Method on 3D Dense Point Cloud Recovery of Geographical Scene

2013 ◽  
Vol 748 ◽  
pp. 619-623 ◽  
Author(s):  
Yan Liang ◽  
Ye Hua Sheng ◽  
Ka Zhang
Keyword(s):  
Computer Vision ◽  
Virtual Reality ◽  
High Precision ◽  
Point Cloud ◽  
Low Cost ◽  
Experimental Results ◽  
Affine Invariant ◽  
Invariant Features ◽  
Dense Point

The object of this research is to reconstruct 3D dense point cloud of geographical scene. With the technology and method of computer vision , first affine invariant features are extracted and matched, then cameras parameters and 3D dense point cloud are recovered and united under geographical reference. The experimental results show that this method with low cost and high precision of centimeters can satisfy the requirements of measurement, modeling and virtual reality.

scholarly journals GEOREFERENCING AND REPROJECTION ERROR INVESTIGATION ON IMAGE BASED 3D DIGITIZATION AND MAPPING OF HISTORICAL BUILDINGS

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 71-75
Author(s):  
C. Altuntas
Keyword(s):  
Point Cloud ◽  
Large Scale ◽  
Cloud Model ◽  
Low Cost ◽  
Three Dimensional ◽  
Control Points ◽  
Historical Buildings ◽  
Reprojection Error ◽  
Dense Point ◽  
Point Cloud Model

<p><strong>Abstract.</strong> Image based dense point cloud creation is easy and low-cost application for three dimensional digitization of small and large scale objects and surfaces. It is especially attractive method for cultural heritage documentation. Reprojection error on conjugate keypoints indicates accuracy of the model and keypoint localisation in this method. In addition, sequential registration of the images from large scale historical buildings creates big cumulative registration error. Thus, accuracy of the model should be increased with the control points or loop close imaging. The registration of point point cloud model into the georeference system is performed using control points. In this study historical Sultan Selim Mosque that was built in sixteen century by Great Architect Sinan was modelled via photogrammetric dense point cloud. The reprojection error and number of keypoints were evaluated for different base/length ratio. In addition, georeferencing accuracy was evaluated with many configuration of control points with loop and without loop closure imaging.</p>

scholarly journals A 3D Reconstruction Pipeline of Urban Drainage Pipes Based on MultiviewImage Matching Using Low-Cost Panoramic Video Cameras

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2101 ◽  
Author(s):  
Zhang ◽  
Zhao ◽  
Hu ◽  
Wang ◽  
Ai ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
High Precision ◽  
Image Matching ◽  
Low Cost ◽  
Geometric Distortion ◽  
Urban Drainage ◽  
Affine Invariant ◽  
Pipe Inspection ◽  
Video Cameras ◽  
Panoramic Video

Urban drainage pipe networks have complex spatial contributions, andthey are now facing problems such as damage, defects, and aging. A rapid and high-precision pipe inspection strategy is thekey to ensuring thesustainable development of urban water supply and drainage system. In this paper, a three-dimensional (3D) reconstruction pipeline of urban drainage pipes based on multiview image matching using low-cost panoramic video cameras is proposed, which provides an innovative technical approach for pipe inspection. Firstly, we extracted frames from the panoramic video of the pipes andcorrected the geometric distortion using a spherical reprojection to obtain multiview pipe images. Second, the robust feature matching method using support lines and affine-invariant ratios isintroduced to conduct pipe image matching. Finally, the photogrammetric processing, using structure from motion (SfM) and dense reconstruction, wasintroduced to achieve the 3D modeling of drainage pipes. Several typical drainage pipes and shafts of the real scenes were taken for the 3D reconstruction experiments. Theresults show that our strategy can realize high-precision 3D reconstruction of different types of pipes, which can provide effective technical support for rapid and efficient inspection of urban pipes with broad application prospects in the daily management of sustainable urban drainage systems (SUDSs).

The Use of the Terrestrial Photogrammetry in Reverse Engineering Applications

2015 ◽  
Vol 4 (2) ◽  
pp. 48-57
Author(s):  
Naci Yastikli ◽  
Zehra Erisir ◽  
Pelin Altintas ◽  
Tugba Cak
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Low Cost ◽  
Line Drawing ◽  
Engineering Application ◽  
3D Models ◽  
Engineering Applications ◽  
Ship Model ◽  
Dense Point ◽  
Terrestrial Photogrammetry

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an existing product or a spare part, reproduction of an existing surface, elimination of the defect or improvement of the available product are the goals of industrial reverse engineering applications. The first and the most important step in reverse engineering applications is the generation of the three dimensional (3D) metric model of an existing product in computer environment. After this stage, many operations such as the preparation of molds for mass production, the performance testing, the comparison of the existing product with other products and prototypes which are available on the market are performed by using the generated 3D models. In reverse engineering applications, the laser scanner system or digital terrestrial photogrammetry methods, also called contactless method, are preferred for the generation of the 3D models. In particular, terrestrial photogrammetry has become a popular method since require only photographs for the 3-dimensional drawing, the generation of the dense point cloud using the image matching algorithms and the orthoimage generation as well as its low cost. In this paper, an industrial application of 3D information modelling is presented which concerns the measurement and 3D metric modelling of the ship model. The possible usage of terrestrial photogrammetry in reverse engineering application is investigated based on low cost photogrammetric system. The main aim was the generation of the dense point cloud and 3D line drawing of the ship model by using terrestrial photogrammetry, for the production of the ship in real size as a reverse engineering application. For this purpose, the images were recorded with digital SLR camera and orientations have been performed. Then 3D line drawing operations, point cloud and orthoimage generations have been accomplished by using PhotoModeler software. As a result of the proposed terrestrial photogrammetric steps, 0.5 mm spaced dense point cloud and orthoimage have been generated. The obtained results from experimental study were discussed and possible use of proposed methods was evaluated for reverse engineering application.

A Low-Cost Head Supported Eye Tracker with High Precision

2013 ◽  
Vol 772 ◽  
pp. 455-460
Author(s):  
Jie Chun Chen ◽  
Shi Quan Ma ◽  
Li Ping Zhao
Keyword(s):  
High Precision ◽  
Relative Position ◽  
Low Cost ◽  
Experimental Results ◽  
Average Error ◽  
Eye Tracker ◽  
Experimental Apparatus ◽  
The Subject ◽  
Maximal Average

This paper discusses a low cost head-supported eye tracker. To measure the coordinates associated with a subjects gaze point fallen on a monitor, the subject places his head on a head support and keeps his head fixed. Meanwhile, a camera is used to capture images of the subjects left or right eye. The subjects gaze point fallen on a monitor can be determined according to the relative position of the pupil and glint in an eye image. This paper presents not only the principle of this eye tracker, but also the methods used to detect the pupil and glint in an eye image. At last, this paper presents some experimental results, and the experimental results show that the maximal average error of the experimental apparatus is 15 pixels or 0.4 in degrees.

scholarly journals Extraction of Affine Invariant Features Using Fractal

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jianwei Yang ◽  
Guosheng Cheng ◽  
Ming Li
Keyword(s):  
Pattern Recognition ◽  
Feature Vector ◽  
Fractal Dimensions ◽  
Input Pattern ◽  
Experimental Results ◽  
Central Projection ◽  
Affine Invariant ◽  
Invariant Features ◽  
General Contour ◽  
New Feature

An approach based on fractal is presented for extracting affine invariant features. Central projection transformation is employed to reduce the dimensionality of the original input pattern, and general contour (GC) of the pattern is derived. Affine invariant features cannot be extracted from GC directly due to shearing. To address this problem, a group of curves (which are called shift curves) are constructed from the obtained GC. Fractal dimensions of these curves can readily be computed and constitute a new feature vector for the original pattern. The derived feature vector is used in question for pattern recognition. Several experiments have been conducted to evaluate the performance of the proposed method. Experimental results show that the proposed method can be used for object classification.

scholarly journals Accuracy Analysis of a 3D Model of Excavation, Created from Images Acquired with an Action Camera from Low Altitudes

2019 ◽  
Vol 8 (2) ◽  
pp. 83 ◽  
Author(s):  
Damian Wierzbicki ◽  
Marcin Nienaltowski
Keyword(s):  
Point Cloud ◽  
3D Model ◽  
Reference Model ◽  
Low Cost ◽  
Satellite System ◽  
Practical Aspect ◽  
Average Height ◽  
Digital Cameras ◽  
Aerial Photogrammetry ◽  
Dense Point

In the last few years, Unmanned Aerial Vehicles (UAVs) equipped with compact digital cameras, have become a cheap and efficient alternative to classic aerial photogrammetry and close-range photogrammetry. Low-altitude photogrammetry has great potential not only in the development of orthophoto maps but is also increasingly used in surveying and rapid mapping. This paper presents a practical aspect of the application of the custom homemade low-cost UAV, equipped with an action camera, to obtain images from low altitudes and develop a digital elevation model of the excavation. The conducted analyses examine the possibilities of using low-cost UAVs to deliver useful photogrammetric products. The experiments were carried out on a closed excavation in the town of Mince (north-eastern Poland). The flight over the examined area was carried out autonomously. A photogrammetric network was designed, and the reference areas in the mine were measured using the Global Navigation Satellite System-Real Time Kinematic (GNSS-RTK) method to perform accuracy analyses of the excavation 3D model. Representation of the created numerical terrain model was a dense point cloud. The average height difference between the generated dense point cloud and the reference model was within the range of 0.01–0.13 m. The difference between the volume of the excavation measured by the GNSS kinematic method and the volume measured on the basis of a dense point cloud was less than 1%. The obtained results show that the application of the low-cost UAV equipped with an action camera with a wide-angle lens, allows for obtaining high-accuracy images comparable to classic, compact digital cameras.

Time Discriminating Design for High Precision Pulsed TOF Laser Rangefinder

2011 ◽  
Vol 105-107 ◽  
pp. 1951-1956
Author(s):  
Dong Qing Shen ◽  
Jian Yong Chen ◽  
Wan Cai Li ◽  
Hong Jiang ◽  
Zhen Yu Li
Keyword(s):  
Experimental Evidence ◽  
High Precision ◽  
Input Signal ◽  
High Performance ◽  
Low Cost ◽  
Threshold Value ◽  
Experimental Results ◽  
Measuring System ◽  
Laser Rangefinder ◽  
Constant Fraction Discriminator

The purpose of a time discriminator is to decide when the input is something you are interested in. It does this by putting out a logic pulse when the input signal meets an adjustable threshold value. A low cost high performance constant fraction discriminator (CFD) for laser rangefinder using pulsed TOF (time of flight) is proposed with the accuracy been improved. The theory of CFD is deduced and discussed and a distance measuring system has been established and experimental evidence is presented to show the feasibility of solving the time walking error problem to amend the precision and improving the environmental applicability, the distance error of +/-0.5mm was observed in the lab condition. The advantages of this instrument are highlighted and the experimental results are presented.

scholarly journals TECHNICAL CONSIDERATIONS IN LOW-COST HERITAGE DOCUMENTATION

2019 ◽  
Vol XLII-2/W17 ◽  
pp. 225-232
Author(s):  
A. Murtiyoso ◽  
P. Grussenmeyer ◽  
D. Suwardhi
Keyword(s):  
Point Cloud ◽  
Low Cost ◽  
Bundle Adjustment ◽  
Ease Of Use ◽  
Cloud Data ◽  
Heritage Sites ◽  
Common Reference ◽  
Trade Offs ◽  
Dense Point

Abstract. The use of photogrammetry in 3D heritage documentation has matured over the recent years. In the same time, many types of sensors have also been developed in the field of imaging. While photogrammetry is considered as a low-cost alternative to TLS, several options exist in terms of sensor type with trade-offs between price, ease of use, and quality of resolution. Nevertheless, a proper knowledge on the acquisition and processing is still required to generate acceptable results. This paper aims to compare three photogrammetric sensors, namely a classical DSLR camera, a drone, and a spherical 360° camera in documenting heritage sites. Main comparison points include quality of the bundle adjustment and quality of the dense point cloud. However, an important point of the paper is also to determine whether a sensor at a given cost and effort is enough for documentation purposes. A TLS point cloud data was used as a common reference, as well as control and check points issued from geodetic surveying. In the aftermath of the comparison, several technical suggestions and recommendations were proposed as regards to the use of each sensor.

The Use of the Terrestrial Photogrammetry in Reverse Engineering Applications

3D Printing ◽  
2017 ◽  
pp. 241-250
Author(s):  
Naci Yastikli ◽  
Zehra Erisir ◽  
Pelin Altintas ◽  
Tugba Cak
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Low Cost ◽  
Line Drawing ◽  
Engineering Application ◽  
3D Models ◽  
Engineering Applications ◽  
Ship Model ◽  
Dense Point ◽  
Terrestrial Photogrammetry

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an existing product or a spare part, reproduction of an existing surface, elimination of the defect or improvement of the available product are the goals of industrial reverse engineering applications. The first and the most important step in reverse engineering applications is the generation of the three dimensional (3D) metric model of an existing product in computer environment. After this stage, many operations such as the preparation of molds for mass production, the performance testing, the comparison of the existing product with other products and prototypes which are available on the market are performed by using the generated 3D models. In reverse engineering applications, the laser scanner system or digital terrestrial photogrammetry methods, also called contactless method, are preferred for the generation of the 3D models. In particular, terrestrial photogrammetry has become a popular method since require only photographs for the 3-dimensional drawing, the generation of the dense point cloud using the image matching algorithms and the orthoimage generation as well as its low cost. In this paper, an industrial application of 3D information modelling is presented which concerns the measurement and 3D metric modelling of the ship model. The possible usage of terrestrial photogrammetry in reverse engineering application is investigated based on low cost photogrammetric system. The main aim was the generation of the dense point cloud and 3D line drawing of the ship model by using terrestrial photogrammetry, for the production of the ship in real size as a reverse engineering application. For this purpose, the images were recorded with digital SLR camera and orientations have been performed. Then 3D line drawing operations, point cloud and orthoimage generations have been accomplished by using PhotoModeler software. As a result of the proposed terrestrial photogrammetric steps, 0.5 mm spaced dense point cloud and orthoimage have been generated. The obtained results from experimental study were discussed and possible use of proposed methods was evaluated for reverse engineering application.

Error Compensation for Single Pair-Pole Encoder Based on Ellipse Hypothesis

2012 ◽  
Vol 591-593 ◽  
pp. 1231-1235 ◽  
Author(s):  
Yi Fan Zeng ◽  
Fang Fang Jiang
Keyword(s):  
High Precision ◽  
Error Compensation ◽  
Compensation Effect ◽  
Low Cost ◽  
Compensation Method ◽  
Experimental Results ◽  
Single Pair ◽  
Quadrature Error ◽  
The Common ◽  
Interference Error

An error compensation method for the single pair-pole encoder has been discussed in this paper. This article analyzed offset, sensitivity error, quadrature error and ferromagnetic interference error of single-pole magnetic encoder to obtain the expression of each error. In order to facilitate error compensation, the common expression for describing the error has been summed up. The process for formatting the error can be assumed as the process of changing from circle to ellipse. Therefore the inverse of this process is the same as the process of error compensation. The experimental results show that the accuracy of magnetic encoder which used this method could reach ±1, thus the error compensation effect is obvious. The magnetic encoder which applied this method has the advantages of low-cost, high-precision and convenient to use.

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