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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Nouvelle génération de systèmes de vision temps réel à grande dynamique

Lapray, Pierre-Jean 18 October 2013 (has links) (PDF)
Cette thèse s'intègre dans le cadre du projet européen EUREKA "High Dynamic Range - Low NoiseCMOS imagers", qui a pour but de développer de nouvelles approches de fabrication de capteursd'images CMOS à haute performance. L'objectif de la thèse est la conception d'un système de visiontemps réel à grande gamme dynamique (HDR). L'axe principal sera la reconstruction, en temps réelet à la cadence du capteur (60 images/sec), d'une vidéo à grande dynamique sur une architecturede calcul embarquée.La plupart des capteurs actuels produisent une image numérique qui n'est pas capable de reproduireles vraies échelles d'intensités lumineuses du monde réel. De la même manière, les écrans, impri-mantes et afficheurs courants ne permettent pas la restitution effective d'une gamme tonale étendue.L'approche envisagée dans cette thèse est la capture multiple d'images acquises avec des tempsd'exposition différents permettant de palier les limites des dispositifs actuels.Afin de concevoir un système capable de s'adapter temporellement aux conditions lumineuses,l'étude d'algorithmes dédiés à la grande dynamique, tels que les techniques d'auto exposition, dereproduction de tons, en passant par la génération de cartes de radiances est réalisée. Le nouveausystème matériel de type "smart caméra" est capable de capturer, générer et restituer du contenu àgrande dynamique dans un contexte de parallélisation et de traitement des flux vidéos en temps réel
42

Numerical Simulation of a Hot Dry Rock Geothermal Reservoir in the Cooper Basin, South Australia

Bronwyn Muller Unknown Date (has links)
This thesis describes the development and production of numerical simulations of the creation of a Hot Dry Rock (HDR) geothermal reservoir. This geothermal reservoir that was simulated is owned by Geodynamics Limited and is located in the Cooper Basin, South Australia. The simulations show the geometry of the geothermal reservoir and predict the productive lifespan of the reservoir. Geothermal energy, which is the thermal energy that is stored in the interior of the earth, is an enormous energy source and as such there is great interest in technology that allows this energy to be harnessed. The HDR process of extracting the geothermal energy from rock involves drilling a borehole to a suitable depth and injecting cold water into the rock via this well (known as the injection well) to create a reservoir by opening up fractures in the rock. As water is forced through the reservoir, heat is extracted from the rock via conduction and transferred to the water, creating an heat exchange. Warm water is brought to the surface via another well known as the extraction well. The heat from the water is used to generate electricity and then the water is fed back into the injection well, completing the cycle. The creation of a HDR geothermal reservoir comprises of many aspects: the injection of the fluid into the jointed rock system, the opening and shearing of the joints, the creation of the fluid reservoir in the rock and the temperature effects of the fluid flow through the joints. This work incorporates all of these aspects. Due to the multi-physics nature of this process multiple computational modelling strategies were implemented to allow for authentic simulation of the entire process. The mechanical rock behaviour was primarily simulated the Distinct Element Method. This two dimensional Distinct Element Method program allowed for a realistically scaled model of the whole geothermal reservoir to be developed. This model was particularly useful for modelling the joint behaviour as the discrete nature of this method compares well with the joint system on such a scale. A discrete particle based model was used to model the joint behaviour on a small scale. These models demonstrated the behaviour of joints under compressional strain, showing slip and the effects of joint dilatancy. The productive lifespan of the geothermal reservoir was modelled using a Finite Element Method program based on Darcy's Law and an height-averaged heat equation. The aim of this model was to simulate the effects on the rock temperature of the fluid flow through the reservoir. The lifespan of the reservoir with differing well geometries was tested using this model to show which geometry would extend the productive lifetime of the geothermal reservoir. The results produced from the DEM models showed that the reservoir geometry is very much dependent upon the joint angle, and under the Cooper Basin stress regime steeper joints will be more likely to open. Joint dilatancy also affects the fluid flow rates as the amount of joint opening is dependent upon the joint dilatancy angle. The modelling of the temperature drawdown of the rock due to the fluid flow showed that a square configuration of wells is the ideal configuration to prolong the productive lifespan of the HDR geothermal reservoir. Results produced with the modelling parameters provided by Geodynamics Limited indicate that the productive lifespan of the Cooper Basin HDR geothermal reservoir created is approximately 50 years. This reservoir is only one of many that can be created at the site to prolong the productivity of the energy plant. The combined results of this modelling strategy give an overall image of the creation and lifetime of the HDR geothermal energy plant in the Cooper Basin.
43

Numerical Simulation of a Hot Dry Rock Geothermal Reservoir in the Cooper Basin, South Australia

Bronwyn Muller Unknown Date (has links)
This thesis describes the development and production of numerical simulations of the creation of a Hot Dry Rock (HDR) geothermal reservoir. This geothermal reservoir that was simulated is owned by Geodynamics Limited and is located in the Cooper Basin, South Australia. The simulations show the geometry of the geothermal reservoir and predict the productive lifespan of the reservoir. Geothermal energy, which is the thermal energy that is stored in the interior of the earth, is an enormous energy source and as such there is great interest in technology that allows this energy to be harnessed. The HDR process of extracting the geothermal energy from rock involves drilling a borehole to a suitable depth and injecting cold water into the rock via this well (known as the injection well) to create a reservoir by opening up fractures in the rock. As water is forced through the reservoir, heat is extracted from the rock via conduction and transferred to the water, creating an heat exchange. Warm water is brought to the surface via another well known as the extraction well. The heat from the water is used to generate electricity and then the water is fed back into the injection well, completing the cycle. The creation of a HDR geothermal reservoir comprises of many aspects: the injection of the fluid into the jointed rock system, the opening and shearing of the joints, the creation of the fluid reservoir in the rock and the temperature effects of the fluid flow through the joints. This work incorporates all of these aspects. Due to the multi-physics nature of this process multiple computational modelling strategies were implemented to allow for authentic simulation of the entire process. The mechanical rock behaviour was primarily simulated the Distinct Element Method. This two dimensional Distinct Element Method program allowed for a realistically scaled model of the whole geothermal reservoir to be developed. This model was particularly useful for modelling the joint behaviour as the discrete nature of this method compares well with the joint system on such a scale. A discrete particle based model was used to model the joint behaviour on a small scale. These models demonstrated the behaviour of joints under compressional strain, showing slip and the effects of joint dilatancy. The productive lifespan of the geothermal reservoir was modelled using a Finite Element Method program based on Darcy's Law and an height-averaged heat equation. The aim of this model was to simulate the effects on the rock temperature of the fluid flow through the reservoir. The lifespan of the reservoir with differing well geometries was tested using this model to show which geometry would extend the productive lifetime of the geothermal reservoir. The results produced from the DEM models showed that the reservoir geometry is very much dependent upon the joint angle, and under the Cooper Basin stress regime steeper joints will be more likely to open. Joint dilatancy also affects the fluid flow rates as the amount of joint opening is dependent upon the joint dilatancy angle. The modelling of the temperature drawdown of the rock due to the fluid flow showed that a square configuration of wells is the ideal configuration to prolong the productive lifespan of the HDR geothermal reservoir. Results produced with the modelling parameters provided by Geodynamics Limited indicate that the productive lifespan of the Cooper Basin HDR geothermal reservoir created is approximately 50 years. This reservoir is only one of many that can be created at the site to prolong the productivity of the energy plant. The combined results of this modelling strategy give an overall image of the creation and lifetime of the HDR geothermal energy plant in the Cooper Basin.
44

Numerical Simulation of a Hot Dry Rock Geothermal Reservoir in the Cooper Basin, South Australia

Bronwyn Muller Unknown Date (has links)
This thesis describes the development and production of numerical simulations of the creation of a Hot Dry Rock (HDR) geothermal reservoir. This geothermal reservoir that was simulated is owned by Geodynamics Limited and is located in the Cooper Basin, South Australia. The simulations show the geometry of the geothermal reservoir and predict the productive lifespan of the reservoir. Geothermal energy, which is the thermal energy that is stored in the interior of the earth, is an enormous energy source and as such there is great interest in technology that allows this energy to be harnessed. The HDR process of extracting the geothermal energy from rock involves drilling a borehole to a suitable depth and injecting cold water into the rock via this well (known as the injection well) to create a reservoir by opening up fractures in the rock. As water is forced through the reservoir, heat is extracted from the rock via conduction and transferred to the water, creating an heat exchange. Warm water is brought to the surface via another well known as the extraction well. The heat from the water is used to generate electricity and then the water is fed back into the injection well, completing the cycle. The creation of a HDR geothermal reservoir comprises of many aspects: the injection of the fluid into the jointed rock system, the opening and shearing of the joints, the creation of the fluid reservoir in the rock and the temperature effects of the fluid flow through the joints. This work incorporates all of these aspects. Due to the multi-physics nature of this process multiple computational modelling strategies were implemented to allow for authentic simulation of the entire process. The mechanical rock behaviour was primarily simulated the Distinct Element Method. This two dimensional Distinct Element Method program allowed for a realistically scaled model of the whole geothermal reservoir to be developed. This model was particularly useful for modelling the joint behaviour as the discrete nature of this method compares well with the joint system on such a scale. A discrete particle based model was used to model the joint behaviour on a small scale. These models demonstrated the behaviour of joints under compressional strain, showing slip and the effects of joint dilatancy. The productive lifespan of the geothermal reservoir was modelled using a Finite Element Method program based on Darcy's Law and an height-averaged heat equation. The aim of this model was to simulate the effects on the rock temperature of the fluid flow through the reservoir. The lifespan of the reservoir with differing well geometries was tested using this model to show which geometry would extend the productive lifetime of the geothermal reservoir. The results produced from the DEM models showed that the reservoir geometry is very much dependent upon the joint angle, and under the Cooper Basin stress regime steeper joints will be more likely to open. Joint dilatancy also affects the fluid flow rates as the amount of joint opening is dependent upon the joint dilatancy angle. The modelling of the temperature drawdown of the rock due to the fluid flow showed that a square configuration of wells is the ideal configuration to prolong the productive lifespan of the HDR geothermal reservoir. Results produced with the modelling parameters provided by Geodynamics Limited indicate that the productive lifespan of the Cooper Basin HDR geothermal reservoir created is approximately 50 years. This reservoir is only one of many that can be created at the site to prolong the productivity of the energy plant. The combined results of this modelling strategy give an overall image of the creation and lifetime of the HDR geothermal energy plant in the Cooper Basin.
45

Improving high dose rate and pulsed dose rate prostate brachytherapy - alternative prostate definition and treatment delivery verification methods

Howie, Andrew Gordon, howie.andrew@gmail.com January 2009 (has links)
Brachytherapy is a form of radiotherapy in which radioactive sources are placed at short distances from, or even inside the target volume. The use of high dose rate brachytherapy is a widely accepted and clinically proven treatment for some stages of prostate cancer. The aim of this project was to investigate potential improvements on two of the most important aspects of high dose rate (HDR) and pulsed dose rate (PDR) prostate brachytherapy - prostate definition and treatment delivery verification. The use of magnetic resonance (MR) imaging in addition to the conventional computed tomography (CT) imaging methods currently used routinely for brachytherapy planning may provide some benefit in accurately defining the prostate and surrounding critical structures. The methods used in this project involved analysis of data sets provided by two Radiation Oncologists. The results presented showed inter-observer and intra-observer variations in the size and shape of the prostate, as well as analysis of the dosimetric differences that may be reported due to the differences in prostate size and shape. The results also included analysis of critical structure dosimetry - dose to the surrounding radio-sensitive rectum and urethra. In summary, the results showed that the prostate was defined to be smaller using MR imaging than CT, however the consistency between Oncologists was not significantly improved using MR imaging. MR imaging may be useful in reducing the dose to normal tissue surrounding the prostate and in obtaining better coverage of the smaller target volume, without compromising the critical structures. The use of LiF:Mg,Ti thermoluminescent dosimeters (TLDs) is a potential avenue for in vivo dose verification of an HDR or PDR prostate brachytherapy treatment plan. This project included a phantom study of these TLDs with the aim to determine their feasibility for clinical use. Cylindrical TLD rods (6 mm length x 1 mm diameter) were used, as these fit inside the brachytherapy needles implanted into the prostate, and therefore had potential to be used clinically to verify the dose delivered in the prostate. This study was extended to include determination of a correction factor to allow an independent radiation source (6 MV photon beam from a linear accelerator) to be used to obtain control readings for this relative dosimetric method. The results showed these TLDs to be a promising in vivo dosimeter for prostate brachytherapy with potential errors in the order of 4%. Their potential lies in the fact that they could detect and flag significant calculation errors in treatment plans, and they utilise equipment used routinely for external beam radiotherapy dosimetry in many treatment facilities, reducing the cost of implementing such a procedure.
46

Numerical Simulation of a Hot Dry Rock Geothermal Reservoir in the Cooper Basin, South Australia

Bronwyn Muller Unknown Date (has links)
This thesis describes the development and production of numerical simulations of the creation of a Hot Dry Rock (HDR) geothermal reservoir. This geothermal reservoir that was simulated is owned by Geodynamics Limited and is located in the Cooper Basin, South Australia. The simulations show the geometry of the geothermal reservoir and predict the productive lifespan of the reservoir. Geothermal energy, which is the thermal energy that is stored in the interior of the earth, is an enormous energy source and as such there is great interest in technology that allows this energy to be harnessed. The HDR process of extracting the geothermal energy from rock involves drilling a borehole to a suitable depth and injecting cold water into the rock via this well (known as the injection well) to create a reservoir by opening up fractures in the rock. As water is forced through the reservoir, heat is extracted from the rock via conduction and transferred to the water, creating an heat exchange. Warm water is brought to the surface via another well known as the extraction well. The heat from the water is used to generate electricity and then the water is fed back into the injection well, completing the cycle. The creation of a HDR geothermal reservoir comprises of many aspects: the injection of the fluid into the jointed rock system, the opening and shearing of the joints, the creation of the fluid reservoir in the rock and the temperature effects of the fluid flow through the joints. This work incorporates all of these aspects. Due to the multi-physics nature of this process multiple computational modelling strategies were implemented to allow for authentic simulation of the entire process. The mechanical rock behaviour was primarily simulated the Distinct Element Method. This two dimensional Distinct Element Method program allowed for a realistically scaled model of the whole geothermal reservoir to be developed. This model was particularly useful for modelling the joint behaviour as the discrete nature of this method compares well with the joint system on such a scale. A discrete particle based model was used to model the joint behaviour on a small scale. These models demonstrated the behaviour of joints under compressional strain, showing slip and the effects of joint dilatancy. The productive lifespan of the geothermal reservoir was modelled using a Finite Element Method program based on Darcy's Law and an height-averaged heat equation. The aim of this model was to simulate the effects on the rock temperature of the fluid flow through the reservoir. The lifespan of the reservoir with differing well geometries was tested using this model to show which geometry would extend the productive lifetime of the geothermal reservoir. The results produced from the DEM models showed that the reservoir geometry is very much dependent upon the joint angle, and under the Cooper Basin stress regime steeper joints will be more likely to open. Joint dilatancy also affects the fluid flow rates as the amount of joint opening is dependent upon the joint dilatancy angle. The modelling of the temperature drawdown of the rock due to the fluid flow showed that a square configuration of wells is the ideal configuration to prolong the productive lifespan of the HDR geothermal reservoir. Results produced with the modelling parameters provided by Geodynamics Limited indicate that the productive lifespan of the Cooper Basin HDR geothermal reservoir created is approximately 50 years. This reservoir is only one of many that can be created at the site to prolong the productivity of the energy plant. The combined results of this modelling strategy give an overall image of the creation and lifetime of the HDR geothermal energy plant in the Cooper Basin.
47

Radiobiological models based evaluation of the consequences of possible changes in the implant geometry and anatomy in the HDR erachytherapy of the prostate cancer

Katsilieri, Zaira - Christiana 31 March 2010 (has links)
The purpose of this work is to investigate the influence of possible patient movement and anatomy alteration on the quality of delivered prostate US based HDR-brachytherapy. The effect of patient movement and anatomy change (after the needle implantation and 3D image set acquisition) on catheter and organ dislocation and the consequences that this generated on the DVHs, conformity index and on radiobiological parameters. Materials and methods: This work is based on 3D image sets and treatment plans of 48 patients obtained right after the needle implantation (clinical plan is based on this 3D image set) and before and after the irradiation. In our institution the 3D-US based pre-planning, the transperineal implantation of needles using template and the intraoperative planning and irradiation is realized using the real-time dynamic planning system Oncentra Prostate. All pre-plans and all the inverse optimization of clinical plans were based on HIPO using the modulation restriction option. The patient body/OARs/catheters movement are generated from the clinical, pre- and post- irradiation plans and its influence on DVH-, COIN and radiobiological parameters of PTV and OARs are calculated and presented. Results: It is observed a slight decrease of treatment plan quality with increase of time between the clinical image set acquisition and the patient irradiation. Also, we show that the patient body movement/anatomy alteration and/or catheters dislocation results in decreased plan quality; change of values of the COIN, DVH- and radiobiological parameters. Conclusion: The measured mean shift of anatomy and needles (beams) is as low as 1.0mm that is lower by an order of magnitude to values known from external beam irradiation. For high modulated plans as those in HDR Brachytherapy such small shifts result in dosimetric changes which are in general lower than 5%. Our results demonstrate that quality assurance procedures have to be clinically implemented to guarantee anatomy and implant stability of the order of 1mm. This can only be realized without any manipulation of the implant and anatomy as done, for instance in the case of removing the US-probe before treatment delivery or moving the patient from one bed to another for the irradiation purposes / Σκοπός της εργασίας αυτής είναι να διερευνήσει την επιδραση που έχει η πιθανή μετακίνηση του ασθενούς και η αλλαγή της ανατομίας στην ποιότητα της Βραχυθεραπείας. Η μετακίνηση του ασθενούς, οι αλλαγές της ανατομίας ( μετά την εμφύτευση των βελονών και την συλλογή των τρισδιάστατων 3D εικόνων), η μετακίνηση των καθετήρων και των οργάνων επιφέρουν αλλαγές που παρουσιάζονται μέσα από τα ιστογράμματα δόσης - όγκου (DVH), δείκτη συμμορφίας (conformity index) και των ραδιοβιολογικών παραμέτρων. Υλικά και Μέθοδοι: Η μελέτη αυτή βασίζεται στην συλλογή τρισδιάστατων εικόνων υπερήχων (3D set) και στους σχεδιασμούς θεραπείας (treatment plans) από 48 ασθενείς που συλλέχθηκαν σε τρείς φάσεις: μετά την εμφύτευση των καθετήρων (κλινικός σχεδιασμός θεραπείας (clinical plan) βασίζεται σε αυτή την συλλογή 3D εικόνων), πριν την ακτινοβόληση και μετά την ακτινοβόληση.Στην κλινική μας ο προσχεδιασμός της θεραπείας (pre-planing) που βασίζεται στο τρισδιάστατο υπερηχογράφημα (3D-US), η διαπερινεϊκή εμφύτευση των καθετήρων με την βοήθεια του οδηγού template, ο διεγχειρητικός σχεδιασμός της θεραπείας (intraoperative planning) και η ακτινοβόληση πραγματοποιούνται με την χρήση του Real-time dynamic planning system Oncentra Prostate. Όλα τα pre-plans και όλα τα inverse optimization clinical plans βασίζονται στο HIPO χρησιμοποιώντας την επιλογή του modulation restriction. Οι μετακινήσεις του σώματος του ασθενούς/ των ευαίσθητων σε κίνδυνο οργάνων (OARs)/ και των καθετήρων αναπαράγονται από τα clinical, pre και post- irradiation plans. Κατόπιν υπολογίζεται και παρουσιάζεται η επίδρασή τους στο DVH, COIN και στις ραδιοβιολογικές παραμέτρους του όγκου στόχου σχεδιασμού (PTV) και των (OARs). Αποτελέσματα: Παρατηρείται μια ελαφρά μείωση της ποιότητας του σχεδιασμού θεραπείας με την αύξηση του χρόνου μεταξύ του κλινικού σχεδιασμού και της ακτινοβόλησης του ασθενούς. Επίσης παρουσιάζουμε ότι η μετακίνηση του ασθενούς/ η αλλαγή στην ανατομία ή/ και η μετακίνηση των καθετήρων έχει ως αποτέλεσμα στην μείωση της ποιότητας του σχεδιασμού. Έχουμε αλλαγή στις αλλαγές στις τιμές του COIN, του DVH και των ραδιοβιολογικών παραμέτρων. Συμπέρασματα: Η μέση τιμή των μετρούμενων μετακινήσεων της ανατομίας και των βελονών είναι ιδιαίτερα μικρή περίπου 1.0mm σε σύγκριση με τις γνωστές τιμές από την εξωτερική ακτινοθεραπεία. Για τους υψηλής διαμόρφωσης σχεδιασμούς, όπως αυτοί της HDR βραχυθεραπείας, μικρές μετακινήσεις οδηγούν σε δοσιμετρικές αλλαγές γενικά μικρότερες από 5%. Τα αποτελέσματα μας παρουσιάζουν ότι λαμβάνοντας υπόψη τις διαδικασίες εξασφάλισης ποιότητας επιτυγχάνεται η ακινητοποίηση του εμφυτεύματος της τάξης του 1mm. Αυτό μπορεί να επιτευχθεί μόνο με ακινητοποίηση του εμφυτεύματος και της ανατομίας, για παράδειγμα στην περίπτωση όπου μετακινούμε την κεφαλή της συσκευής υπερήχων (US- probe) πριν την ακτινοβόληση ή μετακινώντας τον ασθενή από ένα κρεβάτι σε ένα άλλο για τις ανάγκες τις ακτινοβόλησης.
48

Influência do posicionamento da paciente na modificação da dose em órgãos críticos na braquiterapia de alta taxa de dose em câncer de colo uterino

MELO, Jonathan Azevedo 31 January 2008 (has links)
Made available in DSpace on 2014-06-12T23:16:12Z (GMT). No. of bitstreams: 2 arquivo8650_1.pdf: 2039315 bytes, checksum: 6db8d7483f97b83b6a619297c7384a00 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / A braquiterapia de alta taxa de dose é um procedimento médico que utiliza radioisótopos com taxa de dose acima de 0,2 Gy/min. Este tipo de tratamento é comumente utilizado no câncer de colo uterino em suas fases mais avançadas. Este tipo de braquiterapia tem substituído a modalidade de baixa taxa de dose por ser um tratamento dado de forma ambulatorial e sem a necessidade de anestesia. O principal fator limitante do uso da técnica de braquiterapia com alta taxa de dose para o tratamento das neoplasias de colo uterino é seu risco potencial de sequelas actínicas nos órgão normais adjacentes, como a bexiga, o reto e o cólon sigmóide. Por outro lado, a mudança da posição da paciente numa mesa de exame faz com que haja modificações da posição dos órgãos internos. A maior distância destes órgãos da região a ser irradiada pode fazer com que seja obtida uma menor dose e, por consequência, mitigação dos efeitos indesejáveis. Atualmente, não existe na literatura científica uma recomendação do posicionamento de decúbito para tratamento destas pacientes. Neste contexto, o objetivo deste trabalho foi identificar a influência destes posicionamentos por meio da comparação das doses absorvidas na bexiga, reto e sigmóide das pacientes em decúbito dorsal, com as pernas em litotomia (elevadas), e com as pernas estendidas (abaixadas). Os resultados apresentaram uma diminuição significativa da dose na bexiga com o posicionamento da paciente com as pernas abaixadas, porém houve um aumento da dose na região do cólon sigmóide, que pode ser minimizado por meio de otimização dos tempos de parada da fonte radioativa. A dose no reto não foi influenciada pelo posicionamento. Com isso, os resultados obtidos nesta pesquisa indicam que as pacientes submetidas à braquiterapia de alta taxa de dose devem ser tratadas em posição de pernas baixas e estendidas
49

Nouvelle génération de systèmes de vision temps réel à grande dynamique / New generation of high dynamic range vision systems

Lapray, Pierre-Jean 18 October 2013 (has links)
Cette thèse s’intègre dans le cadre du projet européen EUREKA "High Dynamic Range - Low NoiseCMOS imagers", qui a pour but de développer de nouvelles approches de fabrication de capteursd’images CMOS à haute performance. L’objectif de la thèse est la conception d’un système de visiontemps réel à grande gamme dynamique (HDR). L’axe principal sera la reconstruction, en temps réelet à la cadence du capteur (60 images/sec), d’une vidéo à grande dynamique sur une architecturede calcul embarquée.La plupart des capteurs actuels produisent une image numérique qui n’est pas capable de reproduireles vraies échelles d’intensités lumineuses du monde réel. De la même manière, les écrans, impri-mantes et afficheurs courants ne permettent pas la restitution effective d’une gamme tonale étendue.L’approche envisagée dans cette thèse est la capture multiple d’images acquises avec des tempsd’exposition différents permettant de palier les limites des dispositifs actuels.Afin de concevoir un système capable de s’adapter temporellement aux conditions lumineuses,l’étude d’algorithmes dédiés à la grande dynamique, tels que les techniques d’auto exposition, dereproduction de tons, en passant par la génération de cartes de radiances est réalisée. Le nouveausystème matériel de type "smart caméra" est capable de capturer, générer et restituer du contenu àgrande dynamique dans un contexte de parallélisation et de traitement des flux vidéos en temps réel / This thesis is a part of the EUREKA European project called "High Dynamic Range - Low NoiseCMOS imagers", which developped new approaches to design high performance CMOS sensors.The purpose of this thesis is to design a real-time high dynamic range (HDR) vision system. Themain focus will be the real-time video reconstruction at 60 frames/sec in an embedded architecture.Most of the sensors produce a digital image that is not able to reproduce the real world light inten-sities. Similarly, monitors, printers and current displays do not recover of a wide tonal range. Theapproach proposed in this thesis is multiple acquisitions, taken with different exposure times, to over-come the limitations of the standard devices.To temporally adapt the light conditions, the study of algorithms dedicated to the high dynamic rangetechniques is performed. Our new smart camera system is able to capture, generate and showcontent in a highly parallelizable context for a real time processing
50

Towards automatic asset management for real-time visualization of urban environments

Olsson, Erik January 2017 (has links)
This thesis describes how a pipeline was obtained to reconstruct an urban environment from terrestrial laser scanning and photogrammetric 3D maps of Norrköping, visualized in first prison and real-time. Together with LIU University and the city planning office of Norrköping the project was carried out as a preliminary study to get an idea of how much work is needed and in what accuracy we can recreate a few buildings. The visualization is intended to demonstrate a new way of exploring the city in virtual reality as well as visualize the geometrical and textural details in a higher quality comparing to the 3D map that Municipality of Norrköping uses today. Before, the map has only been intended to be displayed from a bird’s eye view and has poor resolution from closer ranges. In order to improve the resolution, HDR photos were used to texture the laser scanned model and cover a particular area of the low res 3D map. This thesis will explain which method was used to process a point based environment for texturing and setting up an environment in Unreal using both the 3d map and the laser scanned model.

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