Independent Measurement ◽  
Field Control ◽  
Accuracy Check

The purpose of this article is to determine the potential of imaging obtained using an unmannedaerial platform (UAV) to create a digital model of terrain for aggregate heaps (DTMs). In addition, the intermediategoal is to carry out an independent accuracy check of the calculated 3D model, which in the study will be referred to an independent measurement using GNSS technology. The research object was a heap of natural aggregate with irregular shape and height differences up to 11 meters. Three point clouds with different detail parameters were generated from the acquired images. For further analysis, a point cloud with the best ratio of terrain reflection accuracy to the calculated RMSE value was selected. Independent control of 3D model accuracy was based on seven heap control points measured in the field and the same points generated on the 3D model . The deviations of several centimeters between field control points and points from the model may indicate the great potential of UAV technology and the possibility of its use in various engineering tasks.

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