scholarly journals EVALUATION OF MODEL RECOGNITION FOR GRAMMAR-BASED AUTOMATIC 3D BUILDING MODEL RECONSTRUCTION

2016 ◽  
Vol XLI-B4 ◽  
pp. 63-69
Author(s):  
Qian Yu ◽  
Petra Helmholz ◽  
David Belton
Keyword(s):  
Laser Scanning ◽  
Quality Evaluation ◽  
Evaluation Process ◽  
3D Models ◽  
Point Of View ◽  
Three Dimensions ◽  
Public And Private ◽  
Building Models ◽  
Evaluation Point ◽  
Increasing Demand

In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.

scholarly journals EVALUATION OF MODEL RECOGNITION FOR GRAMMAR-BASED AUTOMATIC 3D BUILDING MODEL RECONSTRUCTION

2016 ◽  
Vol XLI-B4 ◽  
pp. 63-69 ◽  
Author(s):  
Qian Yu ◽  
Petra Helmholz ◽  
David Belton
Keyword(s):  
Laser Scanning ◽  
Quality Evaluation ◽  
Evaluation Process ◽  
3D Models ◽  
Point Of View ◽  
Three Dimensions ◽  
Public And Private ◽  
Building Models ◽  
Evaluation Point ◽  
Increasing Demand

In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.

scholarly journals ANALYSIS OF 3D BUILDING MODELS ACCURACY BASED ON THE AIRBORNE LASER SCANNING POINT CLOUDS

2018 ◽  
Vol XLII-2 ◽  
pp. 797-804 ◽  
Author(s):  
W. Ostrowski ◽  
M. Pilarska ◽  
J. Charyton ◽  
K. Bakuła
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Large Scale ◽  
Point Clouds ◽  
3D Models ◽  
Airborne Laser Scanning ◽  
Aerial Images ◽  
Statistical Parameters ◽  
Airborne Laser ◽  
Building Models

Creating 3D building models in large scale is becoming more popular and finds many applications. Nowadays, a wide term “3D building models” can be applied to several types of products: well-known CityGML solid models (available on few Levels of Detail), which are mainly generated from Airborne Laser Scanning (ALS) data, as well as 3D mesh models that can be created from both nadir and oblique aerial images. City authorities and national mapping agencies are interested in obtaining the 3D building models. Apart from the completeness of the models, the accuracy aspect is also important. Final accuracy of a building model depends on various factors (accuracy of the source data, complexity of the roof shapes, etc.). In this paper the methodology of inspection of dataset containing 3D models is presented. The proposed approach check all building in dataset with comparison to ALS point clouds testing both: accuracy and level of details. Using analysis of statistical parameters for normal heights for reference point cloud and tested planes and segmentation of point cloud provides the tool that can indicate which building and which roof plane in do not fulfill requirement of model accuracy and detail correctness. Proposed method was tested on two datasets: solid and mesh model.

scholarly journals Crystallizer’s Desks Surface Diagnostics with Usage of Robotic System

2013 ◽  
Vol 58 (3) ◽  
pp. 907-910 ◽  
Author(s):  
J. David ◽  
Z. Jančíiková ◽  
R. Frischer ◽  
M. Vrožina
Keyword(s):  
Laser Scanning ◽  
Quality Evaluation ◽  
Cooling System ◽  
Continuous Steel Casting ◽  
Point Of View ◽  
Laser Sensor ◽  
Measuring Device ◽  
First Results ◽  
Surface Diagnostics

Abstract Discussed problems are solved in Arcelor Mittal Ostrava a.s. company. VSB-TU Ostrava has its share on this solution in the frame of grant project TIP. The project has several goals, which relate with primary cooling system area in CSCD (Continuous Steel Casting Device). One target is concerned about surface quality of crystallizer’s desks, also from point of view of its quality evaluation.in terms of project solution was solved a crystallizer’s desks defects catalogue and methodology of their evaluation. Also was made methodology for quality evaluation of narrow crystallizer’s desks, which are dismantled in maintenance area. There were proposed a laser scanning of the crystallizer’s desks surface with usage of Laser sensor. In cooperation with DASFOS CZ, s.r.o. was proposed new method of inner crystallizer’s chamber measuring. In this paper are presented partial results of this solution, including first results from prototyped measuring device.

scholarly journals 3D HIGH-QUALITY MODELING OF SMALL AND COMPLEX ARCHAEOLOGICAL INSCRIBED OBJECTS: RELEVANT ISSUES AND PROPOSED METHODOLOGY

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 699-706
Author(s):  
L. Lastilla ◽  
R. Ravanelli ◽  
S. Ferrara
Keyword(s):  
Laser Scanning ◽  
Visual Inspection ◽  
3D Models ◽  
3D Modelling ◽  
Point Of View ◽  
Acquisition Time ◽  
High Frequencies ◽  
Geometric Point ◽  
Automatic Alignment ◽  
Quality Modeling

<p><strong>Abstract.</strong> 3D modelling of inscribed archaeological finds (such as tablets or small objects) has to consider issues related to the correct acquisition and reading of ancient inscriptions, whose size and degree of conservation may vary greatly, in order to guarantee the needed requirements for visual inspection and analysis of the signs. In this work, photogrammetry and laser scanning were tested in order to find the optimal sensors and settings, useful to the complete 3D reconstruction of such inscribed archaeological finds, paying specific attention to the final geometric accuracy and operative feasibility in terms of required sensors and necessary time. Several 3D modelling tests were thus carried out on four replicas of inscribed objects, which are characterized by different size, material and epigraphic peculiarities. Specifically, in relation to photogrammetry, different cameras and lenses were used and a robust acquisition setup, able to guarantee a correct and automatic alignment of images during the photogrammetric process, was identified. The focus stacking technique was also investigated. The Canon EOS 1200D camera equipped with prime lenses and iPad camera showed respectively the best and the worst accuracy. From an overall geometric point of view, 50&amp;thinsp;mm and 100&amp;thinsp;mm lenses achieved very similar results, but the reconstruction of the smallest details with the 50&amp;thinsp;mm lens was not appropriate. On the other hand, the acquisition time for the 50&amp;thinsp;mm lens was considerably lower than the 100&amp;thinsp;mm one. In relation to laser scanning, the ScanRider 1.2 model was used. The 3D models produced (in less time than using photogrammetry) clearly highlight how this scanner is able to reconstruct even the high frequencies with high resolution. However, the models in this case are not provided with texture. For these reasons, a robust procedure for integrating the texture of photogrammetry models with the mesh of laser scanning models was also carried out.</p>

scholarly journals AN AUTOMATED 3D INDOOR TOPOLOGICAL NAVIGATION NETWORK MODELLING

2015 ◽  
Vol II-2/W2 ◽  
pp. 47-53 ◽  
Author(s):  
A. Jamali ◽  
A. A. Rahman ◽  
P. Boguslawski ◽  
C. M. Gold
Keyword(s):  
Indoor Environment ◽  
Laser Scanning ◽  
3D Models ◽  
Indoor Navigation ◽  
Control Points ◽  
Network Modelling ◽  
Building Model ◽  
Building Models ◽  
Data Acquisition Process ◽  
Topological Navigation

Indoor navigation is important for various applications such as disaster management and safety analysis. In the last decade, indoor environment has been a focus of wide research; that includes developing techniques for acquiring indoor data (e.g. Terrestrial laser scanning), 3D indoor modelling and 3D indoor navigation models. In this paper, an automated 3D topological indoor network generated from inaccurate 3D building models is proposed. In a normal scenario, 3D indoor navigation network derivation needs accurate 3D models with no errors (e.g. gap, intersect) and two cells (e.g. rooms, corridors) should touch each other to build their connections. The presented 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. For reducing time and cost of indoor building data acquisition process, Trimble LaserAce 1000 as surveying instrument is used. The modelling results were validated against an accurate geometry of indoor building environment which was acquired using Trimble M3 total station.

scholarly journals FOOTPRINT MAP PARTITIONING USING AIRBORNE LASER SCANNING DATA

2016 ◽  
Vol III-3 ◽  
pp. 241-247
Author(s):  
B. Xiong ◽  
S. Oude Elberink ◽  
G. Vosselman
Keyword(s):  
Decision Making ◽  
Laser Scanning ◽  
State Of The Art ◽  
3D Models ◽  
Airborne Laser Scanning ◽  
The Other ◽  
Advantages And Disadvantages ◽  
Airborne Laser ◽  
Building Models ◽  
Height Data

Nowadays many cities and countries are creating their 3D building models for a better daily management and smarter decision making. The newly created 3D models are required to be consistent with existing 2D footprint maps. Thereby the 2D maps are usually combined with height data for the task of 3D reconstruction. Many buildings are often composed by parts that are discontinuous over height. Building parts can be reconstructed independently and combined into a complete building. Therefore, most of the state-of-the-art work on 3D building reconstruction first decomposes a footprint map into parts. However, those works usually change the footprint maps for easier partitioning and cannot detect building parts that are fully inside the footprint polygon. In order to solve those problems, we introduce two methodologies, one more dependent on height data, and the other one more dependent on footprints. We also experimentally evaluate the two methodologies and compare their advantages and disadvantages. The experiments use Airborne Laser Scanning (ALS) data and two vector maps, one with 1:10,000 scale and another one with 1:500 scale.

scholarly journals FOOTPRINT MAP PARTITIONING USING AIRBORNE LASER SCANNING DATA

2016 ◽  
Vol III-3 ◽  
pp. 241-247 ◽  
Author(s):  
B. Xiong ◽  
S. Oude Elberink ◽  
G. Vosselman
Keyword(s):  
Decision Making ◽  
Laser Scanning ◽  
State Of The Art ◽  
3D Models ◽  
Airborne Laser Scanning ◽  
The Other ◽  
Advantages And Disadvantages ◽  
Airborne Laser ◽  
Building Models ◽  
Height Data

Nowadays many cities and countries are creating their 3D building models for a better daily management and smarter decision making. The newly created 3D models are required to be consistent with existing 2D footprint maps. Thereby the 2D maps are usually combined with height data for the task of 3D reconstruction. Many buildings are often composed by parts that are discontinuous over height. Building parts can be reconstructed independently and combined into a complete building. Therefore, most of the state-of-the-art work on 3D building reconstruction first decomposes a footprint map into parts. However, those works usually change the footprint maps for easier partitioning and cannot detect building parts that are fully inside the footprint polygon. In order to solve those problems, we introduce two methodologies, one more dependent on height data, and the other one more dependent on footprints. We also experimentally evaluate the two methodologies and compare their advantages and disadvantages. The experiments use Airborne Laser Scanning (ALS) data and two vector maps, one with 1:10,000 scale and another one with 1:500 scale.

scholarly journals V3Geo: A cloud-based repository for virtual 3D models in geoscience

2021 ◽  
Author(s):  
Simon John Buckley ◽  
John Anthony Howell ◽  
Nicole Naumann ◽  
Conor Lewis ◽  
Magda Chmielewska ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Storage System ◽  
3D Models ◽  
Field Trips ◽  
Measurement Tool ◽  
Geoscience Education ◽  
Virtual Field Trips ◽  
Public And Private ◽  
Creative Commons ◽  
Virtual Field

Abstract. V3Geo is a cloud-based repository for publishing virtual 3D models in geoscience. The system allows storage, search and visualisation of models typically acquired using techniques such as photogrammetry and laser scanning. The platform has been developed to handle models at the range of scales typically used by geoscientists, from microscopic, hand samples and fossils through to outcrop sections covering metres to tens of kilometres. The cloud storage system serves the models to a purpose-built 3D web viewer. Models are tiled to ensure efficient streaming over the internet. The web viewer allows 3D models to be interactively explored without the need for specialist software to be installed. A measurement tool enables users to measure simple dimensions, such as widths, thicknesses, fault throws and more. V3Geo allows very large models comprising multiple sections and is designed to include additional interpretation layers. The specific focus on geoscience data is supported by defined metadata and a classification schema. Public and private storage are available, and public models are assigned Creative Commons licenses to govern content usage. This paper presents V3Geo as a sustainable resource for the geoscience community, including the motivation, main characteristics, and features. Example usage scenarios are highlighted: from undergraduate geology teaching, supporting virtual geoscience education, and preparing virtual field trips based on V3Geo models. Finally, best practise guidelines for preparing 3D model contributions for publication on V3Geo are included as an Appendix.

scholarly journals Archaeological anastylosis of two Macedonian tombs in a 3D virtual environment

2020 ◽  
Vol 11 (22) ◽  
pp. 26
Author(s):  
Maria Stampouloglou ◽  
Olympia Toska ◽  
Sevi Tapinaki ◽  
Georgia Kontogianni ◽  
Margarita Skamantzari ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
3D Models ◽  
Point Of View ◽  
Actual Process ◽  
Northern Greece ◽  
Geometric Information ◽  
Data Acquisition And Processing ◽  
International Conventions ◽  
High Degree

<p class="VARAbstract">Archaeological restoration of monuments is a practice requiring extreme caution and thorough study. Archaeologists and conservation experts are very reluctant to proceed to restoration and indeed to reconstruction actions without detailed consultation and thought. Nowadays, anastylosis executed on the real object is practically prohibited. Contemporary technologies have provided archaeologists and other conservation experts with the tools to embark on virtual restorations or anastyloses, thus testing various alternatives without physical intervention on the monument itself. In this way, the values of the monuments are respected according to international conventions. In this paper, two such examples of virtual archaeological anastyloses of two important Macedonian tombs in northern Greece are presented. The anastyloses were performed on three-dimensional (3D) models which have been produced using modern digital 3D documentation techniques, such as image-based modelling and terrestrial laser scanning. The reader is introduced to the history and importance –as well as the peculiarities– of the Macedonian tombs. In addition, the two tombs are described in detail mainly from an archaeological point of view The process of field data acquisition and processing to produce the 3D models are described. Simple and more or less standard methods were employed in acquiring the raw data. Processing was carried out using commercial software. The resulting 3D models and other documentation products are assessed for their accuracy and completeness. The decisions for the virtual anastylosis are explained in detail and the actual process is also described. The restored monuments are presented and evaluated by the conservation experts. Thus, it is shown how important virtual anastylosis of monuments is to archaeological researchers, as it enables them to conduct in-depth studies, without actually tampering with the monuments themselves. Digital 3D models are contributing to many disciplines, especially in archaeology, as they enable a wider audience to easily access both archaeological and geometric information as well as offering a high degree of interaction possibilities.</p>

Five-Dimensional Microscopy using Widefield-Deconvolution: Practical Considerations and Biological Applications

1996 ◽  
Vol 54 ◽  
pp. 268-269
Author(s):  
W.F. Marshall ◽  
K. Oegema ◽  
J. Nunnari ◽  
A.F. Straight ◽  
D.A. Agard ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
High Speed ◽  
Laser Scanning ◽  
Ccd Camera ◽  
Image Plane ◽  
Time Lapse ◽  
Laser Scanning Confocal Microscopy ◽  
Three Dimensions ◽  
Excitation Light ◽  
Cooled Ccd

The ability to image cells in three dimensions has brought about a revolution in biological microscopy, enabling many questions to be asked which would be inaccessible without this capability. There are currently two major methods of three dimensional microscopy: laser-scanning confocal microscopy and widefield-deconvolution microscopy. The method of widefield-deconvolution uses a cooled CCD to acquire images from a standard widefield microscope, and then computationally removes out of focus blur. Using such a scheme, it is easy to acquire time-lapse 3D images of living cells without killing them, and to do so for multiple wavelengths (using computer-controlled filter wheels). Thus, it is now not only feasible, but routine, to perform five dimensional microscopy (three spatial dimensions, plus time, plus wavelength).Widefield-deconvolution has several advantages over confocal microscopy. The two main advantages are high speed of acquisition (because there is no scanning, a single optical section is acquired at a time by using a cooled CCD camera) and the use of low excitation light levels Excitation intensity can be much lower than in a confocal microscope for three reasons: 1) longer exposures can be taken since the entire 512x512 image plane is acquired in parallel, so that dwell time is not an issue, 2) the higher quantum efficiently of a CCD detect over those typically used in confocal microscopy (although this is expected to change due to advances in confocal detector technology), and 3) because no pinhole is used to reject light, a much larger fraction of the emitted light is collected. Thus we can typically acquire images with thousands of photons per pixel using a mercury lamp, instead of a laser, for illumination. The use of low excitation light is critical for living samples, and also reduces bleaching. The high speed of widefield microscopy is also essential for time-lapse 3D microscopy, since one must acquire images quickly enough to resolve interesting events.

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