To see the other types of publications on this topic, follow the link: Binocular vision. Computer vision.
Dissertations / Theses on the topic 'Binocular vision. Computer vision'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Binocular vision. Computer vision.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Pollard, Stephen. "Identifying correspondences in binocular stereo." Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283563.
Full text
2
Zheng, Bibo. "Multiresolution fixation of a binocular vision system." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-07112009-040450/.
Full text
3
Tsang, Kong Chau. "Confidence measures for disparity estimates from energy neuron populations /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20TSANG.
Full text
4
Tsang, Kong Chau. "Preference for phase-based disparity in a neuromorphic implementation of the binocular energy model /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20TSANG.
Full textAbstract:
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 64-66). Also available in electronic version. Access restricted to campus users.
5
Sanchez, Miguel Angel. "A fuzzy approach to solve the stereo correspondence problem using phase correlation." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Full text
6
Nogueira, Fernando Marques de Almeida. "Reconstrução tridimensional por visão estereo e detecção de oclusões." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260689.
Full textAbstract:
Orientador: Clesio Luis Tozzi<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação<br>Made available in DSpace on 2018-08-10T17:08:02Z (GMT). No. of bitstreams: 1
Nogueira_FernandoMarquesdeAlmeida_D.pdf: 5973806 bytes, checksum: ec2975af264084ab2665aa65eca49541 (MD5)
Previous issue date: 2007<br>Resumo: Este trabalho apresenta uma nova abordagem iterativa e hierárquica para a obtenção de mapas densos de disparidade, a partir de um par de imagens estereoscópicas retificadas, na qual oclusões são explicitamente identificadas. Esta abordagem se fundamenta num processo de busca hierárquica onde são determinados pares homólogos prioritários sobre os quais é aplicada a Injunção de Ordem. Pares homólogos prioritários consistem nos pontos que apresentam a propriedade de Correspondência Bidirecional para o maior número de janelas de busca organizadas em ordem crescente de tamanho. A aplicação da Injunção de Ordem aos pares homólogos prioritários elimina, já nas primeiras iterações, uma grande quantidade de correspondências ambíguas aumentando o índice de acertos e reduzindo o tempo de processamento. A abordagem proposta destaca-se pela utilização de apenas dois parâmetros que devem ser fornecidos a priori de maneira empírica: o tamanho inicial da janela e o número de níveis hierárquicos. A eficiência do algoritmo proposto foi avaliada a partir de imagens reais e simuladas e os resultados comparados com outras abordagens descritas na literatura<br>Abstract: This work presents a new hierarchical and iterative approach to obtain dense disparity maps from a pair of rectified stereoscopic images in which occlusions are explicitly identified. This approach is based on a process of hierarchical searching where priority matches are determined and upon which is applied the Order Constraint. Priority matches consist of points that present a property of Bidirectional Correspondence for the greatest number of searching windows, these ones organized in a size ascending order. The Order Constraint application on the priority matches eliminates, usually after the first iterations, a lot of ambiguous matches, increasing the rate of true matches and reducing the execution time. The proposed approach stands out by using only two parameters that must be provided a priori in an empirical way: the initial window size and the number of hierarquical levels. The efficiency of the proposed algorithm was evaluated using real and simulated images and the results were compared to other approaches described in the literature<br>Doutorado<br>Automação<br>Doutor em Engenharia Elétrica
7
Zhou, Wei. "Scene illuminant estimation with binocular stereo matching." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 2.74Mb, 160 p, 2005. http://wwwlib.umi.com/dissertations/fullcit/3181859.
Full text
8
Aragon, Camarasa Gerardo. "A hierarchical active binocular robot vision architecture for scene exploration and object appearance learning." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3640/.
Full textAbstract:
This thesis presents an investigation of a computational model of hierarchical visual behaviours within an active binocular robot vision architecture. The robot vision system is able to localise multiple instances of the same object class, while simultaneously maintaining vergence and directing its gaze to attend and recognise objects within cluttered, complex scenes. This is achieved by implementing all image analysis in an egocentric symbolic space without creating explicit pixel-space maps and without the need for calibration or other knowledge of the camera geometry. One of the important aspects of the active binocular vision paradigm requires that visual features in both camera eyes must be bound together in order to drive visual search to saccade, locate and recognise putative objects or salient locations in the robot's field of view. The system structure is based on the “attentional spotlight” metaphor of biological systems and a collection of abstract and reactive visual behaviours arranged in a hierarchical structure. Several studies have shown that the human brain represents and learns objects for recognition by snapshots of 2-dimensional views of the imaged scene that happens to contain the object of interest during active interaction (exploration) of the environment. Likewise, psychophysical findings specify that the primate’s visual cortex represents common everyday objects by a hierarchical structure of their parts or sub-features and, consequently, recognise by simple but imperfect 2D view object part approximations. This thesis incorporates the above observations into an active visual learning behaviour in the hierarchical active binocular robot vision architecture. By actively exploring the object viewing sphere (as higher mammals do), the robot vision system automatically synthesises and creates its own part-based object representation from multiple observations while a human teacher indicates the object and supplies a classification name. Its is proposed to adopt the computational concepts of a visual learning exploration mechanism that controls the accumulation of visual evidence and directs attention towards the spatial salient object parts. The behavioural structure of the binocular robot vision architecture is loosely modelled by a WHAT and WHERE visual streams. The WHERE stream maintains and binds spatial attention on the object part coordinates that egocentrically characterises the location of the object of interest and extracts spatio-temporal properties of feature coordinates and descriptors. The WHAT stream either determines the identity of an object or triggers a learning behaviour that stores view-invariant feature descriptions of the object part. Therefore, the robot vision is capable to perform a collection of different specific visual tasks such as vergence, detection, discrimination, recognition localisation and multiple same-instance identification. This classification of tasks enables the robot vision system to execute and fulfil specified high-level tasks, e.g. autonomous scene exploration and active object appearance learning.
9
Abdul, Rahim Muhammad Afzam Shah Bin. "An investigation of computer vision syndrome with smart devices." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/12813.
Full textAbstract:
The overarching theme of the thesis was to investigate the association between smart device use and computer vision syndrome. The initial study designed and developed the Open Field Tear film Analyser (OFTA) enabling a continuous, real-time assessment of the tear film and blink characteristics during smart device use. The monocular OFTA prototype was validated and showed good intra- and inter-observer repeatability relative to the Oculus Keratograph 5M and Bausch and Lomb one position keratometer. Subsequently, tear osmolarity following engagement with reading and gaming tasks on smart device and paper platforms was investigated. Discrete measures of osmolarity pre- and post-engagement with the tasks were obtained with the TearLab osmometer; osmolarity values differed between platforms when participants were engaged in a gaming task but no such difference was observed with the reading task. In addition, the influence of repeated measurements on tear osmolarity was also explored. To simulate the habitual binocular viewing conditions normally associated with smart device use, the binocular OFTA was developed. The device was used to assess the tear film and blink characteristics whilst engaging with reading and gaming tasks on smart device and paper platforms. The results revealed differences in blink characteristics and non-invasive tear break up time between the different platforms and tasks assessed. In addition, the thesis also reports on an investigation examining the real-time accommodative response to various targets displayed on smart devices using an open-field autorefractor with a Badal lens system adaptation. The results showed that accommodative latency, accommodative lag, mean velocity of accommodation, speed of disaccommodation and mean velocity of disaccommodation varied across the different platforms. Through the use of validated subjective questionnaires and smartphone apps, the relationship between duration of smartphone use and symptoms of dry eye were examined. The findings of this study demonstrated that longer duration of smartphone and personal computer use were associated with higher risk of dry eyes as indicated by subjective questionnaire outcomes.
10
Roos, André Filipe. "Controle de fixação atentivo para uma cabeça robótica com visão binocular." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/2648.
Full textAbstract:
A pesquisa em visão computacional ainda está distante de replicar a adaptabilidade e o desempenho do Sistema Visual Humano. Grande parte das técnicas consolidadas são válidas apenas em cenas estáticas e condições restritivas. Cabeças robóticas representam um avanço em flexibilidade, pois carregam câmeras que podem ser movimentadas livremente para a exploração dos arredores. A observação artificial de um ambiente dinâmico exige a solução de pelo menos dois problemas: determinar quais informações perceptuais relevantes extrair dos sensores e como controlar seu movimento para mudar e manter a fixação de alvos com forma e movimento arbitrários. Neste trabalho, um sistema de controle de fixação binocular geral é proposto, e o subsistema responsável pela seleção de alvos e fixação de deslocamentos laterais é projetado, experimentado e avaliado em uma cabeça robótica com quatro graus de liberdade. O subsistema emprega um popular modelo de atenção visual de baixo nível para detectar o ponto mais saliente da cena e um controlador proporcional-integral gera um movimento conjuntivo das duas câmeras para centralizá-lo na imagem da câmera esquerda, assumida como dominante. O desenvolvimento do sistema envolveu primeiramente a modelagem física detalhada do mecanismo de pan e tilt das câmeras. Então, a estrutura linearizada obtida foi ajustada por mínimos quadrados aos dados experimentais de entrada-saída. Por fim, os ganhos do controlador foram sintonizados por otimização e ajuste manual. A implementação em C++ com a biblioteca OpenCV permitiu operação em tempo real a 30 Hz. Experimentos demonstram que o sistema é capaz de fixar alvos estáticos e altamente salientes sem conhecimento prévio ou fortes suposições. Alvos em movimento harmônico são perseguidos naturalmente, embora com defasamento. Em cenas visualmente densas, onde múltiplos alvos em potencial competem pela atenção, o sistema pode apresentar comportamento oscilatório, exigindo o ajuste fino dos pesos do algoritmo para operação suave. A adição de um controlador para o pescoço e de um controlador de vergência para a compensação de deslocamentos em profundidade são os próximos passos rumo a um observador artificial genérico.<br>Computer vision research is still far from replicating the adaptability and performance of the Human Visual System. Most of its consolidated techniques are valid only over static scenes and restrictive conditions. Robot heads represent an advance in terms of flexibility by carrying cameras that can be freely moved to explore the surroundings. Artificial observation of dynamic environments requires the solution of at least two problems: to determine what is the relevant perceptual information to be extracted from the sensors and how to control their movement in order to shift and hold gaze on targets featuring arbitrary shapes and motions. In this work, a general binocular gaze control system is proposed, and the subsystem responsible for targeting and following lateral displacements is designed, tested and assessed in a four degrees-of-freedom robot head. The subsystem employs a popular low-level visual attention model to detect the most salient point in the scene, and a proportional-integral controller generates a conjunctive movement of the cameras to center it in the left camera image, assumed to be dominant. The development started with a detailed physical modeling of the pan and tilt mechanism that drives the cameras. Then, the linearized structure obtained was fitted via least squares estimation to experimental input-output data. Finally, the controller gains were tuned by optimization and manual adjustment. The OpenCV-based implementation in C++ allowed real-time execution at 30 Hz. Experiments demonstrate that the system is capable of fixating highly salient and static targets without any prior knowledge or strong assumptions. Targets describing harmonic motion are naturally pursued, albeit with a phase shift. In cluttered scenes, where multiple potential targets compete for attention, the system may present oscillatory behavior, requiring fine adjustment of algorithm weights for smooth operation. The addition of a controller for the neck and a vergence controller to compensate for depth displacements are the next steps towards a generic artificial observer.
11
José, Marcelo Archanjo. "Reconstrução tridimensional de baixo custo a partir de par de imagens estéreo." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-13082008-133946/.
Full textAbstract:
A obtenção e a reconstrução da geometria tridimensional (3D) de objetos e ambientes têm importância crescente em áreas como visão computacional e computação gráfica. As formas atuais de obtenção e reconstrução 3D necessitam de equipamentos e montagens sofisticadas que, por conseqüência, têm custos elevados e aplicação limitada. Este trabalho apresenta criticamente os principais algoritmos para a reconstrução 3D a partir de par de imagens estéreo e identifica os mais viáveis para utilização com equipamentos convencionais. Por meio da implementação de alguns destes algoritmos, da comparação dos resultados obtidos em sua execução e também pela comparação com os resultados encontrados na literatura, são identificadas as principais deficiências. São propostas adequações aos algoritmos existentes, em particular, é apresentada a proposta da técnica das faixas que proporciona a redução drástica no consumo de memória para o processamento da geometria 3D e que possui desempenho computacional melhor em relação às técnicas tradicionais. Foi implementado um protótipo de sistema de reconstrução 3D que permite a reconstrução pelas diferentes técnicas estudadas e propostas, bem como permite visualizar o cenário reconstruído sob diferentes pontos de vista de forma interativa.<br>The acquisition and reconstruction of three-dimensional (3D) geometry of objects and environments have their importance growing in areas such as Computer Vision and Computer Graphics. The current methods to acquire and reconstruct three-dimensional data need sophisticated equipments and assemblies, which have expensive costs and limited applications. This work presents the main algorithms for 3D reconstruction using a pair of stereo images and identifies which are viable to use with conventional equipments. Through the implementation of some of these algorithms, by comparing the results obtained and comparing with the results presented in the literature, the main limitations were identified. This work proposes adjustments in the existing algorithms, in particular it proposes the stripping technique, which provides a huge memory usage reduction for 3D geometry processing and better computing performance if compared with traditional approaches. A prototype system for 3D reconstruction was implemented, which allows the reconstruction using the different researched and proposed techniques and allows interactive visualization of the reconstructed scene in different angles.
12
Gomes, Marcelo Marques. "Recuperação de informações tridimensionais a partir de múltiplas imagens." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258881.
Full textAbstract:
Orientador: Clésio Luis Tozzi<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação<br>Made available in DSpace on 2018-08-20T02:20:27Z (GMT). No. of bitstreams: 1
Gomes_MarceloMarques_M.pdf: 2920969 bytes, checksum: 0ae0c041b47241b92c32e9792f18d608 (MD5)
Previous issue date: 2012<br>Resumo: Este trabalho aborda a solução para o problema da recuperação da informação tridimensional somente a partir de imagens da cena ou do objeto que se deseja modelar desconhecidas as informações a respeito das câmeras utilizadas. A solução apresentada divide-se em duas partes: na primeira se estabelece a relação entre pares ou trios de câmeras utilizando matriz fundamental ou tensor trifocal, respectivamente e a partir dessas relações obtém-se por meio de triangulação uma reconstrução tridimensional da cena ou do objeto observado em função de uma transformação projetiva arbitrária. Na segunda parte determina-se uma transformação que leva a cena ou o objeto obtidos no espaço projetivo para o espaço métrico. Essa transformação que leva o objeto recuperado no espaço projetivo para o espaço métrico é encontrada por meio de autocalibração utilizando o plano no infinito e a cônica absoluta que apresentam a propriedade de serem invariantes a rotação, translação e escala, em relação a um referencial escolhido arbitrariamente. Dependendo do número de imagens disponíveis é necessário inserir restrições nos parâmetros intrínsecos das câmeras para viabilizar o cálculo da transformação. Essas restrições são inseridas na forma de suposições a respeito dos parâmetros intrínsecos das câmeras, como pontos principais conhecidos ou constantes entre as câmeras, skew nulo, relação de aspecto unitária etc. Os resultados da reconstrução no espaço projetivo obtidos com o uso da matriz fundamental e do tensor trifocal foram comparados em relação ao erro de reconstrução utilizando protótipo implementado em Matlab e imagens sintéticas. A solução geral foi avaliada em relação ao erro de reprojeção, reconstrução no espaço métrico com base em imagens sintéticas e imagens reais de objetos conhecidos, utilizando um protótipo desenvolvido na plataforma Embarcadero Delphi<br>Abstract: This work addresses a solution to the problem of recovering three-dimensional information from images of a scene or modeled object based only on images and without any information of the cameras parameters. The presented solution is divided in two parts: in the first part it is established the relationship between a pair or a triple of cameras using the fundamental matrix or trifocal tensor, respectively, and obtained by triangulation a three-dimensional reconstruction of the observed scene or object in function of an arbitrary projective transformation. In the second part it is determined a transformation to covert the obtained scene or object reconstruction from the projective space to the metric space. This transformation is found by auto-calibration using the plane at infinity and the absolute conic which have the property of being invariant to rotation, translation and scale in relation to an arbitrarily chosen reference frame. According to the number of available images, restrictions on the intrinsic parameters may be necessary in order to obtain a valid transformation. These restrictions are inserted in the form of assumptions about the values of the intrinsic parameters of the cameras or relations between then, like known principal points or constant values for the cameras, zero skew, unit aspect ratio and so on. Using synthetic images and a prototype implemented in Matlab, the results of reconstruction in projective space based on the fundamental matrix and trifocal tensor were compared in relation to the error of reconstruction. Based on synthetic images and real images of known objects and a prototype developed in the Embarcadero Delphi platform, the general solution was evaluated in relation to the reprojection error and the error of reconstruction in the metric space<br>Mestrado<br>Engenharia de Computação<br>Mestre em Engenharia Elétrica
13
Val, Petran. "BINOCULAR DEPTH PERCEPTION, PROBABILITY, FUZZY LOGIC, AND CONTINUOUS QUANTIFICATION OF UNIQUENESS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1504749439893027.
Full text
14
Decoux, Benoît. "Un modèle connexionniste de vision 3-D : imagettes rétiniennes, convergence stéréoscopique, et apprentissage auto-supervisé de la fusion." Rouen, 1995. http://www.theses.fr/1995ROUES056.
Full textAbstract:
Les études destinées à apporter l'apprentissage non-supervisé à la vision stéréoscopique artificielle s'inscrivent dans la recherche en auto-organisation des systèmes, et constituent une avancée dans la modélisation de la vision stéréo naturelle. Le principal objectif de cette thèse est de participer à cette recherche. Après quelques données sur la vision naturelle, des propriétés importantes des réseaux neuronaux sont présentées. L'accent est mis ensuite sur les propriétés d'auto-organisation de ces derniers, ainsi que sur leurs capacités sensorimotrices. Un passage en revue non-exhaustif des modèles connexionnistes de vision stéréo existant, est alors effectué. Enfin, un modèle connexionniste de vision stéréo est proposé. Ce modèle comporte deux processus complémentaires : 1) la convergence stéréo met en correspondance des régions, par minimisation d'une disparité globale. Elle simule un processus de convergence visio-motrice; 2) la fusion stéréo recherche alors la correspondance entre des éléments caractéristiques. La fusion est obtenue après une phase d'apprentissage auto-supervisé. Le type de l'apprentissage est ainsi dénommé parce que la règle utilisée est une règle d'apprentissage supervisé, mais dans laquelle l'information de supervision est extraite automatiquement des entrées visuelles par le modèle. Les scènes visuelles sont perçues au moyen d'un ensemble d'imagettes rétiniennes : il s'agit de petites images de différents champs visuels et résolutions.
15
Tan, Pauline. "Précision de modèle et efficacité algorithmique : exemples du traitement de l'occultation en stéréovision binoculaire et de l'accélération de deux algorithmes en optimisation convexe." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX092/document.
Full textAbstract:
Le présent manuscrit est composé de deux parties relativement indépendantes.La première partie est consacrée au problème de la stéréovision binoculaire, et plus particulièrement au traitement de l'occultation. En partant d'une analyse de ce phénomène, nous en déduisons un modèle de régularité qui inclut une contrainte convexe de visibilité. La fonctionnelle d'énergie qui en résulte est minimisée par relaxation convexe. Les zones occultées sont alors détectées grâce à la pente horizontale de la carte de disparité avant d'être densifiées.Une autre méthode gérant l'occultation est la méthode des graph cuts proposée par Kolmogorov et Zabih. L'efficacité de cette méthode justifie son adaptation à deux problèmes auxiliaires rencontrés en stéréovision, qui sont la densification de cartes éparses et le raffinement subpixellique de cartes pixelliques.La seconde partie de ce manuscrit traite de manière plus générale de deux algorithmes d'optimisation convexe, pour lequels deux variantes accélérées sont proposées. Le premier est la méthode des directions alternées (ADMM). On montre qu'un léger relâchement de contraintes dans les paramètres de cette méthode permet d'obtenir un taux de convergence théorique plus intéressant.Le second est un algorithme de descentes proximales alternées, qui permet de paralléliser la résolution approchée du problème Rudin-Osher-Fatemi (ROF) de débruitage pur dans le cas des images couleurs. Une accélération de type FISTA est également proposée<br>This thesis is splitted into two relatively independant parts. The first part is devoted to the binocular stereovision problem, specifically to the occlusion handling. An analysis of this phenomena leads to a regularity model which includes a convex visibility constraint. The resulting energy functional is minimized by convex relaxation. The occluded areas are then detected thanks to the horizontal slope of the disparity map and densified. Another method with occlusion handling was proposed by Kolmogorov and Zabih. Because of its efficiency, we adapted it to two auxiliary problems encountered in stereovision, namely the densification of sparse disparity maps and the subpixel refinement of pixel-accurate maps.The second part of this thesis studies two convex optimization algorithms, for which an acceleration is proposed. The first one is the Alternating Direction Method of Multipliers (ADMM). A slight relaxation in the parameter choice is shown to enhance the convergence rate. The second one is an alternating proximal descent algorithm, which allows a parallel approximate resolution of the Rudin-Osher-Fatemi (ROF) pure denoising model, in color-image case. A FISTA-like acceleration is also proposed
16
Nikolova, Mirela. "Binocular vision in reading." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/417785/.
Full textAbstract:
Binocularity is a fundamental characteristic of human visual function. It plays an important part for a crucial socially acquired complex psychological skill: reading. A large number of studies have been dedicated to the exploration of binocular vision, its underlying physiological and neural mechanisms, its role in depth perception and stereopsis, and its pathology and treatment. Similarly, a vast and detailed literature has been devoted to the empirical investigation of oculomotor control during reading and the cognitive processes associated with written language comprehension. There are, however, surprisingly few examples of studies that have considered the role of binocular vision in relation to written text processing. Thus, the mechanisms via which binocularity influences the decisions of when and where to move the eyes in reading have remained largely unspecified. The aim of this thesis is to address these limitations by presenting three empirical papers which investigate the intricate relationship between binocular vision, oculomotor control and cognitive processing during reading. The documented experiments have 1) considered the role of vertical motor and sensory fusion during word identification, 2) explored binocular advantages in reading and 3) investigated the mechanisms via which binocular vision influences processing of foveal and parafoveal text. Overall, the empirical work presented in this thesis brings the field a step closer to bridging the gap between the existing understanding of human binocular vision and the conscious visual experience of a fused, unified binocular percept upon which written language comprehension is fundamentally based.
17
Midgley, Caroline Ann. "Binocular interactions in human vision." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4839/.
Full textAbstract:
Early visual processing is subject to binocular interactions because cells in striate cortex show binocular responses and ocular dominance (Hubel & Weisel, 1968). The work presented in this thesis suggests that these physiological interactions can be revealed in psychophysical experiments using normal human observers. In the region corresponding to the blind spot, where binocular interactions differ from areas of the visual field which are represented by two eyes, monocular contrast sensitivity is increased. This finding can be partially explained by an absence of normal binocular interactions in this location (Chapter 2). A hemianopic patient was studied in an attempt to discover whether the effect in normal observers was mediated by either a mechanism in striate cortex or via a subcortical pathway. However, the results were unable to distinguish between these two explanations (Chapter 3).In a visual search task, no difference in reaction time was observed for targets presented to the region corresponding to the blind spot compared with targets presented to adjacent binocularly represented areas of the visual field. Since performance was unaffected by the monocularity of the region corresponding to the blind, pop-out for orientation may be mediated beyond striate cortex where cells are binocularly balanced (Chapter 5). Further support for this contention was provided by studies of orientation pop-out in central vision which found that dichoptic presentation of stimuli did not affect the degree of pop-out obtained and that in general, visual search for a target based solely on eye of origin is impossible (Chapter 6). However, a task that measured orientation difference sensitivity more directly than the search experiments, found that thresholds were higher for dichoptically presented stimuli. This suggests the involvement of neurons that receive a weighted input from each eye. A model of orientation difference coding can account for the results by assuming that the range of inhibition across which orientation differences are coded is narrower for dichoptic stimuli leading to a greater resolvable orientation difference (Chapter 7).
18
Chambon, Sylvie. "Mise en correspondance stéréoscopique d'images couleur en présence d'occultations." Phd thesis, Université Paul Sabatier - Toulouse III, 2005. http://tel.archives-ouvertes.fr/tel-00011437.
Full textAbstract:
Cette thèse se situe dans le cadre de la vision par ordinateur et concerne plus précisément l'étape de mise en correspondance de pixels en stéréovision binoculaire. Cette étape consiste à retrouver les pixels homologues dans deux images d'une même scène, prises de deux points de vue différents. Une des manières de réaliser la mise en correspondance est de faire appel à des mesures de corrélation. Les algorithmes utilisés se heurtent alors aux difficultés suivantes : les changements de luminosité, les bruits, les raccourcissements, les zones peu texturées et les occultations. Les travaux qui ont été réalisés sont une étude sur les méthodes à base de corrélation, en prenant en compte le problème des occultations et l'utilisation d'images couleur.<br /><br />Dans un premier chapitre, nous établissons un état de l'art des méthodes de mise en correspondance de pixels. Nous donnons un modèle générique des méthodes s'appuyant sur la définition d'éléments constituants. Nous distinguons alors quatre catégories de méthodes : les méthodes locales, les méthodes globales, les méthodes mixtes et les méthodes à multiples passages. <br /><br />Le second chapitre aborde le problème de l'évaluation des méthodes de mise en correspondance de pixels. Après avoir donné un état de l'art des protocoles existants, nous proposons un protocole d'évaluation et de comparaison qui prend en compte des images avec vérité terrain et qui distingue différentes zones d'occultations. <br /><br />Dans le troisième chapitre, nous proposons une taxonomie des mesures de corrélation regroupées en cinq familles : les mesures de corrélation croisée, les mesures utilisant des outils de statistiques classiques, les mesures utilisant les dérivées des images, les mesures s'appuyant sur des outils des statistiques non paramétriques et les mesures exploitant des outils des statistiques robustes. Parmi cette dernière famille, nous proposons dix-sept mesures. Les résultats obtenus avec notre protocole montrent que ces mesures obtiennent les meilleurs résultats dans les zones d'occultations. <br /><br />Le quatrième chapitre concerne la généralisation à la couleur des méthodes de mise en correspondance à base de corrélation. Après avoir présenté les systèmes de représentation de la couleur que nous testons, nous abordons la généralisation des méthodes à base de corrélation en passant par l'adaptation des mesures de corrélation à la couleur. Nous proposons trois méthodes différentes : fusion des résultats sur chaque composante, utilisation d'une analyse en composante principale et utilisation d'une mesure de corrélation couleur. Les résultats obtenus avec notre protocole mettent en évidence la meilleure méthode qui consiste à fusionner les scores de corrélation. <br /><br />Dans le dernier chapitre, pour prendre en compte les occultations, nous proposons des méthodes hybrides qui s'appuient sur l'utilisation de deux mesures de corrélation : une mesure classique dans les zones sans occultation et une mesure robuste dans les zones d'occultations. Nous distinguons quatre types de méthodes à base de détection de contours, de corrélation pondérée, de post-détection des occultations et de fusion de cartes de disparités. Les résultats obtenus avec notre protocole montrent que la méthode la plus performante consiste à fusionner deux cartes de disparités.
19
Ajzenman, Heather. "Binocular vision skills in human observers /." South Hadley, Mass. : [s.n.],, 2008. http://ada.mtholyoke.edu/setr/websrc/pdfs/www/2008/293.pdf.
Full text
20
Hood, Alison S. "The dependence of binocular contrast sensitivity on binocular single vision." Thesis, University of Glasgow, 1999. http://theses.gla.ac.uk/6253/.
Full textAbstract:
This study involved the determination of the effects of binocular viewing on contrast sensitivities in 11 normal subjects and in different categories of amblyopes. These were simple anisometropic amblyopes (n=9), micro-esotropic amblyopes with anomalous BSV (n=6), esotropic amblyopes with anomalous BSV (n=3) esotropic without BSV 9n=5), exotropic amblyopes without BSV (n=2) and a group of non-amblyopic strabismics (non-amblyopic esotropes without BSV (n=4); non-amblyopic exotropes without BSV (n=2).An ophthalmic examination was carried out on all individuals. The examination procedures undertaken comprised determination of the visual acuity, subjective refraction, the results of which were confirmed by retinoscopy, and assessment of uniocular fixation patterns. The state of BSV, the direction and magnitude of the angle of deviation, the amplitude of accommodation and pupillary diameter were also determined. The subjects were accordingly placed into the appropriate groups on the basis of the basis of the results of the ophthalmic examination. Measurement of uniocular and binocular contrast sensitivities in response to stationary vertical sinusoidal grating patterns were undertaken. The stimulus display consisted of a Tektronix 5103 cathode ray tube (CRT) with a screen subtense of 2 degrees. Mean contrast threshold values were measured for monocular and binocular viewing over the range of spatial frequencies studied which varied between 8c/deg to 40c/deg depending on the group being examined. The conclusions reached were, first, in individuals with BSV (normal or anomalous), binocular enhancement of contrast sensitivities occurred. However, strabismic amblyopes without BSV and non-amblyopic strabismics without BSV did not exhibit enhanced binocular contrast sensitivities; on the contrary, binocular contrast sensitivities were reduced compared to those obtained through the better eye. Furthermore, when bifoveal stimulation was effected, a further reduction in binocular contrast sensitivity occurred. This study has thus shown that binocular contrast sensitivities are augmented compared with monocular contrast sensitivities when BSV is present, but are decreased when BSV is absent. Furthermore, correction of the angle of squint in strabismics, whether BSV is present or not, further reduces the binocular contrast sensitivities.
21
Griffiths, Helen Jane. "Saccades in the absence of binocular vision." Thesis, University of Sheffield, 2003. http://etheses.whiterose.ac.uk/3031/.
Full textAbstract:
The mechanism of suppression in strabismus is unclear and contribution of the suppressing eye to the generation of eye movements has received little attention. A series of nine experiments tested how the strabismic eye contributes to saccade generation in the presence of suppression and also considered the effect of the strabismic eye in the presence of abnormal retinal correspondence (ARC). These data were compared with data from subjects with normal binocular single vision (BSV). Chapters 2 and 3 describe the equipment, laboratory set-up and testing of the equipment used in the thesis for measuring eye movements, Skalar IRIS 6500 infrared limbal tracker, and presenting stimuli to each eye separately. The design of a novel method for dissociation of the eyes using four liquid crystal polymer shutters is presented. Chapter 4 compares the characteristics of saccades made by subjects with normal BSV (n=5) and strabismus (n=8). The effect of distractors on saccades is explored in Chapter 5 in subjects with normal BSV (n=5). The experiment documents the distractor effect produced in the described laboratory set-up, and compares it with that previously reported by Walker et al (1997). This is investigated further by comparing the effect of distractor presentations to the dominant eye, non-dominant eye or both eyes. There was no difference in the effect on saccade latency or gain with distractors presented to the dominant or non-dominant eye. The effect of binocular distractors on saccade gain was greater than monocular presentations. Chapter 6 repeats the experiment of Chapter 5 in subjects with constant strabismus and suppression (n=6) and constant strabismus with ARC (n=2) and found that distractors in the strabismic eye did affect saccades however the response differed from normal BSV. This was true even though it was shown that the distractor was not perceived by the strabismic eye. Chapter 7 investigates the influence of the central fixation target in the strabismic eye on saccade generation by inducing disconjugate saccade adaptation in subjects with normal BSV (n=8) and constant strabismus and suppression (n=6). The findings were that in the presence of suppression, disconjugate adaptation similar to that in normal BSV was possible. The conclusion of this thesis is to suggest that information from the suppressed eye is available to the saccadic system by either a sub-cortical pathway or processed cortically without conscious awareness.
22
Burge, R. "Recognition of shape and orientation using binocular vision." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/NQ48611.pdf.
Full text
23
Conrad, Joseph Samuel. "Vision Therapy for Binocular Dysfunction Post Brain Injury." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306554563.
Full text
24
Ho, Pik-ki, and 何碧琪. "Visual crowding and binocular vision: the locus of crowding relative to binocular rivalry and fusion." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43572091.
Full text
25
Ho, Pik-ki. "Visual crowding and binocular vision the locus of crowding relative to binocular rivalry and fusion /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43572091.
Full text
26
Bridge, Holly. "Neuronal mechanisms underlying the perception of slant and binocular orientation." Thesis, University of Oxford, 2000. http://ora.ox.ac.uk/objects/uuid:bd680f76-7794-41ab-8f05-e4a22df5424a.
Full text
27
Gautier, Josselin. "Un modèle d'attention visuelle dynamique pour conditions 2D et 3D ; codage de cartes de profondeur et synthèse basée inpainting pour les vidéos multi-vues." Phd thesis, Université Rennes 1, 2012. http://tel.archives-ouvertes.fr/tel-00758112.
Full textAbstract:
Cette thèse a pour objet les systèmes 3D émergents et leurs problématiques de codage multi-vues-plus-profondeur, de synthèse de vues virtuelles et de perception stéréoscopique. Des solutions sont proposées au travers d'un codage de carte de profondeur efficace, d'une nouvelle méthode de synthèse par extrapolation et d'un modèle d'attention visuelle dynamique. Premièrement, le rôle de la disparité binoculaire dans le déploiement de l'attention visuelle est étudié. Suite à une analyse statistique de biais potentiels de centre et de profondeur en condition mono et stéréoscopique, un nouveau modèle de saillance est proposé combinant des attributs bas et haut niveau, dont le mécanisme visuel de séparation fond/forme. Les performances confirment la validité de l'approche et la pertinence d'une combinaison d'attributs visuels pondérés au cours du temps. En outre une nouvelle méthode de compression de carte de profondeur est présentée ; celle-ci se base sur la transmission sans perte des contours et permet une reconstruction fiable de la géométrie de la scène pour des synthèses de vues précises. Cette méthode est évaluée par des métriques de qualité objectives ainsi que par des tests subjectifs. Enfin une nouvelle méthode d'inpainting directionnelle est présentée pour l'extrapolation de nouveaux points de vues à la fois pour la 3DTV et la FTV. La structure située à l'arrière-plan est propagée en priorité dans les zones découvertes. Le calcul d'isophotes, robuste car basée tenseur, ainsi que le remplissage directionnel assurent une synthèse de vue plausible. Ces résultats sont visuellement prometteurs que ce soit à faible ou large écart de la vue d'origine.
28
Yekta, Karizbala A. A. "The clinical significance of fixation disparity in binocular vision." Thesis, University of Bradford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233694.
Full text
29
Gampher, John Eric. "Perception of motion-in-depth induced motion effects on monocular and binocular cues /." Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2009r/gampher.pdf.
Full textAbstract:
Thesis (Ph. D.)--University of Alabama at Birmingham, 2008.<br>Title from PDF title page (viewed Mar. 30, 2010). Additional advisors: Franklin R. Amthor, James E. Cox, Timothy J. Gawne, Rosalyn E. Weller. Includes bibliographical references (p. 104-114).
30
Grossmann, Jon K. "Competition in multistable vision is attribute-specific." Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2007r/grossmann.pdf.
Full textAbstract:
Thesis (Ph. D.)--University of Alabama at Birmingham, 2007.<br>Additional advisors: Timothy Gawne, Richard Gray, Michael Loop, Michael Sloane, Donald Twieg. Description based on contents viewed Mar. 3, 2008; title from title screen. Includes bibliographical references (p. 88-97).
31
Agrawal, Ritwick. "Psychophysical studies of binocular and spatial vision in humans with anisometropic and strabismic amblyopia." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3497.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2004.<br>Title from document title page. Document formatted into pages; contains vii, 49 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 45-47).
32
Salama, Gouda Ismail Mohamed. "Monocular and Binocular Visual Tracking." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/37179.
Full textAbstract:
Visual tracking is one of the most important applications of computer vision. Several tracking systems have been developed which either focus mainly on the tracking of targets moving on a plane, or attempt to reduce the 3-dimensional tracking problem to the tracking of a set of characteristic points of the target. These approaches are seriously handicapped in complex visual situations, particularly those involving significant perspective, textures, repeating patterns, or occlusion.
This dissertation describes a new approach to visual tracking for monocular and binocular image sequences, and for both passive and active cameras. The method combines Kalman-type prediction with steepest-descent search for correspondences, using 2-dimensional affine mappings between images. This approach differs significantly from many recent tracking systems, which emphasize the recovery of 3-dimensional motion and/or structure of objects in the scene. We argue that 2-dimensional area-based matching is sufficient in many situations of interest, and we present experimental results with real image sequences to illustrate the efficacy of this approach.
Image matching between two images is a simple one to one mapping, if there is no occlusion. In the presence of occlusion wrong matching is inevitable. Few approaches have been developed to address this issue. This dissertation considers the effect of occlusion on tracking a moving object for both monocular and binocular image sequences. The visual tracking system described here attempts to detect occlusion based on the residual error computed by the matching method. If the residual matching error exceeds a user-defined threshold, this means that the tracked object may be occluded by another object. When occlusion is detected, tracking continues with the predicted locations based on Kalman filtering. This serves as a predictor of the target position until it reemerges from the occlusion again. Although the method uses a constant image velocity Kalman filtering, it has been shown to function reasonably well in a non-constant velocity situation. Experimental results show that tracking can be maintained during periods of substantial occlusion.
The area-based approach to image matching often involves correlation-based comparisons between images, and this requires the specification of a size for the correlation windows. Accordingly, a new approach based on moment invariants was developed to select window size adaptively. This approach is based on the sudden increasing or decreasing in the first Maitra moment invariant. We applied a robust regression model to smooth the first Maitra moment invariant to make the method robust against noise.
This dissertation also considers the effect of spatial quantization on several moment invariants. Of particular interest are the affine moment invariants, which have emerged, in recent years as a useful tool for image reconstruction, image registration, and recognition of deformed objects. Traditional analysis assumes moments and moment invariants for images that are defined in the continuous domain. Quantization of the image plane is necessary, because otherwise the image cannot be processed digitally. Image acquisition by a digital system imposes spatial and intensity quantization that, in turn, introduce errors into moment and invariant computations. This dissertation also derives expressions for quantization-induced error in several important cases. Although it considers spatial quantization only, this represents an important extension of work by other researchers.
A mathematical theory for a visual tracking approach of a moving object is presented in this dissertation. This approach can track a moving object in an image sequence where the camera is passive, and when the camera is actively controlled. The algorithm used here is computationally cheap and suitable for real-time implementation. We implemented the proposed method on an active vision system, and carried out experiments of monocular and binocular tracking for various kinds of objects in different environments. These experiments demonstrated that very good performance using real images for fairly complicated situations.<br>Ph. D.
33
Lin, Wei. "Evaluation of computerised programs for the diagnosis and treatment of binocular anomalies." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/evaluation-of-computerised-programs-for-the-diagnosis-and-treatment-of-binocular-anomalies(668477e4-5a2c-4bc2-b29f-c2270295bc6c).html.
Full textAbstract:
Computerised diagnostic testing and computerised vision training (VT) have been developed for the orthoptic management of binocular vision (BV) anomalies in clinical practice. Computerised measurement of BV is assumed to assist accurate diagnosis of BV anomalies because variability of testing resulting from subjective judgements of examiners is eliminated by automatic measurements. Computerised VT is thought to be effective in the treatment of BV anomalies because the computer games used for vision training will enhance the patient's motivation. However, these assumptions were lacking scientific support. This thesis reports a range of studies to investigate the computerised programs of diagnostic testing (HTS-BVA) and vision training (HTS-iNet) in comparison with corresponding traditional approaches, respectively. The first study was to investigate inter-session repeatability of computerised testing on BV functions. The study results showed that computerised testing on measuring near horizontal fusional vergence (FV) and accommodative facility (AF) did not present higher inter-session repeatability than corresponding traditional testing. The second study was a pilot study for a future rigorous randomized clinical trial (RCT) investigating effectiveness of computerised VT as a home-based treatment for convergence insufficiency (CI). The study results showed the subjects with CI demonstrated improvement of near point of convergence (NPC), near base-out FV and symptoms associated with CI after an 8-week treatment regime. The third study, following from the first study, was to investigate whether accommodative responses (AR) are affected by the novel accommodative stimuli used in computerised AF testing. The study results showed the AR might be affected by the colours of accommodative targets and the colour filter used. Especially, the data of accommodative demand of 4 dioptres revealed that blue targets presented poorer AR than red targets, and the targets seen with colour filters presented poorer AR than those seen without colour filters. The fourth study, also following from the first study, was to investigate whether a prolonged near vision task affects measurements made relating to the near FV system, thus contributing to the variability of clinical findings. The study results showed statistically significant changes in NPC and near dissociated phoria. In further sub-group analyses, the subjects with an initially poor NPC (n = 9) presented greater changes in the NPC and near dissociated phoria than the subjects with normal poor NPC (n = 25).Overall, the computerised testing did not show more repeatable BV measurements than the traditional testing. Finally, an RCT is needed to determine if the computerised VT is more effective than placebo computerised VT as a home-based treatment for CI.
34
Faulkner, Stuart. "The nature of binocular interactions in developmental disorders of vision." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55414/.
Full text
35
Rojas-Anaya, HeÌctor. "A computerised system for the clinical study of binocular vision." Thesis, University of Sussex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398361.
Full text
36
Smith, Joss. "The development of binocular vision in normal and strabismic infants." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317902.
Full text
37
Tidbury, L. "Dynamic and static cues for binocular vision : a systematic comparison." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3007325/.
Full textAbstract:
Background: Patients who are diagnosed as stereo blind, during clinical assessment have reported a compelling, volumetric perception of depth during stereoscopic viewing at the cinema. This effect cannot entirely be explained by the monocular cues present in the cinematic presentation. This lead to the theory that depth from binocular cues may be more apparent when motion is included in the scene. As an object approaches in space is detected through the use of two binocular cues, changing disparity over time, and intraocular velocity difference. These cues have been previously investigated in terms of detecting the presence of motion and discriminating the direction of motion. In this thesis I am to investigate the contribution of stereomotion to the detection of depth. Methods: A four alternate forced choice adaptive staircase presentation paradigm was used to assess the ability of participants to detect which of four random dot patterned stimuli patches appeared closest to them in space. The outcome measure for every experiment was depth detection threshold. The experiments were presented using either linear polarised or dichoptic stereoscopic display methods. The stimulus patches were designed to only define depth through binocular disparity, with care taken to avoid any monocular cues. The target patch was identical to all other stimuli patches other than variations to test the following dynamic characteristics: z-location change, X-location change, changing disparity only, interocular velocity difference change only and changes in pattern. These were all comparable to a static condition, where depth was defined by disparity only. All z-axis (or depth) changes were defined by ‘on-screen’ separations of half images (the images separated to the left and right eyes in turn). A number of control experiments were also included to assess the effect of fusional demand, of spurious temporal correlations, of variations in speed of changes in depth and of cue construction on depth detection thresholds. Results: 410 subjects were assessed, (aged mean (SD) age 21(5) years) across all experiments. In comparison to the static disparity conditions (415”), depth detection thresholds were statistically significantly lower for the stereomotion conditions, with (CDOT 360”) and without (Z-LOCATION CHANGE 310”) pattern change (p < 0.001). The presence of a changing pattern in isolation (p=0.71) (STATIC PATTERN CHANGE 410”) or a horizontal shift (p=0.41) (X-LOCATION CHANGE 420”) did not significantly affect the thresholds. The presence of fusional demand or spurious temporal cues did not cause any statistically significant change in thresholds (P > 0.05). Conclusion: The threshold for detecting depth in stimuli that contain z-motion, is better (lower) than for static stimuli, providing an explanation for the experience of compelling depth at the cinema. As z-motion depth detection thresholds were significantly lower than static thresholds, this suggests motion provides an advantage to extracting depth, above serial static disparity detection alone. The assessment of stereoacuity should include the measurement of depth detection thresholds using changing depth stimuli, in order to fully investigate binocular potential.
38
Revell, James Duncan. "Computer vision elastography." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412361.
Full text
39
Chiu, Kevin (Kevin Geeyoung). "Vision on tap : an online computer vision toolkit." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67714.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student submitted PDF version of thesis.<br>Includes bibliographical references (p. 60-64).<br>In this thesis, we present an online toolkit, based on a combination of a Scratch-based programming environment and computer vision libraries, manifested as blocks within the environment, integrated with a community platform for diffusing advances in computer vision to a general populace. We show that by providing these tools, non-developers are able to create and publish computer vision applications. The visual development environment includes a collection of algorithms that, despite being well known in the computer vision community, provide capabilities to commodity cameras that are not yet common knowledge. In support of this visual development environment, we also present an online community that allows users to share applications made in the environment, assisting the dissemination of both the knowledge of camera capabilities and advanced camera capabilities to users who have not yet been exposed to their existence or comfortable with their use. Initial evaluations consist of user studies that quantify the abilities afforded to the novice computer vision users by the toolkit, baselined against experienced computer vision users.<br>by Kevin Chiu.<br>S.M.
40
Pitrolo, Yuenan Sun. "fMRI studies of binocular suppression in human amblyopic subjects." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4743.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2006.<br>Title from document title page. Document formatted into pages; contains vii, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-94).
41
Vedamurthy, Indu Optometry & Vision Science Faculty of Science UNSW. "Interocular interactions in normal and amblyopic visual systems." Awarded by:University of New South Wales. School of Optometry and Vision Science, 2006. http://handle.unsw.edu.au/1959.4/24931.
Full textAbstract:
The aim of this study was to add to our understanding of interocular interactions in normally sighted children (Group I, N=20), normal adults (Group II, N=20) and adults with anisometropic amblyopia (N=12) by investigating responses to a range of visual functions under three kinds of viewing condition. Visual functions tested were visual acuity, contrast sensitivity and alignment sensitivity. Stimuli were generated on a Cambridge VSG card driving a high resolution monitor and FE liquid crystal goggles, enabling three kinds of viewing conditions: 1. Monocular (non-tested eye occluded), used as a baseline for most functions. 2. Dichoptic (uniform field presented to the non-tested eye but with a binocular fusion lock). 3. Binocular. In general, binocular performance was better than monocular (binocular summation) but so too was dichoptic performance (dichoptic advantage). However there was much variation within individuals (the three functions showing different summation/advantage pattern) and between individuals. Significant conclusions include: (a) Maturational windows for interocular interactions differ for different spatial visual functions. (b) Interpretations of results from one visual function cannot be applied automatically to other functions. (c) Care must be taken in interpreting results based on 5 or fewer subjects.
42
Glennerster, Andrew. "The role of spatial scale in binocular stereopsis." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:13ecf058-eea2-4c4c-8d25-332a8827b774.
Full textAbstract:
A model of stereopsis is proposed in which information from each eye's image is organised as a scale-based hierarchy before binocular comparison. The algorithm incorporates coarse-to-fine matching (like Marr and Poggio, 1979) but differs from previous models in that the position, and hence disparity, of features is defined relatively rather than by their retinal co-ordinate. Thus, fine scale disparities are measured and recorded relative to coarse scale disparities. Local surface slant and curvature is represented explicitly at a range of spatial scales. The theory is based on a hierarchical model of encoding position (Watt, 1988). The first experiment investigates the time course of shape discrimination in random dot stereograms. The results are compatible with a model in which the scale of analysis changes from coarse to fine over the first second of viewing. The second experiment measures the magnitude of a new "3-D" Müller-Lyer illusion and compares it to that of the classical (2-D) illusion. Both these and the cyclopean Müller-Lyer illusion are consistent with a model in which hierarchical encoding of position is used by the visual system for 2-D (length comparison) and 3-D (slant) judgements. The third experiment compares the detection of large disparities and large displacements. "D<sub>max</sub>" for the motion and stereo tasks is shown to be similar over a wide range of dot densities. The results are interpreted as evidence that similar spatial primitives are used in the correspondence process in both domains. The spacing of MIRAGE centroids (Watt and Morgan, 1985) fit the data well. The proposed hierarchical model is similar to that put forward by Mitchison and McKee (1987), although their scheme was not based on spatial scale. The model bridges the gap between a primal and a 2 1/2-D sketch (Marr, 1982) and has important implications for many issues within stereopsis.
43
Dusek, Wolfgang Anton. "Treatment of Binocular Vision Anomalies that Underlie Reading and Writing Difficulties." Thesis, University of Ulster, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.564499.
Full textAbstract:
The importance of good vision for acquiring a sound fundamental base in reading and writing skills, in early years, has implications for scholastic achievement and future prospects in adult life. Where the underlying problems in children, who have difficulties in school, are not related to intellect, the ocular and visual systems need to be examined. This thesis is based on observations of 1153 school-children, aged from 7 to 14 years, who had been found to have problems with reading and writing but had no intellectual impediments to learning. The results have shown that the vast majority 72% of these children demonstrate binocular vision problems that can be treated. Treatment options for convergence insufficiency and convergence excess were trialled. It was found that prismatic correction, reading glasses and muscle exercise therapy were effective. Reading speed and efficiency could be improved to normal levels within a period of four weeks. These findings indicate that there is significant plasticity in the visual systems of the eyes of children and that any dysfunctions should be rapidly treated. The thesis has also shown the basis on which the level of prismatic correction is derived. It is also the first to show a comparison of calibrated reading tests in German and English. The physiological mechanisms in the developing and growing eye may have an influence on other measures. Muscular forces within the eyeball (controlling accommodation) and externally placed (controlling eye movements) may have an influence on the pressure with the eye. Little is known about the normal variations with age in intraocular pressure in children. This study has shown that there is an age-related increase in intraocular pressure that plateaus after age 9 and that there are differences between children with binocular vision problems and controls. Reasons for these differences are discussed and further investigations suggested.
44
Cornell, Elaine. "Binocular alignment and vergence errors in free space." University of Sydney, 2004. http://hdl.handle.net/2123/5411.
Full textAbstract:
Doctor of Philosophy<br>The human, along with other primates, has forward placed eyes, and an area of acute vision (the fovea) on each retina. The overlap of the visual fields and the hemi-decussation of the visual pathways at the optic chiasm provide the basis for binocular vision, in particular stereopsis, the accurate perception of the position of objects in three dimensional space and an improved ability to perceive the form of solid objects. An intricate system of eye movements is needed to achieve and maintain stable foveal fixation on each eye in an environment where visual targets vary in direction and depth, where the visual environment may be moving, the eyes or the rest of the body is moving. The purpose of this study is to evaluate the accuracy of binocular alignment for far and near fixations, under relatively natural conditions. To achieve binocular fixation, accurate vergence eye movements are required to align the eyes, and to maintain this alignment when a person changes fixation to objects situated at different distances from the eyes. ‘Pure’ vergence eye movements occur when these objects are situated along the mid sagittal plane, however, in natural conditions other eye movement systems are also involved. To understand the contribution of different eye movement systems to binocular fixation at different distances, the accuracy of binocular alignment in subjects with normal binocular single vision was evaluated in subjects with normal binocular vision under the following conditions • Fixation on targets along the mid sagittal plane (vergence eye movements only) • Fixation on targets displaced to either side of the mid sagittal plane (combined vergence eye movements and saccades • Fixation on earth fixed targets situated straight ahead in space, but with the head tilted to either side (combined vergence eye movements, saccades and torsional eye movements). The protocol for all experiments was approved by the Human Ethics Committee of the University of Sydney and followed the tenets of the Declaration of Helsinki. Throughout this thesis the term ‘binocular alignment’ will be used to describe the position of each eye during or following a change in vergence. The term ‘vergence error’ will refer to situations where the angle of vergence alignment is different from that required, so that the image of the fixation target does not fall on the fovea of one or both eyes.
45
Raufdeen, Ramzi A. "SE4S toolkit extension project vision diagramming tool build your vision." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10147325.
Full textAbstract:
<p> Sustainability is an important topic when developing software because it helps develop ecofriendly programs. Software can contribute towards sustainability by supporting sustainable goals, which can be efficiently supported if considered early on in a project by requirements engineers. This project helps requirements engineers make that sustainable contribution through the development of the SE4S toolkit extension project–a vision diagramming tool that contributes towards sustainability. This interactive tool is developed using HTML, SVG, and JointJS library. The vision diagramming tool is an open source project that can be used in any browser, which allows requirements engineers to bring their visions to life while keeping sustainability in mind. Requirements engineers, with help from this tool, would be able to easily demonstrate their sustainability vision to their stakeholders and pass it on to rest of the development team.</p>
46
Vondrick, Carl (Carl Martin). "Predictive vision." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112001.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 95-106).<br>Anticipating outcomes is the root of intelligence. This thesis investigates Predictive Vision with the goal to develop robust methods that anticipate the next events that may happen in images or videos. Importantly, we develop methods for eciently scaling learning algorithms to learn an extensive set of rules that enable richer visual understanding. While large annotated datasets fuel progress in object recognition, the knowledge required for event understanding is vast and potentially ambiguous. To tackle this challenge, we develop predictive vision algorithms that instead learn these rules directly from large amounts of raw, unlabeled data. Capitalizing on millions of natural videos, this work develops algorithms that learn to anticipate the visual future, forecast human actions, and recognize ambient sounds.<br>by Carl Vondrick.<br>Ph. D.
47
Grove, Philip M. "Binocular visual direction the bifixation space, empirical corresponding points in the central binocular field, and visual direction of features belonging to partially occluded surfaces /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ66349.pdf.
Full text
48
Howard, Margaret. "An investigation into the relationship between binocular vision and physical motor skills." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424656.
Full text
49
Vale, Anna. "The Effects of Binocular Vision Impairment on Adaptive Gait. The effects of binocular vision impairment due to monocular refractive blur on adaptive gait involving negotiation of a raised surface." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4931.
Full textAbstract:
Impairment of stereoacuity is common in the elderly population and is found to be a risk factor for falls. The purpose of these experiments was to extend knowledge regarding impairment of binocular vision and adaptive gait. Firstly using a 3D motion analysis system to measure how impairment of stereopsis affected adaptive gait during a negotiation of a step, secondly by determining which clinical stereotest was the most reliable for measuring stereoacuity in elderly subjects and finally investigating how manipulating the perceived height of a step in both binocular and monocular conditions affected negotiation of a step. In conditions of impaired stereopsis induced by acutely presented monocular blur, both young and elderly subjects adopted a safety strategy of increasing toe clearance of the step edge, even at low levels of monocular blur (+0.50DS) and the effect was greater when the dominant eye was blurred. The same adaptation was not found for individuals with chronic monocular blur, where vertical toe clearance did not change but variability of toe clearance increased compared to full binocular correction. Findings indicate stereopsis is important for accurately judging the height of a step, and offers support to epidemiological findings that impaired stereoacuity is a risk for falls. Poor agreement was found between clinical stereotests. The Frisby test was found to have the best repeatability. Finally, a visual illusion that caused a step to be perceived as taller led to increased toe elevation. This demonstrates a potential way of increasing toe clearance when stepping up and hence increase safety on stairs.
50
Scarfe, Peter. "Human use of horizontal disparity for perception and visuomotor control." Thesis, St Andrews, 2007. http://hdl.handle.net/10023/368.
Full text