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Changes in technology are coming at an ever increasing pace. This holds for photogrammetry and remote sensing as well. “Everything moves” – this is why I chose this topic to shed some light on some of the recent developments. Naturally, this undertaking can never be complete in the sense of covering all developments in Photogrammetry and Remote Sensing. Besides, the impact of Deep Learning in photogrammetry is not mentioned in this paper. This is a very personal account. People may not agree with some of my findings, but this is in the nature of science. In any case, this contribution is meant as a tribute to Gottfried’s successful lifelong work. It is not a scientific paper in the traditional sense but rather a collection of thoughts that emerged over the 50 years of my professional career. It is also meant for an audience who has not necessarily a deep photogrammetric expert know-how.
Armin Gruen. Everything moves: The rapid changes in photogrammetry and remote sensing. Geo-spatial Information Science 2021, 24, 33 -49.
AMA StyleArmin Gruen. Everything moves: The rapid changes in photogrammetry and remote sensing. Geo-spatial Information Science. 2021; 24 (1):33-49.
Chicago/Turabian StyleArmin Gruen. 2021. "Everything moves: The rapid changes in photogrammetry and remote sensing." Geo-spatial Information Science 24, no. 1: 33-49.
The latest advances in technical characteristics of unmanned aerial systems (UAS) and their onboard sensors opened the way for smart flying vehicles exploiting new application areas and allowing to perform missions seemed to be impossible before. One of these complicated tasks is the 3D reconstruction and monitoring of large-size, complex, grid-like structures as radio or television towers. Although image-based 3D survey contains a lot of visual and geometrical information useful for making preliminary conclusions on construction health, standard photogrammetric processing fails to perform dense and robust 3D reconstruction of complex large-size mesh structures. The main problem of such objects is repeated and self-occlusive similar elements resulting in false feature matching. This paper presents a method developed for an accurate Multi-View Stereo (MVS) dense 3D reconstruction of the Shukhov Radio Tower in Moscow (Russia) based on UAS photogrammetric survey. A key element for the successful image-based 3D reconstruction is the developed WireNetV2 neural network model for robust automatic semantic segmentation of wire structures. The proposed neural network provides high matching quality due to an accurate masking of the tower elements. The main contributions of the paper are: (1) a deep learning WireNetV2 convolutional neural network model that outperforms the state-of-the-art results of semantic segmentation on a dataset containing images of grid structures of complicated topology with repeated elements, holes, self-occlusions, thus providing robust grid structure masking and, as a result, accurate 3D reconstruction, (2) an advanced image-based pipeline aided by a neural network for the accurate 3D reconstruction of the large-size and complex grid structured, evaluated on UAS imagery of Shukhov radio tower in Moscow.
Vladimir Knyaz; Vladimir Kniaz; Fabio Remondino; Sergey Zheltov; Armin Gruen. 3D Reconstruction of a Complex Grid Structure Combining UAS Images and Deep Learning. Remote Sensing 2020, 12, 3128 .
AMA StyleVladimir Knyaz, Vladimir Kniaz, Fabio Remondino, Sergey Zheltov, Armin Gruen. 3D Reconstruction of a Complex Grid Structure Combining UAS Images and Deep Learning. Remote Sensing. 2020; 12 (19):3128.
Chicago/Turabian StyleVladimir Knyaz; Vladimir Kniaz; Fabio Remondino; Sergey Zheltov; Armin Gruen. 2020. "3D Reconstruction of a Complex Grid Structure Combining UAS Images and Deep Learning." Remote Sensing 12, no. 19: 3128.
Underwater photogrammetry is increasingly being used by marine ecologists because of its ability to produce accurate, spatially detailed, non-destructive measurements of benthic communities, coupled with affordability and ease of use. However, independent quality control, rigorous imaging system set-up, optimal geometry design and a strict modeling of the imaging process are essential to achieving a high degree of measurable accuracy and resolution. If a proper photogrammetric approach that enables the formal description of the propagation of measurement error and modeling uncertainties is not undertaken, statements regarding the statistical significance of the results are limited. In this paper, we tackle these critical topics, based on the experience gained in the Moorea Island Digital Ecosystem Avatar (IDEA) project, where we have developed a rigorous underwater photogrammetric pipeline for coral reef monitoring and change detection. Here, we discuss the need for a permanent, underwater geodetic network, which serves to define a temporally stable reference datum and a check for the time series of photogrammetrically derived three-dimensional (3D) models of the reef structure. We present a methodology to evaluate the suitability of several underwater camera systems for photogrammetric and multi-temporal monitoring purposes and stress the importance of camera network geometry to minimize the deformations of photogrammetrically derived 3D reef models. Finally, we incorporate the measurement and modeling uncertainties of the full photogrammetric process into a simple and flexible framework for detecting statistically significant changes among a time series of models.
Erica Nocerino; Fabio Menna; Armin Gruen; Matthias Troyer; Alessandro Capra; Cristina Castagnetti; Paolo Rossi; Andrew Brooks; Russell Schmitt; Sally Holbrook. Coral Reef Monitoring by Scuba Divers Using Underwater Photogrammetry and Geodetic Surveying. Remote Sensing 2020, 12, 3036 .
AMA StyleErica Nocerino, Fabio Menna, Armin Gruen, Matthias Troyer, Alessandro Capra, Cristina Castagnetti, Paolo Rossi, Andrew Brooks, Russell Schmitt, Sally Holbrook. Coral Reef Monitoring by Scuba Divers Using Underwater Photogrammetry and Geodetic Surveying. Remote Sensing. 2020; 12 (18):3036.
Chicago/Turabian StyleErica Nocerino; Fabio Menna; Armin Gruen; Matthias Troyer; Alessandro Capra; Cristina Castagnetti; Paolo Rossi; Andrew Brooks; Russell Schmitt; Sally Holbrook. 2020. "Coral Reef Monitoring by Scuba Divers Using Underwater Photogrammetry and Geodetic Surveying." Remote Sensing 12, no. 18: 3036.
As a continuation of Ice, Cloud, and Land Elevation Satellite-1 (ICESat-1), the ICESat-2/Advanced Topographic Laser Altimeter System (ATLAS) employs a micro-pulse multi-beam photon counting approach to produce photon data for measuring global terrain. Few studies have assessed the accuracy of different ATLAS channels in retrieving ground topography in forested terrain. This study aims to assess the accuracy of measuring ground topography in forested terrain using different ATLAS channels and the correlation between laser intensity parameters, laser pointing angle parameters, and elevation error. The accuracy of ground topography measured by the ATLAS footprints is evaluated by comparing the derived Digital Terrain Model (DTM) from the ATL03 (Global Geolocated Photon Data) and ATL08 (Land and Vegetation Height) products with that from the airborne Light Detection And Ranging (LiDAR). Results show that the ATLAS product performed well in the study area at all laser intensities and laser pointing angles, and correlations were found between the ATLAS DTM and airborne LiDAR DTM (coefficient of determination––R2 = 1.00, root mean squared error––RMSE = 0.75 m). Considering different laser intensities, there is a significant correlation between the tx_pulse_energy parameter and elevation error. With different laser pointing angles, there is no significant correlation between the tx_pulse_skew_est, tx_pulse_width_lower, tx_pulse_width_upper parameters and the elevation error.
Yanqiu Xing; Jiapeng Huang; Armin Gruen; Lei Qin. Assessing the Performance of ICESat-2/ATLAS Multi-Channel Photon Data for Estimating Ground Topography in Forested Terrain. Remote Sensing 2020, 12, 2084 .
AMA StyleYanqiu Xing, Jiapeng Huang, Armin Gruen, Lei Qin. Assessing the Performance of ICESat-2/ATLAS Multi-Channel Photon Data for Estimating Ground Topography in Forested Terrain. Remote Sensing. 2020; 12 (13):2084.
Chicago/Turabian StyleYanqiu Xing; Jiapeng Huang; Armin Gruen; Lei Qin. 2020. "Assessing the Performance of ICESat-2/ATLAS Multi-Channel Photon Data for Estimating Ground Topography in Forested Terrain." Remote Sensing 12, no. 13: 2084.
Openings such as windows and doors are essential components of architectural wall surfaces. It is still a challenge to reconstruct them robustly from unstructured 3D point clouds because of occlusions, noises and non-uniformly distributed points. Current research primarily focuses on meliorating the robustness of detection and pays little attention to the geometric correctness. To improve the reconstruction quality, assumptions on the opening layout are usually applied as rules to support the reconstruction algorithm. The commonly used assumptions, such as the strict grid and symmetry pattern, however, are not suitable in many cases. In this paper, we propose a novel approach, named an inference machine, to identify and use flexible rules in wall opening modelling. Our method first detects and models openings through a data-driven method and then refines the opening boundaries by global and flexible rules. The key is to identify the global flexible rules from the detected openings, composed by various combinations of alignments. As our method is oblivious of the type of architectural layout, it can be applied to both interior wall surfaces and exterior building facades. We demonstrate the flexibility of our approach in both outdoor and indoor scenes with a variety of opening layouts. The qualitative and quantitative evaluation results indicate the potential of the approach to be a general method in opening detection and modelling. However, this data-driven method suffers from the existence of occlusions and non-planar wall surfaces.
Jiaqiang Li; Biao Xiong; Rongjun Qin; Armin Gruen. A Flexible Inference Machine for Global Alignment of Wall Openings. Remote Sensing 2020, 12, 1968 .
AMA StyleJiaqiang Li, Biao Xiong, Rongjun Qin, Armin Gruen. A Flexible Inference Machine for Global Alignment of Wall Openings. Remote Sensing. 2020; 12 (12):1968.
Chicago/Turabian StyleJiaqiang Li; Biao Xiong; Rongjun Qin; Armin Gruen. 2020. "A Flexible Inference Machine for Global Alignment of Wall Openings." Remote Sensing 12, no. 12: 1968.
Forest agencies give special attention to forest fires where post-disaster loss can rarely be gauged in a quick and economic way unless an appropriate technology is adopted. Determination of the planimetric and volumetric changes between pre- and post-fire is in high demand. The FORSAT system (a satellite processing platform for high resolution forest assessment) was developed to meet the relevant demands. It has the capability of extracting of 3D geometric information from the very-high resolution (VHR) imagery from satellite optical sensors and automatic 3D change detection. FORSAT includes two main units. The first one is dedicated to the geometric and radiometric processing of satellite optical imagery and 2D/3D information extraction. This includes: image radiometric pre-processing, image and ground point measurement, improvement of geometric sensor orientation, quasi-epipolar image generation for stereo measurements, digital surface model (DSM) extraction by using a precise and robust image matching approach specially designed for VHR satellite imagery, generation of orthoimages, and 3D measurements in single images using mono-plotting and in stereo images. FORSAT supports most of the VHR optically imagery commonly used for civil applications: IKONOS, OrbView – 3, SPOT – 5 HRS, SPOT – 5 HRG, QuickBird, GeoEye-1, WorldView-1/2, Pléiades 1A/1B, SPOT 6/7. The second unit of FORSAT is dedicated to 3D surface comparison for change detection. It allows users to import DSMs, to co-register them using an advanced 3D surface matching approach and to calculate the planimetric and volumetric changes between epochs. The capacity and benefits of FORSAT have been tested in two real cases, where are burned areas located in Cyprus and Austria. The geometric characteristics of burned forest areas have been identified both in 2D plane and 3D volume dimensions, using pre- and post-fire optical data from different sensors. FORSAT is a single source and flexible forest information solution, allowing expert and non-expert remote sensing users to monitor forests in three and four dimensions from VHR optical imagery for many forest information needs.
D. Akca; E. Stylianidis; D. Poli; A. Gruen; O Altan; M. Hofer; K. Smagas; V. Sanchez Martin; A. Walli; E. Jimeno; A. Garcia. 3-DIMENSIONAL PRE- AND POST-FIRE COMPARISON OF FOREST AREAS. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2018, XLII-3/W4, 9 -16.
AMA StyleD. Akca, E. Stylianidis, D. Poli, A. Gruen, O Altan, M. Hofer, K. Smagas, V. Sanchez Martin, A. Walli, E. Jimeno, A. Garcia. 3-DIMENSIONAL PRE- AND POST-FIRE COMPARISON OF FOREST AREAS. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2018; XLII-3/W4 ():9-16.
Chicago/Turabian StyleD. Akca; E. Stylianidis; D. Poli; A. Gruen; O Altan; M. Hofer; K. Smagas; V. Sanchez Martin; A. Walli; E. Jimeno; A. Garcia. 2018. "3-DIMENSIONAL PRE- AND POST-FIRE COMPARISON OF FOREST AREAS." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W4, no. : 9-16.
Quick and economical ways of detecting of planimetric and volumetric changes of forest areas are in high demand. A research platform, called FORSAT (A satellite processing platform for high resolution forest assessment), was developed for the extraction of 3D geometric information from VHR (very-high resolution) imagery from satellite optical sensors and automatic change detection. This 3D forest information solution was developed during a Eurostars project. FORSAT includes two main units. The first one is dedicated to the geometric and radiometric processing of satellite optical imagery and 2D/3D information extraction. This includes: image radiometric pre-processing, image and ground point measurement, improvement of geometric sensor orientation, quasiepipolar image generation for stereo measurements, digital surface model (DSM) extraction by using a precise and robust image matching approach specially designed for VHR satellite imagery, generation of orthoimages, and 3D measurements in single images using mono-plotting and in stereo images as well as triplets. FORSAT supports most of the VHR optically imagery commonly used for civil applications: IKONOS, OrbView – 3, SPOT – 5 HRS, SPOT – 5 HRG, QuickBird, GeoEye-1, WorldView-1/2, Pléiades 1A/1B, SPOT 6/7, and sensors of similar type to be expected in the future. The second unit of FORSAT is dedicated to 3D surface comparison for change detection. It allows users to import digital elevation models (DEMs), align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes between epochs. To this end our 3D surface matching method LS3D is being used. FORSAT is a single source and flexible forest information solution with a very competitive price/quality ratio, allowing expert and non-expert remote sensing users to monitor forests in three and four dimensions from VHR optical imagery for many forest information needs. The capacity and benefits of FORSAT have been tested in six case studies located in Austria, Cyprus, Spain, Switzerland and Turkey, using optical data from different sensors and with the purpose to monitor forest with different geometric characteristics. The validation run on Cyprus dataset is reported and commented.
Devrim Akca; Efstratios Stylianidis; Konstantinos Smagas; Martin Hofer; Daniela Poli; Armin Gruen; Victor Sanchez Martin; Orhan Altan; Andreas Walli; Elisa Jimeno; Alejandro Garcia. VOLUMETRIC FOREST CHANGE DETECTION THROUGH VHR SATELLITE IMAGERY. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2016, XLI-B8, 1213 -1220.
AMA StyleDevrim Akca, Efstratios Stylianidis, Konstantinos Smagas, Martin Hofer, Daniela Poli, Armin Gruen, Victor Sanchez Martin, Orhan Altan, Andreas Walli, Elisa Jimeno, Alejandro Garcia. VOLUMETRIC FOREST CHANGE DETECTION THROUGH VHR SATELLITE IMAGERY. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2016; XLI-B8 ():1213-1220.
Chicago/Turabian StyleDevrim Akca; Efstratios Stylianidis; Konstantinos Smagas; Martin Hofer; Daniela Poli; Armin Gruen; Victor Sanchez Martin; Orhan Altan; Andreas Walli; Elisa Jimeno; Alejandro Garcia. 2016. "VOLUMETRIC FOREST CHANGE DETECTION THROUGH VHR SATELLITE IMAGERY." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8, no. : 1213-1220.
Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.
T. Guo; A. Capra; M. Troyer; A. Gruen; A. J. Brooks; J. L. Hench; R. J. Schmitt; S. J. Holbrook; M. Dubbini. ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2016, XLI-B5, 821 -828.
AMA StyleT. Guo, A. Capra, M. Troyer, A. Gruen, A. J. Brooks, J. L. Hench, R. J. Schmitt, S. J. Holbrook, M. Dubbini. ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2016; XLI-B5 ():821-828.
Chicago/Turabian StyleT. Guo; A. Capra; M. Troyer; A. Gruen; A. J. Brooks; J. L. Hench; R. J. Schmitt; S. J. Holbrook; M. Dubbini. 2016. "ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5, no. : 821-828.
Both unmanned aerial vehicle (UAV) technology and Mobile Mapping Systems (MMS) are important techniques for surveying and mapping. In recent years, the UAV technology has seen tremendous interest, both in the mapping community and in many other fields of application. Carrying off-the shelf digital cameras, the UAV can collect high quality aerial optical images for city modeling using photogrammetric techniques. In addition, a MMS can acquire high density point clouds of ground objects along the roads. The UAV, if operated in an aerial mode, has difficulties in acquiring information of ground objects under the trees and along façades of buildings. On the contrary, the MMS collects accurate point clouds of objects from the ground, together with stereo images, but it suffers from system errors due to loss of GPS signals, and also lacks the information of the roofs. Therefore, both technologies are complementary. This paper focuses on the integration of UAV images, MMS point cloud data and terrestrial images to build very high resolution 3D city models. The work we will show is a practical modeling project of the National University of Singapore (NUS) campus, which includes buildings, some of them very high, roads and other man-made objects, dense tropical vegetation and DTM. This is an intermediate report. We present work in progress.
A. Gruen; X. Huang; R. Qin; T. Du; W. Fang; J. Boavida; A. Oliveira. JOINT PROCESSING OF UAV IMAGERY AND TERRESTRIAL MOBILE MAPPING SYSTEM DATA FOR VERY HIGH RESOLUTION CITY MODELING. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2013, XL-1/W2, 175 -182.
AMA StyleA. Gruen, X. Huang, R. Qin, T. Du, W. Fang, J. Boavida, A. Oliveira. JOINT PROCESSING OF UAV IMAGERY AND TERRESTRIAL MOBILE MAPPING SYSTEM DATA FOR VERY HIGH RESOLUTION CITY MODELING. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2013; XL-1/W2 ():175-182.
Chicago/Turabian StyleA. Gruen; X. Huang; R. Qin; T. Du; W. Fang; J. Boavida; A. Oliveira. 2013. "JOINT PROCESSING OF UAV IMAGERY AND TERRESTRIAL MOBILE MAPPING SYSTEM DATA FOR VERY HIGH RESOLUTION CITY MODELING." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1/W2, no. : 175-182.
With digital globes like Google Earth or Microsoft Bing Maps the access to virtual, geo-referenced 3D data has become considerably easier and these sources of information are now frequently used by a worldwide audience. The underlying technologies in sensors and data processing have strongly influenced many disciplines and have led in many cases to completely novel as to how the work is conducted, with new possibilities for improved data acquisition, processing, analysis, representation, and dissemination. Archaeology and cultural heritage are definitely among those fields that have drawn many advantages from this situation. Advanced 3D modelling of landscapes, sites, single architectures, statues, findings, and artefacts have given the experts in the field and office new tools for better analysis and interpretation of processes, developments, and relations. This article, after a brief review of the currently available sensor technology and an introduction to the photogrammetric data acquisition and processing procedures, will show how this technology works and what kind of products can be generated. We will touch upon the use of satellite, aerial, and terrestrial images, but also address laser scanning and structured light systems. The use of different imaging sensors in the case of the recording of large sites will be shown, presenting results from our Bamiyan, Afghanistan project. With our Tucume, Peru project we will demonstrate how we can go back in time using image-based techniques. With different examples of terrestrial applications we emphasize the wide variety of available sensors and applications.
Armin Gruen. Reality-Based Virtual Models in Cultural Heritage. Authenticity in Architectural Heritage Conservation 2013, 109 -126.
AMA StyleArmin Gruen. Reality-Based Virtual Models in Cultural Heritage. Authenticity in Architectural Heritage Conservation. 2013; ():109-126.
Chicago/Turabian StyleArmin Gruen. 2013. "Reality-Based Virtual Models in Cultural Heritage." Authenticity in Architectural Heritage Conservation , no. : 109-126.
The article describes the 3D surveying and modeling of the Behaim globe, the oldest still existing and intact globe of the earth, preserved at the German National Museum of Nuremberg, Germany. The work is primarily performed using high-resolution digital images and automatic photogrammetric techniques. Triangulation-based laser scanning is also employed to fill some gaps in the derived image-based 3D geometry and perform geometric comparisons. Major problems are encountered in texture mapping. The 3D modeling project and the creation of high-resolution map-projections is performed for scientific, conservation, visualization and education purposes.
Fabio Menna; A. Rizzi; Erica Nocerino; F. Remondino; A. Gruen. \\HIGH RESOLUTION 3D MODELING OF THE BEHAIM GLOBE. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2012, XXXIX-B5, 115 -120.
AMA StyleFabio Menna, A. Rizzi, Erica Nocerino, F. Remondino, A. Gruen. \\HIGH RESOLUTION 3D MODELING OF THE BEHAIM GLOBE. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2012; XXXIX-B5 ():115-120.
Chicago/Turabian StyleFabio Menna; A. Rizzi; Erica Nocerino; F. Remondino; A. Gruen. 2012. "\\HIGH RESOLUTION 3D MODELING OF THE BEHAIM GLOBE." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXIX-B5, no. : 115-120.
The Buddhist fortress Drapham Dzong is located in the Bumthang District in central Bhutan on a mountain ridge at approximately 2930 m altitude. A surveying mission was carried out with the goal to produce a textured 3D model of the site, together with a conventional 2D map and an orthophoto. The remote and exposed location of the site makes traditional surveying, including terrestrial laser-scanning a tedious undertaking. Aerial images of reasonable quality are not available in Bhutan. Satellite images, even of very high resolution (50 cm footprint) do not show sufficient detail for the modelling of the man-made structures. Therefore this project leads itself very well to the use of an appropriate UAV. This paper describes briefly the raw data acquisition by UAV and terrestrial images, and then focuses on the procedures for data processing. The 3D model of the man-made objects is embedded into a large area model of the environment, generated from a GeoEye-1 stereo model. Overall, the project is a typical example of a multi-image concept, making use of imagery of quite different resolutions (satellite, UAV, terrestrial). Given a textured accurate 3D model, 2D maps and orthoimages are nothing but derivatives of this general product. The project also shows how lightweight equipment can be used in remote and not easily accessible areas for surveying and 3D modelling purposes.
A. Gruen; Z. Zhang; H. Eisenbeiss. UAV PHOTOGRAMMETRY IN REMOTE AREAS – 3D MODELING OF DRAPHAM DZONG BHUTAN. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2012, XXXIX-B1, 375 -379.
AMA StyleA. Gruen, Z. Zhang, H. Eisenbeiss. UAV PHOTOGRAMMETRY IN REMOTE AREAS – 3D MODELING OF DRAPHAM DZONG BHUTAN. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2012; XXXIX-B1 ():375-379.
Chicago/Turabian StyleA. Gruen; Z. Zhang; H. Eisenbeiss. 2012. "UAV PHOTOGRAMMETRY IN REMOTE AREAS – 3D MODELING OF DRAPHAM DZONG BHUTAN." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXIX-B1, no. : 375-379.
Image and template matching is probably the most important function in digital photogrammetry and also in automated modelling and mapping. Many approaches for matching have evolved over the years, but the problem is still unsolved in general terms. This paper describes the development of image matching techniques in photogrammetry over the past 50 years, addresses the results of some empirical accuracy studies and also provides a critical account of some of the problems that remain.Although automated approaches have quite a number of advantages, the quality of the results is still not satisfactory and, in some cases, far from acceptable. Even with the most advanced techniques, it is not yet possible to achieve the quality of results that a human operator can produce. There is an urgent need for further improvements and innovations, be it through more powerful multi‐sensor approaches, thereby enlarging the information spectrum, and/or through advancements in image understanding algorithms, thus coming closer to human capabilities of reading and understanding image content. L’appariement d’images et de formes est sans doute l’opération la plus importante en photogrammétrie numérique et en modélisation et cartographie automatiques. De nombreuses approches se sont succédé depuis des années mais le problème n’est toujours pas totalement résolu. Cet article décrit le développement des techniques d’appariement d’images en photogrammetrie pendant les 50 dernières années, présente les résultats obtenus dans quelques études de précision empiriques, et dresse un bilan critique des problèmes qui subsistent. Bien que les approches automatiques aient un grand nombre d’avantages, la qualité des résultats n’est toujours pas satisfaisante, et même loin d’être acceptable dans certains cas. Même avec les techniques les plus avancées, nous sommes toujours dans l’incapacité d’atteindre la qualité des résultats obtenus par un opérateur humain. Il y a un besoin urgent d’améliorations et d’innovations, soit à travers des approches multi‐capteurs plus puissantes et consistant àélargir le spectre d’information, soit à travers une amélioration des algorithmes de compréhension d’images visant à les rendre plus proches des possibilités humaines de lecture et de compréhension du contenu des images. Bild‐ und Musterkorrelation gehören zu den wichtigsten Grundfunktionen der Digitalen Photogrammetrie und somit auch der automatischen 3D Modellierung und Kartierung. Viele Ansätze zur Korrelation wurden über die Jahre entwickelt, aber das Problem gilt grundsätzlich noch immer als ungelöst. Dieser Beitrag beschreibt die Entwicklung der Verfahren der Bildkorrelation in der Photogrammetrie über die letzten 50 Jahre, verweist auf die Ergebnisse einiger empirischer Genauigkeitsstudien und diskutiert einige der immer noch bestehenden Probleme.Obwohl automatische Verfahren eine ganze Reihe von Vorteilen aufweisen, ist doch die Qualität der Ergebnisse meist nicht ausreichend, teilweise ja sogar weit entfernt von jeglicher Akzeptanz. Selbst mit den höchstentwickelten Verfahren sind wir immer noch nicht in der Lage, die Qualität der Ergebnisse eines menschlichen Operateurs zu erreichen. Wir benötigen dringend weitere Verbesserungen und Innovationen. Dazu gibt es gegenwärtig zwei grundsätzlich gangbare Wege: (a) Nutzung von Multi‐Sensor Informationen und somit Erweiterung der Informationsgrundlagen und/oder (b) durch Fortschritte bei den Algorithmen des Bildverstehens und somit besserer Modellierung des menschlichen Prozesses des Bildverstehens. La correspondencia de imágenes y muestras es, probablemente, la función más importante en la fotogrametría digital, en el modelado 3D y en la cartografía automática. Muchos métodos de correspondencia han evolucionado a lo largo de los años pero, en términos generales, el problema se considera aún no resuelto completamente. Este artículo describe la evolución de las técnicas de correspondencia de imágenes en la fotogrametría a lo largo de los últimos 50 años, analiza los resultados de algunos estudios empíricos de la exactitud, y ofrece una valoración crítica de los problemas aún sin resolver. Aunque los métodos automáticos poseen un gran número de ventajas, la calidad de los resultados no es todavía satisfactoria y, en algunos casos, incluso está lejos de ser aceptable. Incluso con las más avanzadas técnicas no somos capaces de lograr la calidad de los resultados que un operador humano puede conseguir. Hay una necesidad urgente de continuar las mejoras e innovaciones, ya sea mediante la utilización de múltiples sensores que incrementen el espectro de la información, o por avances en los algoritmos de comprensión de la imagen que permitan acercarnos más a la capacidad humana de lectura e interpretación de su contenido.
Armin Gruen. Development and Status of Image Matching in Photogrammetry. The Photogrammetric Record 2012, 27, 36 -57.
AMA StyleArmin Gruen. Development and Status of Image Matching in Photogrammetry. The Photogrammetric Record. 2012; 27 (137):36-57.
Chicago/Turabian StyleArmin Gruen. 2012. "Development and Status of Image Matching in Photogrammetry." The Photogrammetric Record 27, no. 137: 36-57.
This paper contains two main parts. First, we give an overview of photogrammetric and remote sensing techniques in applications related to disaster management procedures. Remotely sensed data potentially provide valuable seismicity-related data in terms of both assessing the potential of risk and defining the state of vulnerability. The paper illustrates the use of advanced remote sensing technologies and methods for urban inventory and damage assessment. Second, we explain our proposed method for automatic damage assessment using multi view aerial images. We document the use of a novel methodology for assessing the damages of man-made objects. The problem is formulated in general, and for validation the approach is applied to a study area. This area is a part of the city of Bam, Iran that was hit by a strong earthquake on 26 December 2003. For our purpose digital surface models (DSMs) were created automatically from pre- and post-earthquake aerial images. We have explored the use of different kinds of extracted features, defined in both object and image spaces. This method utilises a methodology of applying Bayesian networks to a multi-view and multi-modal damaged objects description. By comparing pre- and post-earthquake data the amount of damage can be assessed. Based on visual inspection of the stereo images, three levels of damage (total collapse, partial collapse, no damage) were considered. The overall success rate – total number of correctly classified objects divided by the total number of samples – was found to be 80.7%. The results of the analysis show that a good degree of agreement has been reached between the assessment results and the reference data. The suggested approach is promising, but there is room for improvement.
Mehdi Rezaeian; Armin Gruen. Automatic 3D building extraction from aerial and space images for earthquake risk management. Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards 2011, 5, 77 -96.
AMA StyleMehdi Rezaeian, Armin Gruen. Automatic 3D building extraction from aerial and space images for earthquake risk management. Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards. 2011; 5 (1):77-96.
Chicago/Turabian StyleMehdi Rezaeian; Armin Gruen. 2011. "Automatic 3D building extraction from aerial and space images for earthquake risk management." Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards 5, no. 1: 77-96.
Three‐dimensional building models are often now produced from lidar and photogrammetric data. The quality control of these models is a relevant issue both from the scientific and practical points of view. This work presents a method for the quality control of such models. The input model (3D building data) is co‐registered to the verification data using a 3D surface matching method. The 3D surface matching evaluates the Euclidean distances between the verification and input data‐sets. The Euclidean distances give appropriate metrics for the 3D model quality. This metric is independent of the method of data capture. The proposed method can favourably address the reference system accuracy, positional accuracy and completeness. Three practical examples of the method are provided for demonstration. De nos jours, les modèles de bâtiments en 3D sont très souvent produits à partir de données lidar et photogrammétriques. Le contrôle de qualité de ces modèles est une question pertinente, autant d’un point de vue scientifique que pratique. Cette étude présente une méthode de contrôle de qualité pour ce type de modèle. Le modèle en entrée (représentant les bâtiments en 3D) est apparié aux données de vérification grâce à une méthode d’appariement de surfaces en 3D. L’appariement de surfaces en 3D évalue les distances euclidiennes entre les données de vérification et les données en entrée. Les distances euclidiennes fournissent une mesure adéquate de la qualité des modèles 3D. Elles sont indépendantes de la méthode de relevé des données. La méthode proposée renseigne sur la précision du système de référence, la précision géométrique et l’exhaustivité. Trois exemples pratiques sont présentés pour la démonstration de la méthode. 3D Gebäudemodelle werden heutzutage häufig aus lidar und photogrammetrischen Daten erzeugt. Die Qualitätskontrolle dieser Modelle spielt unter wissenschaftlichen und praktischen Aspekten eine wichtige Fragestellung. Diese Arbeit präsentiert eine Methode für die Qualitätskontrolle solcher Modelle. Das Input Modell (3D Gebäudedaten) ist ko‐registriert zu den Referenzdaten unter Verwendung eines Verfahrens zur 3D Oberflächenzuordnung. Die 3D Oberflächenzuordnung evaluiert die Euklidische Distanz zwischen den Referenzdaten und dem Input Datensatz. Die Euklidische Distanz gibt eine geeignete Metrik für die 3D Modellqualität. Diese Metrik ist unabhängig von der Methode der Datenerfassung. Die vorgestellte Methode geht auf die Genauigkeit des Referenzsystems, die Positionsgenauigkeit und die Vollständigkeit ein. Drei praktische Bespiele werden vorgestellt, die die Methode verdeutlichen. En la actualidad los modelos tridimensionales de edificaciones se generan a menudo a partir de datos fotogramétricos y lidar. El control de calidad de estos modelos es una cuestión relevante desde los puntos de vista científico y práctico. Este trabajo describe un método de control de calidad de los modelos. El modelo de entrada (datos tridimensionales de edificaciones) se corregistra con los datos de verificación empleando un método de ajuste de superficies tridimensionales. Este ajuste evalúa las distancias euclídeas entre los conjuntos de datos de verificación y de entrada. Las distancias euclídeas proporcionan una medida apropiada de la calidad del modelo tridimensional. Esta medida es independiente del método de obtención de datos. El método propuesto puede resolver de forma adecuada la exactitud del sistema de referencia, la exactitud posicional y la completitud. Como demostración se aportan tres ejemplos prácticos de aplicación del método.
Mehmet Devrim Akça; Mark Freeman; Isabel M J Sargent; Armin Gruen. Quality assessment of 3D building data. The Photogrammetric Record 2010, 25, 339 -355.
AMA StyleMehmet Devrim Akça, Mark Freeman, Isabel M J Sargent, Armin Gruen. Quality assessment of 3D building data. The Photogrammetric Record. 2010; 25 (132):339-355.
Chicago/Turabian StyleMehmet Devrim Akça; Mark Freeman; Isabel M J Sargent; Armin Gruen. 2010. "Quality assessment of 3D building data." The Photogrammetric Record 25, no. 132: 339-355.
The methods and technologies for generating large area and high-resolution three-dimensional (3D) building and city models offer new possibilities for realistic visualization as well as for multiple analytical interpretations. The major techniques used in reality-based city model generation are considered for their application to building stocks. 3D descriptions of objects are exemplified in CC-Modeller, a semi-automated procedure for value-added data generation from images. 3D city modelling and life cycle-oriented 3D building stock modelling, in particular the combination of geometric and semantic information and related standards, are discussed. The potential needs of building stock research and management and the possibility to extract the desired information from images are examined. Key challenges are the handling of temporal data combined with exploratory visualization, understanding user perceptions at different scales/detail along with time-dependent representations. Les méthodes et les technologies permettant de générer des modèles de bâtiments et de villes tridimensionnels (3D) en haute résolution sur de grandes surfaces offrent de nouvelles possibilités pour une visualisation réaliste comme pour de multiples interprétations analytiques. Les principales techniques utilisées pour générer des modèles urbains basés sur la réalité sont examinées sous l'angle de leur application aux parcs bâtis. Les descriptions en 3D des objets sont illustrées dans CCModeller, une procédure semi-automatique permettant de générer des données à valeur ajoutée à partir d'images. Il est discuté de la modélisation urbaine en 3D et de la modélisation de parcs bâtis en 3D axée sur le cycle de vie, en particulier de la combinaison de données géométriques et sémantiques et des normes qui s'y rapportent. Sont examinés les besoins potentiels en matière de recherche et de gestion concernant les parcs bâtis et la possibilité d'extraire d'images les données souhaitées. Les principaux problèmes qui se posent sont le traitement de données temporelles conjointement à une visualisation exploratoire, la compréhension de ce que perçoit l'utilisateur selon les échelles/les niveaux de détail, ainsi que les représentations en fonction du temps. Mots clés: maquettes numériques des bâtiments, parcs bâtis, modélisation urbaine, Systèmes d'Information Géographique ou géomatique (SIG), description intégrée, modèles sémantiques, modèles tridimensionnels (3D), visualisation
Armin Gruen; Martin Behnisch; Niklaus Kohler. Perspectives in the reality-based generation,nD modelling, and operation of buildings and building stocks. Building Research & Information 2009, 37, 503 -519.
AMA StyleArmin Gruen, Martin Behnisch, Niklaus Kohler. Perspectives in the reality-based generation,nD modelling, and operation of buildings and building stocks. Building Research & Information. 2009; 37 (5-6):503-519.
Chicago/Turabian StyleArmin Gruen; Martin Behnisch; Niklaus Kohler. 2009. "Perspectives in the reality-based generation,nD modelling, and operation of buildings and building stocks." Building Research & Information 37, no. 5-6: 503-519.
This paper examines the potential of mobile phones to be used as front‐end sensors for photogrammetric procedures and applications. For this purpose, two mobile phone cameras (Sony Ericsson K750i and Nokia N93) were calibrated over an indoor 3D testfield, using a self‐calibrating bundle adjustment. Geometric accuracy tests were carried out in order to evaluate their metric performances and to compare the results with respect to two off‐the‐shelf digital still video cameras (Sony DSC W100 and Sony DSC F828). The geometric accuracy evaluation comprised an absolute accuracy test, JPEG test and temporal stability test. The radiometric capabilities of all cameras (except that the DSC W100 was replaced with a DSC T100 camera) were also evaluated and compared by carrying out modulation transfer function (MTF) analysis, image noise analysis and an operating range test. Substantial systematic errors were diagnosed in some systems. However, with proper calibration it is believed that these devices can be used for many photogrammetric tasks. Cet article examine le potentiel des téléphones portables comme capteurs frontaux pour des procédures et des applications photogrammétriques. À cette fin, les caméras de deux téléphones portables (Sony Ericsson K750i et Nokia N93) ont étéétalonnées sur notre dispositif d’étalonnage 3D en salle, en utilisant une compensation par faisceaux auto‐étalonnante. Des tests de précision géométrique ont été effectués afin d’évaluer leur performance métrique et de la comparer à deux appareils photo numériques du commerce (Sony DSC W100 et Sony DSC F828). L’évaluation de la précision géométrique comprend un test de précision absolue, un test JPEG et un test de stabilité temporelle. Nous avons aussi évalué et comparé les performances radiométriques de toutes les caméras (excepté la caméra DSC W100 qui a été remplacée par la caméra DSC T100) par l’analyse de la fonction de transfert de modulation (FTM), l’analyse du bruit et un test d’autonomie. Dans certains systèmes, nous avons détecté des erreurs systématiques importantes. Toutefois, il semble que l’on puisse utiliser ces appareils pour de nombreux travaux photogrammétriques pour peu qu’ils aient été correctement étalonnés. Dieser Beitrag untersucht, inwieweit integrierte Handykameras zur Bilddatengewinnung in der Photogrammetrie nutzbringend eingesetzt werden können. Zu diesem Zweck kalibrierten wir die Kameras der Handys Sony Ericsson K750i und Nokia N93 unter Benutzung unseres 3D Testfelds und unter Einsatz des Verfahrens der Selbstkalibrierung. Gleichzeitig benutzten wir das Testfeld für Genauigkeitsstudien. Wir bestimmten die metrischen Qualitäten dieser Kameras und verglichen diese mit denen dreier handelsüblicher Stillvideo‐Kameras. Dieses beinhaltete einen Test auf absolute 3D Genauigkeit im Objektraum, die Untersuchung des Einflusses der JPEG Komprimierung und einen Test auf zeitabhängige Stabilität. Wir bestimmten das radiometrische Verhalten aller Kameras, indem wir die MTF, das Bildrauschen und die Linearität analysierten. In einigen dieser Kameras haben wir signifikante systematische Fehler diagnostiziert, die sich nicht mit den üblichen globalen Funktionen block‐invarianter zusätzlicher Parameter kompensieren lassen. Dennoch erhielten wir mit diesen Handykameras erstaunlich gute Genauigkeiten. Sie eignen sich somit nach erfolgter Kalibrierung sehr wohl zum Einsatz in einer Vielzahl photogrammetrischer Anwendungen. Este artículo evalúa la capacidad de los teléfonos móviles para ser utilizados como sensores en aplicaciones y procedimientos fotogramétricos. Con este objetivo, se calibraron dos cámaras de teléfonos móviles (Sony Ericsson K750i y Nokia N93) en un campo de pruebas tridimensional interior, mediante un ajuste de haces con autocalibración. Las pruebas de exactitud geométrica se realizaron para evaluar su comportamiento métrico y para comparar los resultados con los de dos cámaras estacionarias de vídeo comerciales (Sony DSC W100 y Sony DSC F828). La evaluación de la exactitud geométrica consistió en una prueba de exactitud absoluta, prueba JPEG y prueba de estabilidad temporal. Se estimaron también las capacidades radiométricas de todas las cámaras (a excepción de la DSC W100 que fue sustituida por la cámara DSC T100) y se compararon mediante un análisis de la función de transferencia de modulación (FTM), un análisis del ruido de la imagen y del rango de operación. Se identificaron varios errores sistemáticos sustanciales en algunos equipos. Sin embargo, se confía en que, con una apropiada calibración, estos dispositivos puedan ser utilizados en muchas tareas fotogramétricas.
Devrim Akca; Armin Gruen. Comparative geometric and radiometric evaluation of mobile phone and still video cameras. The Photogrammetric Record 2009, 24, 217 -245.
AMA StyleDevrim Akca, Armin Gruen. Comparative geometric and radiometric evaluation of mobile phone and still video cameras. The Photogrammetric Record. 2009; 24 (127):217-245.
Chicago/Turabian StyleDevrim Akca; Armin Gruen. 2009. "Comparative geometric and radiometric evaluation of mobile phone and still video cameras." The Photogrammetric Record 24, no. 127: 217-245.
The latest developments in sensors and data processing technology have strongly influenced many disciplines and have led in many cases to completely novel ways as to how the respective work is conducted, with new possibilities for improved data acquisition, handling, and analysis. Archaeology and cultural heritage are definitely among those fields that have drawn many advantages from this situation. Advanced 3D modeling of landscapes, sites, single architectures, statues, findings, and artifacts have given the experts in the field and office new tools in their hands for better analysis and interpretation of processes, developments, and relations.
Armin Gruen. Virtual Archaeology – New Methods of Image-Based 3D Modeling. Natural Science in Archaeology 2009, 287 -305.
AMA StyleArmin Gruen. Virtual Archaeology – New Methods of Image-Based 3D Modeling. Natural Science in Archaeology. 2009; ():287-305.
Chicago/Turabian StyleArmin Gruen. 2009. "Virtual Archaeology – New Methods of Image-Based 3D Modeling." Natural Science in Archaeology , no. : 287-305.
Sultan Kocaman; Armin Gruen. Orientation and self-calibration of ALOS PRISM imagery. The Photogrammetric Record 2008, 23, 323 -340.
AMA StyleSultan Kocaman, Armin Gruen. Orientation and self-calibration of ALOS PRISM imagery. The Photogrammetric Record. 2008; 23 (123):323-340.
Chicago/Turabian StyleSultan Kocaman; Armin Gruen. 2008. "Orientation and self-calibration of ALOS PRISM imagery." The Photogrammetric Record 23, no. 123: 323-340.
Digital Earth essentially consists of 3D and moreD models and attached semantic information (attributes). Techniques for generating such models efficiently are required very urgently. Reality-based 3D modelling using images as prime data source plays an important role in this context. Images contain a wealth of information that can be advantageously used for model generation. Images are increasingly available from satellite, aerial and terrestrial platforms. This contribution briefly describes some of the problems which we encounter if the process of model generation is to be automatised. With the help of some examples from Digital Terrain Model generation, Cultural Heritage and 3D city modelling we show briefly what can be achieved. Special attention is directed towards the use of model helicopters for image data acquisition. Some problems with interactive visualisation are discussed. Also, issues surrounding R&D, professional practice and education are also addressed.
A. Gruen. Reality-based generation of virtual environments for digital earth. International Journal of Digital Earth 2008, 1, 88 -106.
AMA StyleA. Gruen. Reality-based generation of virtual environments for digital earth. International Journal of Digital Earth. 2008; 1 (1):88-106.
Chicago/Turabian StyleA. Gruen. 2008. "Reality-based generation of virtual environments for digital earth." International Journal of Digital Earth 1, no. 1: 88-106.