scholarly journals Image Based Modeling from Spherical Photogrammetry and Structure for Motion. The Case of the Treasury, Nabatean Architecture in Petra

2011 ◽  
Vol 6 ◽  
pp. 62-73 ◽  
Author(s):  
E. D’Annibale
Keyword(s):  
Web Service ◽  
Real Time ◽  
Ad Hoc ◽  
Low Cost ◽  
Point Clouds ◽  
Model Reconstruction ◽  
Interactive Approach ◽  
3D Model Reconstruction ◽  
Panoramic Images ◽  
Set Up

This research deals with an efficient and low cost methodology to obtain a metric and photorealstic survey of a complex architecture. Photomodeling is an already tested interactive approach to produce a detailed and quick 3D model reconstruction. Photomodeling goes along with the creation of a rough surface over which oriented images can be back-projected in real time. Lastly the model can be enhanced checking the coincidence between the surface and the projected texture. The challenge of this research is to combine the advantages of two technologies already set up and used in many projects: spherical photogrammetry (Fangi, 2007,2008,2009,2010) and structure for motion (Photosynth web service and Bundler + CMVS2 + PMVS2). The input images are taken from the same points of view to form the set of panoramic photos paying attention to use well-suited projections: equirectangular for spherical photogrammetry and rectilinear for Photosynth web service. The performance of the spherical photogrammetry is already known in terms of its metric accuracy and acquisition quickness but time is required in the restitution step because of the manual homologous point recognition from different panoramas. In Photosynth instead the restitution is quick and automated: the provided point clouds are useful benchmarks to start with the model reconstruction even if lacking in details and scale. The proposed workflow needs of ad-hoc tools to capture high resolution rectilinear panoramic images and visualize Photosynth point clouds and orientation camera parameters. All of them are developed in VVVV programming environment. 3DStudio Max environment is then chosen because of its performance in terms of interactive modeling, UV mapping parameters handling and real time visualization of projected texture on the model surface. Experimental results show how is possible to obtain a 3D photorealistic model using the scale of the spherical photogrammetry restitution to orient web provided point clouds. Moreover the proposed research highlights how is possible to speed up the model reconstruction without losing metric and photometric accuracy. In the same time, using the same panorama dataset, it picks out a useful chance to compare the orientations coming from the two mentioned technologies (Spherical Photogrammetry and Structure for Motion).

scholarly journals EVALUATION OF PHOTOGRAMMETRIC BLOCK ORIENTATION USING QUALITY DESCRIPTORS FROM STATISTICALLY FILTERED TIE POINTS

2018 ◽  
Vol XLII-2 ◽  
pp. 185-191 ◽  
Author(s):  
A. Calantropio ◽  
M. P. Deseilligny ◽  
F. Rinaudo ◽  
E. Rupnik
Keyword(s):  
Best Practices ◽  
Quality Assessment ◽  
Graphical User Interface ◽  
3D Model ◽  
Low Cost ◽  
Relative Orientation ◽  
Model Reconstruction ◽  
Future Directions ◽  
3D Model Reconstruction ◽  
Data Quality Assessment

Due to the increasing number of low-cost sensors, widely accessible on the market, and because of the supposed granted correctness of the semi-automatic workflow for 3D reconstruction, highly implemented in the recent commercial software, more and more users operate nowadays without following the rigorousness of classical photogrammetric methods. This behaviour often naively leads to 3D products that lacks metric quality assessment. This paper proposes and analyses an approach that gives the users the possibility to preserve the trustworthiness of the metric information inherent in the 3D model, without sacrificing the automation offered by modern photogrammetry software. At the beginning, the importance of Data Quality Assessment is outlined, together with some recall of photogrammetry best practices. With the purpose of guiding the user through a correct pipeline for a certified 3D model reconstruction, an operative workflow is proposed, focusing on the first part of the object reconstruction steps (tie-points extraction, camera calibration, and relative orientation). A new GUI (Graphical User Interface) developed for the open source MicMac suite is then presented, and a sample dataset is used for the evaluation of the photogrammetric block orientation using statistically obtained quality descriptors. The results and the future directions are then presented and discussed.

scholarly journals Open source modules for tracking animal behavior and closed-loop stimulation based on Open Ephys and Bonsai

2018 ◽  
Author(s):  
Alessio Paolo Buccino ◽  
Mikkel Elle Lepperød ◽  
Svenn-Arne Dragly ◽  
Philipp Häfliger ◽  
Marianne Fyhn ◽  
...  
Keyword(s):  
Open Source ◽  
Real Time ◽  
Closed Loop ◽  
Low Cost ◽  
Data Formats ◽  
Behavioral Tracking ◽  
Real Time Tracking ◽  
Set Up ◽  
And Behavior ◽  
Closed Loop Stimulation

AbstractObjectiveA major goal in systems neuroscience is to determine the causal relationship between neural activity and behavior. To this end, methods that combine monitoring neural activity, behavioral tracking, and targeted manipulation of neurons in closed-loop are powerful tools. However, commercial systems that allow these types of experiments are usually expensive and rely on non-standardized data formats and proprietary software which may hinder user-modifications for specific needs. In order to promote reproducibility and data-sharing in science, transparent software and standardized data formats are an advantage. Here, we present an open source, low-cost, adaptable, and easy to set-up system for combined behavioral tracking, electrophysiology and closed-loop stimulation.ApproachBased on the Open Ephys system (www.open-ephys.org) we developed multiple modules to include real-time tracking and behavior-based closed-loop stimulation. We describe the equipment and provide a step-by-step guide to set up the system. Combining the open source software Bonsai (bonsai-rx.org) for analyzing camera images in real time with the newly developed modules in Open Ephys, we acquire position information, visualize tracking, and perform tracking-based closed-loop stimulation experiments. To analyze the acquired data we provide an open source file reading package in Python.Main resultsThe system robustly visualizes real-time tracking and reliably recovers tracking information recorded from a range of sampling frequencies (30-1000Hz). We combined electrophysiology with the newly-developed tracking modules in Open Ephys to record place cell and grid cell activity in the hippocampus and in the medial entorhinal cortex, respectively. Moreover, we present a case in which we used the system for closed-loop optogenetic stimulation of entorhinal grid cells.SignificanceExpanding the Open Ephys system to include animal tracking and behavior-based closed-loop stimulation extends the availability of high-quality, low-cost experimental setup within standardized data formats serving the neuroscience community.

scholarly journals Real-time resource efficiency Indicators

atp magazin ◽  
2016 ◽  
Vol 58 ◽  
pp. 64 ◽  
Author(s):  
Marc Kalliski ◽  
Benedikt Beisheim ◽  
Daniel Krahè ◽  
Udo Enste ◽  
Stefan Krämer ◽  
...  
Keyword(s):  
Decision Support ◽  
Real Time ◽  
Ad Hoc ◽  
Resource Efficiency ◽  
Chemical Production ◽  
Material Efficiency ◽  
Production Processes ◽  
Set Up ◽  
Efficiency Indicators ◽  
Time Resource

Operational decisions in the day-to-day business of chemical production processes can have a significant impact on the energy and material efficiency. We propose to use real-time resource efficiency indicators (REI) to accurately monitor the energy and material efficiency in real-time and subsequently to use these in decision support for the operating staff. To guide industrial users during the development of REIs, a Namur ad-hoc working group (AK) Resource Efficiency Indicators for the operational use was set up to prepare a Namur Recommendation.

scholarly journals Assessing Low-Cost Terrestrial Laser Scanners for Deriving Forest Structure Parameters

2021 ◽  
Author(s):  
Atticus E. L. Stovall ◽  
Jeff W Atkins
Keyword(s):  
Structural Parameters ◽  
Low Cost ◽  
Laser Scanner ◽  
Point Clouds ◽  
Model Reconstruction ◽  
Tree Model ◽  
Factors Affecting ◽  
Laser Scanners ◽  
Tree Models ◽  
Profile Reconstruction

The increasingly affordable price point of terrestrial laser scanners has led to a democratization of instrument availability, but the most common low-cost instruments have yet to be compared in terms of the consistency to measure forest structural attributes. Here, we compared two low-cost terrestrial laser scanners (TLS): the Leica BLK360 and the Faro Focus 120 3D. We evaluate the instruments in terms of point cloud quality, forest inventory estimates, tree-model reconstruction, and foliage profile reconstruction. Our direct comparison of the point clouds showed reduced noise in filtered Leica data. Tree diameter and height were consistent across instruments (4.4% and 1.4% error, respectively). Volumetric tree models were less consistent across instruments, with ~29% bias, depending on model reconstruction quality. In the process of comparing foliage profiles, we conducted a sensitivity analysis of factors affecting foliage profile estimates, showing a minimal effect from instrument maximum range (for forests less than ~50 m in height) and surprisingly little impact from degraded scan resolution. Filtered unstructured TLS point clouds must be artificially re-gridded to provide accurate foliage profiles. The factors evaluated in this comparison point towards necessary considerations for future low-cost laser scanner development and application in detecting forest structural parameters.

scholarly journals IMAGE CAPTURE WITH SYNCHRONIZED MULTIPLE-CAMERAS FOR EXTRACTION OF ACCURATE GEOMETRIES

2016 ◽  
Vol XLI-B1 ◽  
pp. 653-660
Author(s):  
M. Koehl ◽  
T. Delacourt ◽  
C. Boutry
Keyword(s):  
Accuracy Assessment ◽  
Low Cost ◽  
Point Clouds ◽  
Image Capture ◽  
Multiple Sensors ◽  
Internal Parameters ◽  
Dense Point ◽  
Set Up ◽  
Major Factors ◽  
Fisheye Lenses

This paper presents a project of recording and modelling tunnels, traffic circles and roads from multiple sensors. The aim is the representation and the accurate 3D modelling of a selection of road infrastructures as dense point clouds in order to extract profiles and metrics from it. Indeed, these models will be used for the sizing of infrastructures in order to simulate exceptional convoy truck routes. The objective is to extract directly from the point clouds the heights, widths and lengths of bridges and tunnels, the diameter of gyrating and to highlight potential obstacles for a convoy. Light, mobile and fast acquisition approaches based on images and videos from a set of synchronized sensors have been tested in order to obtain useable point clouds. The presented solution is based on a combination of multiple low-cost cameras designed on an on-boarded device allowing dynamic captures. The experimental device containing <i>GoPro Hero4</i> cameras has been set up and used for tests in static or mobile acquisitions. That way, various configurations have been tested by using multiple synchronized cameras. These configurations are discussed in order to highlight the best operational configuration according to the shape of the acquired objects. As the precise calibration of each sensor and its optics are major factors in the process of creation of accurate dense point clouds, and in order to reach the best quality available from such cameras, the estimation of the internal parameters of fisheye lenses of the cameras has been processed. Reference measures were also realized by using a 3D TLS (<i>Faro Focus 3D</i>) to allow the accuracy assessment.

scholarly journals Explorations of A Real-Time VR Emotion Prediction System Using Wearable Brain-Computer Interfacing

2021 ◽  
Vol 2129 (1) ◽  
pp. 012064
Author(s):  
Nazmi Sofian Suhaimi ◽  
James Mountstephens ◽  
Jason Teo
Keyword(s):  
Real Time ◽  
Low Cost ◽  
External Noise ◽  
Prediction System ◽  
Emotion Classification ◽  
Signal Collection ◽  
Wearable Eeg ◽  
Set Up ◽  
Brain Computer Interfacing ◽  
The Brain

Abstract The following research describes the potential of using a four-class emotion classification using a four-channel wearable EEG headset combined with VR for evoking emotions from each individual. Multiple researchers have conducted and established emotion recognition by using a 2-D monitor screen for stimulus responses but this introduces artifacts such as the lack of concentration on-screen or external noise disturbance and the bulky and cumbersome wires on an EEG device were difficult and time-consuming to set up thus restricting to only the trained professionals to operate this complex and sensitive medical equipment. Therefore, using a small and portable EEG headset where it was accessible for consumers was used for the brainwave signal collection. The wearable EEG headset collects the brainwave samples at 256Hz at specific locations of the brain (Tp9, Tp10, AF7, AF8) and samples were transformed via FFT to obtain the five bands (Delta, Theta, Alpha, Beta, Gamma) and were classified using random forest classifier. An emotion prediction system was then developed and the trained model was used to benchmark the 4-class emotion prediction accuracy from each individual using a 4-channel low-cost EEG headset. Subsequently, a real-time prediction system was implemented and tested. Early findings showed that it could achieve predictions as high as 76.50% for intra-subject classification results.

scholarly journals GENERATION OF INDOOR POINT CLOUDS EXPLOITING GEOMETRIC SYMMETRIES AND REGULARITIES

2021 ◽  
Vol XLVI-M-1-2021 ◽  
pp. 435-440
Author(s):  
A. Masiero ◽  
A. Guarnieri ◽  
G. Tucci ◽  
A. Vettore
Keyword(s):  
Laser Scanning ◽  
Ad Hoc ◽  
Inertial Sensors ◽  
Low Cost ◽  
Point Clouds ◽  
Satellite System ◽  
Mobile Mapping ◽  
Suitable Alternative ◽  
Planar Surfaces ◽  
Mapping System

Abstract. 3D building modeling is becoming an important support in civil engineering, architecture and cultural heritage applications. Despite static laser scanning can be considered as the state-of-the-art in such kind of applications, mobile mapping techniques can be considered as a suitable alternative to quickly gather geospatial information. Outdoor mobile mapping can be considered as a mature technique, which takes into advantage of the Global Navigation Satellite System (GNSS)-laser scanning information fusion. Instead, indoor mobile mapping is typically more challenging: the unavailability of GNSS makes the mapping system rely either just on the inertial navigation system, or on some control points. A drift in the navigation solution, and consequently in the 3D reconstruction, is typically visible after a while in the former case, whereas the use of other surveying instruments is required in the latter.This work aims at exploiting geometric characteristics of the buildings, such as symmetries and regularities, to reduce the drift effect in indoor mobile mapping, in particular when dealing with affordable systems. The proposed approach is based on the segmentation of the point clouds acquired with a time of flight camera (ToF), detecting in particular vertical planar surfaces. It is well known that aligning planar surfaces can be a viable way for reducing the drift in this kind of applications. Nevertheless, this paper aims also at investigating the use of geometric symmetries to such aim.The proposed approach is tested on a case study, a building of the University of Padova, whose reconstruction was produced by an ad hoc affordable mobile mapping system, integrating low cost inertial sensors, RGB and ToF camera.

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.

Low Cost and Centimeter-Level Global Positioning System Accuracy Using Real-Time Kinematic Library and Real-Time Kinematic GPSA

2019 ◽  
Vol 12 ◽  
Author(s):  
Hemant Kumar Gianey ◽  
Mumtaz Ali ◽  
V. Vijayakumar ◽  
Ashutosh Sharma ◽  
Rajiv Kumar
Keyword(s):  
Real Time ◽  
Global Positioning System ◽  
Low Cost ◽  
Base Station ◽  
Real Time Kinematic ◽  
Global Positioning ◽  
Rtk Gps ◽  
Set Up ◽  
Gps Accuracy ◽  
Gps System

Accuracy and total design and implementation cost of the GPS framework determine the viability of GPS based projects. As the greater part of the advanced framework including telemetry, IoT, Cloud, and AUTOSAR frameworks use GPS to get exact outcomes, finding a software-controlled error correction becomes important. With the execution of open source library such as RTKLIB will help in controlling and revising GPS blunders. The project utilizes the RTKLIB along with two stations for better accuracy. The RTK-GPS framework works under Linux environment, which is embedded in the Beagleboard. The communication between the GPS system is set up utilizing both serial communication protocol and TCP/IP suite. To get high precision inside the network, two GPS modules are utilized. One of them will be mounted on the rover and another GPS is the base station of the setup. Both the GPS will have a double radio wire setup to increase the reception level to reduce the noise and get centimeter-level precision. For long-range communication, Rover utilizes Wi-Fi with TCP/IP stack protocol. In this research paper, setup is intended to accomplish the centimeter level precision through libraries in a Linux environment. The design will be set up and tried on a college campus under various conditions with different error parameters to acquire a low cost and centimeter level GPS accuracy.

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