The aim of this work is to find a method for removing haze from satellite imagery. This is done by taking two algorithms developed for images taken from the sur- face of the earth and adapting them for satellite images. The two algorithms are Single Image Haze Removal Using Dark Channel Prior by He et al. and Color Im- age Dehazing Using the Near-Infrared by Schaul et al. Both algorithms, altered to fit satellite images, plus the combination are applied on four sets of satellite images. The results are compared with each other and the unaltered images. The evaluation is both qualitative, i.e. looking at the images, and quantitative using three properties: colorfulness, contrast and saturated pixels. Both the qualitative and the quantitative evaluation determined that using only the altered version of Dark Channel Prior gives the result with the least amount of haze and whose colors look most like reality.

3D reconstruction is the process of constructing a three-dimensional model from images. It contains multiple steps where each step can induce errors. When doing 3D reconstruction of outdoor scenes, there are some types of scene content that regularly cause problems and affect the resulting 3D model. Two of these are water, due to its fluctuating nature, and sky because of it containing no useful (3D) data. These areas cause different problems throughout the process and do generally not benefit it in any way. Therefore, masking them early in the reconstruction chain could be a useful step in an outdoor scene reconstruction pipeline. Manual masking of images is a time-consuming and boring task and it gets very tedious for big data sets which are often used in large scale 3D reconstructions. This master thesis explores if this can be done automatically using Convolutional Neural Networks for semantic segmentation, and to what degree the masking would benefit a 3D reconstruction pipeline. / 3D-rekonstruktion är teknologin bakom att skapa 3D-modeller utifrån bilder. Det är en process med många steg där varje steg kan medföra fel. Vid 3D-rekonstruktion av stora utomhusmiljöer finns det vissa typer av bildinnehåll som ofta ställer till problem. Två av dessa är vatten och himmel. Vatten är problematiskt då det kan fluktuera mycket från bild till bild samt att det kan innehålla reflektioner som ger olika utseenden från olika vinklar. Himmel å andra sidan ska aldrig ge upphov till 3D-information varför den lika gärna kan maskas bort. Manuell maskning av bilder är väldigt tidskrävande och dyrt. Detta examensarbete undersöker huruvida denna maskning kan göras automatiskt med Faltningsnät för Semantisk Segmentering och hur detta skulle kunna förbättra en 3D-rekonstruktionsprocess.

Gaze tracking is the estimation of the point in space a person is “looking at”. This is widely used in both diagnostic and interactive applications, such as visual attention studies and human-computer interaction. The most common commercial solution used to track gaze today uses a combination of infrared illumination and one or more cameras. These commercial solutions are reliable and accurate, but often expensive. The aim of this thesis is to construct a simple single-camera gaze tracker from off-the-shelf components. The method used for gaze tracking is based on infrared illumination and a schematic model of the human eye. Based on images of reflections of specific light sources in the surfaces of the eye the user’s gaze point will be estimated. Evaluation is also performed on both the software and hardware components separately, and on the system as a whole. Accuracy is measured in spatial and angular deviation and the result is an average accuracy of approximately one degree on synthetic data and 0.24 to 1.5 degrees on real images at a range of 600 mm.

This Master’s thesis describes an evaluation of the stream-based knowledge pro-cessing middleware framework DyKnow in multi-UAV traffic monitoring applica-tions performed at Saab Aerosystems. The purpose of DyKnow is “to providegeneric and well-structured software support for the processes involved in gen-erating state, object, and event abstractions about the environments of complexsystems." It does this by providing the concepts of streams, sources, computa-tional units (CUs), entity frames and chronicles. This evaluation is divided into three parts: A general quality evaluation ofDyKnow using the ISO 9126-1 quality model, a discussion of a series of questionsregarding the specific use and functionality of DyKnow and last, a performanceevaluation. To perform parts of this evaluation, a test application implementinga traffic monitoring scenario was developed using DyKnow and the Java AgentDEvelopment Framework (JADE). The quality evaluation shows that while DyKnow suffers on the usability side,the suitability, accuracy and interoperability were all given high marks. The results of the performance evaluation high-lights the factors that affect thememory and CPU requirements of DyKnow. It is shown that the most significantfactor in the demand placed on the CPU is the number of CUs and streams. Italso shows that DyKnow may suffer dataloss and severe slowdown if the CPU istoo heavily utilized. However, a reasonably sized DyKnow application, such as thescenario implemented in this report, should run without problems on systems atleast half as fast as the one used in the tests.

In recent years, the market for automatized surveillance and use of unmanned ground vehicles (UGVs) has increased considerably. In order for unmanned vehicles to operate autonomously, high level algorithms of artificial intelligence need to be developed and accompanied by some way to make the robots perceive and interpret the environment. The purpose of this work is to investigate methods for real-time obstacle detection using stereo vision and implement these on an existing UGV platform. To reach real-time processing speeds, the algorithms presented in this work are designed for parallel processing architectures and implemented using programmable graphics hardware. The reader will be introduced to the basics of stereo vision and given an overview of the most common real-time stereo algorithms in literature along with possible applications. A novel wide-baseline real-time depth estimation algorithm is presented. The depth estimation is used together with a simple obstacle detection algorithm, producing an occupancy map of the environment allowing for evasion of obstacles and path planning. In addition, a complete system design for autonomous navigation in multi-UGV systems is proposed.

Att undersöka hur elever blir hjälpta av bilder för att förstå vår omvärld var utgångspunkten i denna undersökning. För att försöka få fram det, valdes bland annat att låta eleverna rita egna bilder. Eleverna fick i uppdrag att med hjälp av bilder förklara växthuseffekten samt intervjuades ett urval av elever. Bilderna analyserades och de transkriberade intervjuerna ställdes i förhållande till vad de ritat. En del av elevernas bilder kontrasterar mot deras egna uppfattningar om hur bilder bör ser ut för att på ett bra sätt förklara olika ting och händelseförlopp. En del bilder stämmer överens med deras egna uppfattningar om hur bilder som hjälper att förstå bör se ut. Viktigt för flertalet av elever var att det i bilden fanns förklarande text. Andra viktiga aspekter var användandet av olika färger och att bilderna såg verkliga ut. Om en bild kan visa verkligheten eller inte diskuteras även det i uppsatsen. Min slutsats utifrån detta arbete är att eleverna verkar vara hjälpta av bilder som minneshjälp och för att förklara sammanhang, men för att rättvist kunna bedöma hur eleverna blir hjälpta kräver en djupare studie. Denna undersökning kan inspirera till att resonera kring hur eleverna blir hjälpta av bilder och kanske stimulera till vidare forskning

The pictorial language of the Swedish children is characterized by the idea that a “good” drawing should be in the right perspective and as photographically realistic as possible. This is a study about the pictorial language of the children in the Gambia and Senegal. Is the pictorial language different with the children living in a culture that has a stronger tradition of spoken word and visual communication than the children living in the western civilisation? With the help of different theories concerning children’s creating of art, this study is trying to sort out the differences. It is also explaining about different theories when it comes to development stages in the children’s drawings and how the culture, tradition and conventions influence both the pictorial grammar and the ideal image. The study is based on drawings collected in schools in The Gambia and Senegal and the drawings are analysed with the help of theories in Karin Aronssons “Barns världar – barns bilder”. The study is also based on observations and interviews with children and teachers in a school in the Gambia.

O uso de modelos de manobras representa um auxilio importante no projeto de veículos marinhos, permitindo a verificação do desempenho destes veículos, desenvolver o sistema de piloto automático, dentre outras aplicações durante a fase de projeto. Na área de veículos submarinos, seus modelos são tradicionalmente baseados em equações de movimento que incluem expressões polinomiais para representar os esforços hidrodinâmicos. Estes modelos são derivados de uma expansão em série de Taylor de forças e momentos, sendo representados em função das variáveis de movimento. Entretanto, estes modelos limitam a representatividade dos esforços hidrodinâmicos, e, especialmente para os termos de segunda ou mais altas ordens, eles requerem ensaios custosos em tanque de provas para identificar corretamente cada um dos coeficientes polinomiais. Esta dependência em ensaios de tanque de provas tem um impacto critico, ou até mesmo não realístico, durante o desenvolvimento de veículos autônomos submarinos, AUVs, de baixo ou médio custo. Utilizando métodos atuais da fluidodinâmica computacional (CFD), este trabalho propõe um roteiro alternativo para definir os modelos de manobras não lineares para uma classe de AUVs. As simulações de CFD, verificados e validados por normas rigorosas, são utilizados como base para derivar as funções não lineares que representam os esforços hidrodinâmicos, devido variações na velocidade lateral, velocidade angular e deflexão dos lemes. A abordagem numérica é complementada pelo uso de modelos analíticos e semi-empíricos oriundos da indústria de mísseis, que tiveram que ser melhorados com informações retiradas das simulações de CFD. Ajustes adicionais e derivações nos intervalos de confiança para as estimativas produzidas por métodos numéricos também são fornecidos pelo uso de modelos analíticos e semi-empíricos. Adotando o AUV Pirajuba como caso de estudo, a validação dos modelos de manobra foi realizada em duas etapas. Primeiro, são comparadas as estimativas dos esforços hidrodinâmicos com as medições em tanque de provas de um modelo cativo, e em seguida a resposta dinâmica dos modelos de manobras são comparadas com aquelas obtidas por ensaios em mar, sempre utilizando critérios de verificação e validação. Este tipo de análise indicou uma validação dos esforços hidrodinâmicos e do movimento para grande parte dos ensaios, sendo que nos demais casos o AUV teve seu comportamento dinâmico bem reproduzido. Este resultado demonstra que a metodologia proposta pode ser utilizada para estimar o modelo de manobra de um AUV típico, gerando uma solução de menor custo para a fase de desenvolvimento destes veículos. / The use of maneuvering models represents an important assistance in the project of marine vessels, allowing for the evaluation of the vehicle performance, the autopilot system development, among other tasks during the design phase. In the field of underwater vehicles, those models commonly are based on equations of motion that include polynomial expressions for representing the hydrodynamic efforts. They are derived from Taylor series expansion of forces and moments represented as functions of the motion variables. However, those models limit the representativeness of the hydrodynamic efforts, and, especially for the second order or higher terms, they require expensive trials in towing tank facilities to correctly identify each polynomic coefficient. This dependence on intensive tank tests has a critical impact, or is even unrealistic during the development of middle or low cost autonomous underwater vehicles, AUVs. Using current methods of computational fluid dynamics (CFD), this work proposes an alternative roadmap to construct nonlinear manoeuvring models, which can be applied to a class of AUVs. CFD simulations, verified and validated by rigorous standards, are used as basis to derive nonlinear functions that represent the hydrodynamic efforts due to variations in lateral velocity, angular rate and rudder deflection. The numerical approach is complemented by the use of analytical and semi-empirical models derived from missile industry, which have been improved according to the information taken from the CFD simulations. Further adjustments and derivation of confidence intervals to the estimates produced by the numerical method are also provided by the use of analytical and semi-empirical models. Adopting the Pirajuba AUV as a test bed, the manoeuvring model validation was carried out in two stages. Firstly, estimates of hydrodynamic efforts are compared with measurements obtained from experiments using a captive model in a towing tank. In the second step, the dynamic response predicted by the maneuvering model was compared with the output measured during free model trials. This type of analysis validated the hydrodynamic efforts and motion in most of the experiments, whereas for the remaining cases the AUV had its dynamic behavior well reproduced. This result demonstrates that the proposed methodology can be used to estimate the maneuvering model of a typical type AUV, generating a lower cost solution for the development phase of the vehicle.

Denna avhandling beskriver ett projekt för att skapa en prototypapplikation med syftet att förenkla vägmärkesinventering. Istället för att manuellt analysera en tagen bild och jämföra med en databas av vägmärken för inventing så kan man istället starta denna applikation, ladda in bilden och få ut ett svar på vad skylten har för identifieringskod. Idén är att vägmärkesinventerare ska spara in tiden det tar att gå igenom alla bilder tagna under en dag och istället få systemet att automatiskt lägga in vad vägmärket har för identifieringskod. Grundapplikationen är skriven som en WPF-applikation med hjälp av ramverket EmguCV som i sin tur nyttjar .NET ramverket. Den viktiga aspekten i detta projekt är att se ifall detta kan göras med rimlig beräkningskraft, kunna matcha skyltar på en rimlig tid, vilket gjordes möjligt med EmguCVs FLANN-algoritm. Projektet resulterade i en fungerande applikation där användare kan ladda upp cirkulära hastighetsvägmärken där applikationen detekterar och sedan matchar vägmärket mot en databas för att kunna identifiera det. / This dissertation describes a project for creating a prototype application for the purpose of simplifying road sign inventory. Instead of manually analyzing a captured image and comparing it to a database of inventory road signs, you can instead launch this application, load the image and get the identification code of that road sign. The idea is that road sign inventory takers will save the time it takes to review all the pictures taken during a day and instead, the system will automatically generate the identification code of that road sign. The basic application is written as a WPF application using the EmguCV framework, which in turn uses the .NET framework. The important aspect of this project is to see if matching road signs can can be done with reasonable computation and within reasonable time, this was made possible with EmguCVs FLANN-algorithm. The project resulted in a functional application in which users can upload circular velocity road signs and the application detects and identifies the road sign via a database of road signs.

In this thesis, two real-time stereo methods have been implemented and evaluated. The first one is based on blockmatching and the second one is based on local phase. The goal was to be able to run the algorithms at real-time and examine which one is best. The blockmatching method performed better than the phase based method, both in speed and accuracy. SIMD operations (Single Instruction Multiple Data) have been used in the processor giving a speed boost by a factor of two. / I det här exjobbet har två stereometoder för realtidstillämpningar implementerats och utvärderats. Den ena bygger på blockmatchning och den andra på lokal fas. Målet var att kunna köra metoderna i realtid och undersöka vilken av dem som fungerar bäst. Blockmatchningsmetoden gav gott resultat medan den fasbaserade fungerade sämre, både vad gäller hastighet och precision. SIMD-operationer (Single Instruction Multiple Data) användes hos processorn vilket resulterade en i fördubbling av prestandan.