The goal of this work is to examine the possibility of surface reconstruction from the images produced by the Tobii H5 eye tracker. It starts of by examining classic photometric stereo and its limitations under the illuminator configuration of the eye tracker. It then proceeds to investigate two alternative solutions: photometric stereo under the assumption that the albedo is known and a method that uses the images from the eye tracker as a guide to mold a reference model into the users face. In the second method the pose of the reference model is estimated by minimizing a photometric error under the assumption that the face is Lambertian, using particle swarm optimization. The position of the generic 3D model is then used in an attempt to mold its shape into the face of the user using shape-from-shading.

The company where this thesis was formulated constructs VR applications for the medical environment. The hardware used is ordinary dektops with consumer level graphics cards and haptic devices. In medicin some operations require microscopes or cameras. In order to simulate these in a virtual reality environment for educational purposes, the effect of depth of field or focus have to be considered. A working algorithm that generates this optical occurence in realtime, stereo rendered computer graphics is presented in this thesis. The algorithm is implemented in OpenGL and C++ to later be combined with a VR application simulating eye-surgery which is built with OpenGL Optimizer. Several different approaches are described in this report. The call for realtime stereo rendering (~60 fps) means taking advantage of the graphics hardware to a great extent. In OpenGL this means using the extensions to a specific graphic chip for better performance, in this case the algorithm is implemented for a GeForce3 card. To increase the speed of the algorithm much of the workload is moved from the CPU to the GPU (Graphics Processing Unit). By re-defining parts of the ordinary OpenGL pipeline via vertex programs, a distance-from-focus map can be stored in the alpha channel of the final image with little time loss. This can effectively be used to blend a previously blurred version of the scene with a normal render. Different techniques to quickly blur a renderedimage is discussed, to keep the speed up solutions that require moving data from the graphics card is not an option.

Stereoscopy is a technique that can create an illusion of depth in a flat image. There are many different methods to do this, and here is explained some of the most common and popular ways, with a bigger focus on the anaglyphic method. Since stereoscopy is an old technique, the discovery of it by Charles Wheatstone is explained briefly. In Autodesk Maya 2009, a new stereoscopic plug-in was included which makes the creation of stereoscopic imagery easier. An animated project is made during the course of this research which takes advantage of and tests the functions of the new plug-in. The main purpose of the project is to create a stereoscopic movie which utilized the anaglyph stereoscopic technique. The result is rendered stereoscopic material that is edited with Adobe Premiere Pro to create anaglyphic imagery and a full color alternative using the Infitec technique.

This thesis investigates how disparity estimation may be used to visualize an object on a 3D-screen. The first part looks into different methods of disparity estimation, and the second part examines different ways to visualize an object from one or several stereo pairs and a disparity map. Input to the system is one or several stereo pairs, and output is a sequence of images of the input scene but from more angles. This sequence of images can be shown on Setred AB's 3D-screen. The system has high real time demands and the goal is to do the disparity estimation and visualization in real time. In the first part of the thesis, three different ways to calculate disparity maps are implemented and compared. The three methods are correlation-based, local structure-based and phase-based techniques. The correlation-based methods cannot satisfy the real-time demands due to the large number of 2D-convolutions required per pixel. The local structure-based methods have too much noise and cannot satisfy the quality requirements. Therefore, the best method by far is the phase-based method. This method has been implemented in Matlab and C and comparisons between the different implementations are presented. The quality of the disparity maps is satisfying, but the real-time demands cannot yet be fulfilled. The future work is therefore to optimize the C code and move some functions to a GPU, because a GPU can perform calculations in parallel with the CPU. Another reason is that many of the calculations are related to resizing and warping, which are well-suited to implementation on a GPU.

Le pilotage de véhicule blindé est rendu difficile par la faible visibilité offerte aux pilotes face aux environnements et aux situations complexes qu’ils doivent traverser.La protection des opérateurs de véhicules militaires et l’intégrité de ces véhicules sont des besoins primordiaux pour l’armée de terre.Afin de répondre à la problématique : sécuriser le pilotage des véhicules militaires avec comme périmètre la définition d’un système de perception d’environnement, nous avons procédé à l’étude au sens large de l’aide au pilotage dans le contexte militaire en environnement naturel et semi-structuré afin de mettre en exergue les moyens et les capteurs utilisables pour réaliser un système d’aide au pilotage.Ainsi, nous offrons une réponse technique pour la réalisation d’un tel système au travers premièrement d’une étude des méthodes et algorithmes existants applicables à notre cas d’application. Ensuite nous définissons les capteurs utilisables avec de telles méthodes. De cet état de l’art, nous définissonsune système répondant à notre problématique et nous expliquons sa mise en pratique au travers de la création d’une plateforme d’expérimentation.Cette plateforme se compose des solutions présentées et permet de valider le concept par l’évaluation des solutions d’acquisition de l’environnement afin d’offrir les données nécessaires à une aide au pilotage.Puis, l’étude des moyens d’analyse de cet environnement offre des pistes de réflexion sur le futur système d’aide au pilotage.Enfin, une l’étude d’un moyen alternatif de restitution de l’information à l’opérateur complète la solution présentée en offrant une piste de réflexion sur l’impact de la restitution dans les performances des opérateurs. / Armored vehicule driving is difficult because of low visibility given to pilots in tough environnements conditions and complex situations they have to manage.Soldiers safety and vehicle integrity are part of main topics for French “Armée de Terre”. To answer the problem Make the driving of military vehicles safer by improving environnement perception through driver asssistance systems, we study driving assistance in unstructured environnemnt by looking for sensors and methods which are suitable to realize such a system.First, we study existing methods and algorithms which fit our application case. Conclusion of this study is the definition of our system.Second, thanks to the previous study we explain the creation of an experimentation platform allowing evaluation of our concept. Data obtained from reconstruction are then exploited through environment analysis to bring obstacle extraction methods.Third, study of an alternative display solution is exposed and complete this work in explaining impact of restitution in operating cycle.

The main purpose of this work is to reconstruct 3D model of an entire scene byusing two ordinary cameras. We develop a mobile phone application, based onstereo vision and image analysis algorithms, executed either locally or on a remotehost, to calculate the dietary intake using the current questionnaire and the mobilephone photographs. The information of segmented 3D models are used to calculatethe volume -and then the calories- of a person’s daily intake food. The method ischecked using different solid food samples, in different camera arrangements. Theresults shows that the method successfully reconstructs 3D model of different foodsample with high details.

Afin de répondre à des problématiques bâtimentaires et des enjeux de sécurité incendie, cette thèse aborde l’écoulement de convection mixte à travers un orifice horizontal reliant deux compartiments. L’objectif est d’améliorer la connaissance et la modélisation de l’échange de gaz de masse volumique variable à travers l’orifice. Une étude expérimentale à échelle réduite couplée à une approche théorique est proposée. L'étude est d'abord focalisée sur l’influence du rapport géométrique L/D de l’orifice sur la variation de débit échangé pour un régime de convection naturelle. Les mesures non intrusives de ces débits, par suivit de l'interface entre deux liquides non miscibles lors d'une première approche densimétrique, ainsi que par Stéréo PIV en sortie d'orifice dans une approche thermique, permettent de décrire le processus d'échange bidirectionnel et de conforter les corrélations existantes.Des expériences en régime de convection mixte visent ensuite à caractériser l’influence d’une ventilation mécanique (en soufflage et en extraction) sur les débits échangés. La confrontation des corrélations existantes avec les points expérimentaux montre des écarts importants. Une modification de la corrélation de Cooper 89 est proposée et permet d'en accroître la précision. En parallèle, une approche théorique issue des équations de Navier Stokes simplifiées et sous l’approximation de Boussinesq permet de discuter la construction des corrélations existantes. L'ajustement de coefficients de pertes de charge à partir des points expérimentaux permet de proposer un modèle plus performant que ceux disponibles dans la littérature. / To answer to building issues and fire safety challenges, this thesis deals with the mixed convection flow through a horizontal orifice linking two compartments. The aim is to improve the understanding and modeling of the exchange of variable density gas through the opening. A small scale experimental study and a theoretical approach are proposed.The study is first focussed on the impact of the geometrical ratio L/D of the opening on the exchanged flow rate variation for free convection regime. Non-intrusive measurements of these flow rates, via the tracking of the interface between two non miscible liquids in an isothermal approach, and thanks to the SPIV in a thermal approach, permit to describe the bidirectional exchange process and to consolidate existing correlations.Experiments in mixed convection regime aim to study the impact of mechanical ventilation (in blowing and extracting mode) on the exchanged flow rates. The comparison between existing correlations and experimental data shows large differences. A change making the coorelation of Cooper 89 more accurate is proposed. A theoretical approach from the simplified Navier Stokes equations and with the Boussinesq approximation permits to discuss the construction of existing correlations. From this theory, a model more accurate than those available in the literature is proposed thanks to an adjustment of discharge coefficients from experimental data.

I LKAB:s gruva i Kiirunavaara i Malmfälten tillämpas brytningsmetoden skivrasbrytning, som går ut påatt driva ortar in i malmkroppen, från dem borra uppåtgående hål i malmkroppen, spränga och sedanlasta ut malmen, som med gravitationens hjälp rasar ner i orten.Ett mål för detta examensarbete är att undersöka fragmenterings- och volymmätningens potentiellaeffekt på det dataunderlag som ligger till grund för beslutsfattande i produktionslastningen. Ett målär också att undersöka fragmenteringens effekt på skrymdensiteten vid skivrasbrytning.Analysarbetet baseras på data från ett markörförsök som utfördes i Kiirunavaaragruvan 2013/2014.För att verifiera tillförlitligheten hos det mätdata som ligger till grund för analysen, har metodernaför mätning av massa och skopvolym testats. En känd volym stenmaterial med en givenfragmentering vägdes i en lastmaskin och fotograferades på samma vis som under markörförsöken.Resultatet för volymmätningen visade på en överskattning som minskade med ökande volym och varmindre än 5 % för volymer över 4 m3. Resultatet för viktmätningen indikerade dock ett konsekventfel på över 20 %, vilket dock berodde på felaktig eller inte genomförd kalibrering av just denlastmaskinen.Volymanalysen visade att beräkningsmetoden som LKABs mjukvara för beräkning av järnhalt (WOLIS)använder sig av har utrymme för förbättringar. Efter att de föreslagna ändringarna genomförts,kvarstår dock en överskattning på 14 % av järnutbytet för WOLIS jämfört med volymmätning. Vidjämförelse av järnhalterna vs. utlastningsgrad, så visar WOLIS och volymmätningar liknande trendermed vissa skillnader, och dessa bedöms inte vara stora nog för att påverka lastningsbeslut.Den första hypotesen inför fragmenteringsanalysen var att det skulle finnas ett samband mellanblandad fragmentering och skrymdensitet för skopor som bedömts innehålla endast malm; detta pågrund av att mindre fragment teoretiskt fyller ut hålrummen mellan större fragment. Något sådantsamband kunde inte styrkas utifrån analysen. Den andra hypotesen var att det finns ett sambandmellan grövre fragmentering och lägre skrymdensitet för de analyserade skoporna (både malm- ochgråbergsskopor), och bekräftades av analysen. Detta stämmer väl överens med erfarenheten avbrytningsmetoden, där grövre fragmenterat material ofta inte kommer från malmkroppen, ochdärmed inte är uppsprängt som material i sprängkransarna.Volym- eller fragmenteringsmätning i produktionen rekommenderas inte av detta arbete. Iställetföreslås förändringar av beräkningsmodellen i WOLIS. En systematisk överskattning av malmutbytetkvarstår dock. Överskattningen utreds inte i detta arbete utan föreslås som fortsatt arbete,tillsammans med att se över produktionens rutiner för att motverka förekomsten av överlastning ochutebliven eller felaktig skopvågskalibrering vid service. / In the LKAB-mine in Kiirunavaara in the ore fields of Norrbotten, the mining method Sublevel Cavingis used. Drifts are developed transverse through the orebody from which blast rings are drilledupwards. The ore is blasted while the hangingwall progressively fails and fills the void. By means ofgravity flow both materials may be transported to the drawpoint from which mucking is carried out.One objective of the thesis is to examine the potential effect of volume measurement on the datawhich serves as basis for decision-making in the mucking operation. Another objective is toinvestigate the effect of fragmentation on bulk density. The analysis is based on data acquired from agravity flow study executed in the Kiirunavaara Mine in 2013/2014.In order to verify the reliability of the measured data, which is the basis of the analysis, the methodsfor measurement of bucket mass and bucket volume were tested. A known amount of crushed stoneof a certain size fraction was weighted in an LHD bucket and photographed in the same manner asduring the marker trials. The volume results showed an over-estimation of less than 5 % for bucketswith volumes larger than 4 m3.The error decreased with increasing volume. The weight, however,was consistently off by over 20 %, which could be attributed to improper or overlooked calibration ofthat particular LHD.The volume analysis showed that there is room for improvement in the calculation methods appliedin the software used by LKAB to calculate iron content (WOLIS). With the proposed changeshowever, a 14 %-over-estimation of iron recovery remains for WOLIS compared to the volumemeasureddata. When comparing iron content and extraction rate, the WOLIS-based curves showsimilar trends with some differences. They are not, however, expected to be enough to have bearingon mucking decisions.The first hypothesis for the fragmentation analysis is that a correlation exists betweeninhomogeneous fragmentation and bulk density for buckets containing exclusively ore. Theoretically,smaller fragments should fill the void between larger fragments. Such a correlation could not befound though. The second hypothesis is that coarser fragmentation is correlated to lower bulkdensity (for both ore- and waste rock buckets), which was also confirmed by the analysis. This is inaccordance with the experiences of the mining method, as coarsely fragmented material oftenderives from the hangingwall, and thereby isn’t as finely blasted as the actual blasted ore.A consequent volume measurement is not recommended in the thesis. Instead, changes in thecalculation model of the present measurement system are proposed. A systematic over-estimationof the ore production remains, however. It is suggested to investigate this in a further study. Inaddition it should be paid attention to the current procedures in mucking in particular, the observedoverloading and possible calibration errors.

3D representation nowadays has attracted much more public attention than ever before. One of the most important techniques in this field is depth extraction. In this thesis, we first introduce a well-known stereo matching method using color segmentation and belief propagation, and make an implementation of this framework. The color-segmentation based stereo matching method performs well recently, since this method can keep the object boundaries accurate, which is very important to depth map. Based on the implemented framework of segmentation based stereo matching, we proposed a color segmentation based 2D-to-3D video conversion method using high quality motion information. In our proposed scheme, the original depth map is generated from motion parallax by optical flow calculation. After that we employ color segmentation and plane estimation to optimize the original depth map to get an improved depth map with sharp object boundaries. We also make some adjustments for optical flow calculation to improve its efficiency and accuracy. By using the motion vectors extracted from compressed video as initial values for optical flow calculation, the calculated motion vectors are more accurate within a shorter time compared with the same process without initial values. The experimental results shows that our proposed method indeed gives much more accurate depth maps with high quality edge information. Optical flow with initial values provides good original depth map, and color segmentation with plane estimation further improves the depth map by sharpening its boundaries.

L’implementation de la vision biologique sur machine est un problème majeur que la recherche actuelle a à peine effleuré la surface. Les organismes vivants sont capables de réaliser des tâches visuelles très complexes et de manière très efficace. La stéréovision fait partie de ces mécanismes complexes que les sci- entifiques tentent de reproduire à l’aide de caméras à haute résolution. Cette thèse aborde le problème de la stéréovision d’une manière neuromorphique par l’intermédiaire d’une nouvelle génération de capteurs de vision appelés ”rétines de silicium”. Ces rétines de silicium imitent les rétines biologiques en capturant l’information visuelle sous forme de flux asynchrones d’événements codant les changements de contraste avec une grande précision temporelle. Ces capteurs sont utilisés pour étudier l’importance de la précision et de la dynamiquetemporelledelascènedansleproblèmedemiseencorrespondance stéréo. Nous proposons une des premières méthodes de reconstruction 3D capable de produire des modèles 3D d’une manière totalement asynchrone, á partir de l’information visuelle. Cette approche, outre son originalité, permet également de préserver la dynamique native de la scène. Cette thèse montre que le temps en tant que medium d’information, joue un rôle primordial dans la stéréovision. Le temps peut compléter, compenser, voire remplacer l’information apportée habituellement par la luminance et la géométrie. Ce travail établit également les fondations solides des futures recherches en vision stéréo á haute vitesse et haute dynamique, basée sur les événements. Il ouvre également de nouvelles perspectives prometteuses pour la résolution de problèmes traditionels de vision artificielle grâce à l’apport du nouveau paradigme de la vision asynchrone. / Reproducing biological vision in a machine is a challenging problem for which scientists have just scratched the surface. Living organisms are able to per- form complex tasks in an awestruckly efficient manner. The stereovision is one of these complex mechanisms that computer scientists try to replicate with high resolution cameras. This thesis takes on the stereovision problem in a neuromorphic way by mean of a new generation of vision sensors also called ”silicon retinas”. These silicon retinas mimic biological retinas by cap- turing the visual information into the form of asynchronous stream of events that encode contrast change at high temporal precision. These sensors are used to study the importance of the precise timing and the scene temporal dynamics in solving the stereo correspondence problem. We propose one of the first 3D reconstruction methods which is able to produce 3Dmodelsinatrulyevent-basedandasynchronousmanner, fromevent-based visual information. Besides the novelty of proposing a truly temporal- based asynchronous event-driven approach of 3D reconstructions, this work is also able to preserve the native dynamic of the scene. Time as information medium is proven to have a critical role in stereovision. Time can supplement, compensate and even replace the usual luminance and spatial information. This work lays strong foundations for future research on high temporal and event-based dynamic stereo vision. It also opens new promisingperspectivesforsolvingtraditionalmachinevisionproblemsthanks to the use of the new asynchronous vision paradigm.