Thèses sur le sujet « Digital photogrammetry technique »

Changes in orthopaedic practice have led to an increased reliance upon fluoroscopic image-guidance during fracture fixation (osteosynthesis) procedures. The resulting complexity of surgical techniques, and concerns over X-ray radiation exposure levels to orthopaedic surgeons, has prompted an investigation of robotic-assisted orthopaedic surgery, with a view to improving the precision, repeatability and radiation safety of existing fluoroscopically-guided bone drilling procedures. A prerequisite for such an application is to establish the patient's location with respect to the robotic manipulator. Owing to the inherent nature of osteosynthesis procedures, this intraoperative registration process can only be performed by quantifying the existing fluoroscopic examination process. A digital X-ray photogrammetry based registration technique, which uses a radiolucent robot-mounted X-ray calibration frame, has therefore been investigated. When this calibration frame is simultaneously imaged with the patient, discrete registration markers, corresponding to radiopaque fiducials embedded in the frame, are superimposed into the standard intraoperative X-ray images. Digitising these images, using a PC-based frame grabber card, has allowed semi-automatic image analysis routines to be implemented. Applying correction-calibration software, which provides on-line compensation for image distortion effects, then allows the imaged part of the patient's skeleton to be located, with respect to the calibration frame's coordinate system, thus establishing intraoperative registration. In vitro laboratory-based trials of this registration technique indicate that reconstruction errors are in the sub-millimetre range. As such, this new approach represents a low cost non-invasive registration option, which fully adheres to "operating room compatibility" criteria, and is applicable to a wide range of osteosynthesis procedures. Significantly, by extending the technique to include quantification of the trajectory plarming process, it has also been possible to demonstrate major improvements over existing surgical techniques.

Bibliography: pages 133-156.
The deep-level gold mines on the Witwatersrand (South Africa) are located at depths of over 3,000m below surface. Mining excavations follow tabular reefs that are kilometres in extent, but only a few centimetres thick. Due to the great depths of these excavations and the large overburden of rock, immense pressure is exerted on the rock mass being excavated. In order to relieve this stress in the rock mass being mined, the rock is "pre-conditioned" by pre-fracturing the rock face with large blasts. This has the effect of pushing the critical stress load further into the rock mass, thus increasing safety at the rock face. To better understand the rock behaviour as a result of by pre-conditioning blasts, it is desirable to quantify the deformations of the rock face. Digital photogrammetry provides an ideally suited method of monitoring these deformations, as the necessary equipment is portable and easy to use underground, where the conditions are extreme with temperatures approaching 40°C and humidity levels close to 100%. Digital photogrammetric techniques are also highly accurate, and can be used to detect relatively small three-dimensional movements. The determination of the three-dimensional (XYZ) co-ordinates of the rock face, represented by densely spaced individual points, by means of digital photogrammetric techniques, is reported in this thesis. The novel measurement system developed comprises the following components: * establishment of a stable reference co-ordinate system; * image acquisition; * camera calibration and exterior orientation calculation; * feature extraction; * multi-image matching and space intersection; and * surface modelling. The details of the techniques developed and implemented in order to generate the necessary object space co-ordinates are discussed. Sub-millimetre accuracy point determination, as required for deformation analysis was achieved and a sample of the underground test result data is presented. The final analysis of the underground test data made it apparent that digital photogrammetry is highly suitable for the determination of digital terrain models of the rock surfaces, for subsequent deformation analysis. The relative speed of the process and the convenient size of the equipment makes the technology especially suitable to the demanding underground mining environment. The difficulties, which were experienced as a result of the highly restrictive environment, were overcome through careful planning and pre-analysis. It can thus be concluded that this approach is not only feasible, but it meets the stringent demands of the underground mining industry, as is confirmed by the high accuracy of the final surface point co-ordinates achieved. In addition to being implemented in the underground mining industry, the measurement system developed was used for the mapping of several other textured surfaces. In particular it was used in mapping the 3.6 million-year-old hominid trackway located at Laetoli (Tanzania), the imprints of cheetah and rhinoceros for the purposes of conservation, and for the archaeological documentation of a shipwreck found off the Cape coast (South Africa). All of these applications are discussed and the results achieved presented.

Every year, thousands of people all over the world are loosing their lives in natural disasters. As a second most widespread hazard, landslides are still a disaster problem for Turkey. The long-term monitoring studies of instability phenomena have a paramount importance for Turkey to reduce its both direct and indirect effects. The objective of this thesis is to monitor the activity of the Bü
lbü
lderesi and Bakacak landslides in Asarsuyu Catchment for 42 years period by the digital aerial photogrammetric techniques while evaluating the possible use of archive aerial photography in such analysis. To achieve the purpose of the study an orthophoto map was generated by aerial photographs belonging to 1994 year. The orthophoto map was utilized as a base map for aerial photo interpretation of different sets of aerial photographs corresponding to 1952, 1972, 1984 and 1994 years. As a result of this, 4 landslide activity maps are obtained. In addition, the characteristics of these landslides are analyzed by utilizing digital elevation model (DEM) created from stereo photographs of 1994. As a result of the study, no considerable variation is detected in the position of main boundaries of Bü
lbü
lderesi and Bakacak landslides except some minor differences. However, within the landslides many topographical changes were observed between 1952 and 1994 period. Based on the profiles from toe to crest of the Bü
lbü
lderesi landslide, the approximate length was measured as 4773m whereas the approximate width was about 2614m. The areal extent was calculated as ~12km2 having an approximate slope gradient ranging between 10-15°
with local variations. On the other hand, the approximate length of Bakacak landslide was 4420m and the approximate width was 832m from toe to crest with an area of ~4km2 and with an approximate slope angle 9-14°
.

Submitted by Andrea Bastian (avbastian@uol.com.br) on 2018-05-04T14:02:03Z No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5)
Approved for entry into archive by Biblioteca de Arquitetura (bibarq@ufba.br) on 2018-05-09T14:10:25Z (GMT) No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5)
Made available in DSpace on 2018-05-09T14:10:25Z (GMT). No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5)
Esta pesquisa apresenta um estudo sobre métodos e técnicas de baixo custo para o levantamento métrico de sítios históricos, iniciando com os conceitos de patrimônio cultural e as primeiras recomendações internacionais para conservação e restauro de monumentos. Foram discutidos também, a crescente preocupação com a proteção de bens no Brasil e os diversos inventários já realizados. Foram apresentadas as principais tecnologias para levantamento de formas arquitetônicas baseadas em imagens com ênfase na Fotogrametria Digital, os conceitos e processos envolvidos, os requisitos e orientações para levantamentos fotogramétricos e os principais programas utilizados para restituição. A pesquisa, também, tratou do problema de extração de feições a partir de imagens digitais, discutindo os conceitos e etapas de processamento. A parte prática mostra os estudos de caso realizados com o objetivo de apreender e testar três ferramentas (PhotoModeler, Orthoware e pacote Sphera), avaliando qualidade, limites e potencialidades, gerando como produtos: ortofotos, ortofotomosaico e desenhos de restituição de fachadas, que foram utilizados como fonte de dados para geração de modelos geométricos. Ainda, foram realizados experimentos para extração automática de feições (vetorização automática) de imagens com o intuito de facilitar o processo de vetorização das ortofotos. Pode-se comprovar que a Fotogrametria Digital é uma ferramenta acessível, de custo reduzido que atende à demanda existente de documentação, de forma rápida e precisa; mas, para que isso seja possível, se deve levar em conta o conhecimento das diversas técnicas, a definição dos produtos desejados e as ferramentas existentes para que a escolha recaia sobre a técnica mais adequada.
This thesis presents a study on methods and low-cost techniques for historic sites surveys, it starts with the concepts of culture heritage and the first international recommendations for conservation and restoration of monuments, this study discussed about the evolution of the concern for the protection of property in Brazil and the various inventories already made. It presented the survey technologies for architectural documentation based on images with emphasis on Digital Photogrammetry, the concepts and processes involved the requirements and guidelines for photogrammetric surveys and the main photogrammetric software used to restitution. The survey also addressed the problem of features extraction from digital images, discussing the concepts and processing steps. The practical part presents some case studies that allowed to the apprehending and also the testing of three tools (PhotoModeler, Orthoware and Sphera package), as a way to assess quality, limits and potential to generate products as orthophotos, ortofotomosaico and facades restitution drawings, which were used as data source for generating geometric models. Still, experiments for automatic feature extraction were performed (automatic vectorization) of images in order to facilitate the process of vectorization from orthophotos. Digital Photogrammetry proved to be a handy low-cost tool, which meets the existing demand for documentation, as quickly and accurately as possible, but in order to make this possible is necessary to know the different techniques,the definition of the desired products and existing survey methods to select the most appropriate technique.

This thesis outlines a technique for rapid documentation of historic sites in volatile cultural landscapes. Using Holt Cemetery as an exemplary case study, a workflow was developed incorporating RTK terrain survey, UAS aerial imagery, photogrammetry, GIS, and smartphone data collection in order to create a multifaceted database of the material and spatial conditions, as well as the patterns of use, that exist at the cemetery. The purpose of this research is to create a framework for improving the speed of data creation and increasing the accessibility of information regarding threatened cultural resources. It is intended that these processes can be scaled and adapted for use at any site, and that the products generated can be utilized by researchers, resource management professionals, and preservationists. In utilizing expedited methods, this thesis specifically advocates for documentation of sites that exist in coastal environments and are facing imminent destruction due to environmental degradation.

Constantly growing people’s needs and industrial technologies cause the necessity to increase transport, which simultaneously increases the risk of accidents on the roads and spills of hazardous substances, including leakage of oil, hydraulic fluids, lubricants, and cargo spillage. These substances threaten the safety of road, all the road users and natural environments. Asphalt road surfaces are degraded by fuel or other liquid spillages; they can contribute to increase road surface material damage during vehicles trafficking. The effects of spilled substances on the road surface and consequently on the environment and user safety depend also on the exposure time. Due to the unpredictable of accidental situations and the positioning within the territory, there are situations that are managed at different time. Therefore, the exposure time become a fundamental parameter to be considered in the test to evaluate the different behaviors of road surface and the variation in danger over time. In this scenario, the research aims to evaluate the effects of hazardous liquid spilled from vehicles on the asphalt properties and related safety parameters by means of two combined high-resolution 3D geomatic techniques and over different exposure time. Geomatic techniques employed for the characterization of the asphalt samples belong to two different categories: active triangulation techniques (3D structured light projection scanner) and photogrammetric techniques (digital photogrammetry). These techniques are able to perform a three-dimensional modeling of the detected objects: a process that goes from data acquisition to the creation of a virtual 3D model. Products of these modeling should guarantee the maximum geometry accuracy and photo-realistic nature of the scanned objects. Some indicators have been extracted from high-resolution 3D models to study changes in asphalt performances due to the spillage of five different hazardous substances.

Nesta dissertação é apresentado o desenvolvimento de uma ferramenta computacional para o processamento de pares de imagens estereoscópicas obtidos por câmeras aéreas métricas e não métricas. O programa foi desenvolvido na linguagem C++ e foi utilizado a biblioteca OpenGL. O resultado obtido é uma imagem tridimensional de onde pode ser extraídas cotas de altura e formas de terreno. Estas imagens poderão ser usadas no estudo de áreas de risco em encostas.
In this dissertation is presented the development of a computational tool for the processing of pairs of images estereoscópicas obtained by metric and not metric aerial cameras. The program was developed in the program language C++ and the library was used OpenGL. The result of the program is a three-dimensional image from where it can be extracted height quotas and land forms. These images can be used in the study of risk areas on slopes.

碩士
國立臺灣大學
土木工程學研究所
105
The Light Detection and Ranging (LiDAR) technique is a popular 3D surveying technique nowadays, which is capable of swiftly and precisely acquiring point cloud data with high density, for various engineering monitoring tasks. However, due to the limitation on the mechanism of the used technique, the point cloud data acquired by the LiDAR system frequently reaches unfavorable results, which have the flaws, such as uneven resolution and missing areas. In order to solve this problem, a combined approach for delivering high quality 3D colored point cloud is developed in this study, making the quality improvement of point cloud can be accomplished by integrating accurate geometric data from the LiDAR point cloud with the auxiliary information from images. The proposed approach, firstly determines the camera exterior orientation parameters by applying a semi-automatic process based on image matching technique. Secondly, for improving the geometric integrity of the raw data, the collinearity condition, as well as the geometry information from edge and planar features, will be used for point cloud reconstruction and densification. Finally, the abundant spectral information from multi-view images will be extracted and assigned to the refined point cloud data for generating high-quality result, which can be serve as a reliable and stable data source for further applications. The experiment result indicated that the proposed approach can adequately utilize the information from image data to increase the geometrical detail of the LiDAR point cloud. In conclusion, the quality improvement can be achieved through the use of data from different sources, which can successively reduces the limitation of current 3D surveying techniques, and also provides much more reliable and stable 3D information for applications.

Le tecniche di rilevamento rappresentano un utile strumento per rilevare e caratterizzare i processi gravitativi di versante, in particolare attraverso l’uso di approcci volti ad individuare le aree in movimento. Nel dettaglio, tecniche come il laser scanner terrestre e la fotogrammetria digitale permettono di ottenere rappresentazioni ad alta risoluzione dello scenario osservato sotto forma di una nuvola di punti (point cloud) in tre dimensioni. Durante gli ultimi anni, l’uso delle nuvole di punti per investigare i cambiamenti morfologici a scala temporale e spaziale, è notevolmente aumentato. In questo contesto è maturato il presente progetto di ricerca, durante il quale, l’efficacia dell’utilizzo delle nuvole di punti per la caratterizzazione e il monitoraggio di versanti instabili è stata testata e valutata attraverso lo sviluppo di un tool semi-automatico in linguaggio di programmazione MATLAB. Lo strumento di analisi proposto consente di investigare le principali caratteristiche morfologiche dei versanti instabili indagati e di determinare le variazioni morfologiche e gli spostamenti dalla comparazione di nuvole di punti acquisite in tempi differenti. In seguito, attraverso una tecnica di clustering, il codice permette di estrapolare i gruppi le zone interessate da spostamenti significativi e calcolarne l’area. Il tool introdotto è stato testato su due casi di studio contraddistinti da differenti caratteristiche geologiche e da diversi fenomeni di instabilità: l’ammasso roccioso di San Leo (RN) e il versante presso l’abitato di Ricasoli (AR). Per entrambi i casi di studio, sono state individuate e descritte le aree caratterizzate da deformazione superficiale o accumulo di materiale e le aree caratterizzate da distacco di materiale. Inoltre, sono stati approfonditi i fattori che influenzano i risultati della change detection tra nuvole di punti. Remote sensing techniques represent a powerful instrument to detect and characterise earth’s surface processes, especially using change detection approaches. In particular, TLS (Terrestrial Laser Scanner) and UAV (Unmanned Aerial Vehicles) photogrammetry technique allow to obtain high-resolution representations of the observed scenario as a threedimensional array of points defined by x, y and z coordinates, namely point cloud. During the last years, the use of 3D point clouds to investigate the morphological changes occurring over a range of spatial and temporal scales, is considerably increased. During the three-years PhD research programme, the effectiveness of point cloud exploitation for slope characterization and monitoring was tested and evaluated by developing and applying a semi-automatic MATLAB tool. The proposed tool allows to investigate the main morphological characteristics of unstable slopes by using point clouds and to point out any spatio-temporal morphological changes, by comparing point clouds acquired at different times. Once defined a change detection threshold, the routine permits to execute a cluster analysis and automatically separate zones characterized by significant distances and compute their area. The introduced tool was tested on two test sites characterized by different geological setting and instability phenomena: the San Leo rock cliff (Rimini province, Emilia Romagna region, northern Italy) and a clayey slope near Ricasoli village (Arezzo province, Tuscany region, central Italy). For both case of studies, the main displacement or accumulation zones and detachment zone were mapped and described. Furthermore, the factors influencing the change detection results are discussed in details.

Resource managers frequently require moderate to high resolution imagery within short turnaround periods for use in a GIS-based management system. These spatial data can greatly enhance their ability to make timely, cost-saving decisions and recommendations. MBB Consulting Engineers, Inc., of Pietermaritzburg, South Africa had for many years made use of airborne videography to provide the imagery for several resource-based applications. Applications included detailed land use mapping in various South African river catchments and identification, density classification and mapping of alien vegetation. While the system was low cost and easy to operate, MBB had found that their system was inherently limited, particularly by its lack of automation and poor spatial resolution. This project was started because of a need to address these limitations and provide an airborne remote sensing system that was more automated and could produce higher resolution imagery than the existing system. In addition, the overall cost and time required to produce a map of the resource of interest needed to be reduced. The system developed in this project aimed to improve upon the pre-flight planning and in-flight image acquisition aspects of the existing system. No new post-flight image processing procedures were developed, but possible future refinement of the post-flight image processing routine was considered throughout the development of the system. A pre-flight planning software package was developed that could quickly and efficiently calculate the positions offlight lines and photographs or images with a minimum of user input. The in-flight image acquisition setup developed involved the integration of a high resolution digital still camera, a Global Positioning System (GPS), and camera control software. The use of the rapidly developing and improving technology of a digital still camera was considered to be a better alternative than a video graphic or traditional film camera system for a number of reasons. In particular, digital still cameras produce digital imagery without the need for development and scanning of aerial photographs or frame grabbing of video images. Furthermore, the resolution of current digital still cameras is already significantly better than that of video cameras and is rivalling the resolution of 35rnm film. The system developed was tested by capturing imagery of an urban test area. The images obtained were then rectified using photogrammetric techniques. Results obtained were promising with planimetric accuracies of 5 to 1 Om being obtained. From this test it was concluded that for high accuracy applications involving numerous images, use would be made of softcopy photogrammetric software to semi-automatically position and rectify images, while for applications requiring fewer images and lower accuracy, images could be rectified using the simpler technique of assigning GCPs for each image from scanned orthophotos.
Thesis (MSc.)- University of Natal,Pietermaritzburg, 2000.

碩士
國立中興大學
森林學系
88
Avoiding and extinguishing forest fire is one of the important jobs in the area of forest protection. Under the concept of Prevention is better than cure, finding effective ways to avoid forest fire is essential to reduce and minimize the destruction and lost by forest fire. Therefore the basic fundamental effective ways to avoid forest fire in the area of building up database of all records of forest fires and classificated of potential forest fire risk rating. This study is using Da-Pu working circle as the fields of study, integrated digital photogrammetry and GIS technique to build the geological database of forest fire；using the Analysis of Hierarchical Process (AHP) to construct the framework that reflect the causes of forest fire and calculations of the relative weight value of each causing factor. Furthermore, the techniques provided by GIS on the spatial overlapping method is employed to divide into sectors that the potential forest fire risk rating in Da-Pu working circle. The results are as followed: 1. During the years of 1994-1999, the major causes of forest fires in the Da-pu working circle are human-cause. Incendiarism is the main cause. Hunting and improper managing a fire follow as the major factors. 2. Building the geological database of forest fire is fundamental to Prevention of forest fire. The digital photogremmetry can provide the relating forest fire basic information needed for the study including vector, image and DTM these important inputs. Combining this data inputs and information is the basis for constructing the framework and related methods of this study. 3. Through the result of AHP method, the relative weighting value for the first layer of the analysis is 45.1% environment related factors and 54.9% human related factors. The second layer of analysis point out that improper management of camping fire taking the majority of the causes 33.0%. Followed by incendiarism (21.9%), weather related factors (20.3%), plantation related (12.3%), topographic (8.0%) and soil related factors (4.5%). The above numbers all indicating that human-cause is the main cause of forest fire. 4. this study, using spatial overlapping analytical method in the GIS together with the relative weight value given by the AHP method, calculate and analyze various graphs against and overlapping each other, the result list and categorize the potential risk rating of forest fires happening into five levels including: Slight danger level(4.61%)；Cautious level (47.00%)；Alarming level (33.04%)； Dangerous level (13.59%)and Extremely dangerous level (1.76%). 5. The levels of potential forest fires happening categorized in this study have been proven right against the past six years (1994-1999) records of forest fire. Both the records and the result of the study indicate that 94% of time when an area is in the sector of Alarming level, Dangerous level and extremely dangerous level forest fire had happened. Not only has this proven the validity of this study but more so in the value of every day use. 6. The geological information system has the functions of spatial analysis, combining graphs and information gathered. It will provide more precise detailed information needed in the area of forest fire management in the future. If combined with more quantitative information in the structure, it will further enhance the effectiveness of the system. This study has already categorized the potential levels in the Da-Pu working circle using digital photogrammetry, GIS technique and AHP method. The result can be provided as reference for the potential forest fire risk rating in Da-Pu working circle. However as for the building of the forest fire records database is a long-term process, it need further in depth investigation.

Nell’ambito dell’ingegneria civile e edile la valutazione dello stato di conservazione di un edificio o di un'infrastruttura è di fondamentale importanza, a fini di monitoraggio e di conservazione, tanto più in riferimento al patrimonio architettonico di interesse storico-artistico in condizioni di diffuso degrado. In tale contesto, il rilievo e la diagnostica attualmente fanno riferimento a tecnologie e strumentazioni onerose per costo e tempo, che sovente presuppongono interventi invasivi o di difficile attuazione. Nel campo del monitoraggio di infrastrutture diversi studiosi affrontano queste criticità attraverso l'implementazione di tecnologie digitali come l’image processing o l'intelligenza artificiale. Tuttavia, la maggior parte delle metodologie sono spesso orientate al riconoscimento di un’unica tipologia di difetto, e applicate su dati bidimensionali, comportando quindi la perdita di informazioni tridimensionali. Al contrario, la loro diffusione è ancora piuttosto limitata nel settore dei beni culturali, ambito nel quale i modelli tridimensionali reality-based sono utilizzati principalmente come riferimento geometrico. Inoltre, vi è una mancanza di protocolli unificati per l'acquisizione e l'elaborazione dei dati, finalizzati all’ispezione e al controllo del patrimonio costruito. In virtù di tali considerazioni, il lavoro di ricerca ha preso avvio dalla necessità di definire, in analogia a prassi esplorate in altri settori dell’ingegneria, approcci di diagnostica innovativa, di supporto agli operatori nella fase di conoscenza di un manufatto, preliminare alla progettazione di un intervento. Il progetto di ricerca mira ad un esame delle condizioni generali di un edificio mediante specifiche metodiche di valutazione computerizzata qualitativa e quantitativa di dati fotogrammetrici, volta all’individuazione e alla mappatura delle morfologie di degrado definite nelle normative di settore. Nel dettaglio, tecniche di digital image processing e machine learning sono state implementate su modelli tridimensionali ad alta risoluzione (nuvole di punti, mesh poligonali testurizzate), configurando opportune strategie scalari, ad un livello di dettaglio crescente, in relazione alla tipologia di degrado da investigare (alterazioni basate sulla geometria o sul colore). Tali procedure sono state validate su una pluralità di casi studio di rilevante interesse storico-artistico, appartenenti al patrimonio culturale territoriale, a scala regionale o internazionale. La grande eterogeneità, in termini di epoca, tipologia costruttiva, materiali, componenti architettonici e fenomeni di degrado, ha permesso un’ampia applicazione sperimentale dei flussi di lavoro proposti, dimostrandone l’idoneità e adattabilità alla diagnostica degli edifici. Esempi come la facciata esterna, il portale e i pilastri di palazzo Palmieri (XVIII secolo), la torre nord della fortezza medievale di Bashtovë (XV secolo), oppure gli interni della cattedrale romanica di San Corrado (XII/XIII secolo), sono stati presi in considerazione poiché caratterizzati da patologie associate a cambiamenti nella geometria e nella forma degli elementi architettonici, riconducibili al degrado superficiale della pietra (mancanze, erosioni, alveolizzazioni..) o a fenomeni di instabilità statica (quadri fessurativi). Di contro, alcune aree del sito archeologico di Egnazia (I secolo a.c.), o alcuni ambienti interni degli ex conventi di San Leonardo e dei Cappuccini (XVI secolo), sono prevalentemente interessati da alterazioni su base cromatica, attribuibili soprattutto a problemi di umidità. Tali condizioni sono state monitorate in intervalli di anni, al fine di osservarne l’evoluzione nel tempo. La presente ricerca propone un avanzamento nell'analisi e nel controllo dello stato di conservazione degli edifici, in particolare nel settore dei beni culturali, attraverso un articolato flusso di lavoro metodologico, finalizzato ad ottenere informazioni utili per la fase di pre-diagnosi. I principali contributi riguardano la possibilità di ottenere un approfondimento qualitativo e quantitativo su diverse morfologie di degrado, a partire da dati tridimensionali reality-based, mediante procedure remote, non invasive, e semi-automatiche, a supporto delle attività diagnostiche. Inoltre, la flessibilità e la scalabilità dell’approccio sono condizioni fondamentali, nell’ottica di una limitazione di costi e tempi, di una semplificazione del piano di indagini e di una riduzione della soggettività e dipendenza degli esiti dalle competenze del tecnico.
IIn Civil or Building engineering, the assessment of the state of conservation of a building or an infrastructure is fundamental, for monitoring and conservation purposes. This is of paramount importance also in the context of Cultural Heritage, where artefacts are denoted by historic-artistic interest, and often in widespread damaged conditions. The actual state of practice refers to costly and time-consuming technologies and equipment, often requiring invasive actions, or difficult applications. In Civil Engineering, several research works address these criticalities through the implementation of digital technologies like image processing or artificial intelligence. However, most proposals are applied on 2D data, with substantial losses of 3D information, and often single-defect oriented. On the contrary, in Cultural Heritage domain their diffusion is still scarce, with reality-based 3D data used mainly as reference for geometrical survey. In addition, there is a substantial lack of unified protocols for the acquisition and processing of data, finalized to the quantitative inspection of built heritages. In light of this, the aim of this research is to define, analogously to other fields of Engineering, innovative diagnostic approaches, to support the experts in the phase of knowledge, before planning an intervention. The evaluation of the general conditions of a building has been proposed through the analysis of reality-based 3D data, acquired by means of photogrammetry. Specific mapping and computerized evaluation routines have been created, for the detection of various decay morphologies, as defined by sectorial standards, through qualitative and quantitative analysis systems. Digital Image Processing and Machine Learning techniques have been adopted and implemented on high resolution three-dimensional models (dense point clouds, texturized polygonal meshes), to define distinct pipelines tailored on the basis of the kind of damage to investigate (geometry-based or colour-based alterations). A scalar strategy was outlined, articulated in different paths and levels of details. Furthermore, they have been tested on a plurality of case studies of significant historical-artistic interest, belonging to the territorial, regional or international, cultural heritage. Their heterogeneity, in terms of epoch, building type, surface material, architectural components and decay phenomena, allowed the experimental application of the proposed workflows, demonstrating their suitability and adaptability to the building diagnostic domain. Indeed, exterior walls, portals and pillars of Palmieri residential palace (XVIII century), portions of a tower in the medieval fortress of Bashtovë (XV century), or the interiors of the Romanesque cathedral of San Corrado (XII/XIII century), were considered because they are all characterized by decay phenomena expressed by changes in the geometry and shape, like stone surface decay (lacks, erosions, alveolizations..) or static instabilities (crack patterns). While specific areas of the archaeological site of Egnatia (I century B.C), or internal environments of ex-convents, like San Leonardo and Cappuccini, were selected, in light of chromatic-based modifications consistently affecting them, mainly ascribable to humidity problems. Those conditions have been monitored within intervals of years, in order to control their evolution overtime. The present research lays out an advancement in the analysis and control of the state of conservation of buildings, especially in cultural heritage domain, providing an articulated methodological workflow, to obtain and collect investigation data for the pre-diagnosis phase. Some principal contributions concern the possibility to achieve both qualitative and quantitative insights on different decay morphologies, starting from reality-based 3D data, with remote, non-invasive, semi-automatic procedures, in support of diagnostic activities. Furthermore, flexibility and scalability are paramount conditions, to address the peculiarity of the diagnostic process, in the perspective of a reduction of time cost requirements, a simplification of the investigation plan and a minimization of dependence from the technician’s expertise.

Text in English, with abstracts and keywords in English, Zulu and Xhosa
Link to the dataset (catalogue): https://doi.org/10.25399/UnisaData.14101913.v1
Digital image editing is rooted in the analog practices of photographic retouching from the late nineteenth century. This study interrogated how novel contributions of new media practice can inform understanding of the relationship between digital and analog media. The study also sought to explore new conceptual avenues in the creation of digital art that incorporates key aspects of both new and traditional media. This study employed a literature review of selected discourses related to new media studies. Specifically, the work of scholars Lev Manovich, Jay David Bolter, Richard Grusin, and Filipe Pais on the interplay between traditional and new media formed the cornerstone of the analysis. These discourses contextualise an analysis of several contemporary case studies of digital artists, with a particular focus on John Craig Freeman and the Oddviz collective. These works were selected for the way in which they destabilise conventional notions of digital photography in new media and the way digital content can be ‘displaced’ into a physical space. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography, and intermediality. The dissertation concludes with an overview of my work that incorporates the concepts derived from my analysis of the case studies. It discusses how my exhibition Digital Tourist, a mixed media installation, makes use of photogrammetry and AR to displace the private connections of an individual life into the public space of the gallery.
Ukuhlelwa kwezithombe zezindaba zedijithali kususelwe emikhubeni ye-analokhu yokuthwebula kabusha izithombe kusukela ngasekupheleni kwekhulu leshumi nesishiyagalolunye leminyaka.. Lolu cwaningo luphenye ukuthi iminikelo yenoveli emisha yokwenziwa kwezezindaba ezintsha zingakwazisa kanjani ukuqonda kobudlelwano phakathi kwezindaba zedijithali ne-analokhu. Ucwaningo luphinde lwafuna ukubheka izindlela ezintsha zomqondo ekwakhiweni kobuciko bedijithali obufaka izinndaba ezibalulekile kokubili kwezokuxhumana nezendabuko ezintsha. Izinkulumo ezikhethiwe ezihlobene nezifundo zezindaba ezintsha zibuyekeziwe. Ngokuqondile, umsebenzi wezazi uLev Manovich, Jay David Bolter, Richard Grusin noFilipe Pais ekusebenzisaneni phakathi kwabezindaba bendabuko nabasha kwakha okuzobhekwa ngqo uma kuhlaziywa. Lezi zinkulumo zigxila ekuhlaziyweni kwezifundo zamanje zamaciko edijithali, kugxilwe kakhulu kuJohn Craig Freeman kanye neqoqo le-Oddviz. Le misebenzi yakhethwa ngendlela yokuthi ingazinzisi imiqondo ejwayelekile yokuthwebula izithombe zedijithali emithonjeni emisha kanye nokuthi okuqukethwe kwedijithali "kungahanjiswa kanjani" endaweni ebonakalayo. Ukusuka kulokhu kuhlaziywa kuvela imiqondo eminingana esebenza njengezimpawu ezihlukanisayo zokufuduswa kwabezindaba. Lezi zingqikithi zifaka phakathi ukwakheka, inkumbulo, ukwakheka kobunikazi, ukuziphendulela kanye nokuzibandakanya. Idezetheyishini iphetha ngokubuka konke ngomsebenzi wami ohlanganisa imiqondo esuselwe ekuhlaziyweni kwami kwezifundo zocwaningo. Ingxoxo ihlanganisa ukuthi umbukiso wami we-Zivakashi zeDijithali, ukufakwa kwabezindaba okuxubile, isebenzisa uhlelo lokuthwebula olusebenzisa ulimi noma ifothogrametri ne-AR ukukhipha ukuxhumana kwangasese kwempilo yomuntu ngamunye endaweni yomphakathi yegalari.
Ukuhlela imifanekiso yedijithali yinkqubo eyendeleyo, nowaqalwa kwiminyaka yokugqibela yenkulungwane yeshumi elinethoba, kwimisebenzi yezifaniso/yeanalogu ekuhlaziyweni kweefoto. Esi sifundo siphonononga ukuba igalelo elikhethekileyo leendlela ezintsha zonxibelelwano lwemiboniso/imidiya lingenza njani ukuqinisa ukuqonda unxulumano phakathi kwemiboniso yedijithali neyeanalogu. Kwakhona, esi sifundo sizama ukuphanda iindlela ezintsha ezisetyenziswa kubugcisa bedijithali neziquka imiba ephambili yemiboniso yale mihla neyakudala. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography and intermediality. Kuphononongwe iingxoxo ezithile ezimalunga nezifundo zemiboniso yale mihla. Kuqwalaselwe ngakumbi imisebenzi yeengcali ooLev Manovich, Jay David Bolter, Richard Grusin kunye noFilipe Pais malunga nonxulumano phakathi kwemiboniso yakudala neyale mihla njengesiseko solu hlalutyo. Ezi ngxoxo zifaka emxholweni uhlalutyo lwezifundo zokuzekelisa zale mihla malunga nabazobi bale mihla, kugxininiswa kwindibanisela ka John Craig Freeman nekaOddviz. Le misebenzi ikhethwe ngenxa yokuba iyazichitha iingcinga eziqhelekileyo malunga nokufota ngedijithali kwimiboniso yale mihla nangendlela iziqulatho zedijithali “zinokushenxiswa” zisiwe kwindawo ebambekayo. Olu hlalutyo luveze iingcinga eziliqela nezisebenza njengeempawu zoshenxiso lwemiboniso. Imixholo iquka imifuziselo, ukukhumbula, ukwenziwa kwesazisi, ukuzazisa ngezinto onazo, unxulumano phakathi kwemiboniso eyahlukeneyo Le ngxelo yophando igqibela ngokushwankathela umsebenzi wam ohlanganisa iingcinga ezivele ekuhlalutyeni kwam izifundo ezingumzekelo. Ingxoxo ibonisa ukuba umboniso wengqokelela yemisebenzi yam owaziwa ngokuba yiDigital Tourist, ubusebenzise njani ubuchwepheshe ekuthiwa yifotogrametri (obokufumana ulwazi ngokuhlalutya imifanekiso) ekushenxiseni unxulumano lwabucala lobomi bomntu ibubeke kwindawo ebonwa nguwonkewonke apho kubukwa imifanekiso neefoto (igalari).
https://doi.org/10.25399/UnisaData.14101913.v1
Arts and Music
M.A. (Visual Arts)