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Tone mapping reverso de alta qualidade para uma ampla gama de exposições / High-quality reverse tone mapping for awide range of exposuresKovaleski, Rafael Pacheco January 2013 (has links)
Operadores de tone mapping reverso (RTMOs) realçam imagens e vídeos de baixa faixa dinâmica para visualização em monitores de alta faixa dinâmica. Um problema comum encontrado por operadores anteriores é a maneira com que tratam conteúdo sub ou superexposto. Sob tais condições, eles podem não ser eficientes, e até mesmo causar perda e reversão de contraste visível. Apresentamos uma classe de operadores de tone mapping reverso, baseados no filtro bilateral cruzado (cross bilateral filter), capazes de gerar imagens HDR de alta qualidade. Experimentos utilizando uma métrica objetiva de avaliação de imagens demostram que nosso método é a única técnica capaz de realçar detalhes perceptíveis ao longo de uma grande gama de exposições de imagem, a qual inclui desde imagens subexpostas até imagens superexpostas. / Reverse tone mapping operators (rTMOs) enhance low-dynamic-range images and videos for display on high dynamic range monitors. A common problem faced by previous rTMOs is the handling of under or overexposed content. Under such conditions, they may not be effective, and even cause loss and reversal of visible contrast. We present a class of local rTMOs based on cross bilateral filtering that is capable of generating highquality HDR images and videos for a wide range of exposure conditions. Experiments performed using an objective image quality metric show that our approach is the only single technique available that can gracefully enhance perceived details across a large range of image exposures.
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Tone mapping reverso de alta qualidade para uma ampla gama de exposições / High-quality reverse tone mapping for awide range of exposuresKovaleski, Rafael Pacheco January 2013 (has links)
Operadores de tone mapping reverso (RTMOs) realçam imagens e vídeos de baixa faixa dinâmica para visualização em monitores de alta faixa dinâmica. Um problema comum encontrado por operadores anteriores é a maneira com que tratam conteúdo sub ou superexposto. Sob tais condições, eles podem não ser eficientes, e até mesmo causar perda e reversão de contraste visível. Apresentamos uma classe de operadores de tone mapping reverso, baseados no filtro bilateral cruzado (cross bilateral filter), capazes de gerar imagens HDR de alta qualidade. Experimentos utilizando uma métrica objetiva de avaliação de imagens demostram que nosso método é a única técnica capaz de realçar detalhes perceptíveis ao longo de uma grande gama de exposições de imagem, a qual inclui desde imagens subexpostas até imagens superexpostas. / Reverse tone mapping operators (rTMOs) enhance low-dynamic-range images and videos for display on high dynamic range monitors. A common problem faced by previous rTMOs is the handling of under or overexposed content. Under such conditions, they may not be effective, and even cause loss and reversal of visible contrast. We present a class of local rTMOs based on cross bilateral filtering that is capable of generating highquality HDR images and videos for a wide range of exposure conditions. Experiments performed using an objective image quality metric show that our approach is the only single technique available that can gracefully enhance perceived details across a large range of image exposures.
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Legible Tone Mapping : An evaluation of text processed by tone mapping operatorsKarlsson, Christoffer, Schachtschabel, Lukas January 2016 (has links)
Context. Tone mapping operators (TMO) are designed to reduce the dynamicrange of high dynamic range images so that they can be presented onstandard dynamic range display devices. Many operators focus on creatingperceptually similar images. Objectives. This thesis aims to investigate how dierent TMOs reproducephotographed text. The underlying reason being to test the contrast reproductionof each TMO. Methods. An experiment has been performed in order to investigate thelegibility of photographed and tone mapped text. A user study was conducted,in which 18 respondents partook, where respondents were to ratehow much of the text in each photograph that they found to be legible. Results. Due to low participation, the results of the experiment are mostlyinconclusive. However, some tendencies have been observed and analyzedand they fall in line with previous work within the area. Conclusions. The main conclusion that can be drawn from the results isthat the TMO presented by Kuang [11] is rated as better than the TMOsby Fattal [7] and Kim and Kautz [10].
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Backward compatible approaches for the compression of high dynamic range videos / Approches rétro-compatibles pour la compression de vidéos à grande gamme dynamiqueLe Pendu, Mikaël 17 March 2016 (has links)
Les technologies d'écran ont connu récemment une évolution rapide. De la télévision 3D à l'Ultra Haute Définition, la tendance est maintenant aux écrans HDR (pour ''High Dynamic Range'') permettant de reproduire une gamme de luminance bien plus élevée que les écrans classiques. L'émergence de cette technologie implique de nouveaux travaux de standardisation dans le domaine de la compression vidéo. Une question essentielle pour la distribution à grande échelle de contenu HDR est celle de la rétro-compatibilité. Tandis que la future génération d'écrans de télévision sera adaptée à ce nouveau format, il est nécessaire de permettre aux équipements plus anciens de décoder et afficher une version du même contenu dont la dynamique a été préalablement réduite par un procédé appelé ''tone mapping''. Cette thèse vise à explorer les schémas de compression HDR rétro-compatibles. Dans une première approche, un algorithme de tone mapping spécifié par l'encodeur est appliqué à l'image HDR. L'image générée, alors appelée LDR (pour ''Low Dynamic Range''), peut être encodée et décodée dans un format classique. L'encodeur transmet par ailleurs une quantité réduite d'information permettant à un décodeur HDR d'inverser l'opération de tone mapping et de reconstruire une version HDR. L'étude de ces schémas est axée sur la définition de méthodes de tone mapping optimisées pour les performances de compression. La suite de la thèse se concentre sur l'approche scalable dans laquelle les deux versions sont fournies à l'encodeur sans connaissance à priori sur l'opérateur de tone mapping utilisé. Le producteur garde donc le contrôle sur la création du contenu LDR. Cette version LDR est d'abord compressée comme une première couche. L'image reconstruite est utilisée par le codeur scalable pour compresser plus efficacement la couche HDR grâce à un mécanisme de prédiction inter-couches. Notre approche locale et non linéaire nous permet d'améliorer les performances de codage par rapport aux méthodes scalables existantes, en particulier dans le cas où un tone mapping complexe est utilisé pour générer la version LDR. / In recent years, the display technologies have been rapidly evolving. From 3D television to Ultra High Definition, the trend is now towards High Dynamic Range (HDR) displays that can reproduce a luminance range far beyond the capabilities of conventional displays. The emergence of this technology involves new standardization effort in the field of video compression. In terms of large scale content distribution, the question of backward compatibility is critical. While the future generation of television displays will be adapted to this new format, it is necessary to enable the older equipment to decode and display a version of the same content whose dynamic range has been previously reduced by a process called “tone mapping”. This thesis aims at exploring the backward compatible HDR compression schemes. In a first approach, a tone mapping operator specified by the encoder is applied to the HDR image. The resulting image, called Low Dynamic Range (LDR), can then be encoded and decoded in a conventional format. The encoder additionally transmits a small amount of information enabling a HDR capable decoder to inverse the tone mapping operator and retrieve the HDR version. The study of these schemes is directed towards the definition of tone mapping operators optimized for the compression performance. We then focus on scalable approaches, where both versions are given to the encoder without prior knowledge on the tone mapping operator used. The producer thus keeps full control on the LDR content creation process. This LDR version is compressed as a first layer. The reconstructed image is used by the scalable encoder to compress the HDR layer efficiently by performing inter-layer predictions. Thanks to a local and non-linear approach, the proposed schemes improve the coding performance compared to the existing scalable methods, especially in the case where a complex tone mapping is used for generating the LDR version.
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Návrh magnetického obvodu rychlého magnetoreologického tlumiče bez použití feritů / The design of fast magnetorheological valves without the use of ferritesStrmiska, Tomáš January 2017 (has links)
This diploma thesis deals with development of a new generation of magnetic circuits of fast magnetoreological (MR) dampers that will not use problematic ferrite materials. To ensure a short response time, eddy currents must be avoided. Using the Finite Element Method, 2 solutions were proposed - the use of soft magnetic composites with high electrical resistance and the cutting of grooves in metallic material. Subsequently, 2 magnetic circuits were produced - one from Sintex SMC prototyping material composite and one from 11SMn30 steel with 48 deep grooves 0,35 mm wide. Both were implemented into the MR damper and tested on a hydraulic pulsator. The results of the experiments were compared with 2 different MR dampers: one with 11SMn30 magnetic circuit without grooves and another with the Epcos N87 ferrite magnetic core. It has been found that both new circuits have ensured an equally short response of the damper force to the change of electric current like ferrite. At the same time, a much larger dynamic range was ensured. Compared to 11SMn30 without grooves, the new circuits provided approximately 7x faster response.
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Tone-mapping HDR obrazů / HDR Tone-MappingVančura, Jan January 2010 (has links)
This thesis concerns with the introduction to the problematics of images with high dynamic range (HDR) and possibilities of HDR images compression options for display on devices with a low dynamic range (LDR). In the introduction is described historical evolution of recording of reality. It is focusing towards point of view of physics, human visual perception and digital recording. There are described the ways of generating and holding of HDR images. The thesis is corncerned to the techniques of HDR compression, it means the tone-mapping. The different techniques of tone-mapping are explained and specific aproach is targeted to the gradient domain high dynamic range compresion.
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"Magic Lantern" videodekodér pro fotoaparát Canon 5D / Magic Lantern Video Decoder for Canon 5D CameraŠkvařilová, Radka January 2015 (has links)
Tato práce představuje návrh na vytvoření dekodéru pro video zaznamenané pomocí softwaru Magic Lantern, který může být nainstalován na Canon 5D. Toto video je význačné pro svoji velikost 14-bitů v raw formátu a proto může produkovat velmi kvalitní výstup. Práce má za cíl rozdělit video do jednotlivých snímků, ve vhodném formátu, který umí pracovat také s formáty obrazů s vysokým dynamickým rozsahem.
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Aplikace pro zpracování a vyhodnocení náměrů z optického reflektometru / GUI for the processing of measurements from the optical reflectometerVitek, Vojtech January 2017 (has links)
This diploma thesis is focused on realisation of the application, that process and display measured data from OTDR device. The first section describes optical fibers, transmission characteristics of fibers and measurement methods of the attenuation on optical path. The second section describes the principle of the OTDR method and measured events on optical path. Final part is dedicated to realisation of the appication by the assignment.
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Computer vision at low lightAbhiram Gnanasambandam (12863432) 14 June 2022 (has links)
<p>Imaging in low light is difficult because the number of photons arriving at the image sensor is low. This is a major technological challenge for applications such as surveillance and autonomous driving. Conventional CMOS image sensors (CIS) circumvent this issue by using techniques such as burst photography. However, this process is slow and it does not solve the underlying problem that the CIS cannot efficiently capture the signals arriving at the sensors. This dissertation focuses on solving this problem using a combination of better image sensors (Quanta Image Sensors) and computational imaging techniques.</p>
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<p>The first part of the thesis involves understanding how the quanta image sensors work and how they can be used to solve the low light imaging problem. The second part is about the algorithms that can deal with images obtained in low light. The contributions in this part include – 1. Understanding and proposing solutions for the Poisson noise model, 2. Proposing a new machine learning scheme called student-teacher learning for helping neural networks deal with noise, and 3. Developing solutions that work not only for low light but also for a wide range of signal and noise levels. Using the ideas, we can solve a variety of applications in low light, such as color imaging, dynamic scene reconstruction, deblurring, and object detection.</p>
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Uživatelské rozhraní systému pro práci s HDR obrazem / User Interface for HDR Tone Mapping SystemJedlička, Jan January 2021 (has links)
The goal of this thesis is to improve graphical user interface of Tone Mapping Studio(TMS) program. This program is being developed on the Faculty of Information Technology(FIT), Brno University of Technology (BUT) by doc. Ing. Martin Čadík, PhD. The current program is using framework Qt3 , which is old and not compatible with modern libraries. This program has to be rewritten to support current version Qt5. I will analyze other programs in the area of working with High Dynamic Range (HDR) images and video. Changes for improving the interface will be proposed and UX tests will be done. Second part will consist of comparing plug-ins for converting images to grayscale that already exists in TMS.
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