Tesi sul tema "Contour"
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1
Bouvier, Christian. "Segmentation région-contour des contours des lèvres". Phd thesis, Université Laval, 2010. http://tel.archives-ouvertes.fr/tel-00462022.
Testo completoAbstract (sommario):
La thèse présentée a été effectuée en cotutelle entre l'Institut Polytechnique de Grenoble et l'université Laval à Québec. Les travaux ont impliqué les laboratoires universitaire GIPSAlab à Grenoble et le Laboratoire de Vision et Systèmes Numériques de l'Université Laval (LVSN). Notre étude porte sur la segmentation des contours internes et externes des lèvres. L'objectif visé dans notre étude est de proposer un ensemble de méthodes permettant de modéliser précisément la zone de la bouche avec la meilleure robustesse possible. Par robustesse, notre entendons obtenir une méthode fiable qui ne nécessite pas de réglage de paramètres et qui permette une segmentation fidèle des contours externes et internes de la bouche. Dans un premier temps, une approche combinée région-contour est introduite dans le but d'obtenir une segmentation multi-locuteur de la bouche sur des images de visage en couleurs. Nous décrivons une approche par décorrélation permettant d'augmenter le contraste entre la peau et les lèvres sur des images en couleurs ainsi qu'une étude sur les gradients multi-échelles pour améliorer la robustesse de la modélisation des contours de la bouche. Ensuite nous présentons notre méthode de localisation et de segmentation régioncontour de la bouche sur des images de visage en couleurs. Dans un second temps nous nous sommes intéressés à la détection de l'état de la bouche. L'étape de détection de l'état de la bouche est nécessaire à la modélisation de la région interne qui présente une grande variabilité de forme et de texture. Une approche bioinspirée, basée sur un modèle de rétine et de cortex visuel conduisant au calcul d'un spectre Log-polaire, a été développée pour modéliser la zone de la bouche. Ces spectres sont, ensuite, utilisés pour entraîner un réseau SVM destiné à identifier l'état de la bouche. D'autre part, de nombreux auteurs ont suggéré d'utiliser la modalité infrarouge en analyse faciale. Le LVSN possédant une solide expertise dans le domaine de la vision infrarouge, une étude sur la pertinence de la modalité infrarouge dans le cadre de la segmentation des lèvres est proposée. Après avoir localisé la bouche et identifié l'état de la bouche, nous nous intéressons alors à la segmentation des contours externes et internes de la bouche. Un modèle polynomial de contour externe, dont la complexité sera automatiquement adaptée en fonction de la bouche traitée, est présenté. L'aspect de la zone interne de la bouche pouvant varier très rapidement, l'extraction du contour interne est particulièrement difficile. Nous proposons de traiter ce problème par une méthode de classification non-supervisée pour sélectionner les régions internes de la bouche. La méthode de modélisation de contour par un modèle polynomial est par la suite appliquée pour extraire le contour interne de la bouche. Enfin, une analyse quantitative de la performance globale de l'extraction des contours internes et externes est réalisée par comparaison avec des vérités-terrain.
2
Bouvier, Christian. "Segmentation région-contour des contours des lèvres". Phd thesis, Grenoble INPG, 2010. http://www.theses.fr/2010INPG0009.
Testo completoAbstract (sommario):
La thèse présentée a été effectuée en cotutelle entre l'Institut Polytechnique de Grenoble et l'université Laval à Québec. Les travaux ont impliqué les laboratoires universitaire GIPSAlab à Grenoble et le Laboratoire de Vision et Systèmes Numériques de l'Université Laval (LVSN). Notre étude porte sur la segmentation des contours internes et externes des lèvres. L'objectif visé dans notre étude est de proposer un ensemble de méthodes permettant de modéliser précisément la zone de la bouche avec la meilleure robustesse possible. Par robustesse, notre entendons obtenir une méthode fiable qui ne nécessite pas de réglage de paramètres et qui permette une segmentation fidèle des contours externes et internes de la bouche. Dans un premier temps, une approche combinée région-contour est introduite dans le but d'obtenir une segmentation multi-locuteur de la bouche sur des images de visage en couleurs. Nous décrivons une approche par décorrélation permettant d'augmenter le contraste entre la peau et les lèvres sur des images en couleurs ainsi qu'une étude sur les gradients multi-échelles pour améliorer la robustesse de la modélisation des contours de la bouche. Ensuite nous présentons notre méthode de localisation et de segmentation régioncontour de la bouche sur des images de visage en couleurs. Dans un second temps nous nous sommes intéressés à la détection de l'état de la bouche. L'étape de détection de l'état de la bouche est nécessaire à la modélisation de la région interne qui présente une grande variabilité de forme et de texture. Une approche bioinspirée, basée sur un modèle de rétine et de cortex visuel conduisant au calcul d'un spectre Log-polaire, a été développée pour modéliser la zone de la bouche. Ces spectres sont, ensuite, utilisés pour entraîner un réseau SVM destiné à identifier l'état de la bouche. D'autre part, de nombreux auteurs ont suggéré d'utiliser la modalité infrarouge en analyse faciale. Le LVSN possédant une solide expertise dans le domaine de la vision infrarouge, une étude sur la pertinence de la modalité infrarouge dans le cadre de la segmentation des lèvres est proposée. Après avoir localisé la bouche et identifié l'état de la bouche, nous nous intéressons alors à la segmentation des contours externes et internes de la bouche. Un modèle polynomial de contour externe, dont la complexité sera automatiquement adaptée en fonction de la bouche traitée, est présenté. L'aspect de la zone interne de la bouche pouvant varier très rapidement, l'extraction du contour interne est particulièrement difficile. Nous proposons de traiter ce problème par une méthode de classification non-supervisée pour sélectionner les régions internes de la bouche. La méthode de modélisation de contour par un modèle polynomial est par la suite appliquée pour extraire le contour interne de la bouche. Enfin, une analyse quantitative de la performance globale de l'extraction des contours internes et externes est réalisée par comparaison avec des vérités-terrainThis report presents the thesis that has been jointly conducted at the Grenoble Institute of Technology in France and at the Laval University in Canada. The work involves the GIPSA-lab in Grenoble and the CVSL of the Laval University. The aim of the thesis is to propose a set of robust methods to segment the lips outer and inner contours. In terms of robustness, we intend to propose a reliable lips contours segmentation that does not require the tuning of parameters. In the fist chapter a state of the art of mouth analysis is given. In the second chapter of this report, we will introduce our “region-contour” based approach to segment a binary mask of the lips on static face color images. First, we will describe the decorrelation-stretch algorithm we use to enhance the contrast between lips pixels and skin pixels and then a multi-scale gradients approach to contour modeling. The last part of the chapter will focus on the segmentation of a lips binary mask by automatic thresholding of a specific chromatic component. In chapter three we will be interested in the mouth state identification problem. The knowledge of mouth state is critical if one is to propose a robust segmentation of the lips internal contours. A bio-inspired approach based on retina and visual cortex models has been developed to compute a scale invariant mouth description: the log-polar spectrum. Log-polar spectrums, computed on a manually classified mouth images database, are used to train a SVM network. The goal of the network is to classify unknown mouth images in 2 clusters: open mouth and closed mouth. Recently, infrared based approaches have become popular in face analysis, especially for face recognition problems. Infrared thermography is an area of extensive expertise at the CVSL. In order to enhance the robustness of the lips contours segmentation, we studied the potential of the information given by infrared face images. A combined visible/infrared face image database has been constructed for that purpose. Chapter 4 describes the construction of the combined visible/infrared database and the statistical study of the skin/lips contrast on infrared face images. The last chapter deals with the outer and inner lips contours segmentation. The mouth outer contour is processed first. Using the lips binary mask given by the algorithm described in chapter 2, we have developed an adaptive contour model for the external mouth contour. The contour will be described by a polynomial curve. The complexity of the curve will be adapted using color and multi-scale gradients information. For the inner lips contour, we proposed an unsupervised classification method to segment the inner areas of the mouth. This gives us a binary mask of the inner areas of the mouth. Finally, given the mask of the inner areas of the mouth, the contour is extracted by using the same method that has been applied on the outer contour. The last section of chapter 5 will deal with the performance evaluation of our segmentation algorithms. An original approach for contour comparison, based on Fourier descriptors, has been developed for that purpose
3
Nordberg, Johan. "Contour". Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17074.
Testo completoAbstract (sommario):
Traditional sketching with pen on paper can be seen as to visualize the memory. Limited to a framework of influences, experiences and ideas the outcome will result in something already known.In searching for knowledge an experimental sketch method counteracts this framework. The aim of this work is to explore morph animation of archetypical garments. Shape interpolation in Adobe Flash software makes it possible to calculate the way between two silhouettes. The result is a third silhouette, a morph of selected garments and depends on where the animation is paused. The work also deals with the gap between visualize(sketching) and making(construction/realization). In the investigation a new way of using animation as an sketch method have been found. Also how to use computer based 3D sketching in fashion design and an alternative construction method based on paper craft techniques have been developed. The collection consists of garments based on a morph between a classic skirt and a blazer to discuss new visions and possibility’s in fashion. Can the way we sketch, construct and produce affect garment definitions? And how could the findings in this work being used in a commercial industry.Program: Modedesignutbildningen
4
Wang, Jiankang. "Actively searching contour models for contour extraction". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0014/NQ59691.pdf.
Testo completo
5
Ananta, Soujanya Siddavaram. "Contour Extraction of Drosophila Embryos Using Active Contours in Scale Space". TopSCHOLAR®, 2012. http://digitalcommons.wku.edu/theses/1222.
Testo completoAbstract (sommario):
Contour extraction of Drosophila embryos is an important step to build a computational system for pattern matching of embryonic images which aids in the discovery of genes. Automatic contour extraction of embryos is challenging due to several image variations such as size, shape, orientation and neigh- boring embryos such as touching and non-touching embryos. In this thesis, we introduce a framework for contour extraction based on the connected components in the gaussian scale space of an embryonic image. The active contour model is applied on the images to refine embryo contours. Data cleaning methods are applied to smooth the jaggy contours caused by blurred embryo boundaries. The scale space theory is applied to improve the performance of the result. The active contour adjusts better to the object for finer scales. The proposed framework contains three components. In the first component, we find the connected components of the image. The second component is to find the largest component of the image. Finally, we analyze the largest component across scales by selecting the optimal scale corresponding to the largest component having largest area. The optimal scale at which maximum area is attained is assumed to give information about the feature being extracted. We tested the proposed framework on BDGP images, and the results achieved promising accuracy in extracting the targeting embryo.
6
WANG, XUN. "ON CONSTRAINED CONTOUR ENERGY MINIMIZATION: A NEW APPROACH TO DEFORMABLE CONTOUR METHODS". University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1106795223.
Testo completo
7
劉藹欣 e Oi-yan Elizabeth Lau. "Wrist pulse contour analysis". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B35273525.
Testo completo
8
Lau, Oi-yan Elizabeth. "Wrist pulse contour analysis". Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25085463.
Testo completo
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Wang, Xun. "On constrained contour energy minimization". Cincinnati, Ohio : University of Cincinnati, 2004. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1106795223.
Testo completo
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Nelson, Christopher. "Contour encoded compression and transmission /". Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1613.pdf.
Testo completo
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Ferland, Mark B. "Infants' categorization of melodic contour". Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74028.
Testo completo
12
Scheuhammer, Joseph Edward. "Contour completion at edge endings". Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/17228.
Testo completo
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Lam, Shu Yan. "Advances in active contour algorithms". HKBU Institutional Repository, 2002. http://repository.hkbu.edu.hk/etd_ra/453.
Testo completo
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Nelson, Christopher B. "Contour Encoded Compression and Transmission". BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/1096.
Testo completoAbstract (sommario):
As the need for digital libraries, especially genealogical libraries, continues to rise, the need for efficient document image compression is becoming more and more apparent. In addition, because many digital library users access them from dial-up Internet connections, efficient strategies for compression and progressive transmission become essential to facilitate browsing operations. To meet this need, we developed a novel method for representing document images in a parametric form. Like other “hybrid" image compression operations, the Contour Encoded Compression and Transmission (CECAT) system first divides images into foreground and background layers. The emphasis of this thesis revolves around improving the compression of the bitonal foreground layer. The parametric vectorization approach put forth by the CECAT system compares favorably to current approaches to document image compression. Because many documents, specifically handwritten genealogical documents, contain a wide variety of shapes, fitting Bezier curves to connected component contours can provide better compression than current glyph library or other codebook compression methods. In addition to better compression, the CECAT system divides the image into layers and tiles that can be used as a progressive transmission strategy to support browsing operations.
15
Prodöhl, Carsten. "On the recognition of objects by contour parts and the early development of biological contour processing". [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=978875621.
Testo completo
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Breton, Pierre. "Recovering shape from shading and contour". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28694.
Testo completoAbstract (sommario):
The classical approach to shape from shading problems is to find a numerical solution of the image irradiance partial differential equation. It is usually assumed that the parameters of this equation (the light source direction and surface albedo) can be estimated in advance. For images which contain shadows and occluding contours, this decoupling of problems is artificial and the classical approach fails. We develop a new approach to solving these equations using the image geometric structures instead of the image photometric structure. Our approach is based on modern differential geometry, and solves for light source and surface shape changes concurrently. Local scene elements (scenels) are estimated from the shading flow field and the tangent field, and smoothness, material, and light source compatibility conditions resolve them to consistent scene descriptions. Shadows and related difficulties for the classical approach are discussed.
17
Thoe, T. B. "Ultrasonic Contour Machining of Ceramic Materials". Thesis, University of Birmingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525493.
Testo completo
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Hughes, Alex. "Shape analysis and pose from contour". Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428406.
Testo completo
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Haida, Maksim, e Максим Володимирович Гайда. "Video surveillance system of target contour". Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50751.
Testo completoAbstract (sommario):
1. Программирование компьютерного зрения на языке Python / Ян Эрик Солем, пер. с англ. Слинкин А.А. – М.: ДМК Пресс, 2016. – 312.с.: ил.
2. Системи відеоспостереження та методи виділення контурів на зображеннях / K. Гжешчик, Д. Загородня, А. Саченко, Б. Русин – «Управління проектами та розвиток виробництва», 2018, №3(67).
3. Advances in Computer Vision and Pattern Recognition / Giovanni Maria Farinella, Sebastiano Battiato, Roberto Cipolla – Springer-Verlag London 2013.
4. Детекторы углов. URL: https://habr.com/ru/post/244541/ (дата звернення: 23.02.2021).Computer vision is the science and technology of making machines that see. It is concerned with the theory, design and implementation of algorithms that can automatically process visual data to recognize objects, track and recover their shape and spatial layout. When recognizing objects, the most informative part of the image is the contour. An object contour is a part of an object that contains a lot of information about the shape of the object and almost does not depend on the color and texture of the image. You can analyze the shape of the object along the contour. In many cases, information about the shape of the object is sufficient to organize automated or automatic systems. In addition, the transition to object recognition by their contours allows to reduce the amount of processed information by several times, as a plus, the contours are invariant to the brightness transformations.The first element of an intelligent video surveillance system is a video sensor. Examples of video sensors are digital or IP cameras. For ease of use, installation and taking into account the cost of the module, I will use a WEB camera without an ultraviolet filter, with a resolution of 1280×720 pixels and a video recording rate of 25 frames per second.
Комп’ютерне бачення – це наука і технологія виготовлення машин, які бачать. Він займається теорією, розробкою та реалізацією алгоритмів, які можуть автоматично обробляти візуальні дані для розпізнавання об’єктів, відстеження та відновлення їх форми та просторового розташування. При розпізнаванні об’єктів найбільш інформативною частиною зображення є контур. Контур об’єкта - це частина об’єкта, що містить багато інформації про форму об’єкта і майже не залежить від кольору та текстури зображення. Ви можете проаналізувати форму предмета по контуру. У багатьох випадках інформації про форму предмета достатньо для організації автоматизованих або автоматичних систем. Крім того, перехід до розпізнавання об’єктів за їх контурами дозволяє зменшити оброблену інформацію в кілька разів, плюс, контури інваріантні до перетворень яскравості. Першим елементом інтелектуальної системи відеоспостереження є відеодатчик. Прикладами відеосенсорів є цифрові або IP-камери. Для зручності використання, встановлення та врахування вартості модуля я буду використовувати веб-камеру без ультрафіолетового фільтра, з роздільною здатністю 1280 × 720 пікселів та швидкістю запису відео 25 кадрів в секунду.
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Dowd, Justin Matthew. "Contour and Layers: An Architectural Exploration". Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/33374.
Testo completoAbstract (sommario):
The book is a series of plates, pictures and writings which are the results of an architectural thesis exploring, line, contour and layers. The plates are scans of original work by the author, made in a combination of media including: pencil, pastel, watercolor, photograph, study models, hand-drafted drawings, and computer aided drawings. A transcript of the presentation of the work at the thesis defense is included. The simple idea is the impression of contour by the expression of layers. The contour is a line tracing the motion and movement of architecture. Resulting from practice in drawing using pastels, pencil and paper the line, through continuity, can twist, pass over, go under and around- joining parts into an organized whole. Following a program of a modern bath, an architectural space is made, built by layers. The thesis is an architectural exploration of layers and the resultant contours. The best representation of this work is available in printed form at the Art and Architecture Library on the Virginia Tech campus in Blacksburg, Virginia.Master of Architecture
21
Campbell, Andrew S. "Recycled Aggregate & Robotic Contour Crafting". University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1554119761226049.
Testo completo
22
Wong, Yin Yung. "Enhanced snakes algorithm for contour detection". HKBU Institutional Repository, 1997. http://repository.hkbu.edu.hk/etd_ra/144.
Testo completo
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TANG, YINGJIE. "ON CLOSE CONTOUR PRESENTATION AND MATCHING PROBLEMS WITH BIOMEDICAL IMAGE APPLICATIONS". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin983567833.
Testo completo
24
August, Jonas. "From contour fragment grouping to shape decomposition". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0006/MQ29580.pdf.
Testo completo
25
Khayat, Paul. "Attention and eye movements during contour grouping". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2004. http://dare.uva.nl/document/72169.
Testo completo
26
August, Jonas. "From contour fragment grouping to shape decomposition". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26770.
Testo completoAbstract (sommario):
Bounding contours of physical objects are often fragmented by other occluding objects. This creates the need for perceptual grouping, or the association of those fragments corresponding to the same object. Perceptual grouping is currently a bottleneck to computer vision, since previous approaches either were heuristic, assumed the object belonged to restricted classes in order to exploit geometric invariants, or hypothesized boundary continuations. I introduce an alternative by invoking the principle that those fragments should be grouped whose fragmentation can be accounted for by a virtual occluder, and introduce the gap skeleton as a representation of this occluder. Properties of gap skeleton are proved, and an algorithm for computing it is given. Finally, a different perspective on gap skeleton is obtained in the domain of shape decomposition, where ligature emerges as the analog to gap skeleton. This leads to a new definition of a limb as a formal part, and suggests that both grouping and shape decomposition share a common basis.
27
Elder, James H. "Contour closure and the perception of shape". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56775.
Testo completoAbstract (sommario):
By modulating the degree of closure of the outlines, I show that two-dimensional shape processing is rapid for closed stimuli but slow for open stimuli. I further show that search speed can be characterized as a smooth, monotonic function of the degree of closure, supporting the notion of a perceptual closure continuum. This continuum is shown to be naturally parameterized by a dot-spacing metric, and experiments with different types of fragmentation lead to the hypothesis of a Minimax Principle of closure, which imposes a partial ordering over all fragmentations of a given contour. Using search speed as a metric for the perceptual closure of various figures leads to an equivalence relation between perceptual closure and the confidence of object inference. Under this metric, perceptual closure is found to be independent from various surface completion and texture processes and highly sensitive to contrast sign reversal, supporting the existence of a limited-complexity shape from contour process in early vision. Perceptual closure is shown to be nonlinear in several respects: a simple model of one such nonlinearity is proposed.
28
Johnson, Gregory. "Residual stress measurements using the contour method". Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489521.
Testo completoAbstract (sommario):
The aim of this dissertation is to explore and evaluate the contour method, a recently developed destructive technique for measuring residual stresses. It is a valuable addition to the suite of tools available to the researcher.
29
Lee, Chong U. "Contour motion compensation for image sequence coding". Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14515.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.Includes bibliographical references (leaves 124-130).
by Chong Uk Lee.
Ph.D.
30
Metge, Caroline. "Les produits pour le contour de l'oeil". Toulouse 3, 1994. http://www.theses.fr/1994TOU32028.
Testo completo
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Anderle, Peter. "Design 3D tiskárny pro technologii Contour Crafting". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400420.
Testo completo
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Chu, I.-Hsine (Jack). "CONTOUR GUIDED DISSEMINATION FOR NETWORKED EMBEDDED SYSTEMS". University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1159522840.
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Duan, Minlan. "Quality of Service in Contour Guided Dissemination". University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1184805314.
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Mamidisetty, Kranthi Kumar. "Generalizing Contour Guided Dissemination in Mesh Topologies". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1208206994.
Testo completo
35
Lampert, Thomas. "Spectrogram track detection : an active contour algorithm". Thesis, University of York, 2010. http://etheses.whiterose.ac.uk/956/.
Testo completoAbstract (sommario):
In many areas of science, near-periodic phenomena represent important information within time-series data. This thesis takes the example of the detection of non-transitory frequency components in passive sonar data, a problem which finds many applications. This problem is typically transformed into the pattern recognition domain by representing the time-series data as a spectrogram, in which slowly varying periodic signals appear as curvilinear tracks. The research is initiated with a survey of the literature, which is focused upon research into the detection of tracks within spectrograms. An investigation into low-level feature detection reveals that none of the evaluated methods perform adequately within the low signal-to-noise ratios of real-life spectrograms and, therefore, two novel feature detectors are proposed. An investigation into the various sources of information available to the detection process shows that the most simple of these, the individual pixel intensity values, used by most existing algorithms, is not sufficient for the problem. To overcome these limitations, a novel low-level feature detector is integrated into a novel active contour track detection algorithm, and this serves to greatly increase detection rates at low signal-to-noise ratios. Furthermore, the algorithm integrates a priori knowledge of the harmonic process, which describes the relative positions of tracks, to augment the available information in difficult conditions. Empirical evaluation of the algorithm demonstrates that it is effective at detecting tracks at signal-to-noise ratios as low as: 0.5 dB with vertical; 3 dB with oblique; and 2 dB with sinusoidal variation of harmonic features. It is also concluded that the proposed potential energy increases the active contour's effectiveness in detecting all the track structures by a factor of eight (as determined by the line location accuracy measure), even at relatively high signal-to-noise ratios, and that incorporating a priori knowledge of the harmonic process increases the detection rate by a factor of two.
36
Wang, Qi. "Improved biologically-inspired methods for contour detection". Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/improved-biologicallyinspired-methods-for-contour-detection(05765ae2-698b-4a95-983d-6267666528f7).html.
Testo completoAbstract (sommario):
Contour detection is the process of finding meaningful smooth curves within an image， such as the boundaries of objects. It is a process at which the biological visual system excels and is also a fundamental technique and crucial step for many applications in computer vision. This thesis is primarily concerned with biologically-inspired approaches to contour detection. In this thesis, some biologically-inspired contour detection algorithms were improved. Such improvement included the better performance obtained from different extended versions of an existing biologically-inspired method, simplification of a non-biologically-inspired method to a biologically-inspired method without degrading performance, and application of a biologically-inspired method to improve other biologically-inspired and non-biologically-inspired methods. All of the contour detection results mentioned in this thesis were both qualitatively and quantitatively evaluated by the BSDS300 and/or BSDS500 benchmarks using the quantitative measures: F-score and/or ODS, OIS and AP. All the parameter values of the evaluated methods were determined by operating the algorithm on training images in this benchmark and observing the alteration of F-score or ODS. A neurophysiologically-inspired model, the PC/BC model of V1 devised to locate boundaries defined by intensity discontinuities, was first extended to also be able to locate boundaries defined by colour discontinuities. This extension was inspired by neurophysiological data from single neurons in macaque V1. The colour PC/BC model of V1 (F-score 0.67) have significantly better performance compared with the original PC/BC model of V1 (F-score 0.61) and slightly outperform some recently proposed contour detection algorithms which use more cues and/or require a complicated training procedure. The PC/BC model of V1 was also extended to simulate the second visual cortical area (V2) in an attempt to detect texture boundaries and corners. The two versions of the PC/BC model of V2 for texture boundary and corner detection were integrated with the PC/BC model of V1 to successfully locate some texture boundaries and enhance some weak contours obtained from the PC/BC model of V1. However, the integrated PC/BC model for texture boundary detection (F-score 0.60) and corner detection (F-score 0.51) both generated worse performance compared to the original PC/BC model of V1 (F-score 0.61). A simplified and biologically-inspired version of the texture gradient method used in the probability of boundary (Pb) algorithm is also proposed in this thesis. The Pb algorithm is the first stage of a recent near state-of-the-art contour detection algorithm. The proposed texture gradient method (F-score 0.58) has similar performance in detecting texture boundaries to the Pb texture gradient method (F-score 0.58) but also reduces computation time by about 240 seconds when tested on 100 images and simulates texture boundary detection in V2 of human/animal visual system. Finally, in this thesis, a modified version of the sparse reconstruction-based discrimination (SRBD) method inspired by the neurophysiological evidence for sparse coding in the biological visual system was applied to refine the contour detection results produced by the colour PC/BC model of V1 and two leading contour detection algorithms. Previously, the SRBD method (F-score 0.66) had been applied to significantly improving the contour detection results of the Canny edge detector (F-score 0.58). Here, the modified version of the biologically-inspired SRBD is shown to improve the result derived from three previously proposed contour detection methods with at least one of the quantitative measures used in the BSDS500 benchmark increased by 0.01.
37
Wen, Shuangyue. "Automatic Tongue Contour Segmentation using Deep Learning". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38343.
Testo completoAbstract (sommario):
Ultrasound is one of the primary technologies used for clinical purposes. Ultrasound systems have favorable real-time capabilities, are fast and relatively inexpensive, portable and non-invasive. Recent interest in using ultrasound imaging for tongue motion has various applications in linguistic study, speech therapy as well as in foreign language education, where visual-feedback of tongue motion complements conventional audio feedback.
Ultrasound images are known to be difficult to recognize. The anatomical structure in them, the rapidity of tongue movements, also missing segments in some frames and the limited frame rate of ultrasound systems have made automatic tongue contour extraction and tracking very challenging and especially hard for real-time applications. Traditional image processing-based approaches have many practical limitations in terms of automation, speed, and accuracy.
Recent progress in deep convolutional neural networks has been successfully exploited in a variety of computer vision problems such as detection, classification, and segmentation. In the past few years, deep belief networks for tongue segmentation and convolutional neural networks for the classification of tongue motion have been proposed. However, none of these claim fully-automatic or real-time performance. U-Net is one of the most popular deep learning algorithms for image segmentation, and it is composed of several convolutions and deconvolution layers.
In this thesis, we proposed a fully automatic system to extract tongue dorsum from ultrasound videos in real-time using a simplified version of U-Net, which we call sU-Net. Two databases from different machines were collected, and different training schemes were applied for testing the learning capability of the model. Our experiment on ultrasound video data demonstrates that the proposed method is very competitive compared with other methods in terms of performance and accuracy.
38
Niedfeldt, John Clyde. "RapidSCAT Slice Spatial Response Function Contour Parameterization". BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6260.
Testo completoAbstract (sommario):
The spatial response function (SRF) of the backscatter measurements for a radar scatterometer is often used in reconstruction. It has been found that in many cases the SRF can be approximated as a binary function that is 1 inside the - 6 dB contour of the SRF and 0 outside. This improves the computation speed of reconstruction. Computing the SRF contour can still be a lengthy computation, which can be simplified by precomputing and tabulating key SRF contours. The tabular parameterization for many spinning scatterometers, i.e., QuikSCAT, is straight-forward. For RapidSCAT, this estimation is more involved than other radars due to the irregular orbit of its host platform, the International Space Station (ISS). This thesis presents a process for parameterizing the slice contours for RapidSCAT that are acceptable for reconstruction purposes. This thesis develops a new process for parameterizing slice contours. First, RapidSCAT SRFs are calculated using XfactorRS3, and -6 dB slice contours are found using matplotlib. Then, a suitable filter is found for reducing noise present in slice contours due to quantization error and interpolation inaccuracies. Afterwards, the polygon comparison algorithm is used to determine a set of approximation points. With the approximation points selected, the 3-rd order linear approximation is calculated using parameters available in the L1B data files for RapidSCAT. Finally, analysis of the parameterization is performed. Overall, I developed a process that parameterizes RapidSCAT slice contours with an average root mean square (RMS) error of roughly 1.5 km. This is acceptable for the application of the slice parameterization algorithm and significantly reduces computation compared to fully computing the SRF.
39
Pötzsch, Michael. "Object contour statistics extracted from natural image sequences". [S.l.] : [s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=959485570.
Testo completo
40
Zhao, Ping. "A Contour-based Separation of VerticallyAttached Traffic Signs". Thesis, Högskolan Dalarna, Datateknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:du-3033.
Testo completoAbstract (sommario):
This report presents an algorithm for locating the cut points for and separatingvertically attached traffic signs in Sweden. This algorithm provides severaladvanced digital image processing features: binary image which representsvisual object and its complex rectangle background with number one and zerorespectively, improved cross correlation which shows the similarity of 2Dobjects and filters traffic sign candidates, simplified shape decompositionwhich smoothes contour of visual object iteratively in order to reduce whitenoises, flipping point detection which locates black noises candidates, chasmfilling algorithm which eliminates black noises, determines the final cut pointsand separates originally attached traffic signs into individual ones. At each step,the mediate results as well as the efficiency in practice would be presented toshow the advantages and disadvantages of the developed algorithm. Thisreport concentrates on contour-based recognition of Swedish traffic signs. Thegeneral shapes cover upward triangle, downward triangle, circle, rectangle andoctagon. At last, a demonstration program would be presented to show howthe algorithm works in real-time environment.
41
Wu, Chung-Yao, e 吳仲堯. "Active Contour Model and Continuation Method Based Contour Model". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/dtdh67.
Testo completoAbstract (sommario):
碩士大同大學
資訊工程學系(所)
102
Feature extraction methods are used in many applications, including object tracking, object segmentation, face detection and medical image analysis. Most feature extraction algorithms are designed for 2D images, not applicable for 3D models. Active contour model[1] is one such example. Bischoff et al. (2005)[2] proposed 3D active contour model on triangle meshes. However, 3D active contour model has several drawbacks. In this study, we develop a new contouring algorithm based on continuation method. Our algorithm improves the shortcomings of original 3D active contour models, and facilitate real-time feature extraction on triangle meshes. Users load a 3D model, and produce different contours with different contour functions. Our algorithm can produce contours in real-time for animation effects, and allows users to edit 3D model with contours.
42
Su, Ke-Han, e 蘇科翰. "Study on Contour Error Control in Parametric Free-Form Contour Following". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/12448263382156670571.
Testo completoAbstract (sommario):
博士國立成功大學
電機工程學系碩博士班
96
Reducing contour error is an important issue in multi-axis contour following tasks. To reduce contour error, this dissertation presents three different motion control schemes. First, to improve contouring accuracy, a Tangential Contouring Controller (TCC) based motion control scheme was developed. The scheme consists of a position loop controller with velocity command feedforward, a TCC, a real time contour error estimator, and a fuzzy logic based feedrate regulator. The feedrate regulator is designed to reduce contour error based on dynamic machining error information, which adaptively adjusts the desired feedrate value. The second scheme focuses on improving the machining accuracy in free-form contour following tasks. This scheme consists of a velocity command feedforward, a modified Cross-Coupled Controller (CCC), and a fuzzy logic based feedrate regulator different from the one employed in the first scheme. The feedrate regulator, which can adaptively adjust the desired feedrate to a proper value, is designed based on the dynamic machining error and curvature information. In addition, the modified CCC extends the conventional CCC to arbitrary types of contour following tasks. Finally, the third scheme, using the CCC concept as a starting point, develops a Position Error Compensator (PEC) approach to reduce contour error. The main advantage of PEC is that it can simultaneously improve tracking and contouring performance by compensating for position errors in advance. To further meet contouring accuracy and efficiency requirements, the integrated motion control scheme equipped with a fuzzy logic based feedrate regulator and PEC is developed. To test the feasibility of the proposed approaches, several parametric free-form contour following experiments were conducted, in which the position commands were generated by a real-time NURBS (Non-Uniform Rational B-Spline) interpolator. Experimental results demonstrate that all of the proposed approaches can significantly reduce contour error for biaxial contour following tasks. Additionally, the results demonstrate that the contouring efficiency and accuracy of the proposed approaches meet machining requirements.
43
Chiu, Cheng-Li, e 邱正利. "Adaptive Snake Model with Automatic Force Adaptation and Contour Refinement Contour Refinement". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/43409150149162534545.
Testo completoAbstract (sommario):
碩士國立嘉義大學
資訊工程學系研究所
94
Image segmentation is defined as partitioning an image into non-overlapping regions based on the intensity or texture. The active contour model (Snake model) is one of the preferred approaches for image segmentation because of their computational efficiency and simplicity. But, these methods have some problems is hard to overcome. The first problem is the concave boundary which traditional snake is impossible to capture the concave boundary of interested image region. The second problem is the background texture and noisy of image significantly influence the segmentation result. Furthermore, the model’s weight parameters are hard to design, find out the suitable parameters for each different image is a exhausted work. So most applications of snake model are domain-specific, while specifying fixed snake coefficients to an image in problem. In this paper, we propose content-triggered adaptive snake model (CASM) to lead all the parameters of snake model to be automatically adapted to various images in the noisy environment. First, the CASM applies a fast estimation method to find the possible ranges of gradient magnitudes of object boundary. As soon as the gradient magnitude of progressing snaxels falls in those ranges, CASM will adapt the weights within the snake forces of these snaxels according to encountered changes in gray levels and influences of various forces in the resided snake segments. And, it simultaneously renormalizes their external and internal forces. After primary convergence, CASM fires a compensation evolution to rectify the unqualified snaxels far from the object boundary. The unqualified snaxels, which are discovered by block-based texture analysis, can be pushed inward or pulled outward to the object border by so-called directional compensation evolution using an efficient alternative for force directions in revived evolutions. The simulation results demonstrate that CASM can improve the performance of snake very much, and outperform Gradient Vector Flow (GVF) in noisy images.
44
Yang, Tzuen-Fu, e 楊尊富. "Multidimensional Contour Control Based on Equivalent Contour Error and Iterative Learning Control". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/x3k8e7.
Testo completo
45
Prince, Jon. "Mental representations of contour". 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370481&T=F.
Testo completo
46
Gebert, Mark Allen. "Nonparametric density contour estimation". Thesis, 1998. http://hdl.handle.net/1911/19261.
Testo completoAbstract (sommario):
Estimation of the level sets for an unknown probability density is done with no specific assumed form for that density, that is, non-parametrically. Methods for tackling this problem are presented. Earlier research showed existence and properties of an estimate based on a kernel density estimate in one dimension. Monte Carlo methods further demonstrated the reasonability of extending this approach to two dimensions. An alternative procedure is now considered that focuses on properties of the contour itself; procedures wherein we define and make use of an objective function based on the characterization of contours as enclosing regions of minimum area given a constraint on probability. Restricting our attention to (possibly non-convex) polygons as candidate contours, numeric optimization of this difficult non-smooth objective function is accomplished using pdsopt, for Parallel Direct Search OPTimization, a set of routines developed for minimization of a scalar-valued function over a high-dimensional domain. Motivation for this method is given, as well as results of simulations done to test it; these include exploration of a Lagrange-multiplier penalty on area and the need which arises for addition of a penalty on the "roughness" of a polygonal contour.
47
Braga, Daniel Filipe Oliveira. "Contour method : procedure optimization". Master's thesis, 2012. http://hdl.handle.net/10216/63286.
Testo completo
48
Braga, Daniel Filipe Oliveira. "Contour method : procedure optimization". Dissertação, 2012. http://hdl.handle.net/10216/63286.
Testo completo
49
-WEN, CHOU，MAIO, e 周妙文. "The contour of emotions". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/tpm5dj.
Testo completoAbstract (sommario):
碩士東海大學
美術學系
107
By sorting out my creative forms in the past, I analyze the rigorous way of creation. Under the covered inertia thinking and within the whitewashed oppressive creation, it is customary for me to present the works in a perfect form in the creation. The creative expression of beautiful female appearance implies a deliberate construction of beautiful exterior whitewash, but there is a repression of internal and external contradictions and conflicts. In order to re-create the art works of clay material, I narrate my original family life experience which has never been mentioned in my life and creations, and I express the growth of my mentality through the emotions towards my father's alcoholism, violence and depression hidden in my inner heart, transforming the accumulated and derived emotional shadow from the state of my personal past emotions into a concretely specific image concept of the emotional outline as a new form of creative expression. I hope that the long-disturbed emotional obstacles enclosed in the heart can be output in the repeated moulding process. By narrating the emotions, my self will be re-viewed in the clay sculptures, which also give me another possibility and freedom to present in the form of creation. Through re-drawing nourishment from these elements of life experience, I can establish a new stage of self from the true face and consciousness of condensed inner emotions in creation, re-recognize my self and my creation, my surrounding environment, my will, and explore my value of self-existence. Under these thinking contexts, I am more determined and more purely sculptural technique-oriented, and re-understand the physical characteristics and changing mood of the clay materials, combining the creative ideas with the inner emotions of self-consciousness, expressing the emotions directly. It is only a single shape, allowing my emotions sprayed in the creation of sculpture forms, so that the emotions released by them are transformed into concrete shapes, which can be seen more clearly in vision. Facing the shadows of the past bad moods, I find the direction on the road towards the continuation of life freely and indifferently. I release the negative energy stored for a long time so as to stimulate my self to stop being stuck in the bondage and restraint, and to be able to freely follow the stream of my ideas at the moment of creation for returning to the simplicity and purity of life emotions, just as the clay material, returning to the purity of matter itself and no more so much concealment and disguise, experiencing the clay from a new viewpoint, getting more imagination development and freedom while immersed in the creation. Key words: emotion, outline, shape, pottery
50
Kao, Ping-Wen, e 高秉文. "An Initial Edge Point Selection and Segmental Contour Tracing for Object Contour Extraction". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87q9d3.
Testo completoAbstract (sommario):
碩士國立嘉義大學
資訊工程學系研究所
97
Image segmentation is a technique which is used to segment region of interest in the image for further image processing. In general, the accuracy of segmentation result would affect result of further image processing or applications. Contour extraction is one of the most important image segmentation methods. When applying contour extraction to application of industrial inspection or machine vision with low-level processor, we not only consider accuracy but also consider automation and computational complexity. In this study, a contour extraction method is proposed, which consist of two parts. The first part is an automatic initial contour point selection mechanism for finding the initial contour points of contour segmental method for the second part of segmental contour tracing method, where contour pixels is obtain according to gradient value, direction and distance along two initial contour points. Finally, the result of the proposed method is compared with other methods.