De nombreuses applications de la vision par ordinateur requièrent la détection, la localisation et le suivi de régions ou d’objets d’intérêt dans une image ou une séquence d’images. De nombreux modèles d’attention visuelle, inspirés de la vision humaine, qui détectent de manière automatique les régions d’intérêt dans une image ou une vidéo, ont récemment été développés et utilisés avec succès dans différentes applications. Néanmoins, la plupart des approches existantes sont limitées à l’analyse de scènes statiques et très peu de méthodes exploitent la nature temporelle des séquences d’images.L'objectif principal de ce travail de thèse est donc l'étude de modèles d'attention visuelle pour l'analyse de scènes dynamiques complexes. Une carte de saliance est habituellement obtenue par la fusion d'une carte statitque (saliance spatiale dans une image) d'une part, et d'une carte dynamique (salience temporelle entre une série d'image) d'autre part. Dans notre travail, nous modélisons les changements dynamiques par un opérateur de texture LBP-TOP (Local Binary Patterns) et nous utilisons l'information couleur pour l'aspect spatial.Les deux cartes de saliances sont calculées en utilisant une formulation discriminante inspirée du système visuel humain, et fuionnées de manière appropriée en une carte de saliance spatio-temporelle.De nombreuses expériences avec des bases de données publiques, montrent que notre approche obteint des résulats meilleurs ou comparables avec les approches de la littérature. / Visual saliency is an important research topic in the field of computer vision due to its numerouspossible applications. It helps to focus on regions of interest instead of processingthe whole image or video data. Detecting visual saliency in still images has been widelyaddressed in literature with several formulations. However, visual saliency detection invideos has attracted little attention, and is a more challenging task due to additional temporalinformation. Indeed, a video contains strong spatio-temporal correlation betweenthe regions of consecutive frames, and, furthermore, motion of foreground objects dramaticallychanges the importance of the objects in a scene. The main objective of thethesis is to develop a spatio-temporal saliency method that works well for complex dynamicscenes.A spatio-temporal saliency map is usually obtained by the fusion of a static saliency mapand a dynamic saliency map. In our work, we model the dynamic textures in a dynamicscene with Local Binary Patterns (LBP-TOP) to compute the dynamic saliency map, andwe use color features to compute the static saliency map. Both saliency maps are computedusing a bio-inspired mechanism of Human Visual System (HVS) with a discriminantformulation known as center surround saliency, and are fused in a proper way.The proposed models have been extensively evaluated with diverse publicly availabledatasets which contain several videos of dynamic scenes. The evaluation is performed intwo parts. First, the method in locating interesting foreground objects in complex scene.Secondly, we evaluate our model on the task of predicting human observers fixations.The proposed method is also compared against state-of-the art methods, and the resultsshow that the proposed approach achieves competitive results.In this thesis we also evaluate the performance of different fusion techniques, because fusionplays a critical role in the accuracy of the spatio-temporal saliency map. We evaluatethe performances of different fusion techniques on a large and diverse complex datasetand the results show that a fusion method must be selected depending on the characteristics,in terms of color and motion contrasts, of a sequence. Overall, fusion techniqueswhich take the best of each saliency map (static and dynamic) in the final spatio-temporalmap achieve best results.

Several disequilibrium textures are found to occur within the hanging wall and footwall of the UG2 chromitite layer of the Bushveld Complex, South Africa. These textures include plagioclase chadacrysts found included within orthopyroxene and clinopyroxene as well as the orthopyroxenes exhibiting round crystal boundaries that appear to be resorbed. Textures found within the UG2 stratigraphy such as linear boundaries and 120° triple junctions at interfaces of adjacent plagioclase or pyroxene grains also suggest that recrystallization has taken place. The presence of both disequilibrium textures and recrystallization textures would suggest that a complex emplacement history has occurred. Ideally, this would be expected to be manifested by minerals of the same type but which are texturally distinct showing different composition. However this has been found not to be the case; minerals that suggest disequilibrium textures show similar compositions to the minerals which appear to have formed in equilibrium. This is also the same for recrystallized crystals which show the same compositions as crystals that have not been recrystallized. For example tabular clinopyroxene, which has a compositional range of En 44.6 to En 50.5, is indistinguishable from clinopyroxene occuring as discontinuous rims, En 44.3-48.2, and as intergranular necking connecting primocrysts of orthopyroxene ( En 44.3-50.4). Similarly, plagioclase occurring as inclusions with An 66.3-76.0 is indistinguishable from plagioclase occurring as zoned or recrystallized interstitial grains ( An 69.0- An 77.4). Compositional variation has however, been found to be controlled to an extent by stratigraphy in that minerals show different compositions within one layer to the same minerals within another layer, consistent with an evolving magma composition. It is concluded therefore that while composition is not texturally controlled it is to an extent stratigraphy controlled and that the evidence collected within the study supports two models for the formation of chromite within the Bushveld complex. The evidence is consistent with a combination of the magma mixing model and magma injection model to account for the textures and compositional variations found within the study. The evidence may also show support for models involving late modification of minerals by magmatic fluids but not as prominently as for the models mentioned above / Microsoft� Word 2010 / Adobe Acrobat 9.53 Paper Capture Plug-in

The goal of this thesis is to design and implement a program capable of automatically generating synthetic images of eye retinas. The generated images should be similar to those of real retinas, which are hard to obtain, so they could be used for development of various algorithms, which work with eye retina images in their place. This thesis describes anatomic properties of the eye retina, ways to take images of it and also usage of eye retina recognition in biometric and medicinal applications. Design of the program and the way in which individual parts of the retina are assembled together into the final image is also explained in this thesis. These individual parts are created using procedural textures in separate layers of the image. Next chapter of this work describes implementation details of the program. The conclusion then experimentally verifies suitability of the generated images for algorithmic processing.

The content of this thesis is to introduce with the issues taught in the course MGMP and create tutorials and 3D models in Blender for computer exercises of course MGMP. The first part is devoted to some similar courses taught at universities in the Czech Republic. Another parts are dealing with the method of Catmull-Clark subdivision surfaces, texture mapping issues, issues of curves and animation of objects with using curves. The last part is about shading 3D models and about various methods which have been developed and are in use to this day. The output of work are video tutorials and models for MGMP course, dealing with different parts of the thesis.

Tato disertační práce se zabývá vlivem mělkých mikro-textur na tření a tloušťku filmu v mazaných nekonformních kontaktech za extrémních podmínek a za podmínek hladovění kontaktu. Měření byla realizována na tribometru v konfiguraci ball-on-disk. Kontakt byl pozorován pomocí vysokorychlostní kamery. Pro stanovení součinitele tření byl využit snímač krouticího momentu. V této studii byly popsány dva typy mikrotextur – mikrovtisky a příčné mikrodrážky. Výsledky naznačují, že za podmínek hladovění vedou mikrovtisky ke snížení tření a to díky nárůstu tloušťky mazacího filmu. Mechanismus doplňování mikrovtisků čerstvým mazivem je pravděpodobně způsoben kapilárními jevy ve vstupní oblasti. Třecí plochy s příčnými mikrodrážkami, jejichž délka byla menší než průměr Hertzova kontaktu, potom obecně vykazovaly lepší tribologické parametry ve srovnání s hladkými povrchy. Příčné mikrodrážky vedly k výraznému nárůstu tloušťky mazacího filmu za podmínek hladovění i za extrémních provozních podmínek (protisměrný pohyb). Numerické simulace přechodových jevů příčných mikrodrážek ukázaly dobrou shodu s experimentálními výsledky.

L'évolution de la texture ou de la forme d'une tumeur à l'imagerie médicale reflète les modifications internes dues à la progression (naturelle ou sous traitement) d'une lésion tumorale. Dans ces travaux nous avons souhaité étudier l'apport des caractéristiques delta-radiomiques pour prédire l'évolution de la maladie. Nous cherchons à fournir un pipeline complet de la reconstruction des lésions à la prédiction, en utilisant seulement les données obtenues en routine clinique.Tout d'abord, nous avons étudié un sous ensemble de marqueurs radiomiques calculés sur IRM, en cherchant à établir quelles conditions sont nécessaires pour assurer leur robustesse. Des jeux de données artificiels et cliniques nous permettent d'évaluer l'impact de la reconstruction 3D des zones d'intérêt et celui du traitement de l'image.Une première analyse d'un cas clinique met en évidence des descripteurs de texture statistiquement associés à la survie sans évènement de patients atteints d'un carcinome du canal anal dès le diagnostic.Dans un second temps, nous avons développé des modèles d'apprentissage statistique. Une seconde étude clinique révèle qu'une signature radiomique IRM en T2 à trois paramètres apprise par un modèle de forêts aléatoires donne des résultats prometteurs pour prédire la réponse histologique des sarcomes des tissus mous à la chimiothérapie néoadjuvante.Le pipeline d'apprentissage est ensuite testé sur un jeu de données de taille moyenne sans images, dans le but cette fois de prédire la rechute métastatique à court terme de patientes atteinte d'un cancer du sein. La classification des patientes est ensuite comparée à la prédiction du temps de rechute fournie par un modèle mécanistique de l'évolution des lésions.Enfin nous discutons de l'apport des techniques plus avancées de l'apprentissage statistique pour étendre l'automatisation de notre chaîne de traitement (segmentation automatique des tumeurs, analyse quantitative de l'oedème péri-tumoral). / Tumor shape and texture evolution may highlight internal modifications resulting from the progression of cancer. In this work, we want to study the contribution of delta-radiomics features to cancer-evolution prediction. Our goal is to provide a complete pipeline from the 3D reconstruction of the volume of interest to the prediction of its evolution, using routinely acquired data only.To this end, we first analyse a subset of MRI(-extracted) radiomics biomarquers in order to determine conditions that ensure their robustness. Then, we determine the prerequisites of features reliability and explore the impact of both reconstruction and image processing (rescaling, grey-level normalization). A first clinical study emphasizes some statistically-relevant MRI radiomics features associated with event-free survival in anal carcinoma.We then develop machine-learning models to improve our results.Radiomics and machine learning approaches were then combined in a study on high grade soft tissu sarcoma (STS). Combining Radiomics and machine-learning approaches in a study on high-grade soft tissue sarcoma, we find out that a T2-MRI delta-radiomic signature with only three features is enough to construct a classifier able to predict the STS histological response to neoadjuvant chemotherapy. Our ML pipeline is then trained and tested on a middle-size clinical dataset in order to predict early metastatic relapse of patients with breast cancer. This classification model is then compared to the relapsing time predicted by the mechanistic model.Finally we discuss the contribution of deep-learning techniques to extend our pipeline with tumor automatic segmentation or edema detection.

In nature, microscopic surface textures impact useful function, such as the drag reduction of shark skin (Dean & Bhushan, 2010) and superhydrophobicity of the lotus leaf(Pan, Kota, Mabry, & Tuteja, 2013). In this study, we explore these phenomena by re-creating microscopic surface textures via the method of interfacial flow instability in drying polyvinylidene fluoride (PVDF) acetone solutions. In general, PVDF films can be made using either spin coating or electrospray deposition with various weight concentrations in acetone. In order to study the morphology of the porous structure of PVDF films, wet deposition samples were fabricated by spin coating or near-field electrospray. Possible theories are discussed and examined to explain the formation of these porous structures resulting in development of a well-controlled method to create porous PVDF films with various pore sizes and pore densities. All samples are characterized and found to exhibit superhydrophobicity and drag reduction. To connect porous PVDF film morphology to the established field of dry particle fabrication, PVDF particle synthesis by far-field electrospray is also reviewed and discussed. An established method to generate polymer particles of different morphologies in other polymers (Almeria-Diez, 2012) by electrospray drying is confirmed using PVDF as well. Due to the ability of scalable and re-configurable electrospray, the microscopic surface textures can be applied to areas of any size to reduce drag or impart water-repelling properties.

This Master’s thesis investigates the application of dynamically generated procedural terrain textures for texturing 3D representations of the Earth’s surface. The study explores techniques to overcome limitations of the currently most common method – projecting satellite imagery onto the mesh – such as insufficient resolution for close-up views and challenges in accommodating external lighting models. Textures for sand, rock and grass were generated procedurally on the GPU. Aliasing was prevented using a clamping technique, dynamically changing the level of detail when freely navigating across diverse landscapes. The general color of each terrain type was extracted from the satellite images, guided by land cover rasters, in a process where shadows were eliminated using HSV color space conversion and filtering. The procedurally generated textures provide significantly more details than the satellite images in close-up views, while missing some information in medium- to far-distance views, due to the satellite images containing information lacking in the 3D mesh. A qualitative analysis spanning six data sets from diverse global locations demonstrates that the proposed methods are applicable across a range of landscapes and climates.

Neural Rendering has recently shown potential for real-time applications such as video games. However, current state of the art Neural Rendering approaches still suffer from a high memory footprint and often require multiple inferences of large neural networks to produce a properly filtered output. This cost associated to filtering the output of Neural Rendering models makes real-time multiscale rendering difficult. In this work, we propose a neural architecture based on multiscale embeddings that take advantage of current rasterization pipelines to produce a filtered output in a single evaluation, allowing for a continuous appearance through scale using a very small neural network. The model is trained directly on a filtered signal in order to learn a continuous representation of the material instead of relying on a post-processing step. The proposed architecture enables efficient sampling on GPU both in texel position and in level of detail, and closely reproduces material textures while drastically reducing their memory footprint. The results show that this approach is a viable candidate for integration in rendering pipelines, as it can be inferred efficiently in regular fragment shaders and on consumer-level hardware inducing less than 1 millisecond of overhead compared to traditional pipelines while producing an output of similar quality with a 33% reduction in memory footprint. The model also produces a smooth reconstruction through scale, free of artifacts and visual discontinuities that would typically be observed for an unfiltered output. / Neural rendering har på senare år visat potential i realtidsapplikationer som t ex inom dataspel. Dessvärre begränsas dagens state-of-the-art metoder inom neural rendering av hög minnesanvändning och kräver ofta att multipla inferenser görs av relativt stora neuronnät för att skapa adekvat filtrerade resultat. Det är därför svårt att direkt tillämpa neural rendering i spelutveckling. I detta arbete föreslås en neural arkitektur som baserar sig på multiscale embeddings som tar tillvara på egenskaperna hos dagens renderingspipelines för att producera adekvat filtrerade resultat med endast en inferens, vilket möjliggör kontinuerliga utseendeegenskaper genom skalning med ett mycket litet neuronnät. Modellen tränas direkt på en filtrerad signal för att lära en kontinuerlig representation av materialet istället för att behöva ett separat post-processingsteg. Den föreslagna arkitekturen möjliggör effektiv sampling på GPU både i texelposition och level of detail, och reproducerar materialtexturerna väl, samtidigt som den reducerar minnesanvändningen drastiskt. Resultaten visar att denna metod är en gångbar kandidat för integration i en renderingspipeline, eftersom den kan inferreras effektivt i en vanlig fragmentsshader på konsumenthårdvara med under en millisekunds tidstillägg jämfört med en traditionell pipeline utan avkall på kvalitet med 33% lägre minnesanvändning. Modellen producerar också en slät rekonstruktion genom skalning, fri från artefakter och visuella diskontinuiteter som annars ofta syns i ett ofiltrerat resultat.

Résumé : La dénutrition subséquente à la dysphagie chez les résidents en centre d’hébergement et de soins de longue durée (CHSLD) est un problème majeur en raison de ses conséquences délétères, de sa prévalence élevée et de ses multiples facteurs de risque. La principale intervention nutritionnelle chez cette clientèle est de faciliter l’alimentation avec un régime de textures adaptées (ex. : purée, hachée). Cependant, des taux élevés de dénutrition sont constatés, malgré les interventions. La production d’aliments à textures adaptées, souvent réalisée en institution, comporte de nombreux défis (qualités organoleptiques, valeur nutritive, textures) alors que les produits commerciaux peuvent présenter plusieurs avantages. Les aliments Épikura© se distinguent avec des valeurs nutritives standardisées, des textures mesurées et un aspect visuel amélioré, en plus d’une efficacité clinique montrée lors d’une étude pilote. Le manque de données probantes dans le domaine a inspiré l’idée d’évaluer l’effet des aliments Épikura© sur les apports nutritionnels et le poids de résidents dysphagiques en CHSLD. Pour ce faire, nous avons réalisé un essai clinique randomisé. Les participants ont reçu, de façon aléatoire, les aliments Épikura© (groupe expérimental) ou les aliments à textures adaptées institutionnels (groupe témoin) pendant 20 semaines. Dû à des contraintes organisationnelles et à la fragilité de la clientèle, la taille d’échantillon optimale (n calculé = 48) n’a pu être atteinte (n réel = 17). Une augmentation significative des apports énergétiques, glucidiques et lipidiques (p < 0,05) a tout de même été observée dans le groupe expérimental (n = 7), en comparaison avec le groupe témoin (n = 10). Les participants des deux groupes ont conservé un poids stable, toutefois une tendance à la baisse a été observée dans le groupe témoin. Nos résultats montrent que les aliments Épikura© ont le potentiel d’améliorer les apports énergétiques et nutritionnels chez les résidents dysphagiques en CHSLD. De plus, l’étude souligne les défis méthodologiques reliés à la recherche en milieu clinique et d’hébergement et met en évidence les perspectives de la recherche dans le domaine des aliments à textures adaptées. / Abstract : Malnutrition resulting from dysphagia among older adults living in a residential longterm care (LTC) facility is a major concern as regards its high prevalence, multiple risk factors and severe consequences. The main intervention among this clientele is to provide a texture-modified diet in order to facilitate feeding. However, despite interventions, high prevalence of malnutrition is observed. In-house production of texture-modified foods is common and challenging (organoleptic qualities, nutritional value, texture) whereas commercial products can provide several advantages. Epikura© foods distinguished itself by its standardized nutritional values, rheological measures and improved visual aspect, in addition to a clinical efficacy shown in a previous pilot study. The goal of this study is to assess the effect of Epikura© foods on nutritional intakes and weight of dysphagic residents of LTC facility. A randomized clinical trial was conducted where participants were randomly allocated to receive either Epikura© foods (experimental group) or in-house texture-modified foods (control group) during 20 weeks. Due to organizational constraints and the frailty of this clientele, optimal sample size (calculated n = 48) could not be reached (actual n = 17). Significant increase in energy, carbohydrates and lipids intakes (p < 0.05) has nevertheless been oberved in the experimental group (n = 7), in comparison with the control group (n = 10). Participants of both groups maintain a stable weight, although the control group experienced a downward trend. Our results showed that Epikura© foods have the potential to improve nutritional intakes among dysphagic residents of LTC facility. Moreover, this study highlights methodological challenges of conducting research in a clinical setting and emphasizes new research opportunities in the area of texture-modified foods.