Institut für Raumbezogene Informations- und Messtechnik
Hochschule Mainz - University of Applied Sciences

Suche

Publikationen

2017

Analyse von Bildresiduen mit Machine-Learning im Rahmen von Kamera-Kalibrierungen

2017

Waldemar Kisser, F Boochs, Dietrich PAULUS

n.A.
<p>Photogrammetrie ermöglicht es, Objekte mithilfe von Digitalbildern zu vermessen. Bei optimalen Messbedingungen sind Qualitätsunterschiede der abgeleiteten Maße vor allem auf die mathematische Modellierung des verwendeten Sensors und des Objektivs zurückzuführen. Photogrammetrische Kalibrierungen erfolgen meist mittels Bündelblockausgleichung. Diese gestattet es, vielerlei statistische Kennzahlen abzuleiten. Eine tiefer gehende Analyse der berechneten Parameter, Standardabweichungen, Korrelationen und deren Verteilungen kann Aufschluss darüber geben, ob das verwendete Kalibriermodell Schwächen aufweist. Solche Defizite können sich durch systematische Restfehler im Bild- oder Objektraum äußern. Da solche Restfehler auch zu Ungenauigkeiten in den daraus abgeleiteten Informationen führen können, ist deren mathematischer Nachweis und anschließende Kompensation zur Erzielung höchster Genauigkeiten unausweichlich. Neueste Ansätze nutzen Korrekturterme, um Residuensystematiken schon während der Bündelblockausgleichung zu modellieren. Dieser Beitrag beschreibt, wie auch Machine-Learning-<br />Techniken dabei helfen können, verbliebene systematische Abweichungen in Bildresiduen nachzuweisen, ohne dass hierzu ein Eingriff in die Bündelblockausgleichung notwendig ist. Dies wird im ersten Schritt anhand von Beispieldaten erläutert. Im zweiten Schritt wird die Wirkung dieser Vorgehensweise an einer realen Kamerakalibrierung verdeutlicht. Abschließend erfolgt eine Diskussion der im Zuge dieser Arbeit erzielten Resultate und möglicher Eignung dieses Verfahrens in der Praxis.</p>

COSCH - Vier Jahre interdisziplinärer Dialog zum Nutzen des kulturellen Erbes.

2017

S Wefers

KulturBetrieb - Magazin für innovative und wirtschaftliche Lösungen in Museen, Bibliotheken und Archiven









Ontology-based Knowledge Representation for Recommendation of Optimal Recording Strategies - Photogrammetry and Laser Scanning as Examples.

2017

S Wefers, A Karmacharya, F Boochs

gis.Science
<p><span style="color: rgb(73, 72, 72); font-family: Roboto, Roboto, &quot;Helvetica Neue&quot;, sans-serif; font-size: 14px; text-align: justify;">Experts&rsquo; knowledge about optical technologies for spatial and spectral recording is logically structured and stored in an ontology-based knowledge representation with the aim to provide objective recommendations for recording strategies. Besides operational functionalities and technical parameters such as measurement principles, instruments, and setups further factors such as the targeted application, data, physical characteristics of the object, and external influences are considered creating a holistic view on spectral and spatial recording strategies. Through this approach impacting factors on the technologies and generated data are identified. Semantic technologies allow to flexibly store this knowledge in a hierarchical class structure with dependencies, interrelations and description logic statements. Through an inference system the knowledge can be retrieved adapted to individual needs.</span></p>

How to optimally record cultural heritage objects? Decision support through connected knowledge.

2017

S Wefers, A Karmacharya, F Boochs, G Heinz

EVA Berlin 2017. Elektronische Medien & Kunst, Kultur und Historie 24. Berliner Veranstaltung der internationalen EVA-Serie Electronic Media and Visual Arts, 2017
<p>Optical recording of material cultural heritage (CH) is a multidisciplinary activity where the understanding of cross-disciplinary semantics is vital for a successful completion. In many cases, a lack of understanding of transdisciplinary semantics slows this process down. The end users who are mostly humanities experts lack the technical knowledge of spatial and spectral recording and could therefore demand more than what is actually required or sufficient for the intended CH application. The negotiations between technical experts and the end users are a tedious process. We present a semantic-based decision support system, COSCH<sup>KR</sup>, that employs reasoning and recommends optimal recording technology(ies) according to the application requirements of the recorded and processed data. COSCH<sup>KR</sup> is an ontology-based knowledge model that implies the development of semantic technologies within the Semantic Web framework. It represents formalized knowledge of the disciplines involved in the process of optical recording of material CH. The paper describes the applicability of the model in spatial, spectral, and visualization applications and summarises current possibilities and challenges.</p>

2016

Development of a platform recommending 3D and spectral digitisation strategies.

2016

S Wefers, A Karmacharya, F Boochs

Virtual Archaeology Review
<p>Spatial and spectral recording of cultural heritage objects is a complex task including data acquisition, processing and analysis involving different technical disciplines. Additionally, the development of a suitable digitisation strategy satisfying the expectations of the humanities experts needs an interdisciplinary dialogue often suffering from misunderstanding and knowledge gaps on both the technical and humanities sides. Through a concerted discussion, experts from the cultural heritage and technical domains currently develop a so-called COSCH KR (Colour and Space in Cultural Heritage Knowledge Representation) platform that will give recommendations for spatial and spectral recording strategies adapted to the needs of the cultural heritage application. The platform will make use of an ontology through which the relevant parameters of the different domains involved in the recording, processing, analysis, and dissemination of cultural heritage objects are hierarchically structured and related through rule-based dependencies. Background and basis for this ontology is the fact that a deterministic relation exists between (1) the requirements of a cultural heritage application on spatial, spectral, as well as visual digital information of a cultural heritage object which itself has concrete physical characteristics and (2) the technical possibilities of the spectral and spatial recording devices. Through a case study which deals with the deformation analysis of wooden samples of cultural heritage artefacts, this deterministic relationship is illustrated explaining the overall structure and development of the ontology. The aim of the COSCH KR platform is to support cultural heritage experts finding the best suitable recording strategy for their often unique physical cultural heritage object and research question. The platform will support them and will make them aware of the relevant parameters and limitations of the recording strategy with respect to the characteristics of the cultural heritage object, external influences, application, recording devices, and data.</p>

3D-Scanning und virtuelle 3D-Modelle zur UnterstĂĽtzung der Untersuchung und virtuellen Rekonstruktionen des Grabmals von Frankfurt am Main - Zeilsheim

2016

A Cramer, G Heinz, C Justus, T Reich

P. Fasold, A. Hampel, M. Scholz, M. Tabaczek, Der römische Bestattungsplatz von Frankfurt am Main - Zeilsheim. Grabbau und Gräber der provinzialen Oberschicht









3D Survey and Documentation of an Early Iron Age Burial from Otzing, near Deggendorf in Lower Bavaria

2016

T Reich, Robert Schumann

COSCH e-Bulletin 3-2016









UAV photogrammetry and 3D analyses of CH sites. The millstone quarry district of Mayen (DE) as a case study

2016

S Wefers, P Atorf, Klonowski, J.

W. Börner, S. Uhlirz (eds), Proceedings of the 20th International Conference on Cultural Heritage and New Technologies 2015 (CHNT 20, 2015)
<p>Application and analysis capabilities of 3D data sets generated through UAV photogrammetry are presented on the basis of an exemplary millstone quarry of the so-called Mayen quarry district (Germany). In general, millstone quarries are technical cultural heritage sites which give evidence for economic interpretations as they are of interest for the reconstruction of ancient procurement patterns. Particularly those quarries which had a high economic impact cover large areas with often arduous accessibility. Therefore, photogrammetric recording using a UAV is the best approach for fast and inexpensive high-quality documentation. The images are used to create a 3D data set and orthophoto. For analysis and interpretation the Spatial Image analysis and Visualisation Tool (SIVT) of i3mainz is used allowing a variety of interactive visualization functionalities. The 3D data are transformed into 2.5D data enabling segmentation of spatial information and volume calculations. Both functionalities support the cultural heritage expert&#39;s research: On the one hand the interactive segmentation allows producing a map of the quarry displaying only those parts associated with the extraction. On the other hand the output of the quarry including debris and millstone blanks can be calculated easily. All in all, the entire workflow beginning with data capture using a UAV followed by data processing, (2.5D / 3D) data analyses and visualisation of the results is presented.</p>

2015

Die Mühlenkaskade von Ephesos. Technikgeschichtliche Studien zur Versorgung einer spätantiken bis frühbyzantinischen Stadt.

2015

S Wefers, A Cramer, G Heinz, R BrĂĽdern, A Waldner, G SĂĽrmelihindi, C Passchier, F Mangartz, K Menchen, T Gluhak

Monographien RGZM









Grabungen 2014 innerhalb der Befestigung auf dem Kapellenberg bei Hofheim am Taunus

2015

T Lang, A Cramer, D Gronenborn, U Recker, S Fiedler, H Thiemeyer

hessenARCHĂ„OLOGIE









Netzmessungen mit dem Leica Absolute Tracker AT402 zur Bestimmung geodätischer Prüfstrecken

2015

P. Arent, R. Bretscher, M SchlĂĽter

Allgemeine Vermessungs-Nachrichten (avn)
<p>Zur Bestimmung geodätischer Prüfstrecken unter Nutzung eines Leica Absolute Trackers AT402 stellen wir Konzept und Ergebnisse vor. Dazu greifen wir die positiven Erfahrungen mit Lasertrackern beim Ringversuch auf der neuen Kalibrierbasis der Universität der Bundeswehr München zwischen 2009 und 2011 auf.<br />Im Unterschied zum Ringversuch konzentrieren wir uns auf die Bestimmung neuer und bestehender Prüfstrecken im derzeit üblichen Pfeilerdesign mit einer Pfeilerkopf-Abschlussplatte mit 5/8-Zoll-Gewindezapfen zur Dreifußaufnahme. Dafür schlagen wir eine Netzmessung unter Verwendung einfacher Pfeiler-Aufsatzadapter vor. Abschließend vergleichen wir unsere Ergebnisse, die bei unterschiedlichen meteorologischen<br />Bedingungen auf der Eichstrecke Weinolsheim des Landes Rheinland-Pfalz gewonnen wurden.</p>

Modulare Digitalkameratachymeter

2015

M SchlĂĽter, S. Hauth

n.A.
<p>Das Vorhaben will einen Innovationsschub für die Anwendung vermessungstechnischer<br />Tachymeter (auch Totalstationen, mobile Polarmesssysteme großer Reichweite)<br />auslösen.<br />Ermöglicht wird dieser Innovationsschub durch die Integration bildgebender Sensoren<br />mit einem konsequent modularen Lösungsansatz an Stelle der bislang mit nur<br />mäßigem Erfolg unternommenen monolithischen Lösungsansätze. Durch unser Konzept<br />werden die stark unterschiedlichen Entwicklungszyklen der zentralen Systemkomponenten<br />entkoppelt. Dadurch werden mittelfristig insbesondere KMU, Entwicklungseinrichtungen<br />und Hochschulen in die Lage versetzt, anwendungsspezifische<br />Lösungen für den expandierenden Markt von Geoinformationen und den steigenden<br />Bedarf an räumlichen Geometriedaten zu entwickeln und in der Folge auch eigenständig<br />zu vermarkten.</p>

SIVT – Processing, viewing and analysis of 3D scans of the porthole slab and slab b2 of Züschen I

2015

S Wefers, T Reich, Burkhard Tietz, F Boochs

CAA









Support of Petroglyph analysis through processing and viewing of 3D scans.

2015

T Reich, F Boochs, S Wefers, B Tietz

43rd Conference of Computer Applications and Quantitative Methods in Archaeology, CAA 2015, Siena, Book of Abstracts.
<p>Traditionally stone inscriptions or drawings are documented through pictures or rubbings. The latter ones represent an analogue copy of the stone&rsquo;s surface and its features which are reproduced on paper. The disadvantage of this technique is the physical impact to the stone and the contained elements. Images reproduce the surface without contact. However, they might be affected by geometrical distortions and need appropriate lighting conditions to show the signs properly.</p><p>These problems will be avoided by means of non-contact 3D measuring techniques, like fringe projection. Such high resolution 3D techniques provide an exact geometrical copy of the original petroglyph, offering better results in legibility compared to traditional techniques. Moreover, it gives a more objective base for analysis and has less impact on the sometimes sensitive and eroded surfaces. Furthermore 3D data allows more extensive and further possibilities in processing and gives better preconditions for the interpretation.</p><p>However, depending on factors like resolution, scanned surface and degree of overlap between individual scans original 3D datasets may represent large up to really massive volumes of data. An effective use of such datasets can only be realised if they are condensed and prepared in a suitable way. This means reduction of the data volume, minimising any disturbing influence emerging from the spatial shape of the surface and emphasizing relevant information. The corresponding preparation of the data will then be a good base for a interpretation performed by the human science specialist through an adapted visualization. In addition the data should be prepared for high performance presentation to a wider community via the internet.</p><p>Processed digital copies of the Petroglyphs are visualised in order to enable the user to inspect the processed scans of the objects. By inspecting the scans the application provides a mass of functionality for achieving different views into the Petroglyphs and their appearance. This comprises on the one hand a simple 2D viewer for the processed data, and on the other hand a 3D viewer with interactive changeable light positions and water levels as well as a viewer for applying various lookup tables (colour), predefined image filters (convolution) and template matching (matching) regarding individual characters.</p><p>Provided functionality of the 3D viewer is based on features of 3D computer graphics. Surface normal vectors from the grey values of the processed scans and a light direction vector from an interactively changeable light source are computed. In addition shading is complemented by water filling, whereby the gray values are limited by the water level selected. Individual modifications are possible to improve the subjective impression by the user, trying to support him in his process of interpretation. Interactive changes of the light source directly affect the shading of the surface and provide a better idea of the 3D surface of the inscription board. Dynamic virtual water filling enables the user to obtain an even better impression of the depth of the individual characters and emphasise weathered characters.</p><p>The paper will explain the developed techniques and document its potential at selected data sets.</p>

Semantic based Structuring of 3D technologies for their optimized use in cultural heritage documentation.

2015

A Karmacharya, S Wefers, F Boochs

43rd Conference of Computer Applications and Quantitative Methods in Archaeology, CAA 2015, Siena, Book of Abstracts.
<p>Constant technological progress results in new possibilities to produce reliable and rich spatial data of cultural heritage objects: for instance, museums have started to digitize their collections, more and more archaeological excavations or features and entire CH buildings have been documented in 3D. It is now necessary to establish connections among different CH disciplines and several technical disciplines, and to work on collaborative projects.</p><p>Technicians and CH experts together evaluate the best technique for specific CH object documentation, implementation and use. This discussion arises from the knowledge gaps of each counterpart in respect to the other discipline. Projects such as Agora 3D (see below) clearly demonstrate the need for an evaluation of the different available techniques.</p><p>In order to make optimal use of these technological capabilities, it is important to identify and name the information required to best serve the reasoning processes in these application fields. Correspondingly it is necessary to know about the characteristics of digitization techniques producing the content adapted to the needs of the applications. Due to the considerable complexity of instruments and processes producing the data, it is helpful to have a clear structure which relates the capabilities of the instruments to the requirements of the applications.</p><p>The COST Action TD1201 &ldquo;Colour and Space in Cultural Heritage (COSCH)&rdquo; takes this need into account, aiming to enhance the understanding among these disciplines. We will focus on the already listed, structured and evaluated available 3D technologies. At the same time, experts in spectral and CH research started to list, structure, and evaluate their knowledge. These evaluations yield a structure of technologies, and ultimately the techniques and instruments using their characteristics. The understanding of these characteristics provides insights for their potential applications. The ontology knowledge model accessible through so-called &ldquo;COSCH<sup>KR </sup>App&rdquo; provides a knowledge structure. It benefits from the development of semantic technologies from the Semantic Web framework. Semantics, which provide meanings, are captured through the conceptual structure and are defined through the ontology. The overall aim of this ontology is the development of a software tool to enable a better understanding of data acquisition techniques and their support to optimally realize cultural heritage applications.</p>

Korrektur der Ellipsen-Exzentrizität im Kontext von Kamerakalibrierungen

2015

Waldemar Kisser, Burkhard Tietz, F Boochs, Dietrich PAULUS

Photogrammetrie, Laserscanning, Optische 3D-Messtechnik. Beiträge der Oldenburger 3D-Tage 2015
<p>Dieser Beitrag befasst sich mit dem Einfluss der Zielmarkenexzentrizität während der Kamera-<br />Kalibrierung in Kombination mit verschiedenen Kalibrierkörpern. Zunächst wird<br />deren Einfluss auf die Resultate anhand numerischer Simulationen nachgewiesen. In diesen<br />Simulationen wird eine Erfassung des Einflusses der Exzentrizität auf Bildmessung, Objekt-<br />und Kamerageometrie angestrebt. Im zweiten Schritt wird eine Realkalibrierung mit<br />vergleichbarer Aufnahmekonfiguration durchgeführt. Dabei werden Gemeinsamkeiten bzw.<br />Unterschiede der erreichten Ergebnisse diskutiert sowie eine mögliche Kompensation des<br />Einflusses in der Praxis erörtert.</p>

Relevance of ellipse eccentricity for camera calibration

2015

Waldemar Kisser, Burkhard Tietz, F Boochs, Dietrich PAULUS

Proc. SPIE 9528, Videometrics, Range Imaging, and Applications XIII, 95280D
<p>Plane circular targets are widely used within calibrations of optical sensors through photogrammetric set-ups. Due to this popularity, their advantages and disadvantages are also well studied in the scientific community. One main disadvantage occurs when the projected target is not parallel to the image plane. In this geometric constellation, the target has an elliptic geometry with an offset between its geometric and its projected center. This difference is referred to as ellipse eccentricity and is a systematic error which, if not treated accordingly, has a negative impact on the overall achievable accuracy. The magnitude and direction of eccentricity errors are dependent on various factors. The most important one is the target size. The bigger an ellipse in the image is, the bigger the error will be. Although correction models dealing with eccentricity have been available for decades, it is mostly seen as a planning task in which the aim is to choose the target size small enough so that the resulting eccentricity error remains negligible. Besides the fact that advanced mathematical models are available and that the influence of this error on camera calibration results is still not completely investigated, there are various additional reasons why bigger targets can or should not be avoided. One of them is the growing image resolution as a by-product from advancements in the sensor development. Here, smaller pixels have a lower S/N ratio, necessitating more pixels to assure geometric quality. Another scenario might need bigger targets due to larger scale differences whereas distant targets should still contain enough information in the image. In general, bigger ellipses contain more contour pixels and therefore more information. This supports the target-detection algorithms to perform better even at non-optimal conditions such as data from sensors with a high noise level.</p><p>In contrast to rather simple measuring situations in a stereo or multi-image mode, the impact of ellipse eccentricity on image blocks cannot be modeled in a straight forward fashion. Instead, simulations can help make the impact visible, and to distinguish critical or less critical situations. In particular, this might be of importance for calibrations, as undetected influence on the results will affect further projects where the same camera will be used. This paper therefore aims to point out the influence of ellipse eccentricities on camera calibrations, by using two typical calibration bodies: planar and cube shaped calibration. In the first step, their relevance and influence on the image measurements, object- and camera geometry is shown with numeric examples. Differences and similarities between both calibration bodies are identified and discussed. In the second step, practical relevance of a correction is proven in a real calibration. Finally, a conclusion is drawn followed by recommendations to handle ellipse eccentricity in the practice.</p>

Knowledge guided object detection and identification in 3D point clouds

2015

A Karmacharya, F Boochs, Burkhard Tietz

Videometrics, Range Imaging, and Applications XIII, 952804
<p><span class="Abstract" id="scm6MainContent_rptSections_lblSection_0">Modern instruments like laser scanner and 3D cameras or image based techniques like structure from motion produce huge point clouds as base for further object analysis. This has considerably changed the way of data compilation away from selective manually guided processes towards automatic and computer supported strategies. However it&rsquo;s still a long way to achieve the quality and robustness of manual processes as data sets are mostly very complex. Looking at existing strategies 3D data processing for object detections and reconstruction rely heavily on either data driven or model driven approaches. These approaches come with their limitation on depending highly on the nature of data and inability to handle any deviation. Furthermore, the lack of capabilities to integrate other data or information in between the processing steps further exposes their limitations. This restricts the approaches to be executed with strict predefined strategy and does not allow deviations when and if new unexpected situations arise. We propose a solution that induces intelligence in the processing activities through the usage of semantics. The solution binds the objects along with other related knowledge domains to the numerical processing to facilitate the detection of geometries and then uses experts&rsquo; inference rules to annotate them. The solution was tested within the prototypical application of the research project &ldquo;Wissensbasierte Detektion von Objekten in Punktwolken fĂĽr Anwendungen im Ingenieurbereich (WiDOP)&rdquo;. The flexibility of the solution is demonstrated through two entirely different USE Case scenarios: Deutsche Bahn (German Railway System) for the outdoor scenarios and Fraport (Frankfort Airport) for the indoor scenarios. Apart from the difference in their environments, they provide different conditions, which the solution needs to consider. While locations of the objects in Fraport were previously known, that of DB were not known at the beginning. &copy; (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.</span></p>

2014

Dissemination Design of a 3D Documented Archaeological Feature in Ephesos.

2014

S Wefers, A Cramer

PDF

COSCH e-Bulletin
<p>The paper presents different forms of documentation of a Late Antique and Early Byzantine water-powered workshop and milling complex in what is commonly known as Terrace House 2 in Ephesos, Turkey. The entire complex was documented by means of 3D laser scanning in 2009 and 2010. Geometrical data were processed and used in the form of a point cloud in the archaeological analysis. Narrow parts, complex structures, and small rooms of the well-preserved feature were surveyed efficiently using a 3D laser scanner. Additionally, panoramic images were captured. They offered the possibility to colour the point cloud, thus helping to identify and understand the feature better in the model. The developed consistent 3D point cloud of the entire feature provided the spatial data for analyses, reconstructions and technical drawings, such as ground plots and sectional views for publications.<br />In order to address specific questions, e.g. to determine the course of the chute, or the size and position of the water-wheels, it was essential to be able to work with complete geometric data. For that purpose the data were exported from original files, using a free software plugin, and made usable in an internet browser. The interface is easy to operate and allows measurement and marking of 3D distances and coordinates of single points, within one scanner position. These can be saved and exchanged. In addition, using this technique a selection of the 3D data will be made available to the general user.</p><p><a href="http://www.cosch.info/publications/bulletin-1-2014">http://www.cosch.info/publications/bulletin-1-2014</a></p>

Characterisation of Spatial Techniques for Optimised Use in Cultural Heritage Documentation.

2014

S Wefers, A Karmacharya, F Boochs, Wiemann, A.-K.

Digital Heritage Progress in Cultural Heritage: Documentation, Preservation, and Protection. 5th International Conference, EuroMed 2014 Limassol, Cyprus, November 3-8, 2014 Proceedings
<p>Constant technological progress results in new possibilities to produce reliable and rich spatial data of cultural heritage objects. In order to make optimal use of these capabilities, it is important to identify and name the information required to best serve the reasoning processes in these application fields. Correspondingly it is necessary to know about the characteristics of digitization techniques producing the content adapted to the needs of the applications. Due to the considerable complexity of instruments and processes producing the data, it is helpful to have a clear structure which relates the capabilities of the instruments to the requirements of the applications. This paper addresses this topic and shows a way of structuring spatial techniques as well as how this structure can be related to applications in the field of cultural heritage.</p>

Colour and Space in Cultural Heritage: Key Questions in 3D Optical Documentation of Material Culture for Conservation

2014

F Boochs, Bentkowska-Kafel A., Degrigny Ch., Karaszewski M., Karmacharya A., Kato Z., Picollo M., Sitnik R., Trémeau A., Tsiafaki D., Tamas L.

5th International Conference, EuroMed 2014, Limassol, Cyprus, November 3-8
<div class="abstract-content formatted" itemprop="description"><p class="a-plus-plus">The paper introduces some key interdisciplinary questions concerning the development of optical measuring techniques and electronic imaging applied to documentation and presentation of artefacts, as identified through the work of Colour and Space in Cultural Heritage (www.COSCH.info), a trans-domain European Action (TD1201) in the area of Materials, Physics and Nanosciences (MPNS) supported, since 2013, by the European Cooperation in <a class="reference-link webtrekk-track" href="http://link.springer.com/search?dc.title=Science+and+Technology&amp;facet-content-type=ReferenceWorkEntry&amp;sortOrder=relevance">Science and Technology</a> <span class="a-plus-plus emphasis type-underline">http://www.cost.eu/domains_actions/mpns/Actions/ TD1201</span>. Some 125 international researchers and professionals participate in COSCH activities which have been organised around six main subjects: (1) spectral object documentation; (2) spatial object documentation; (3) algorithms and procedures; (4) analysis and restoration of cultural heritage surfaces and objects; (5) visualisation of cultural heritage objects and its dissemination; and (6) the semantic development of the COSCH Knowledge Representation.</p><p class="a-plus-plus">The Authors outline and illustrate the approaches adopted by COSCH. They indicate future work that is needed to resolve the identified scientific, technical and semantic questions, as well as challenges of interdisciplinary communication, to ensure a wider adoption of specialist technologies and enhanced standards in 3D documentation of material cultural heritage &mdash; being a basis for its understanding, conservation, restoration, long-term preservation, study, presentation and wide dissemination.</p></div><p>&nbsp;</p>

Towards a knowledge model bridging technologies and applications in cultural heritage documentation

2014

F Boochs, Trémeau, A., Murphy, O., Gerke, M., Lerma, J.L., A Karmacharya, Karaszewski, M.

ISPRS Technical Commission V Symposium
<p>This paper documents the formulation of an international, interdisciplinary study, on a concerted European level, to prepare an innovative, reliable, independent and global knowledge base facilitating the use of today&rsquo;s and future optical measuring techniques for the documentation of&nbsp; cultural heritage. Cultural heritage professionals, color engineers and scientists share similar goals for the documentation, curation, long-term preservation and representation of cultural heritage artifacts. Their focus is on accuracy in the digital capture and remediation of artefacts through a range of temporal, spatial and technical constraints. A shared vocabulary to interrogate these shared concerns will transform mutual understanding and facilitate an agreed movement forward in cultural heritage documentation here proposed in the work of the COST Action Color and Space in Cultural Heritage (COSCH). The goal is a model that captures the shared concerns of professionals for a standards-based solution with an organic Linked Data model. The knowledge representation proposed here invokes a GUI interface for non-expert users of capture technologies, facilitates, and formulates their engagement with key questions for the field.</p>

3D-Messen groĂźer Volumen bzw. groĂźer Bauteile

2014

D Berndt, F Boochs, P KĂĽhmstedt

Leitfaden zur optischen 3D-Messtechnik
<p>Große Bauteile entstehen im Fahrzeugbau (PKWs und LKWs in der Automobilproduktion, Flugzeugrumpfschalen oder<br />Turbinenmodule im Flugzeugbau, Rahmen und Außenhaut an Schienenfahrzeugen), im Schiffbau, im Anlagenbau oder bei der Produktion von Energieerzeugungsanlagen (Windenergieanlagen, Großturbinen, usw.). An sie werden hohe Anforderungen hinsichtlich Maßhaltigkeit und Ausführungsqualität gestellt. Typische, sich daraus ergebene Messaufgaben sind das Prüfen geometrischer Merkmale in einem großen Messvolumen (z. B. Maß- und Formabweichungen über mehrere Meter) sowie das dimensionelle Erfassen einer lokalen Bauteilgeometrie oder das Prüfen eines lokalen Montagezustands in einem global registrierten Bauteilkoordinatensystem.<br />Dazu kommen Sensoren zum Einsatz, die nur in einem lokal begrenzten Messvolumen, typischerweise kleiner 1m, Bild und<br />Geometrieinformationen erfassen können. Da die Abmessungen der Großbauteile mehrere Meter bis mehrere zehn Meter<br />betragen, müssen die lokal erfassten Prüfmerkmale für die sich anschließende Auswertung in ein globales Koordinatensystem, üblicherweise das Bauteilkoordinatensystem, transformiert werden.<br />&nbsp;</p>

Innovative concepts for image based data capture and analysis of huge point clouds

2014

F Boochs

n.A.
<p>Results from two sample projects will be presented, showing possibilities to improve quality and precision of data capture and evaluation.</p><p>One example explains the potential to improve the absolute positional accuracy of a robot guided effector when applying photogrammetric strategies. Need and aims of such a tracking process are explained, followed by a description of actual solutions and their restrictions. Then the potential of photogrammetric solutions for such purposes are outlined, followed by a detailed description of the system developed. Finally, practical tests are shown, underlining that the design and realization are able to hold the challenging aims and improve the absolute accuracy of a robot by a factor of 20.</p><p>In an second example possibilities to evaluate huge data sets are presented. Due to the increasing availability of large unstructured point clouds obtained from laser scanning and/or photogrammetric data, there is a growing demand for automatic processing methods. Given the complexity of the underlying problems, several new methods resort to using semantic knowledge in particular for supporting object detection and classification. A novel approach making use of advanced algorithms is shown, in order to benefit from intelligent knowledge management strategies for the processing of 3D point clouds along with object classification in scanned scenes. In particular, these method extends the use of semantic knowledge to all stages of the processing, including the guidance of the 3D processing algorithms. The complete solution consists in a multi-stage iterative concept based on three factors: the modeled knowledge, the package of algorithms, and the classification engine.</p>

Outlook on TLS - based 3D Building Modeling

2014

Julia Ganitseva, K -C Bruhn, Kern, F., Martin Unold

Photogrammetrie, Laserscanning, Optische 3D-Messtechnik
<p>Dense terrestrial laser scanning (TLS) datasets and its various types of representation provide 3D spatial information in a great level of detail. However, to apply TLS data in the spatial studies, first it is necessary to derive a 3D model that accounts for the perspectives. In addition to geometry information these models require integration of complex semantic data. The whole process is often a challenging and time-demanding task, which involves many critical decisions. This paper gives an outlook on current modeling techniques and standard formats that are used to exchange and store 3D building information. Moreover it describes development of the IBR software architecture, which allows users to collect, store and analyze spatial coherences between object geometry and semantic content. The use case of the research focuses on the analysis of complex semantic interrelationships between the objects inside religious interiors. Furthermore it explores the potential to express these relationships through standard formats for 3D building information modeling like CityGML and Industry Foundation Classes (IFC).</p>

Sustainable Documentation in Archaeology

2014

Florian Ströbele, G Heinz, Lu Zhiyong

PDF

Sustainable Documentation in Archaeology
<p class="bodytext">A good documentation of archaeological excavations is of high importance due to the destructive characteristic of the process. Developments in technology and concepts allow new, often more effective approaches in the documentation process during excavation. Recording finds and features in their three-dimensional spatial distribution will aid at understanding the entire archaeological context after finishing field-work. Image-based documentation and 3D-scanning are valuable tools for preserving the site as a virtual excavation space on which informed archaeological analysis can be based.</p><p class="bodytext">The use of digital tools will result in manifold digital data representations. Especially these datasets must comply with certain specifications, such as formats, descriptions, meta information, etc. to be used in the long term, and thus be sustainable beyond the excavation project itself.</p><p class="bodytext">The meeting will deal with technological aspects of documenting the excavation, further archaeological processing, and data archiving.</p>

2013

Autokollimationszielungen mit dem Leica Absolute Tracker AT401

2013

Hauth, S., M SchlĂĽter

Allgemeine Vermessungs-Nachrichten
<p>Autokollimationszielungen ergänzen die hochgenaue 3D-Koordinatenmesstechnik und ermöglichen die präzise Festlegung von Richtungen im Raum auch unter beengten räumlichen Verhältnissen. Exemplarisch untersuchen wir die Durchführung von Autokollimationzielungen mit einem Lasertracker. Um die neuartige Vorgehensweise mit dem Leica Absolute Tracker AT401 dem klassischen Prozedere mit Industrietheodolit und Autokollimationsokular vergleichend gegenüber stellen zu können, vermessen wir einen verspiegelten Prüfkörper dreimal unabhängig voneinander mit unterschiedlichen Gerätesystemen.</p>

Intégration de systèmes d'acquisition de données spatiales et spectrales haute résolution, dans le cadre de la génération d'informations appliquées à la conservation du patrimoine

2013

Simon Chane , Camille

PDF

Université de Bourgogne
<p>Cette thèse s&#39;intéresse au recalage de données issues de capteurs 3D et multispectraux pour l&#39;étude du patrimoine.Lorsque l&#39;on étudie ce type d&#39;objet, il y a souvent peu de points saillants naturels entre ces jeux de données complémentaires. Par ailleurs, l&#39;utilisation de mires optiques est proscrite.Notre problème est donc de recaler des données multimodales sans points caractéristiques.Nous avons développé une méthode de recalage basé sur le suivi des systèmes d&#39;acquisition en utilisant des techniques issues de la photogrammétrie.Des simulations nous ont permis d&#39;évaluer la précision de la méthode dans trois configurations qui représentent des cas typiques dans l&#39;étude d&#39;objets du patrimoine.Ces simulations ont montré que l&#39;on peut atteindre une précision du suivi de 0.020 mm spatialement et 0.100 mrad angulairement en utilisant quatre caméras 5 Mpx lorsque l&#39;on numérise une zone de 400 mm x 700 mm.La précision finale du recalage repose sur le succès d&#39;une série de calibrations optiques et géométriques, ainsi que sur leur stabilité pour la durée du processus d&#39;acquisition.Plusieurs tests ont permis d&#39;évaluer la précision du suivi et du recalage de plusieurs jeux de données indépendants; d&#39;abord seulement 3D, puis 3D et multispecrales.Enfin, nous avons étendu notre méthode d&#39;estimation de la réflectance à partir des données multispectrales lorsque celles-ci sont recalées sur un modèle 3D.</p><p><br />The concern and interest of this PhD thesis is the registration of featureless 3D and multispectral datasets describing cultural heritage objects.In this context, there are few natural salient features between the complementary datasets, and the use of targets is generally proscribed.We thus develop a technique based on the photogrammetric tracking of the acquisition systems in use.A series of simulations was performed to evaluate the accuracy of our method in three configurations chosen to represent a variety of cultural heritage objects.These simulations show that we can achieve a spatial tracking accuracy of 0.020 mm and an angular accuracy of 0.100 mrad using four 5 Mpx cameras when digitizing an area of 400 mm x 700 mm. The accuracy of the final registration relies on the success of a series of optical and geometrical calibrations and their stability for the duration of the full acquisition process.The accuracy of the tracking and registration was extensively tested in laboratory settings. We first evaluated the potential for multiview 3D registration. Then, the method was used for to project of multispectral images on 3D models.Finally, we used the registered data to improve the reflectance estimation from the multispectral datasets&nbsp;</p>

Autokollimationszielungen mit dem Leica Absolute Tracker AT401

2013

Stefan Hauth, M SchlĂĽter

Allgemeine Vermessungs-Nachrichten
<p>Autokollimationszielungen ergänzen die hochgenaue 3D-Koordinatenmesstechnik und ermöglichen die präzise Festlegung von Richtungen im Raum auch unter beengten räumlichen Verhältnissen. Exemplarisch untersuchen wir die Durchführung von Autokollimationzielungen mit einem Lasertracker.</p><p>Um die neuartige Vorgehensweise mit dem Leica Absolute Tracker AT401 dem klassischen Prozedere mit Industrietheodolit und Autokollimationsokular vergleichend gegenüber stellen zu können, vermessen wir einen verspiegelten Prüfkörper dreimal unabhängig voneinander mit unterschiedlichen Gerätesystemen.</p>

Autokollimationszielungen mit dem Leica Absolute Tracker AT401

2013

Hauth, S., M SchlĂĽter

Allgemeine Vermessungs-Nachrichten (avn)
<p>Autokollimationszielungen ergänzen die hochgenaue 3D-Koordinatenmesstechnik und ermöglichen die präzise Festlegung von Richtungen im Raum auch unter beengten räumlichen Verhältnissen. Exemplarisch untersuchen wir die Durchführung von Autokollimationzielungen mit einem Lasertracker. Um die neuartige Vorgehensweise mit dem Leica Absolute Tracker AT401 dem klassischen Prozedere mit Industrietheodolit und Autokollimationsokular vergleichend gegenüber stellen zu können, vermessen wir einen verspiegelten Prüfkörper dreimal unabhängig voneinander mit unterschiedlichen Gerätesystemen.</p>

Automatic object detection in point clouds based on knowledge guided algorithms

2013

Truong, H. Q., A Karmacharya, Waldemar Kisser, F Boochs, C Chudyk, Habed, A., Voisin, Y.

SPIE Optical Metrology, International Society for Optics and Photonics, 2013
<p>The modeling of real-world scenarios through capturing 3D digital data has been proven applicable in a variety of industrial applications, ranging from security, to robotics and to fields in the medical sciences. These different scenarios, along with variable conditions, present a challenge in discovering flexible appropriate solutions. In this paper, we present a novel approach based on a human cognition model to guide processing. Our method turns traditional data-driven processing into a new strategy based on a semantic knowledge system. Robust and adaptive methods for object extraction and identification are modeled in a knowledge domain, which has been created by purely numerical strategies. The goal of the present work is to select and guide algorithms following adaptive and intelligent manners for detecting objects in point clouds. Results show that our approach succeeded in identifying the objects of interest while using various data types.</p>

Einrechnung von Laserterminals LCT fĂĽr Europas Spacedatahighway EDRS

2013

M SchlĂĽter

n.A.
<p><strong>Motivation</strong><br />Tesat Spacecom realisiert laserbasierte Systeme für die optische Kommunikation zwischen Erdsatelliten, sog. Laser Terminals LCT. Eine besondere technische<br />Herausforderung ist es hierbei, den Laserstrahl vom sendenden Satelliten präzise auf den empfangenden Satelliten zu richten, der sich in einer Entfernung<br />von mehreren tausend Kilometern befindet und sich mit einer Geschwindigkeit von ca. 25.000 km/h bewegt. Für das i3mainz ist die Lösung der zugehörigen anspruchsvollen messtechnischen Aufgaben an der Grenze der heute erreichbaren Genauigkeit von großem Interesse, da sich daraus zahlreiche Impulse<br />für messtechnische Lösungen auf der Erde ergeben, insbesondere für Objekte &bdquo;in Bewegung&ldquo;: Zukünftige Einsatzfelder könnten durchaus in der automatisierten Baumaschinensteuerung oder in der Schwingungserfassung und Vibrationsanalyse für die Instandhaltung von technischen Bauwerken liegen. Mit der Unterzeichnung des Rahmenvertrags über die Lieferung von Laserkommunikations-Terminals für EDRS zwischen Tesat und der europäischen Weltraumbehörde ESA gewinnt die kommerzielle Nutzung von Laserterminals deutliche Konturen: Das European Data Relay Satellite System EDRS ist ein System von geostationären Kommunikationssatelliten, die eine kontinuierliche Datenübertragung zwischen Satelliten, unbemannten Flugkörpern (UAVs) und Bodenstationen ermöglicht. Das System soll Vollzeitkommunikation auch mit Satelliten in erdnaher Umlaufbahn erlauben, die derzeit immer nur während des kurzen Zeitfensters eines direkten Überflugs mit der Bodenstation Daten austauschen können. EDRS wird hochaktuelle Geoinformationen am richtigen Ort und zur richtigen Zeit verfügbar machen und damit zum Beispiel Rettungskräfte mit Nahe-Echtzeit-Satellitendaten und Informationen der Krisenregion versorgen, in der sie tätig sind. Die ersten Terminals werden in die beiden niedrig fliegenden LEO-Satelliten Sentinel 1a und Sentinel 2a und den geostationären Satelliten Alphasat montiert.<br /><br /><strong>Aktivitäten</strong><br />Aus Sicht des i3mainz gab die neue Konzeption zur hochgenauen Laborkalibrierung von Laserterminals seitens Prof. Dr. Martin Schlüter Anfang 2006 den<br />Startschuss. Noch in 2006 folgte die Kalibrierung des Laserterminals für den deutschen Erdbeobachtungssatelliten TerraSAR-X. In 2007 schloss sich die Einrechnung des Laserterminals für den amerikanischen Technologiesatelliten NFIRE an. Zwischen diesen beiden Satelliten gelingt bis heute der erfolgreiche Datentransfer zwischen Laserterminals im Orbit um die Erde. In den Jahren 2007 bis 2008 wurde seitens des i3mainz das Kinematische Tracking mit zwei motorisierten Digitalkameratheodoliten auf der Basis von motorisierten Präzisionstheodoliten Leica TM5100 mittels automatisierter Bildverarbeitung realisiert. Diese neuartigen Messsysteme bewährten sich 2009 bei der Einrechnung des Laserterminals MLT. Zukunftsweisend ist die Untersuchung des i3mainz zur Eignung des Lasertrackers Leica AT401 für Autokollimationszielungen auf Referenzwürfel in 2012, mit freundlicher Unterstützung der Hexagon Metrology GmbH. Zur Einrechnung des Laserterminals für Alphasat erweisen sich die i3mainz-Digitalkameratheodolite bereits als bewährte Arbeitspferde.</p>

Automatic Detection and Classification of Objects in Point Clouds using multi-stage Semantics

2013

Truong, H. Q., Ben Hmida, H., F Boochs, Habed, A., Cruz, Ch., Voisin, Y., Nicolle C Cruz C.

PDF

Journal of photogrammetry, remote sensing and geoinformation processing
<p><span style="line-height: 1.538em;">Due to the increasing availability of large unstructured point clouds obtained from laser scanning and/or photogrammetric data, there is a growing demand for automatic processing methods. Given the complexity of the underlying problems, several new methods try to using semantic knowledge in particular for supporting object detection and classification. In this paper, we present a novel approach which makes use of advanced algorithms to benefit from intelligent knowledge management strategies for the processing of 3D point clouds and for object classification in scanned scenes. In particular, our method extends the use of semantic knowledge to all stages of the processing, including the guidance of the 3D processing algorithms. The complete solution consists in a multi-stage iterative concept based on three factors: the modelled knowledge, the package of algorithms, and the classification engine. Two case studies illustrating our approach are presented in this paper. The studies were carried out on scans of the waiting area of an airport and along the tracks of a railway. In both cases the goal was to detect and identify objects within a defined area. With our results we demonstrate the applicability of our approach.</span></p><p>&nbsp;</p><p><span style="line-height: 1.538em;">Automatische Detektion und Klassifikation von Objekten in Punktwolken unter Nutzung mehrschichtiger Semantik. Infolge der zunehmenden Verfügbarkeit großer unstrukturierter Punktwolken aus Laserscanning und Photogrammetrie entsteht wachsender Bedarf für automatisierte Auswerteverfahren. Angesichts der häufig hohen Komplexität der in den Punktwolken enthaltenen Objekte stoßen rein datengetriebene Ansätze an ihre Grenzen. Es entstehen vermehrt Konzepte, die auf verschiedene Weise auch Gebrauch von der Semantik machen. Semantik und Algorithmik sind dabei oft eng miteinander verwoben und führen zu Limitationen in Art und Umfang der nutzbaren Semantik. Mit der vorgestellten Lösung werden Algorithmik und Semantik klar getrennt und mit den exakt auf diese Domänen zugeschnittenen Werkzeugen behandelt. Deren prozedurale Verknüpfung führt dann zu einem neuen Verarbeitungskonzept, das eine nach unserem Kenntnisstand bislang nicht erreichte Flexibilität und Vielseitigkeit in der Nutzung unterschiedlichster Semantiken besitzt und auch die Steuerung der Algorithmen integriert. Die iterative Gesamtlösung fußt auf drei Säulen, nämlich dem modellierten Wissen, dem Pool der Algorithmen und dem Identifikationsprozess. Erreichbare Resultate werden an zwei Beispielen dokumentiert. Ein Beispiel befasst sich mit der Analyse von Punktwolken aus dem Bereich der Lichtraumvermessung an Bahntrassen, das zweite mit Räumlichkeiten in einem Flughafen. In beiden Fällen müssen bestimmte Objektarten aufgefunden und klassifiziert werden.</span></p>

Schneller und ausdauernder als das menschliche Auge: Modulare Okularkameras am Motortachymeter

2013

Hauth, S., M SchlĂĽter, Thiery, F.

Allgemeine Vermessungs-Nachrichten (avn)
<p>Bis zu 62 500 Zielungen pro Sekunde werden derzeit mit einer USB 3.0 Industriekamera am geodätischen Tachymeter erreicht. Exemplarisch betrachten wir die Einsatzmöglichkeiten solcher Systeme für die Erfassung hochfrequenter Schwingungen, stellen aktuelle Grenzen dar und schlagen einen pragmatischen Weg für eine präzise zeitliche Zuordnung der Beobachtungen mithilfe eines GPS-Zeitempfängers vor.</p><p>Neben hochfrequenten Zielungen erlaubt das am Institut für raumbezogene Informations- und Messtechnik i3mainz entwickelte Konzept MoDiTa &ndash; Modulare DigitalkameraTachymeter &ndash; ein hochgenaues Monitoring über lange Zeiträume. Mithilfe der modularen Okularkameras und einem Kollimator als Ziel werden die bekannten Verfahren zur automatischen Zielerfassung und Zielverfolgung von Punkten im Raum (wie z.B. ATR) mit der hochgenauen Erfassung absoluter Ausrichtungen im Raum ergänzt.</p>

Vermessungs- und Dokumentationsarbeiten im Bergland der Krim

2013

A Cramer, G Heinz

Die Höhensiedlungen im Bergland der Krim
<p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>

2012

From Unstructured 3D Point Clouds to Structured Knowledge - A Semantics Approach

2012

F Boochs, Ben Hmida, H., C Cruz, C Nicolle, Muhammad Tanvir Afzal

PDF

Semantics - Advances in Theories and Mathematical Models
<p>Over the last few years, formal ontologies has been suggested as a solution for several engineer problems, since it can efficiently replace standard data bases and relational one with more flexibility and reliability. In fact, well designed ontologies own lots of positive aspects, like those related to defining a controlled vocabulary of terms, inheriting and extending existing terms, declaring a relationship between terms, and inferring relationships by reasoning on existent ones. Ontologies are used to represent formally the knowledge of a domain where the basic idea was to present knowledge using graphs and logical structure to make computers able to understand and process it, (Boochs, et al., 2011). As most recent works, the tendency related to the use of semantic has been explored, (Ben Hmida, et al., 2010) (Hajian, et al., 2009) (Whiting, 2006) where the automatic data extraction from 3D point clouds presents one of the new challenges, especially for map updating, passenger safety and security improvements. However such domain is characterized by a specific vocabulary containing different type of object. In fact, the assumption that knowledge will help the improvement of the automation, the accuracy and the result quality is shared by specialists of the point cloud processing.</p>

Modular Imaging Total Stations - Sensor Fusion for high precision alignment

2012

Hauth, S., M SchlĂĽter, Thiery, F.

PDF

3rd International Conference on Machine Control & Guidance Proceedings
<p>Initialized in 2009, the Institute for Spatial Information and Surveying Technology (i3mainz), Mainz University of Applied Sciences, forces research towards modular concepts for imaging total stations. On the one hand, this research is driven by the successful setup of high precision imaging motor theodolites in the near past, on the other hand it is pushed by the actual introduction of integrated imaging total stations to the positioning market by the manufacturers Leica Geosystems, Sokkia, Pentax, Topcon and Trimble.</p><p>Modular concepts for imaging total stations are manufacturer independent to a large extent and consist of a particular combination of accessory hardware, software and algorithmic procedures. The hardware part consists mainly of an interchangeable eyepiece adapter offering opportunities for digital imaging. An easy assembly and disassembly in the field is possible allowing the user to switch between the classical and the imaging use of a robotic total station. The software part primarily has to ensure hardware control, but several level of algorithmic support might be added and have to be distinguished. Algorithmic procedures allow reaching several levels of calibration concerning the geometry of the external digital camera and the total station. Here the resulting resolution capacity of our sensor fusion and also the accuracy of the system are presented based on examples. We deliver insight in our recent developments and quality characteristics.</p><p>The sensor fusion between camera and polar measuring system allows detecting and measuring different types of targets with high precision. MoDiTa is used to calibrate inclination sensors and to control the long-term stability of laser and tripods.</p>

Entwicklung von Verfahren zur rechnergestĂĽtzten VerknĂĽpfung von Bild- und Laserscandaten auf Basis von Passobjekten

2012

Schilling, K.

PDF

n.A.
<p>Aufgrund der komplementären Eigenschaften von Bild- und Scandaten werden zunehmend<br />digitale Photogrammetrie und terrestrisches Laserscanning simultan für die Erfassung und<br />Dokumentation dreidimensionaler Objekte verwendet. Ihre gemeinsame Nutzung erfordert<br />die Korrespondenzherstellung zwischen den unterschiedlichen, heterogenen Datentypen und<br />die Verknüpfung gleicher Datentypen verschiedener Aufnahmestandpunkte.<br />Das in dieser Arbeit entwickelte Verfahren nutzt spezielle Passobjekte, um bessere Bedingungen<br />für eine Korrespondenzherstellung zu scha ffen. Der Schwerpunkt liegt dabei in der<br />Verknüpfung der Scandaten.<br />Die Eckpunkte von Würfeln werden als Passpunkte zur Bestimmung der Transformationsparameter<br />verwendet. Die Zerlegung des Würfels in seine Einzelelemente (Ebenen, Kanten,<br />Eckpunkte) und die Extraktion der Würfeleckpunkte erfolgt mittels eines RANSAC-Algorithmus<br />sowie der Ausgleichung und Verschneidung der Würfelebenen auf Basis eines<br />topologischen Modells. Dieses erlaubt durch seine Eindeutigkeit die Bestimmung der räumlichen<br />Ausrichtung des Würfels.<br />Die Genauigkeit der berechneten Würfelgeometrie hängt in erster Linie von der Aufnahmeentfernung<br />ab. Für eine Distanz &lt;10m werden maximale Längenabweichungen der Raum- und<br />Flächendiagonalen der Würfel von  4mm erhalten. Die berechneten Werte für die<br />Transformationsparameter bei der Verknüpfung der Scandaten sind vergleichbar mit den Resultaten<br />bestehender Verfahren zur Registrierung von Scandaten. In Abhängigkeit von der<br />Aufnahmekon guration betragen die Restklaff ungen der Passpunkte bis zu 5mm. Im Gegensatz<br />zu bestehenden Verfahren werden mit nur einem Würfel bereits gute Näherungswerte<br />für die Transformationsparameter erhalten. Die Bestimmung der Würfeleckpunkte aus den<br />Scandaten schaff t zugleich gute Voraussetzungen für eine Verknüpfung mit den Bilddaten, die<br />unabhängig von der Position des Scannerstandpunktes aufgenommen werden können.</p>

i3mainz - Jahresbericht 2012

2012

F Boochs, Gundlach, A., J Wachter

PDF

i3mainz - Jahresbericht
<div>Derzeit sind neben neun Professoren am Institut mehr als zwanzig wissenschaftliche Mitarbeiterinnen und Mitarbeiter mit Zeitverträgen angestellt. Neben ihnen sind Studierende mit ihren Abschlussarbeiten, Praktikanten und studentische Mitarbeiterinnen und Mitarbeiter in die Arbeit des Instituts eingebunden.</div><div>Im Jahr 2012 standen Mittel im Gesamtumfang von 1,28 Mio Euro zur Verfügung. Dazu zählten Mittel der FH Mainz, des Landes, öffentlicher Förderprogramme, der Europäischen Union und Drittmittel aus der Wirtschaft.&nbsp;</div>

A knowledge-based approach to the automatic algorithm selection for 3D scene annotation

2012

Truong, H. Q., F Boochs, Habed, A., Voisin, Y.

11th International Conference on Information Science, Signal Processing and their Applications (ISSPA) IEEE
<p>In this paper we present a novel approach for 3D point cloud processing with the aim of annotating objects in a scanned scene. Our method is based on human cognition to guide the 3D processing algorithms and uses semantic knowledge to manage data and identify immediate situation-dependent objectives. In particular, we have built a system that allows an automatic and flexible selection of algorithms. The selection strategy exploits knowledge to identify the geometrical features to be detected as well as the objects to be annotated at each stage of the 3D processing of the point cloud.</p>

2011

Asserting the Precise Position of 3D and Multispectral Acquistion Systems for Multisensor Registration Applied to Cultural Heritage Analysis

2011

F Boochs, SchĂĽtze, R., Simon, C., MARZANI F.

PDF

Advances in Multimedia Modeling
<p>We present a novel method to register multispectral acquisitions on a 3D model. The method is based on the external tracking of the acquisition systems using close-range photogrammetric techniques: multiple calibrated cameras simultaneously observe the successive acquisition systems in use. The views from these cameras are used to precisely determine the position of each acquisition system. All datasets can then be projected in the same coordinate system. The registration is thus independent from the quality and content of the data. This method is well suited to the study of cultural heritage or any other application where we do not wish to place targets on the object. We describe the method and the simulation pipeline used to find an adequate setup for two case studies.</p>

Geometrische Qualität von aus Einzelphotos zusammengesetzten Panoramen

2011

Kern, F., S Mehlig, Siegrist, B., Seyfert, E.

PDF

29. Wissenschaftliche Jahrestagung der DGPF - Mainz - Geodaten - Eine Ressource des 21. Jahrhunderts
<p>Untersucht wird, inwieweit aus mehreren Einzelphotos gerechnete vollsphärische Panoramabilder geometrisch korrekt mit der Software PTGui berechnet werden können. Ausgangsbasis der Qualitätsbeurteilung sind Photos für 80 Panoramen, welche zusammen mit der TLS-Vermessung des UNESCO-Welterbes St. Michaelis zu Hildesheim und der Stadtkirche Michelstadt entstanden sind. Die Photos sind mittels digitaler Spiegelreflexkameras im High-Definition-Range-Modus unter Verwendung hochwertiger Nodalpunktadapter aufgenommen worden. Mit der professionellen Stitching-Software PTGui sind diese zu Panoramen verarbeitet wurden. Sie weisen - rein visuell beurteilt - eine hohe Güte auf mit glatten Detail- und Helligkeitsübergängen. Trotz dieser augenscheinlichen guten Präzision verbleibt eine gewisse Skepsis darüber, ob das Panorama auch hinsichtlich der inneren Geometrie einwandfrei ist; zumal PTGui hierüber keine nachvollziehbaren Angaben liefert. Da zu jedem Panorama zugleich eine hoch aufgelöste 3D-Punktwolke vom gleichen Aufnahmestandort erfasst wurde, kann diese als geometrische Referenz genutzt werden, um die visuelle Güte mit quantitativen Methoden zu prüfen. Über manuell ausgewählte Punktidentitäten im TLS-Remissionsbild und im Panorama werden hierzu einfache Qualitätsuntersuchungen durchgeführt. Es werden Aussagen über die Güte der gegenseitigen Orientierung beider Datenebenen im Sinne einer Starrkörperbewegung getroffen und damit über die Konstanz in der Fixierung der Kamera im Nodalpunktadapter.</p>

Bildverarbeitungsgestütztes Kalibrier-, Prüf- und Feldprüfverfahren für Terrestrische Laserscannersysteme zur Qualitätssteigerung (SigmaTLS+)

2011

Kern, F.

Schlussbericht zum BMBF-Forschungsvorhaben









Toward the automatic generation of semantic VRML model from unorganized 3D point clouds

2011

F Boochs, Ben Hmida, H., Nicolle C Cruz C.

PDF

SEMAPRO 2011 - The Fifth International Conference on Advances in Semantic Processing
<p>This paper presents our experience regarding the creation of 3D semantic facility model out of unorganized 3D point clouds. Thus, a knowledge-based detection approach of objects using the OWL ontology language is presented. This knowledge is used to define SWRL detection rules. In addition, the combination of 3D processing built-ins and topological Built-Ins in SWRL rules aims at combining geometrical analysis of 3D point clouds and specialist&rsquo;s knowledge. This combination allows more flexible and intelligent detection and the annotation of objects contained in 3D point clouds. The created WiDOP prototype takes a set of 3D point clouds as input, and produces an indexed scene of colored objects visualized within VRML language as output. The context of the study is the detection of railway objects materialized within the Deutsche Bahn scene such as signals, technical cupboards, electric poles, etc. Therefore, the resulting enriched and populated domain ontology, that contains the annotations of objects in the point clouds, is used to feed a GIS system.</p>

Mobile 3D-Mapping with a Low-Cost UAV System

2011

Klonowski, J., Neitzel, F.

PDF

International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences; Vol. XXXVIII-1/C22 -Conference on Unmanned Aerial Vehicle in Geomatics-
<p>In this contribution it is shown how an UAV system can be built at low costs. The components of the system, the equipment as well as the control software are presented. Furthermore an implemented programme for photogrammetric flight planning and its execution are described. The main focus of this contribution is on the generation of 3D point clouds from digital imagery. For this web services and free software solutions are presented which automatically generate 3D point clouds from arbitrary image configurations. Possibilities of georeferencing are described whereas the achieved accuracy has been determined. The presented workflow is finally used for the acquisition of 3D geodata. On the example of a landfill survey it is shown that marketable products can be derived using a low-cost UAV.</p>

Knowledge Base Approach for 3D Objects Detection in Point Clouds Using 3D Processing and Specialists Knowledge

2011

F Boochs, Ben Hmida, H., Nicolle C Cruz C.

PDF

International Journal on Advances in Intelligent Systems
<p>This paper presents a knowledge-based detection of objects approach using the OWL ontology language, the Semantic Web Rule Language, and 3D processing built-ins aiming at combining geometrical analysis of 3D point clouds and specialist&rsquo;s knowledge. Here, we share our experience regarding the creation of 3D semantic facility model out of unorganized 3D point clouds. Thus, a knowledge-based detection approach of objects using the OWL ontology language is presented. This knowledge is used to define SWRL detection rules. In addition, the combination of 3D processing built-ins and topological Built-Ins in SWRL rules will allows more flexible and intelligent detection, and the annotation of objects contained in 3D point clouds. The created WiDOP prototype takes a set of 3D point clouds as input, and produces as output a populated ontology corresponding to an indexed scene visualized within VRML language. The context of the study is the detection of railway objects materialized within the Deutsche Bahn scene such as signals, technical cupboards, electric poles, etc. Thus, the resulting enriched and populated ontology, that contains the annotations of objects in the point clouds, is used to feed a GIS system or an IFC file for architecture purposes.</p>

Mobile 3D Mapping mit einem Low-Cost-UAV-System am Beispiel der Deponievermessung

2011

Klonowski, J., Neitzel, F., Siebert, S., J -P Dasbach, T Luhmann, Ch. MĂĽller

Photogrammetrie - Laserscanning Optische 3D-Messtechnik - Beiträge der Oldenburger 3D-Tage 2011









i3mainz - Jahresbericht 2011

2011

F Boochs, K Böhm, K -C Bruhn, Kern, F., Klinge, K.-A., Klonowski, J., H Müller

PDF

i3mainz - Jahresbericht
<div>Angewandte Forschung, Entwicklung und Technologietransfer im fachlichen Umfeld der&nbsp;<span style="line-height: 1.538em;">Geoinformatik und Vermessung sind die Arbeitsschwerpunkte im Institut. Moderne Verfahren&nbsp;</span><span style="line-height: 1.538em;">der Messtechnik für die Gewinnung raumbezogener Daten und die Technologien zu deren&nbsp;</span><span style="line-height: 1.538em;">Weiterverarbeitung, Analyse und Visualisierung stellen dabei die wichtigsten Werkzeuge dar.</span></div><div>&nbsp;</div><div><span style="line-height: 1.538em;">Im Jahr 2011 standen Mittel im Gesamtumfang von ca. &euro; 1.090.000 zur Verfügung, womit das&nbsp;</span><span style="line-height: 1.538em;">Institut erneut die Schwelle von 1 Mio. EUR überschreiten konnte. Diese Mittel wurden vor </span><span style="line-height: 1.538em;">allem zur Bezahlung des Personals verwendet. Der größte Anteil (59%) sind Drittmittel, 20%&nbsp;</span><span style="line-height: 1.538em;">stammen vom Ministerium für Bildung, Wissenschaft Jugend und Kultur Rheinland-Pfalz und&nbsp;</span><span style="line-height: 1.538em;">weitere 21% aus dem Haushalt der Fachhochschule Mainz.</span></div>

Integration of knowledge to support automatic object reconstruction from images and 3D data

2011

F Boochs, Ben Hmida, H., A Karmacharya, Marbs, A., Truong, H. Q., C Cruz, C Nicolle, A : V Habed

PDF

Eighth International Conference on Systems, Signals and Devices (SSD) 2011
<p>Object reconstruction is an important task in many fields of application as it allows to generate digital representations of our physical world used as base for analysis, planning, construction, visualization or other aims. A reconstruction itself normally is based on reliable data (images, 3D point clouds for example) expressing the object in his complete extent. This data then has to be compiled and analyzed in order to extract all necessary geometrical elements, which represent the object and form a digital copy of it. Traditional strategies are largely based on manual interaction and interpretation, because with increasing complexity of objects human understanding is inevitable to achieve acceptable and reliable results. But human interaction is time consuming and expensive, why many researches has already been invested to use algorithmic support, what allows to speed up the process and to reduce manual work load.</p><p>Presently most of such supporting algorithms are datadriven and concentrate on specific features of the objects, being accessible to numerical models. By means of these models, which normally will represent geometrical (flatness, roughness, for example) or physical features (color, texture), the data is classified and analyzed. This is successful for objects with low complexity, but gets to its limits with increasing complexness of objects. Then purely numerical strategies are not able to sufficiently model the reality.</p><p>Therefore, the intention of our approach is to take human cognitive strategy as an example, and to simulate extraction processes based on available human defined knowledge for the objects of interest. Such processes will introduce a semantic structure for the objects and guide the algorithms used to detect and recognize objects, which will yield a higher effectiveness. Hence, our<br />research proposes an approach using knowledge to guide the algorithms in 3D point cloud and image processing.</p>

Introduction of a spatial layer in the Semantic Web framework: a proposition through the Web platform ArchaeoKM

2011

A Karmacharya

PDF

n.A.
<p>Spatial technology has gained momentum under database systems. More specifically, the spatial operations and spatial functions are used to carry out spatial analysis which can be executed through these database systems. In addition, there has been significant amount of research in the field of the geospatial ontology domain in order to achieve the semantic interoperability between different data sources. Although, data interoperability is one of the main objectives of the Semantic Web technologies, the potentiality of the underlying knowledge tools and techniques have not been completely identified. With the growing influence of the Semantic Web technologies towards the application based on knowledge management and intelligent systems, the geospatial application benefits from this influence. This thesis emphasizes on the use of knowledge to manage spatial data within spatial information systems through the Semantic Web framework.<br />This research activity is carried out with the backdrop of the case study of the industrial archaeology. It sets up an ideal environment for the application of knowledge to manage the huge and heterogeneous dataset. The use of knowledge to manage the diversity of information was well executed through the application prototype named ArchaeoKM which is based on the Semantic Web. The ArchaeoKM framework follows the 4Ks processing steps: Knowledge Acquisition, Knowledge Management, Knowledge Visualization and Knowledge Analysis. The same processing principle of 4Ks was implemented during the spatial knowledge processing. A top level ontology was developed in order to serve as the background representation of the case study in order to adjust the spatial components. Keeping the custom, the spatial knowledge processing begins with acquiring spatial signatures of the identified objects. The spatial signatures are stored within the spatial database system with proper mapping to the objects in the knowledge base. The spatial knowledge of these objects is managed through executing the spatial functions at the database level and enriching the knowledge base with the results. This spatially enriched knowledge base is used again to analyze the spatial knowledge. This research thesis benefits from Semantic Web Rule Language in order to infer knowledge. In addition, the spatial built-ins proposed during the course add up spatial dimension to the SWRL for spatial inferences. Similarly, a spatial extension of the query language SPARQL is proposed in order to query spatial knowledge from the knowledge base.<br />Actually, this research thesis provides the initial steps in integrating spatial components within the Semantic Web framework. This integration process is important for both technologies. Regarding the Semantic Web, the integration of non-typical semantic information within this framework opens up doors to other data pattern making the transformation of technologies easier. Likewise, geospatial technologies and GIS systems benefits through the inclusion of knowledge in the analysis process making the analysis much closer and efficient to human interpretation.</p>