23 research outputs found

    Object Tracking

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    Object tracking consists in estimation of trajectory of moving objects in the sequence of images. Automation of the computer object tracking is a difficult task. Dynamics of multiple parameters changes representing features and motion of the objects, and temporary partial or full occlusion of the tracked objects have to be considered. This monograph presents the development of object tracking algorithms, methods and systems. Both, state of the art of object tracking methods and also the new trends in research are described in this book. Fourteen chapters are split into two sections. Section 1 presents new theoretical ideas whereas Section 2 presents real-life applications. Despite the variety of topics contained in this monograph it constitutes a consisted knowledge in the field of computer object tracking. The intention of editor was to follow up the very quick progress in the developing of methods as well as extension of the application

    Analysis and Development of Augmented Reality Applications for the Dissemination of Cultural Heritage

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    Tesis por compendio[ES] La RA consiste en la superposición de elementos virtuales sobre el entorno real, de manera que el usuario percibe estos elementos como si formaran parte de la realidad que está visualizando. Las aplicaciones de RA en dispositivos móviles permiten visualizar el contenido virtual a través de la cámara del dispositivo. La RA es una herramienta de divulgación muy potente ya que permite añadir a la realidad cualquier tipo de información, desde un simple texto informativo a un modelo 3D interactivo. Tiene infinitas utilidades, puede servir de guía en un museo, puede mostrar la recreación de un monumento destruido, o como en el caso de estudio aquí presentado, ayudar a la interpretación de pinturas rupestres. Esta tesis parte de la idea de que la RA puede mejorar mucho la interpretación del arte rupestre sin alterar ni dañar las pinturas. Puede servir para atraer a un público mayor, dar a conocer la historia de las pinturas rupestres y que al mismo tiempo el visitante tenga una experiencia mucho más enriquecedora. A lo largo de la tesis se ha estudiado en profundidad la técnica de visualización de RA mediante dispositivos móviles. Se han analizado las diferentes librerías de programación mediante casos de estudio en entornos reales y examinado los factores que pueden afectar al reconocimiento de las pinturas. Se ha desarrollado una aplicación de RA aplicada a un caso real de pinturas rupestres y posteriormente ha sido evaluada por un grupo de personas. Finalmente, se ha estudiado el efecto de la luz solar y sus cambios a lo largo del día sobre el reconocimiento de imágenes en entornos al aire libre. Este trabajo proporciona un punto de partida para el desarrollo de aplicaciones de RA aplicadas a la difusión del patrimonio cultural, especialmente centrado en el arte rupestre, un entorno que sufre de unas dificultades añadidas debido a su localización, dificultad de reconocimiento de puntos característicos en las pinturas y los cambios en la luz solar, problemas que se han tratado de resolver a lo largo del estudio. Las principales conclusiones han sido muy favorables, partiendo de librerías de programación disponibles y gratuitas. Se han podido desarrollar un conjunto de aplicaciones de RA en diferentes lugares. Las valoraciones han sido muy positivas, los usuarios que han probado las aplicaciones afirman que la interpretación de las pinturas les resulta más fácil y consiguen entender mejor el propósito de las mismas. El principal inconveniente encontrado es la falta de conocimiento sobre esta técnica y la pérdida de realismo en algunos casos debido a la oclusión, es decir, que los objetos virtuales no se posicionen por detrás de los objetos reales. La buena noticia es que esta tecnología evoluciona muy rápido y durante el desarrollo de la tesis ha habido avances muy grandes, entre ellos, el desarrollo de nuevas librerías de programación desarrolladas por Google y Apple, que proporcionan las herramientas necesarias para crear aplicaciones muy potentes e immersivas, donde el usuario se sentirá parte de los entornos creados.[CA] La RA consisteix en la superposició d'elements virtuals sobre l'entorn real, de manera que l'usuari percep aquests elements com si formaren part de la realitat que està visualitzant. Les aplicacions de RA en dispositius mòbils permeten visualitzar el contingut virtual a través de la cambra del dispositiu. La RA és una eina de divulgació molt potent ja que permet afegir a la realitat qualsevol tipus d'informació, des d'un simple text informatiu a un model 3D interactiu. Té infinites utilitats, pot servir de guia en un museu, pot mostrar la recreació d'un monument destruït, o com en el cas d'estudi ací presentat, ajudar a la interpretació de pintures rupestres. Aquesta tesi parteix de la idea que la RA pot millorar molt la interpretació de l'art rupestre sense alterar ni danyar les pintures. Pot servir per a atraure a un públic major, donar a conéixer la història de les pintures rupestres i que al mateix temps el visitant tinga una experiència molt més enriquidora. Al llarg de la tesi s'ha estudiat en profunditat la tècnica de visualització de RA mitjançant dispositius mòbils. S'han analitzat les diferents llibreries de programació mitjançant casos d'estudi en entorns reals i analitzat els factors que poden afectar el reconeixement de les pintures. S'ha desenvolupat una aplicació de RA aplicada a un cas real de pintures rupestres i posteriorment ha sigut avaluada per un grup de persones. Finalment, s'ha estudiat l'efecte de la llum solar i els seus canvis al llarg del dia sobre el reconeixement d'imatges en entorns a l'aire lliure. Aquest treball proporciona un punt de partida per al desenvolupament d'aplicacions de RA aplicades a la difusió del patrimoni cultural, especialment centrat en l'art rupestre, un entorn que pateix d'unes dificultats afegides a causa de la seua localització, dificultat de reconeixement de punts característics en les pintures i els canvis en la llum solar, problemes que s'han tractat de resoldre al llarg de l'estudi. Les principals conclusions han sigut molt favorables, partint de llibreries de programació disponibles i gratuïtes. S'han pogut desenvolupar un conjunt d'aplicacions de RA en diferents llocs. Les valoracions han sigut molt positives, els usuaris que han provat les aplicacions afirmen que la interpretació de les pintures els resulta més fàcil i aconsegueixen entendre millor el propòsit d'aquestes. El principal inconvenient trobat és la falta de coneixement sobre aquesta tècnica i la perduda de realisme en alguns casos a causa de l'oclusió, és a dir, que els objectes virtuals no es posicionen per darrere dels objectes reals. La bona notícia és que aquesta tecnologia evoluciona molt ràpid i durant el desenvolupament de la tesi hi ha hagut avanços molt grans, entre ells, el desenvolupament de noves llibreries de programació per Google i Apple, que proporcionen les eines necessàries per a crear aplicacions molt potents i immersives, on l'usuari se sentirà part dels entorns creats.[EN] AR consists of superimposing virtual elements on the real environment, so that the user perceives these elements as if they were part of the reality they are looking at. AR applications on smartphones allow virtual content to be visualised through the device's camera. AR is a very powerful tool for dissemination as it allows any type of information to be added to reality, from a simple informative text to an interactive 3D model. It can be used as a guide in a museum, it can show the recreation of a destroyed monument, or, as in the case study presented here, it can help in the interpretation of cave paintings. This thesis is based on the idea that AR can greatly enhance the interpretation of rock art without affecting or damaging the paintings. It can be used to attract a wider audience, to introduce the history of the rock art paintings and at the same time provide the visitor with a much more enriching experience. Throughout the thesis, the technique of AR visualisation using mobile devices has been studied in-depth. The different programming libraries have been analysed by means of case studies in real environments as well as the factors that can affect the paintings recognition. An AR application applied to a real case of rock art paintings has been developed and subsequently evaluated by a group of people. Finally, the effect of sunlight and its changes throughout the day on image recognition in outdoor environments has been studied. This work provides a starting point for the AR applications development applied to the dissemination of cultural heritage, especially focused on rock art, an environment that suffers from additional difficulties due to its location, the difficulty of characteristic points recognition and changes in sunlight, problems that have been tried to solve throughout the study. The main outcomes have been very favourable, using freely available programming libraries, and it has been possible to develop a set of AR applications in different places. The evaluations have been very positive, with users who have tested the applications confirming that the interpretation of the paintings is easier for them and they can better understand the purpose of the paintings. The major drawback is the lack of knowledge about this technique and the loss of realism in some cases due to occlusion, i.e. the virtual objects are not positioned behind the real objects. The good news is that this technology is evolving very fast and during the development of the thesis there have been great advances, among them, the development of new programming libraries developed by Google and Apple, which provide the necessary tools to create very powerful and immersive applications, where the user will feel part of the virtual environments created.Blanco Pons, S. (2021). Analysis and Development of Augmented Reality Applications for the Dissemination of Cultural Heritage [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178895TESISCompendi

    Augmented Reality Markerless Multi-Image Outdoor Tracking System for the Historical Buildings on Parliament Hill

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    [EN] Augmented Reality (AR) applications have experienced extraordinary growth recently, evolving into a well-established method for the dissemination and communication of content related to cultural heritage¿including education. AR applications have been used in museums and gallery exhibitions and virtual reconstructions of historic interiors. However, the circumstances of an outdoor environment can be problematic. This paper presents a methodology to develop immersive AR applications based on the recognition of outdoor buildings. To demonstrate this methodology, a case study focused on the Parliament Buildings National Historic Site in Ottawa, Canada has been conducted. The site is currently undergoing a multiyear rehabilitation program that will make access to parts of this national monument inaccessible to the public. AR experiences, including simulated photo merging of historic and present content, are proposed as one tool that can enrich the Parliament Hill visit during the rehabilitation. Outdoor AR experiences are limited by factors, such as variable lighting (and shadows) conditions, caused by changes in the environment (objects height and orientation, obstructions, occlusions), the weather, and the time of day. This paper proposes a workflow to solve some of these issues from a multi-image tracking approach.This work has been developed under the framework of the New Paradigms/New Tools for Heritage Conservation in Canada, a project funded through the Social Sciences and Humanities Research Council of Canada (SSHRC).Blanco-Pons, S.; Carrión-Ruiz, B.; Duong, M.; Chartrand, J.; Fai, S.; Lerma, JL. (2019). Augmented Reality Markerless Multi-Image Outdoor Tracking System for the Historical Buildings on Parliament Hill. Sustainability. 11(16):1-15. https://doi.org/10.3390/su11164268S1151116Bekele, M. K., Pierdicca, R., Frontoni, E., Malinverni, E. S., & Gain, J. (2018). A Survey of Augmented, Virtual, and Mixed Reality for Cultural Heritage. Journal on Computing and Cultural Heritage, 11(2), 1-36. doi:10.1145/3145534Gimeno, J., Portalés, C., Coma, I., Fernández, M., & Martínez, B. (2017). Combining traditional and indirect augmented reality for indoor crowded environments. A case study on the Casa Batlló museum. Computers & Graphics, 69, 92-103. doi:10.1016/j.cag.2017.09.001Kolivand, H., El Rhalibi, A., Shahrizal Sunar, M., & Saba, T. (2018). ReVitAge: Realistic virtual heritage taking shadows and sky illumination into account. Journal of Cultural Heritage, 32, 166-175. doi:10.1016/j.culher.2018.01.020Amakawa, J., & Westin, J. (2017). New Philadelphia: using augmented reality to interpret slavery and reconstruction era historical sites. International Journal of Heritage Studies, 24(3), 315-331. doi:10.1080/13527258.2017.1378909Kim, J.-B., & Park, C. (2011). Development of Mobile AR Tour Application for the National Palace Museum of Korea. Lecture Notes in Computer Science, 55-60. doi:10.1007/978-3-642-22021-0_7Barrile, V., Fotia, A., Bilotta, G., & De Carlo, D. (2019). Integration of geomatics methodologies and creation of a cultural heritage app using augmented reality. Virtual Archaeology Review, 10(20), 40. doi:10.4995/var.2019.10361Analysis of Tracking Accuracy for Single-Camera Square-Marker-Based Tracking. In Third Workshop on Virtual and Augmented Reality of the GI-Fachgruppe VR/AR, Koblenz, Germany, 2006http://campar.in.tum.de/Chair/PublicationDetail?pub=pentenrieder2006giCirulis, A., & Brigmanis, K. B. (2013). 3D Outdoor Augmented Reality for Architecture and Urban Planning. Procedia Computer Science, 25, 71-79. doi:10.1016/j.procs.2013.11.009You, S., Neumann, U., & Azuma, R. (1999). Orientation tracking for outdoor augmented reality registration. IEEE Computer Graphics and Applications, 19(6), 36-42. doi:10.1109/38.799738Wither, J., Tsai, Y.-T., & Azuma, R. (2011). Indirect augmented reality. Computers & Graphics, 35(4), 810-822. doi:10.1016/j.cag.2011.04.010Radkowski, R., & Oliver, J. (2013). Natural Feature Tracking Augmented Reality for On-Site Assembly Assistance Systems. Lecture Notes in Computer Science, 281-290. doi:10.1007/978-3-642-39420-1_30Rao, J., Qiao, Y., Ren, F., Wang, J., & Du, Q. (2017). A Mobile Outdoor Augmented Reality Method Combining Deep Learning Object Detection and Spatial Relationships for Geovisualization. Sensors, 17(9), 1951. doi:10.3390/s17091951Hoppe, H., DeRose, T., Duchamp, T., McDonald, J., & Stuetzle, W. (1993). Mesh optimization. Proceedings of the 20th annual conference on Computer graphics and interactive techniques - SIGGRAPH ’93. doi:10.1145/166117.166119Rossignac, J., & Borrel, P. (1993). Multi-resolution 3D approximations for rendering complex scenes. Modeling in Computer Graphics, 455-465. doi:10.1007/978-3-642-78114-8_29Gross, M. H., Staadt, O. G., & Gatti, R. (1996). Efficient triangular surface approximations using wavelets and quadtree data structures. IEEE Transactions on Visualization and Computer Graphics, 2(2), 130-143. doi:10.1109/2945.506225Botsch, M., Pauly, M., Rossl, C., Bischoff, S., & Kobbelt, L. (2006). Geometric modeling based on triangle meshes. ACM SIGGRAPH 2006 Courses on - SIGGRAPH ’06. doi:10.1145/1185657.1185839Pietroni, N., Tarini, M., & Cignoni, P. (2010). Almost Isometric Mesh Parameterization through Abstract Domains. IEEE Transactions on Visualization and Computer Graphics, 16(4), 621-635. doi:10.1109/tvcg.2009.96Khan, D., Yan, D.-M., Ding, F., Zhuang, Y., & Zhang, X. (2018). Surface remeshing with robust user-guided segmentation. Computational Visual Media, 4(2), 113-122. doi:10.1007/s41095-018-0107-yGuidi, G., Russo, M., Ercoli, S., Remondino, F., Rizzi, A., & Menna, F. (2009). A Multi-Resolution Methodology for the 3D Modeling of Large and Complex Archeological Areas. International Journal of Architectural Computing, 7(1), 39-55. doi:10.1260/147807709788549439Remondino, F., & El-Hakim, S. (2006). Image-based 3D Modelling: A Review. The Photogrammetric Record, 21(115), 269-291. doi:10.1111/j.1477-9730.2006.00383.xBruno, F., Bruno, S., De Sensi, G., Luchi, M.-L., Mancuso, S., & Muzzupappa, M. (2010). From 3D reconstruction to virtual reality: A complete methodology for digital archaeological exhibition. Journal of Cultural Heritage, 11(1), 42-49. doi:10.1016/j.culher.2009.02.006Unity, The Photogrammetry Workflowhttps://unity.com/solutions/photogrammetry.Blanco, S., Carrión, B., & Lerma, J. L. (2016). REVIEW OF AUGMENTED REALITY AND VIRTUAL REALITY TECHNIQUES IN ROCK ART. Proceedings of the ARQUEOLÓGICA 2.0 8th International Congress on Archaeology, Computer Graphics, Cultural Heritage and Innovation. doi:10.4995/arqueologica8.2016.3561Behzadan, A. H., & Kamat, V. R. (2010). Scalable Algorithm for Resolving Incorrect Occlusion in Dynamic Augmented Reality Engineering Environments. Computer-Aided Civil and Infrastructure Engineering, 25(1), 3-19. doi:10.1111/j.1467-8667.2009.00601.xTian, Y., Long, Y., Xia, D., Yao, H., & Zhang, J. (2015). Handling occlusions in augmented reality based on 3D reconstruction method. Neurocomputing, 156, 96-104. doi:10.1016/j.neucom.2014.12.081Tian, Y., Guan, T., & Wang, C. (2010). Real-Time Occlusion Handling in Augmented Reality Based on an Object Tracking Approach. Sensors, 10(4), 2885-2900. doi:10.3390/s10040288

    DEEP LEARNING FOR FASHION AND FORENSICS

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    Deep learning is the new electricity, which has dramatically reshaped people's everyday life. In this thesis, we focus on two emerging applications of deep learning - fashion and forensics. The ubiquity of online fashion shopping demands effective search and recommendation services for customers. To this end, we first propose an automatic spatially-aware concept discovery approach using weakly labeled image-text data from shopping websites. We first fine-tune GoogleNet by jointly modeling clothing images and their corresponding descriptions in a visual-semantic embedding space. Then, for each attribute (word), we generate its spatially-aware representation by combining its semantic word vector representation with its spatial representation derived from the convolutional maps of the fine-tuned network. The resulting spatially-aware representations are further used to cluster attributes into multiple groups to form spatially-aware concepts (e.g., the neckline concept might consist of attributes like v-neck, round-neck}, \textit{etc}). Finally, we decompose the visual-semantic embedding space into multiple concept-specific subspaces, which facilitates structured browsing and attribute-feedback product retrieval by exploiting multimodal linguistic regularities. We conducted extensive experiments on our newly collected Fashion200K dataset, and results on clustering quality evaluation and attribute-feedback product retrieval task demonstrate the effectiveness of our automatically discovered spatially-aware concepts. For fashion recommendation tasks, we study two types of fashion recommendation: (i) suggesting an item that matches existing components in a set to form a stylish outfit (a collection of fashion items), and (ii) generating an outfit with multimodal (images/text) specifications from a user. To this end, we propose to jointly learn a visual-semantic embedding and the compatibility relationships among fashion items in an end-to-end fashion. More specifically, we consider a fashion outfit to be a sequence (usually from top to bottom and then accessories) and each item in the outfit as a time step. Given the fashion items in an outfit, we train a bidirectional LSTM (Bi-LSTM) model to sequentially predict the next item conditioned on previous ones to learn their compatibility relationships. Further, we learn a visual-semantic space by regressing image features to their semantic representations aiming to inject attribute and category information as a regularization for training the LSTM. The trained network can not only perform the aforementioned recommendations effectively but also predict the compatibility of a given outfit. We conduct extensive experiments on our newly collected Polyvore dataset, and the results provide strong qualitative and quantitative evidence that our framework outperforms alternative methods. In addition to searching and recommendation, customers also would like to virtually try-on fashion items. We present an image-based VIirtual Try-On Network (VITON) without using 3D information in any form, which seamlessly transfers a desired clothing item onto the corresponding region of a person using a coarse-to-fine strategy. Conditioned upon a new clothing-agnostic yet descriptive person representation, our framework first generates a coarse synthesized image with the target clothing item overlaid on that same person in the same pose. We further enhance the initial blurry clothing area with a refinement network. The network is trained to learn how much detail to utilize from the target clothing item, and where to apply to the person in order to synthesize a photo-realistic image in which the target item deforms naturally with clear visual patterns. Experiments on our newly collected dataset demonstrate its promise in the image-based virtual try-on task over state-of-the-art generative models. Interestingly, VITON can be modified to swap faces instead of swapping clothing items. Conditioned on the landmarks of a face, generative adversarial networks can synthesize a target identity on to the original face keeping the original facial expression. We achieve this by introducing an identity preserving loss together with a perceptually-aware discriminator. The identity preserving loss tries to keep the synthesized face presents the same identity as the target, while the perceptually-aware discriminator ensures the generated face looks realistic. It is worth noticing that these face-swap techniques can be easily used to manipulated people's faces, and might cause serious social and political consequences. Researchers have developed powerful tools to detect these manipulations. In this dissertation, we utilize convolutional neural networks to boost the detection accuracy of tampered face or person in images. Firstly, a two-stream network is proposed to determine if a face has been tampered with. We train a GoogLeNet to detect tampering artifacts in a face classification stream, and train a patch based triplet network to leverage features capturing local noise residuals and camera characteristics as a second stream. In addition, we use two different online face swapping applications to create a new dataset that consists of 2010 tampered images, each of which contains a tampered face. We evaluate the proposed two-stream network on our newly collected dataset. Experimental results demonstrate the effectiveness of our method. Further, spliced people are also very common in image manipulation. We describe a tampering detection system containing multiple modules, which model different aspects of tampering traces. The system first detects faces in an image. Then, for each detected face, it enlarges the bounding box to include a portrait image of that person. Three models are fused to detect if this person (portrait) is tampered or not: (i) PortraintNet: A binary classifier fine-tuned on ImageNet pre-trained GoogLeNet. (ii) SegNet: A U-Net predicts tampered masks and boundaries, followed by a LeNet to classify if the predicted masks and boundaries indicating the image has been tampered with or not. (iii) EdgeNet: A U-Net predicts the edge mask of each portrait, and the extracted portrait edges are fed into a GoogLeNet for tampering classification. Experiments show that these three models are complementary and can be fused to effectively detect a spliced portrait image

    Virtuaalse proovikabiini 3D kehakujude ja roboti juhtimisalgoritmide uurimine

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    Väitekirja elektrooniline versioon ei sisalda publikatsiooneVirtuaalne riiete proovimine on üks põhilistest teenustest, mille pakkumine võib suurendada rõivapoodide edukust, sest tänu sellele lahendusele väheneb füüsilise töö vajadus proovimise faasis ning riiete proovimine muutub kasutaja jaoks mugavamaks. Samas pole enamikel varem välja pakutud masinnägemise ja graafika meetoditel õnnestunud inimkeha realistlik modelleerimine, eriti terve keha 3D modelleerimine, mis vajab suurt kogust andmeid ja palju arvutuslikku ressurssi. Varasemad katsed on ebaõnnestunud põhiliselt seetõttu, et ei ole suudetud korralikult arvesse võtta samaaegseid muutusi keha pinnal. Lisaks pole varasemad meetodid enamasti suutnud kujutiste liikumisi realistlikult reaalajas visualiseerida. Käesolev projekt kavatseb kõrvaldada eelmainitud puudused nii, et rahuldada virtuaalse proovikabiini vajadusi. Välja pakutud meetod seisneb nii kasutaja keha kui ka riiete skaneerimises, analüüsimises, modelleerimises, mõõtmete arvutamises, orientiiride paigutamises, mannekeenidelt võetud 3D visuaalsete andmete segmenteerimises ning riiete mudeli paigutamises ja visualiseerimises kasutaja kehal. Selle projekti käigus koguti visuaalseid andmeid kasutades 3D laserskannerit ja Kinecti optilist kaamerat ning koostati nendest andmebaas. Neid andmeid kasutati välja töötatud algoritmide testimiseks, mis peamiselt tegelevad riiete realistliku visuaalse kujutamisega inimkehal ja suuruse pakkumise süsteemi täiendamisega virtuaalse proovikabiini kontekstis.Virtual fitting constitutes a fundamental element of the developments expected to rise the commercial prosperity of online garment retailers to a new level, as it is expected to reduce the load of the manual labor and physical efforts required. Nevertheless, most of the previously proposed computer vision and graphics methods have failed to accurately and realistically model the human body, especially, when it comes to the 3D modeling of the whole human body. The failure is largely related to the huge data and calculations required, which in reality is caused mainly by inability to properly account for the simultaneous variations in the body surface. In addition, most of the foregoing techniques cannot render realistic movement representations in real-time. This project intends to overcome the aforementioned shortcomings so as to satisfy the requirements of a virtual fitting room. The proposed methodology consists in scanning and performing some specific analyses of both the user's body and the prospective garment to be virtually fitted, modeling, extracting measurements and assigning reference points on them, and segmenting the 3D visual data imported from the mannequins. Finally, superimposing, adopting and depicting the resulting garment model on the user's body. The project is intended to gather sufficient amounts of visual data using a 3D laser scanner and the Kinect optical camera, to manage it in form of a usable database, in order to experimentally implement the algorithms devised. The latter will provide a realistic visual representation of the garment on the body, and enhance the size-advisor system in the context of the virtual fitting room under study

    NOTIFICATION!!!

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    The full content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

    Synthesizing and Editing Photo-realistic Visual Objects

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    In this thesis we investigate novel methods of synthesizing new images of a deformable visual object using a collection of images of the object. We investigate both parametric and non-parametric methods as well as a combination of the two methods for the problem of image synthesis. Our main focus are complex visual objects, specifically deformable objects and objects with varying numbers of visible parts. We first introduce sketch-driven image synthesis system, which allows the user to draw ellipses and outlines in order to sketch a rough shape of animals as a constraint to the synthesized image. This system interactively provides feedback in the form of ellipse and contour suggestions to the partial sketch of the user. The user's sketch guides the non-parametric synthesis algorithm that blends patches from two exemplar images in a coarse-to-fine fashion to create a final image. We evaluate the method and synthesized images through two user studies. Instead of non-parametric blending of patches, a parametric model of the appearance is more desirable as its appearance representation is shared between all images of the dataset. Hence, we propose Context-Conditioned Component Analysis, a probabilistic generative parametric model, which described images with a linear combination of basis functions. The basis functions are evaluated for each pixel using a context vector computed from the local shape information. We evaluate C-CCA qualitatively and quantitatively on inpainting, appearance transfer and reconstruction tasks. Drawing samples of C-CCA generates novel, globally-coherent images, which, unfortunately, lack high-frequency details due to dimensionality reduction and misalignment. We develop a non-parametric model that enhances the samples of C-CCA with locally-coherent, high-frequency details. The non-parametric model efficiently finds patches from the dataset that match the C-CCA sample and blends the patches together. We analyze the results of the combined method on the datasets of horse and elephant images

    NOTIFICATION !!!

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    All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

    NOTIFICATION !!!

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    All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

    Simulation Guidée par l’Image pour la Réalité Augmentée durant la Chirurgie Hépatique

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    The main objective of this thesis is to provide surgeons with tools for pre and intra-operative decision support during minimally invasive hepaticsurgery. These interventions are usually based on laparoscopic techniques or, more recently, flexible endoscopy. During such operations, the surgeon tries to remove a significant number of liver tumors while preserving the functional role of the liver. This involves defining an optimal hepatectomy, i.e. ensuring that the volume of post-operative liver is at least at 55% of the original liver and the preserving at hepatic vasculature. Although intervention planning can now be considered on the basis of preoperative patient-specific, significant movements of the liver and its deformations during surgery data make this very difficult to use planning in practice. The work proposed in this thesis aims to provide augmented reality tools to be used in intra-operative conditions in order to visualize the position of tumors and hepatic vascular networks at any time.L’objectif principal de cette thèse est de fournir aux chirurgiens des outils d’aide à la décision pré et per-opératoire lors d’interventions minimalement invasives en chirurgie hépatique. Ces interventions reposent en général sur des techniques de laparoscopie ou plus récemment d’endoscopie flexible. Lors de telles interventions, le chirurgien cherche à retirer un nombre souvent important de tumeurs hépatiques, tout en préservant le rôle fonctionnel du foie. Cela implique de définir une hépatectomie optimale, c’est à dire garantissant un volume du foie post-opératoire d’au moins 55% du foie initial et préservant au mieux la vascularisation hépatique. Bien qu’une planification de l’intervention puisse actuellement s’envisager sur la base de données pré-opératoire spécifiques au patient, les mouvements importants du foie et ses déformations lors de l’intervention rendent cette planification très difficile à exploiter en pratique. Les travaux proposés dans cette thèse visent à fournir des outils de réalité augmentée utilisables en conditions per-opératoires et permettant de visualiser à chaque instant la position des tumeurs et réseaux vasculaires hépatiques
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