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Cheung, Tsz Lock Vien. "Approaches to colour camera characterization." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414540.
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Leung, Tin Wah William. "High precision camera-based colour inspection of industrial products." Thesis, University of Huddersfield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338605.
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Gil, Rodríguez Raquel. "Digital camera colour processing pipeline for high dynamic range imaging and colour stabilisation for cinema." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/664378.
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In this thesis we focus on two different image processing challenges: high dynamic range (HDR) image/video generation, and colour matching. In both cases, we redefine these tasks by taking into account the prior knowledge from the different processes the camera performs when capturing the image. High dynamic range techniques have recently become very popular, thanks to the emergence of HDR recording and displaying technology. We propose two different approaches for HDR creation, one for still images, and one for video creation. In case of still images, most of previous methods follow a multiple exposure combination approach. These methods share a set of building assump-tions: i) the full dynamic range of the scene can be recovered, ii) colour channels are independent, and iii) the camera response function remains constant while varying the exposure time. First, we highlight how these assumptions do not apply in general for digital cameras, and then, we propose a method to im-prove multiple exposure combination. Our results outperform state-of-the-art multiple exposure techniques.In case of HDR video, we present a simple and affordable method to gen-erate high quality video from an HDR scene. Our input is an interlaced video alternating row pairs with different ISO values, as some DSLR camera models can provide. The proposed algorithm involves two main steps: i) the compu-tation of two single-ISO full-frame images (one for each ISO value) using an inpainting-based deinterlacing method, and ii) the linear combination of the full-frame ISO’s into a single HDR frame. Finally, the results are tone-mapped into an LDR frame ready for display. Results are free of ghosting artefacts and present little noise.Colour matching approaches attempt to transfer the colours of a reference image, to another source image. In this context, we focus on colour matching two images taken from the same scene. First, we propose a method that mod-ifies logarithmic encoded images, used in cinema for HDR content, in order to behave as gamma encoded images, used in most digital cameras. Then, we ex-tend a previous approach defined just for gamma encoded images. We redefine the transformation between the two images, by considering a projective trans-form, and we estimate the method parameters in a single optimisation step. The method outperforms the state-of-the-art methods and can handle real-life examples.En aquesta tesi ens centrem en dos problemes de processament d’imatges diferents: generació d’imatge/vídeo d’alt rang dinàmic (HDR) i coloració. En tots dos casos, redefinim aquestes tasques tenint en compte el coneixement previ dels diferents processos que realitza la càmera en capturar la imatge. Actualment, les tèniques d’alt rang dinàmic s’han tornat molt populars, gràcies a l’aparició de la tecnologia per capturar i visualitzar HDR. Proposem dos enfocaments diferents per a la creació d’HDR, un per a imatges i un altre per a la creació de video. En el cas d’imatges, la majoria de mètodes combinen múltiples exposicions. Aquests mètodes comparteixen un conjunt d’hipòtesis: i) la recuperació del rang dinàmic complet de l’escena, ii) els canals de color són independents, i iii) la funció de resposta de la càmera es manté constant mentre es varia el temps d’exposició. En primer lloc, destaquem com aquestes suposicions no s’apliquen, en general, a les càmeres digitals, i després proposem un mètode per millorar aquesta tècnica. Els nostres resultats superen l’estat de l’art. En el cas de vídeo HDR, presentem un mètode senzill i assequible per generar vídeos d’alta qualitat d’una escena HDR. El nostre input és un vídeo entrellaçat alternant parells de fileres amb diferents valors d’ISO, com alguns models de càmeres DSLR poden proporcionar. L’algorisme inclou dos passos principals: i) el càlcul de dues imatges full-frame ISO (una per a cada valor d’ISO) utilizant un mètode de desentrella¸cat basat en inpainting, ii) la combinació lineal dels ISOs full-frame en un HDR únic. Finalment, els resultats es mapegen tonalment per obtenir un LDR per mostrar per pantalla. Els resultats no tenen artefactes de ghosting i presenten poc soroll. Els mètodes d’igualació de colors intenten transferir els colors d’una imatge de referència, a una altra imatge d’origen. En aquest context, ens centrem en el cas de dues imatges capturades a la mateixa escena. En primer lloc, proposem un mètode que modifica imatges codificades logarítmicament, utilitzades en el cinema per a continguts HDR, per tal de comportar-se com imatges gamma codificades, que s’utilitzen en la majoria de les càmeres digitals. A continuació, extenem un mètode definit prèviament només per imatges gamma codificades, redefinint la transformació entre les dues imatges, considerant una transformació projectiva i estimant els paràmetres del mètode en un únic pas d’optimització. El mètode supera l’estat de l’art i pot tractar exemples de la vida real.
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Ismail, S. J. "Computing techniques and models for colour correction systems." Thesis, University of Bradford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381027.
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Sandberg, David. "Model-Based Video Coding Using a Colour and Depth Camera." Thesis, Linköpings universitet, Datorseende, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68737.
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In this master thesis, a model-based video coding algorithm has been developed that uses input from a colour and depth camera, such as the Microsoft Kinect. Using a model-based representation of a video has several advantages over the commonly used block-based approach, used by the H.264 standard. For example, videos can be rendered in 3D, be viewed from alternative views, and have objects inserted into them for augmented reality and user interaction. This master thesis demonstrates a very efficient way of encoding the geometry of a scene. The results of the proposed algorithm show that it can reach very low bitrates with comparable results to the H.264 standard.I detta examensarbete har en modellbaserad videokodningsalgoritm utvecklats som använder data från en djup- och färgkamera, exempelvis Microsoft Kinect. Det finns flera fördelar med en modellbaserad representation av en video över den mer vanligt förekommande blockbaserade varianten, vilket används av bland annat H.264. Några exempel är möjligheten att rendera videon i 3D samt från alternativa vyer, placera in objekt i videon samt möjlighet för användaren att interagera med scenen. Detta examensarbete påvisar en väldigt effektiv metod för komprimering av scengeometri. Resultaten av den presenterade algoritmen visar att möjligheten att uppnå väldigt låg bithastighet med jämförelsebara resultat med H.264-standarden.
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Martinkauppi, B. (Birgitta). "Face colour under varying illumination - analysis and applications." Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514267885.
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The colours of objects perceived by a colour camera are dependent on the illumination conditions. For example, when the prevailing illumination condition does not correspond to the one used in the white balancing of the camera, the object colours can change their appearance due to the lack of colour constancy capabilities. Many methods for colour constancy have been suggested but so far their performance has been inadequate. Faces are common and important objects encountered in many applications. Therefore, this thesis is dedicated to studying face colours and their robust use under real world illumination conditions. The main thesis statement is "knowledge about an object's colour, like skin colour changes under different illumination conditions, can be used to develop more robust techniques against illumination changes".
Many face databases exist, and in some cases they contain colour images and even videos. However, from the point of view of this thesis these databases have several limitations: unavailability of spectral data related to image acquisition, undefined illumination conditions of the acquisition, and if illumination change is present it often means only change in illumination direction. To overcome these limitations, two databases, a Physics-Based Face Database and a Face Video Database were created. In addition to the images, the Physics-Based Face Database consists of spectral data part including skin reflectances, channel responsivities of the camera and spectral power distribution of the illumination. The images of faces are taken under four known light sources with different white balancing illumination conditions for over 100 persons. In addition to videos, the Face Video Database has spectral reflectances of skin for selected persons and images taken with the same measurement arrangement as in the Physics-Based Face Database. The images and videos are taken with several cameras.
The databases were used to gather information about skin chromaticities and to provide test material. The skin RGB from images were converted to different colour spaces and the result showed that the normalized colour coordinate was among the most usable colour spaces for skin chromaticity modelling. None of the colour spaces could eliminate the colour shifts in chromaticity. The obtained chromaticity constraint can be implemented as an adaptive skin colour modelling part of face tracking algorithms, like histogram backprojection or mean shift. The performances of these adaptive algorithms were superior compared to those using a fixed skin colour model or model adaptation based on spatial pixel selection. Of course, there are cases when the colour cue is not enough alone and use of other cues like motion or edge data would improve the result. It was also demonstrated that the skin colour model can be used to segment faces and the segmentation results depend on the background due to the method used. Also an application for colour correction using principal component analysis and a simplified dichromatic reflection model was shown to improve colour quality of seriously clipped images. The results of tracking, segmentation and colour correction experiments using the collected data validate the thesis statement.
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Bergman, Lars. "Using Multicoloured Halftone Screens for Offset Print Quality Monitoring." Licentiate thesis, Linköping : Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5573.
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Luwes, N. J. "A technique for tracking an indoor unmanned aerial or automated guided vehicle using a stationary camera and hue colour characteristics." Interim : Interdisciplinary Journal: Vol 9, Issue 2: Central University of Technology Free State Bloemfontein, 2010. http://hdl.handle.net/11462/355.
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Published ArticleToday's industries are based on an automated workplace. These automated workplaces are efficient, reconfigurable and intelligent automated environments. They are filled with technology, robotics, Automated Guided Vehicle (AGV) and, or Unmanned Aerial Vehicles (UAV) etc. For full automation will one need to effectively track an object, unmanned aerial vehicle (UAV) or automated guided vehicle (AGV). Effective tracking of vehicles can be used for control. This could result in less hardware on the craft that leads to a longer battery life, a bigger pay load or more processing power. This system track by using a stationary colour camera placed at an optimal placing in the automated workplace. The vehicle or objects are painted in two colours (colour A and colour B) that are not present in the automated workplace. The images from the camera are hue colour filtered to extract only the object or vehicle. The area, placement in frame and relationship between colour A and B are used for position and determine the orientation of AGV, UAV or object.
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Mohammed, Abdulmalik. "Obstacle detection and emergency exit sign recognition for autonomous navigation using camera phone." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/obstacle-detection-and-emergency-exit-sign-recognition-for-autonomous-navigation-using-camera-phone(e0224d89-e743-47a4-8c68-52f718457098).html.
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In this research work, we develop an obstacle detection and emergency exit sign recognition system on a mobile phone by extending the feature from accelerated segment test detector with Harris corner filter. The first step often required for many vision based applications is the detection of objects of interest in an image. Hence, in this research work, we introduce emergency exit sign detection method using colour histogram. The hue and saturation component of an HSV colour model are processed into features to build a 2D colour histogram. We backproject a 2D colour histogram to detect emergency exit sign from a captured image as the first task required before performing emergency exit sign recognition. The result of classification shows that the 2D histogram is fast and can discriminate between objects and background with accuracy. One of the challenges confronting object recognition methods is the type of image feature to compute. In this work therefore, we present two feature detectors and descriptor methods based on the feature from accelerated segment test detector with Harris corner filter. The first method is called Upright FAST-Harris and binary detector (U-FaHB), while the second method Scale Interpolated FAST-Harris and Binary (SIFaHB). In both methods, feature points are extracted using the accelerated segment test detectors and Harris filter to return the strongest corner points as features. However, in the case of SIFaHB, the extraction of feature points is done across the image plane and along the scale-space. The modular design of these detectors allows for the integration of descriptors of any kind. Therefore, we combine these detectors with binary test descriptor like BRIEF to compute feature regions. These detectors and the combined descriptor are evaluated using different images observed under various geometric and photometric transformations and the performance is compared with other detectors and descriptors. The results obtained show that our proposed feature detector and descriptor method is fast and performs better compared with other methods like SIFT, SURF, ORB, BRISK, CenSurE. Based on the potential of U-FaHB detector and descriptor, we extended it for use in optical flow computation, which we termed the Nearest-flow method. This method has the potential of computing flow vectors for use in obstacle detection. Just like any other new methods, we evaluated the Nearest flow method using real and synthetic image sequences. We compare the performance of the Nearest-flow with other methods like the Lucas and Kanade, Farneback and SIFT-flow. The results obtained show that our Nearest-flow method is faster to compute and performs better on real scene images compared with the other methods. In the final part of this research, we demonstrate the application potential of our proposed methods by developing an obstacle detection and exit sign recognition system on a camera phone and the result obtained shows that the methods have the potential to solve this vision based object detection and recognition problem.
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Vlček, Pavel. "Analýza schopnosti jasového analyzátoru LDA - LumiDISP měřit náhradní teplotu chromatičnosti." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442553.
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This master's thesis deals with the search of commercially available luminance analysers and cameras that use the measurement of correlated colour temperature. It also deals with calculations of correlated colour temperature according to various available methods. The luminance analyser LDA-LumiDISP is based on a DSLR camera. The principle of its operation and possible errors in capturing pictures are discussed here. The work deals with extensive testing of the LDA-LumiDISP luminance analyser, which is primarily intended for measuring luminance in the set scene, but can also be used to measure the correlated colour temperature. The device is being tested in terms of measuring the correlated colour temperature in laboratory and field conditions. The result of the master's thesis is the calculation of measurements uncertainty for certain light sources and the optimization of the measuring algorithm to reduce them.
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Buchriegler, Josef [Verfasser], Jürgen [Gutachter] Faßbender, and Matjaz [Gutachter] Kavcic. "Full-field PIXE imaging using a Colour X-ray Camera : Advantages and drawbacks in elemental mapping of large areas with a poly-capillary optics / Josef Buchriegler ; Gutachter: Jürgen Faßbender, Matjaz Kavcic." Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1235346390/34.
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Blanksby, Andrew J. "Colour cameras in standard CMOS /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phb6419.pdf.
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Bodén, Rikard, and Jonathan Pernow. "SORTED : Serial manipulator with Object Recognition Trough Edge Detection." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264513.
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Today, there is an increasing demand for smart robots that can make decisions on their own and cooperate with humans in changing environments. The application areas for robotic arms with camera vision are likely to increase in the future of artificial intelligence as algorithms become more adaptable and intelligent than ever. The purpose of this bachelor’s thesis is to develop a robotic arm that recognises arbitrarily placed objects with camera vision and has the ability to pick and place the objects when they appear in unpredictable positions. The robotic arm has three degrees of freedom and the construction is modularised and 3D-printed with respect to maintenance, but also in order to be adaptive to new applications. The camera vision sensor is integrated in an external camera tripod with its field of view over the workspace. The camera vision sensor recognises objects through colour filtering and it uses an edge detection algorithm to return measurements of detected objects. The measurements are then used as input for the inverse kinematics, that calculates the rotation of each stepper motor. Moreover, there are three different angular potentiometers integrated in each axis to regulate the rotation by each stepper motor. The results in this thesis show that the robotic arm is able to pick up to 90% of the detected objects when using barrel distortion correction in the algorithm. The findings in this thesis is that barrel distortion, that comes with the camera lens, significantly impacts the precision of the robotic arm and thus the results. It can also be stated that the method for barrel distortion correction is affected by the geometry of detected objects and differences in illumination over the workspace. Another conclusion is that correct illumination is needed in order for the vision sensor to differentiate objects with different hue and saturation.Idag ökar efterfrågan på smarta robotar som kan ta egna beslut och samarbeta med människor i föränderliga miljöer. Tillämpningsområdena för robotar med kamerasensorer kommer sannolikt att öka i en framtid av artificiell intelligens med algoritmer som blir mer intelligenta och anpassningsbara än tidigare. Syftet med detta kandidatexamensarbete är att utveckla en robotarm som, med hjälp av en kamerasensor, kan ta upp och sortera godtyckliga objekt när de uppträder på oförutsägbara positioner. Robotarmen har tre frihetsgrader och hela konstruktionen är 3D-printad och modulariserad för att vara underhållsvänlig, men också anpassningsbar för nya tillämpningsområden. Kamerasensorn ¨ar integrerad i ett externt kamerastativ med sitt synfält över robotarmens arbetsyta. Kamerasensorn detekterar objekt med hjälp av en färgfiltreringsalgoritm och returnerar sedan storlek, position och signatur för objekten med hjälp av en kantdetekteringsalgoritm. Objektens storlek används för att kalibrera kameran och kompensera för den radiella förvrängningen hos linsen. Objektens relativa position används sedan till invers kinematik för att räkna ut hur mycket varje stegmotor ska rotera för att erhålla den önskade vinkeln på varje axel som gör att gripdonet kan nå det detekterade objektet. Robotarmen har även tre olika potentiometrar integrerade i varje axel för att reglera rotationen av varje stegmotor. Resultaten i denna rapport visar att robotarmen kan detektera och plocka upp till 90% av objekten när kamerakalibrering används i algoritmen. Slutsatsen från rapporten är att förvrängningen från kameralinsen har störst påverkan på robotarmens precision och därmed resultatet. Det går även att konstatera att metoden som används för att korrigera kameraförvrängningen påverkas av geometrin samt orienteringen av objekten som ska detekteras, men framför allt variationer i belysning och skuggor över arbetsytan. En annan slutsats är att belysningen över arbetsytan är helt avgörande för om kamerasensorn ska kunna särskilja objekt med olika färgmättad och nyans.
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Hammarlund, Emil. "Target-less and targeted multi-camera color calibration." Thesis, Mittuniversitetet, Avdelningen för informationssystem och -teknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-33876.
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Multiple camera arrays are beginning to see more widespread use in a variety of different applications, be it for research purposes or for enhancing the view- ing experience in entertainment. However, when using multiple cameras the images produced are often not color consistent due to a variety of different rea- sons such as differences in lighting, chip-level differences e.t.c. To address this there exists a multitude of different color calibration algorithms. This paper ex- amines two different color calibration algorithms one targeted and one target- less. Both methods were implemented in Python using the libraries OpenCV, Matplotlib, and NumPy. Once the algorithms had been implemented, they were evaluated based on two metrics; color range homogeneity and color ac- curacy to target values. The targeted color calibration algorithm was more ef- fective improving the color accuracy to ground truth then the target-less color calibration algorithm, but the target-less algorithm deteriorated the color range homogeneity less than the targeted color calibration algorithm. After both methods where tested, an improvement of the targeted color calibration al- gorithm was attempted. The resulting images were then evaluated based on the same two criteria as before, the modified version of the targeted color cal- ibration algorithm performed better than the original targeted algorithm with respect to color range homogeneity while still maintaining a similar level of performance with respect to color accuracy to ground truth as before. Further- more, when the color range homogeneity of the modified targeted algorithm was compared with the color range homogeneity of the target-less algorithm. The performance of the modified targeted algorithm performed similarly to the target-less algorithm. Based on these results, it was concluded that the targeted color calibration was superior to the target-less algorithm.
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Sanders, Nathaniel. "A CAMERA-BASED ENERGY RELAXATION FRAMEWORK TO MINIMIZE COLOR ARTIFACTS IN A PROJECTED DISPLAY." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/431.
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We introduce a technique to automatically correct color inconsistencies in a display composed of one or more digital light projectors (DLP). The method is agnostic to the source of error and can detect and address color problems from a number of sources. Examples include inter- and intra-projector color differences, display surface markings, and environmental lighting differences on the display. In contrast to methods that discover and map all colors into the greatest common color space, we minimize local color discontinuities to create color seamlessness while remaining tolerant to significant color error. The technique makes use of a commodity camera and highdynamic range sensing to measure color gamuts at many different spatial locations. A differentiable energy function is defined that combines both a smoothness and data term. This energy function is globally minimized through the successive application of projective warps defined using gradient descent. After convergence the warps can be applied at runtime to minimize color defects in the display. The framework is demonstrated on displays that suffer from several sources of color error.
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Andersen, Casper Find. "New results in colour characterization of humans and cameras." Thesis, University of East Anglia, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533718.
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Richoz, Guillaume. "Simultaneous ESPI measurements using multiple wavelengths and a color camera." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50501.
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Electronic Speckle Pattern Interferometry (ESPI) is typically done using a single monochromatic light source with a monochrome camera. This arrangement enables full-field measurements of a single deformation quantity according to the particular arrangement of the optical system. If a further deformation quantity is to be measured, then the associated optical arrangement must be used sequentially. Here, an alternative approach is described where multiple interferometric measurements are simultaneously made using a color camera imaging monochromatic light sources of different wavelengths. The Red-Green-Blue (RGB) sensors of a conventional Bayer type camera can be read separately, thereby providing three independent color signals and independent ESPI phase maps. An example case is demonstrated here where two Michelson interferometers are combined to form a shearography camera with surface slope sensitivity in two perpendicular directions. By the use of two colors, both surface slopes can be measured simultaneously. ESPI is a relative measuring technique and the third available color is used for absolute phase determination through the Two-Wavelength Method. The availability of the two surface slopes gives the opportunity for the data to be summed numerically to give the surface displacement shape. This application is of significant practical interest because the surface displacement measurement can be made under field conditions by taking advantage of the well-known stability of shearography measurements.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Gubbels, Wade. "3-D Digital Image Correlation using a single color-camera." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50491.
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Digital Image Correlation (DIC) is an optical and numerical method capable of accurately providing full-field, two-dimensional (2-D) and three-dimensional (3-D) surface displacements and strains. 3-D DIC is typically done using two cameras that view the measured object from differing oblique directions. The measured images are independent and must be spatially connected using a detailed calibration procedure. This places a large demand on the practitioner, the optical equipment and the computational method. A novel approach is presented here where a single color-camera is used in place of multiple monochrome cameras. The color-camera measures three independent Red-Green-Blue (RGB) color-coded images. This feature greatly reduces the scale of the required system calibrations and spatial computations because the color images are physically aligned on the camera sensor. The in-plane surface displacements are obtained by performing traditional 2-D DIC in a single color. The out-of-plane information is obtained by a second 2-D DIC analysis and triangulation using oblique illumination from a differently colored light source. Further, the camera perspective errors associated with out-of-plane displacements can independently be measured during this second DIC analysis of the oblique illumination pattern. The 3-D Digital Image Correlation is completed by combining the 2-D correlations for each color. The design and creation of an example apparatus is described here. Experimental results show that the single-camera method can measure 3-D displacements with to within 1% error, with precision of the in-plane and out-of-plane measurements being consistently less than 0.04 and 0.12 pixels, respectively.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Komi, Pauli J. "Plant classification combining colour and spectral cameras for weed control purposes." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/4078.
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This study was conducted to design and evaluate a novel dual camera sensor for use in an accurate single leaf level plant detection and classification system for weed control purposes. The system was to utilise and combine the benefits of colour and spectral imaging technologies together with novel data processing techniques. Such combination of colour and spectral imaging devices has not been previously used in precision agriculture. Environmental consciousness and requirements for production volumes of organic produce are constantly increasing. Reductions or total elimination of chemical spraying is needed, and a technological solution of automating the weed control has been seen as one solution to solve the limitations in current crop production methods. Recent studies have shown automatic plant detection and classification to be the only economically viable solution for the problem of automatic weed control. Previous detection systems have shown adequate capabilities to detect and classify weeds and crop plants with certain limitations. Depending on the system, these limitations have been in spatial accuracy, operation in certain lighting conditions or selection of plants to be classified. A flexible system capable of robust plant classification under any circumstances and plant combinations has not yet been realised. It would be desirable to introduce a system capable of detecting any plant species and plants separately, thus allowing targeted and optimal weed control methods for each plant species. The proposed system addressed the problem of automatic plant detection and classification by providing sub-centimetre level information on plant part locations separately for each plant species. This information could then be directly used to guide mechanical weeding tools or precision sprayers. The detection system was based on a novel combination of a sub-millimetre level colour camera and an accurate hyperspectral line scanning camera (spectrometer) in the spectral range of 400 – 1000 nm. The spatial accuracy of the spectrometer was approximately five times lower than that of the colour camera. The system operated under controlled lighting conditions. The colour camera allowed precise segmentation of plant borders, while the spectral camera produced detailed reflectance information to discriminate between plant types. The system was able to collect data for classification from an area on a plant of approximately 6.5 mm by 6.5 mm, although typically areas as small as 3.5 mm by 3.5 mm were detected. These were also the spatial resolution boundaries of the system with the used test settings. The system was first designed and evaluated in laboratory conditions using controlled lighting and a selection of leaves from 6 plants. Data collection and analysis methods were designed for a scanning system with simultaneous image acquisition from both cameras. Shape, colour and spectral reflectance information were used to correctly classify these individual leaves with a probability of up to 98% using linear stepwise discriminant analysis. A method of classifying separate leaves is not robust in a real field environment where plant leaves are often overlapping. This makes the use of shape calculations difficult. A novel method of extracting data from the small windows was proposed. Colour and spectral data within these windows was classified separately and the windows formed a grid like structure with approximately 3.5 mm spacing between them. This allowed spatial filtering of the classification data and noise reduction for the results by utilising information in a 3 by 3 window neighbourhood around each data window. During laboratory tests the windows for 6 plant leaves were correctly classified at 97.8% when the leaves were separated, and at 85.2% with overlapping leaves. The system operation was also evaluated in real field conditions. Four crop plants and 16 weed plant types were imaged on a field over a period of 11 to 25 days after sowing. Total average classification performance in field conditions with linear discriminant analysis was up to 85.1%, while classification results investigated as a two-class case of crop vs. weed plants was up to 99.5% and 83.8%, respectively. The spatial filtering method was shown to improve results on average by 7.5%. Plant reflectance measurements on different days allowed a novel analysis of short term temporal changes in the plant spectra due to growing conditions and growth stages. Analysis on short term spectral changes and their effects on classification accuracies have not been found in the literature. The temporal analysis showed that the average spectra of any plant type changes considerably over a period of just few days, and has a trend like behaviour when investigated at individual wavelengths. Classification models with training set data from previous days did not perform well. This indicates the need to have an up to date training set available at all times explaining the subtleties in local conditions. The proposed detection and classification system with intelligent data processing methods has been shown to perform at a comparable level with previous systems. The novel system does not suffer from the typical limitations of previous systems, and is flexible to be used with any plant types in their early growth stages. There is also potential to include plant height, shape or any other relevant feature to the classification for increased robustness. The presented data processing method allows considerable processing and data reductions within the camera hardware. Only small fractions of the processed image data would need to be transferred via the camera interface. This would compensate for the increased data flow created by using two cameras. Therefore, the real-time implementation of the system is thought possible with the right hardware choices and optimised data processing algorithms.
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Hemphill, Brian D. "Light Emitting Diodes and a Monochrome Camera to Measure Chemical Optode Response." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354890395.
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Solli, Martin. "Filter characterization in digital cameras." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2667.
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The use of spectrophotometers for color measurements on printed substrates is widely spread among paper producers as well as within the printing industry. Spectrophotometer measurements are precise, but time-consuming procedures and faster methods are desirable. Previously presented work on color calibration of flatbed scanners has shown that they can be used for fast color measurements with acceptable results. Furthermore, the rapid development of digital cameras has made it possible to transfer the methods to a camera-based system, and in this work a moderately priced consumer digital camera is used for color measurements.
Earlier presented methods for color calibration have been implemented in the camera-based system and new modifications that can improve their performance are proposed. Moreover, if the spectral sensitivities of the color filters in the camera sensor can be characterized, this can further improve the performance of the color measurements. Two methods for characterization of the color filters are presented in this work together with methods that use the camera characteristics for color measurements.
The findings of this work show that a consumer digital camera can be used as a fast and inexpensive alternative to spectrophotometers for color measurements on printed substrates.
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Zhang, Chen. "Poisson Noise Parameter Estimation and Color Image Denoising for Real Camera Hardware." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1575968356242716.
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Chandrasekaran, Indumathi. "In vitro Accuracy of Colors of Dental Shades using Different Digital Camera Systems." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1525695073227671.
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Jeong, Kideog. "OBJECT MATCHING IN DISJOINT CAMERAS USING A COLOR TRANSFER APPROACH." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/434.
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Object appearance models are a consequence of illumination, viewing direction, camera intrinsics, and other conditions that are specific to a particular camera. As a result, a model acquired in one view is often inappropriate for use in other viewpoints. In this work we treat this appearance model distortion between two non-overlapping cameras as one in which some unknown color transfer function warps a known appearance model from one view to another. We demonstrate how to recover this function in the case where the distortion function is approximated as general affine and object appearance is represented as a mixture of Gaussians. Appearance models are brought into correspondence by searching for a bijection function that best minimizes an entropic metric for model dissimilarity. These correspondences lead to a solution for the transfer function that brings the parameters of the models into alignment in the UV chromaticity plane. Finally, a set of these transfer functions acquired from a collection of object pairs are generalized to a single camera-pair-specific transfer function via robust fitting. We demonstrate the method in the context of a video surveillance network and show that recognition of subjects in disjoint views can be significantly improved using the new color transfer approach.
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Zins, Matthieu. "Color Fusion and Super-Resolution for Time-of-Flight Cameras." Thesis, Linköpings universitet, Datorseende, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141956.
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The recent emergence of time-of-flight cameras has opened up new possibilities in the world of computer vision. These compact sensors, capable of recording the depth of a scene in real-time, are very advantageous in many applications, such as scene or object reconstruction. This thesis first addresses the problem of fusing depth data with color images. A complete process to combine a time-of-flight camera with a color camera is described and its accuracy is evaluated. The results show that a satisfying precision is reached and that the step of calibration is very important. The second part of the work consists of applying super-resolution techniques to the time-of-flight camera in order to improve its low resolution. Different types of super-resolution algorithms exist but this thesis focuses on the combination of multiple shifted depth maps. The proposed framework is made of two steps: registration and reconstruction. Different methods for each step are tested and compared according to the improvements reached in term of level of details, sharpness and noise reduction. The results obtained show that Lucas-Kanade performs the best for the registration and that a non-uniform interpolation gives the best results in term of reconstruction. Finally, a few suggestions are made about future work and extensions for our solutions.
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Rasmussen, Nathan D. "Combined Visible and Infrared Video for Use in Wilderness Search and Rescue." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd2854.pdf.
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Honda, Kristl J. "Using color management to automate the color reproduction of 3-D images procured via a digital camera/3-D scanner /." Online version of thesis, 1995. http://hdl.handle.net/1850/12249.
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Setkov, Aleksandr. "IVORA (Image and Computer Vision for Augmented Reality) : Color invariance and correspondences for the definition of a camera/video-projector system." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS168/document.
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La Réalité Augmentée Spatiale (SAR) vise à superposer spatialement l'information virtuelle sur des objets physiques. Au cours des dernières décennies ce domaine a connu une grande expansion et est utilisé dans divers domaines, tels que la médecine, le prototypage, le divertissement etc. Cependant, pour obtenir des projections de bonne qualité, on doit résoudre plusieurs problèmes, dont les plus importants sont la gamme de couleurs réduite du projecteur, la lumière ambiante, la couleur du fond, et la configuration arbitraire de la surface de projection dans la scène. Ces facteurs entraînent des distorsions dans les images qui requièrent des processus de compensation complémentaires.Les projections intelligentes (smart projections) sont au cœur des applications de SAR. Composées d'un dispositif de projection et d'un dispositif d'acquisition, elles contrôlent l'aspect de la projection et effectuent des corrections à la volée pour compenser les distorsions. Bien que les méthodes actives de Lumière Structurée aient été utilisées classiquement pour résoudre ces problèmes de compensation géométrique, cette thèse propose une nouvelle approche non intrusive pour la compensation géométrique de plusieurs surfaces planes et pour la reconnaissance des objets en SAR s'appuyant uniquement sur la capture du contenu projeté.Premièrement, cette thèse étude l'usage de l'invariance couleur pour améliorer la qualité de la mise en correspondance entre primitives dans une configuration d'acquisition des images vidéoprojetées. Nous comparons la performance de la plupart des méthodes de l'état de l'art avec celle du descripteur proposé basé sur l'égalisation d'histogramme. Deuxièmement, pour mieux traiter les conditions standard des systèmes projecteur-caméra, deux ensembles de données de captures de projections réelles, ont été spécialement préparés à des fins expérimentales. La performance de tous les algorithmes considérés est analysée de façon approfondie et des propositions de recommandations sont faites sur le choix des algorithmes les mieux adaptés en fonction des conditions expérimentales (paramètres image, disposition spatiale, couleur du fond...). Troisièmement, nous considérons le problème d'ajustement multi-surface pour compenser des distorsions d'homographie dans les images acquises. Une combinaison de mise en correspondance entre les primitives et de Flux Optique est proposée afin d'obtenir une compensation géométrique plus rapide. Quatrièmement, une nouvelle application en reconnaissance d'objet à partir de captures d'images vidéo-projetées est mise en œuvre. Finalement, une implémentation GPU temps réel des algorithmes considérés ouvre des pistes pour la compensation géométrique non intrusive en SAR basée sur la mise en correspondances entre primitivesSpatial Augmented Reality (SAR) aims at spatially superposing virtual information on real-world objects. Over the last decades, it has gained a lot of success and been used in manifold applications in various domains, such as medicine, prototyping, entertainment etc. However, to obtain projections of a good quality one has to deal with multiple problems, among them the most important are the limited projector output gamut, ambient illumination, color background, and arbitrary geometric surface configurations of the projection scene. These factors result in image distortions which require additional compensation steps.Smart-projections are at the core of PAR applications. Equipped with a projection and acquisitions devices, they control the projection appearance and introduce corrections on the fly to compensate distortions. Although active structured-light techniques have been so far the de-facto method to address such problems, this PhD thesis addresses a relatively new unintrusive content-based approach for geometric compensation of multiple planar surfaces and for object recognition in SAR.Firstly, this thesis investigates the use of color-invariance for feature matching quality enhancement in projection-acquisition scenarios. The performance of most state-of-the art methods are studied along with the proposed local histogram equalization-based descriptor. Secondly, to better address the typical conditions encountered when using a projector-camera system, two datasets of real-world projections were specially prepared for experimental purposes. Through a series of evaluation frameworks, the performance of all considered algorithms is thoroughly analyzed, providing several inferences on that which algorithms are more appropriate in each condition. Thirdly, this PhD work addresses the problem of multiple-surface fitting used to compensate different homography distortions in acquired images. A combination of feature matching and Optical Flow tracking is proposed in order to achieve a more low-weight geometric compensation. Fourthly, an example of new application to object recognition from acquired projections is showed. Finally, a real-time implementation of considered methods on GPU shows prospects for the unintrusive feature matching-based geometric compensation in SAR applications
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Appia, Vikram V. "A color filter array interpolation method for digital cameras using alias cancellation." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22542.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Russell Mersereau; Committee Member: Anthony J. Yezzi; Committee Member: Yucel Altunbasak.
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Ylimäki, M. (Markus). "Methods for image-based 3-D modeling using color and depth cameras." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526217352.
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Abstract This work addresses the problems related to three-dimensional modeling of scenes and objects and model evaluation. The work is divided into four main parts. At first, the work concentrates on purely image-based reconstruction while the second part presents a modeling pipeline based on an active depth sensor. Then, the work introduces methods for producing surface meshes from point clouds, and finally, a novel approach for model evaluation is presented. In the first part, this work proposes a multi-view stereo (MVS) reconstruction method that takes a set of images as an input and outputs a model represented as a point cloud. The method is based on match propagation, where a set of initial corresponding points between images is expanded iteratively into larger regions by searching new correspondences in the spatial neighborhood of the existing ones. The expansion is implemented using a best-first strategy, where the most reliable match is always expanded first. The method produces comparable results with the state-of-the-art but significantly faster. In the second part, this work presents a method that merges a sequence of depth maps into a single non-redundant point cloud. In the areas, where the depth maps overlap, the method fuses points together by giving more weight to points which seem to be more reliable. The method overcomes its predecessor both in accuracy and robustness. In addition, this part introduces a method for depth camera calibration. The method develops on an existing calibration approach which was originally designed for the first generation Microsoft Kinect device. The third part of the thesis addresses the problem of converting the point clouds to surface meshes. The work briefly reviews two well-known approaches and compares their ability to produce sparse mesh models without sacrificing accuracy. Finally, the fourth part of this work describes the development of a novel approach for performance evaluation of reconstruction algorithms. In addition to the accuracy and completeness, which are the metrics commonly used in existing evaluation benchmarks, the method also takes the compactness of the models into account. The metric enables the evaluation of the accuracy-compactness trade-off of the modelsTiivistelmä Tässä työssä käsitellään näkymän tai esineen kolmiulotteista mallintamista ja tulosten laadun arviointia. Työ on jaettu neljään osaan. Ensiksi keskitytään pelkästään valokuvia hyödyntävään mallinnukseen ja sitten esitellään menetelmä syvyyskamerapohjaiseen mallinnukseen. Kolmas osa kuvaa menetelmiä verkkomallien luomiseen pistepilvestä ja lopuksi esitellään menetelmä mallien laadun arviointiin. Ensimmäisessä osassa esitellään usean kuvan stereoon perustuva mallinnusmenetelmä, joka saa syötteenä joukon valokuvia ja tuottaa kuvissa näkyvästä kohteesta pistepilvimallin. Menetelmä perustuu vastinpisteiden laajennukseen, jossa kuvien välisiä pistevastaavuuksia laajennetaan iteratiivisesti suuremmiksi vastinalueiksi hakemalla uusia vastinpistepareja jo löydettyjen läheisyydestä. Laajennus käyttää paras ensin -menetelmää, jossa luotettavin pistevastaavuus laajennetaan aina ensin. Menetelmä tuottaa vertailukelpoisia tuloksia johtaviin menetelmiin verrattuna, mutta merkittävästi nopeammin. Toisessa osassa esitellään menetelmä, joka yhdistää joukon syvyyskameralla kaapattuja syvyyskarttoja yhdeksi pistepilveksi. Alueilla, jotka sisältävät syvyysmittauksia useasta syvyyskartasta, päällekkäiset mittaukset yhdistetään painottamalla luotettavammalta vaikuttavaa mittausta. Menetelmä on tarkempi kuin edeltäjänsä ja toimii paremmin kohinaisemmalla datalla. Lisäksi tässä osassa esitellään menetelmä syvyyskameran kalibrointiin. Menetelmä kehittää jo olemassa olevaa kalibrointityökalua, joka alun perin kehitettiin ensimmäisen sukupolven Microsoft Kinect laitteelle. Väitöskirjan kolmas osa käsittelee pintamallin luomista pistepilvestä. Työ esittelee kaksi hyvin tunnettua menetelmää ja vertailee niiden kykyä luoda harvoja, mutta edelleen tarkkoja malleja. Lopuksi esitellään uudenlainen menetelmä mallinnusmenetelmien arviointiin. Tarkkuuden ja kattavuuden lisäksi, jotka ovat yleisimmät arvioinnissa käytetyt metriikat, menetelmä ottaa huomioon myös mallin pistetiheyden. Metriikan avulla on mahdollista arvioida kompromissia mallin tarkkuuden ja tiheyden välillä
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Sun, Kaipeng Verfasser], Klaus [Gutachter] [Schilling, and Hubert [Gutachter] Roth. "Six Degrees of Freedom Object Pose Estimation with Fusion Data from a Time-of-flight Camera and a Color Camera / Kaipeng Sun. Gutachter: Klaus Schilling ; Hubert Roth." Würzburg : Universität Würzburg, 2014. http://d-nb.info/1111783292/34.
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Sun, Kaipeng [Verfasser], Klaus [Gutachter] Schilling, and Hubert [Gutachter] Roth. "Six Degrees of Freedom Object Pose Estimation with Fusion Data from a Time-of-flight Camera and a Color Camera / Kaipeng Sun. Gutachter: Klaus Schilling ; Hubert Roth." Würzburg : Universität Würzburg, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-105089.
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Müller, Franziska [Verfasser]. "Real-time 3D hand reconstruction in challenging scenes from a single color or depth camera / Franziska Müller." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1224883594/34.
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Hamid, Muhammed Hamed. "Hyperspectral Image Generation, Processing and Analysis." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5905.
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Wang, Chong, and 王翀. "Joint color-depth restoration with kinect depth camera and its applications to image-based rendering and hand gesture recognition." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206343.
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Adeeb, Karam, and Adam Alveteg. "SIYA - Slide Into Your Albums : Design and construction of a controllable dolly camera with object recognition." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264450.
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The scope of this project is to design, construct and build an automated camera rig with object recognition. The project explores if there are any advantages with an automated camera rig compared to a manual one, how an external camera module can be implemented to track an object and under what circumstances the camera module can register the objects for optimal performance. The construction is built to travel along a rail of two iron pipes. A camera is mounted on a small wagon that travels on top of the rail with the help of a DC-motor. On the wagon, an external camera module called Pixy2 detects a predetermined object that the user wants the main camera to detect and focus on. Using the feedback data from the Pixy2, two stepper motors run to rotate the main camera horizontally and vertically so that the object is placed in the middle of the frame while the wagon travels along the rail.Syftet med detta projekt är att konstruera och bygga en automatiserad kamerarigg med objektigenkänning. Projektet undersöker om det finns några fördelar med en automatiserad kamerarigg gentemot en manuell, hur en extern kameramodul implementeras för att kamerariggen ska kunna följa ett objekt och under vilka förhållanden kameramodulen registrerar objekten bäst. Kamerariggen är byggd för att åka längsmed en räls som består av två järnrör. En filmkamera är monterad på en vagn som rullar ovanpå denna räls och drivs med hjälp av en DC-motor. Ovanpå vagnen ska en extern kameramodul vid namn Pixy2 upptäcka ett förbestämt objekt som användaren vill att filmkameran ska fokusera på. Med hjälp av återkoppling av datan som Pixy2 registrerar styrs två stycken stegmotorer som antingen roterar filmkameran horisontellt i x-led eller vertikalt i y-led tills objektet är placerat i mitten av Pixy2’s synfält. På detta sätt kommer konstruktionen att fokusera på objektet samtidigt som den rör sig i sidled på rälsen.
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Harouna, Seybou Aboubacar. "Analyse d'images couleurs pour le contrôle qualité non destructif." Thesis, Poitiers, 2016. http://www.theses.fr/2016POIT2282/document.
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La couleur est un critère important dans de nombreux secteurs d'activité pour identifier, comparer ou encore contrôler la qualité de produits. Cette tâche est souvent assumée par un opérateur humain qui effectue un contrôle visuel. Malheureusement la subjectivité de celui-ci rend ces contrôles peu fiables ou répétables. Pour contourner ces limitations, l'utilisation d'une caméra RGB permet d'acquérir et d'extraire des propriétés photométriques. Cette solution est facile à mettre en place et offre une rapidité de contrôle. Cependant, elle est sensible au phénomène de métamérisme. La mesure de réflectance spectrale est alors la solution la plus appropriée pour s'assurer de la conformité colorimétrique entre des échantillons et une référence. Ainsi dans l'imprimerie, des spectrophotomètres sont utilisés pour mesurer des patchs uniformes imprimés sur une bande latérale. Pour contrôler l'ensemble d'une surface imprimée, des caméras multi-spectrales sont utilisées pour estimer la réflectance de chaque pixel. Cependant, elles sont couteuses comparées aux caméras conventionnelles. Dans ces travaux de recherche, nous étudions l'utilisation d'une caméra RGB pour l'estimation de la réflectance dans le cadre de l'imprimerie. Nous proposons une description spectrale complète de la chaîne de reproduction pour réduire le nombre de mesures dans les phases d'apprentissage et pour compenser les limitations de l'acquisition. Notre première contribution concerne la prise en compte des limitations colorimétriques lors de la caractérisation spectrale d'une caméra. La deuxième contribution est l'exploitation du modèle spectrale de l'imprimante dans les méthodes d'estimation de réflectanceColor is a major criterion for many sectors to identify, to compare or simply to control the quality of products. This task is generally assumed by a human operator who performs a visual inspection. Unfortunately, this method is unreliable and not repeatable due to the subjectivity of the operator. To avoid these limitations, a RGB camera can be used to capture and extract the photometric properties. This method is simple to deploy and permits a high speed control. However, it's very sensitive to the metamerism effects. Therefore, the reflectance measurement is the more reliable solution to ensure the conformity between samples and a reference. Thus in printing industry, spectrophotometers are used to measure uniform color patches printed on a lateral band. For a control of the entire printed surface, multispectral cameras are used to estimate the reflectance of each pixel. However, they are very expensive compared to conventional cameras. In this thesis, we study the use of an RGB camera for the spectral reflectance estimation in the context of printing. We propose a complete spectral description of the reproduction chain to reduce the number of measurements in the training stages and to compensate for the acquisition limitations. Our first main contribution concerns the consideration of the colorimetric limitations in the spectral characterization of a camera. The second main contribution is the exploitation of the spectral printer model in the reflectance estimation methods
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Dadej, Vincent. "Raspberry Pi: programování v prostředí Matlab/Simulink." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-320104.
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The diploma thesis focuses on programming in the Matlab for the Raspberry Pi 3 platform. For the purpose of the presentation, there are two applications designed for Raspberry Pi that are using available hardware, camera and servos. The first application serves as colour object detecting and accurate tracking by using camera calibration. The second application serves as a face detection and recognition. These applications are implemented by modern methods and knowledge of computer vision. Tracking of the objects and face recognition are verified by an experiment that reveals the accuracy of the used methods.
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Riseby, Emil, and Alexander Svensson. "Multispectral Imaging for Surveillance Applications." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-115731.
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Silicon based sensors is a commonly used technology in digital cameras today. That has made such cameras relatively cheap and widely used. Unfortunately they are constructed to capture and represent image quality for humans. Several image applications work better without the restrictions of the visible spectrum. Human visual restrictions are often indirectly put on technology by using images showing only visible light. Thinking outside the box in this case is seeing beyond the visible spectrum.
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Campos, João Carlos Baptista 1958. "Cianotipia em grande formato : processo alternativo de reprodução de imagem em camara clara : uma abordagem das dimensões da linguagem, cor e espaço." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/285059.
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Orientador: Haroldo GalloDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes
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Resumo: A tecnologia alternativa de reprodução de imagens através do sistema de impressão negativo-positivo conhecida como Cianotipia possibilita, pela própria característica química dos sais de ferro fotossensíveis da emulsão, ou seja, sensibilidade à luz ultravioleta, a impressão à luz do Sol (rica em UV) por foto-contato, como uma câmara clara, de resultados em grandes formatos através de matrizes produzidas sem a utilização de dispositivo ótico ou câmera fotográfica. Identifica-se, como processo fotográfico histórico e muito antigo, como uma técnica fotográfica, contudo fica evidenciada na Cianotipia uma interferência mais determinante do autor nos resultados obtidos, o que permitiu uma reflexão histórica dos caminhos tomados pela fotografia ¿ das formas de expressão primitivas comparadas à dos tempos atuais ¿ e a conseqüente técnica, própria dos processos artesanais de gestualidade, de interfaces, onde o corpo hibridiza a mediação entre autor e produto visual. A pesquisa objetivou problematizar as dimensões da linguagem, cor e espaço. Linguagem, porque envolve as relações dos elementos constitutivos da tecnologia de reprodução de imagens, como o processo de construção das matrizes em grandes formatos, e também o produto plástico e visual da impressão resultante. Cor, na dimensão construtiva do objeto de estudo, onde a experimentação, a materialização do produto visual à qual se chega, trata, como forma de expressão que se vale dos estímulos visuais de natureza gestual e corpórea, da conseqüência de uma teoria de reflexão analítica, dedutiva, da poética visual dos fenômenos óticos, possíveis na cianotipia. Espaço, enquanto dimensão reveladora da capacidade da cianotipia em articular várias linguagens tridimensionais a serem registradas fotograficamente, e também por constituir-se em si mesma, elemento capaz de participar na própria construção deste espaço. A construção da instalação-ambiente denominada Photosynthesis a partir de cianótipos de grande formato procura exemplificar a dimensão teórico-visual proposta na presente pesquisa
Abstract: The alternative technology of image reproduction through the negative-positive impression system known as Cyanotype allows, by the chemical characters of the iron salts which are photo sensible of emulsion, sensible to the ultraviolet light, to the impression of sun light (rich in UV) through photo-contact, like a bright chamber, with results in huge formats through the mold produced without an optic gadget or a digital camera. It is identified, as an old photograph process, like a photograph technique, however it comes up in the Cyanotype with an important interference from the author in the results obtained, which permitted to do a historical reflection of the way taken by the photography ¿ from the primitive expression compared to the current days ¿ and the consequent technique, characteristic of the craft processes of gestures, of interface, where the body hybrid the mediation between the author and the visual product. The objective of the research was make questions about language dimensions, color and space. Language, because involves the relation of constitutive elements of image reproduction technology, just as the process of construction of the molds in huge formats, as well as the plastic product and visual of impression resulting. Color, in the constructive dimension of the object studied, where the experimentation, materialization of the visual product is treated as an expression way seen from the visual stimulus of the nature of body movements (figure) and gestures, as a consequence of a theory of analytical reflection, deductive, of the poetic visual of optics phenomenon, possible in Cyanotype. Space, while a revelator dimension of the capability of Cyanotype in articulate different 3-D languages to be registered photographically, and also due to constitute itself, element capable to participate in the building of this space. The construction of the installation-atmosphere named Photosynthesis gotten from Cyanotypes in huge formats, looks for exemplify the dimension theoretical-visual proposed in the current research
Mestrado
Artes
Mestre em Artes
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Blazevic, Sasha, and Carl Johan Kesten. "Editing within The Thriller Genre." Thesis, Blekinge Tekniska Högskola, Institutionen för teknik och estetik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-21915.
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Thriller är en favoritgenre för många och har funnits längre än de flesta tror. Ursprungligen som en litteraturgenre har den utvecklats till en av de mest eftertraktade genrerna inom film. Tidiga anmärkningsvärda verk som Alfred Hitchcocks filmer i mitten av 1900-talet har banat vägen för genren och utformat dess redigering och cinematografi till vad vi har idag. Trots sin ödmjuka början i mitten av 1900-talet lyckas teknikerna, även om dem är aningen repetitiva, fortfarande vara relevanta idag och har bara utvecklats med åren. I den här artikeln studerar vi grunderna inom thrillergenren, redigerings- och filmtekniker som används; kameraarbete, klippning, PoV och färgsättning. I denna studie är vårt huvudsakliga fokus att förstå varför dessa tekniker används. Utöver kommer vi också gå djupare in i thrillergenren i helhet och trots genrens repetitivitet, försöka förstå oss på varför den lyckas vara relevant idag och hur redigering och cinematografi spelar en stor roll för att förstärka känslorna i thrillers där dessa tendenser härrör från.Thriller is a favourite genre to many and has been around for longer than most think. Originally starting as a genre of literature, it has evolved into one of the most sought after genres within film. Early notable works such as Alfred Hitchcock's films in the mid 1900s have paved the way for the genre and solidified it’s editing and cinematography into what we have today. Despite its humbling beginnings in the mid 1900s the techniques, although somewhat repetitive, still manage to stay relevant today and have only gotten more advanced with time. In this article, we study the fundamentals within the thriller genre, the editing and cinematography techniques that are utilized; camera framing, cutting, PoV and color. In this study our main focus we intend to work towards is understanding why these techniques are used and the tendencies in which they are facilitated. Although we also intend to go in depth into the thriller genre as a whole and despite the repetitiveness of the genre, why it manages to stay relevant today and how editing and cinematography plays a big part in amplifying the emotions and feelings associated within thrillers in which these tendencies stem from.
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Morita, Yasuhiro. "Study of the effects of background and motion camera on the efficacy of Kalman and particle filter algorithms." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12166/.
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This study compares independent use of two known algorithms (Kalmar filter with background subtraction and Particle Filter) that are commonly deployed in object tracking applications. Object tracking in general is very challenging; it presents numerous problems that need to be addressed by the application in order to facilitate its successful deployment. Such problems range from abrupt object motion, during tracking, to a change in appearance of the scene and the object, as well as object to scene occlusions, and camera motion among others. It is important to take into consideration some issues, such as, accounting for noise associated with the image in question, ability to predict to an acceptable statistical accuracy, the position of the object at a particular time given its current position. This study tackles some of the issues raised above prior to addressing how the use of either of the aforementioned algorithm, minimize or in some cases eliminate the negative effects
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Draper, Teri Snow. "Application of Two-Color Pyrometry to Characterize the Two-Dimensional Temperature and Emissivity of Pulverized-Coal Oxy-Flames." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3206.
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Oxy-combustion is a developing technology that enables carbon dioxide (CO2) capture. Flame temperature and emissivity data were taken on a 150 kWth, pulverized-coal, burner flow reactor (BFR) that has been modified to run oxy-combustion with pure CO2 as simulated recycled flue gas. Data were taken at 78 conditions in which three parameters were varied, namely: the swirl angle of the fuel stream, the location of the oxidizer as it exited the burner, and the flow rate of diluent (pure CO2) added to the outer, secondary stream. At each condition, digital color images were obtained using a calibrated RGB camera. The images were used to determine lift-off length, temperature, and emissivity. The mathematical theory of two-color pyrometry and the calibration process used to measure the camera sensitivity is presented. The two most commonly used emissivity models in two-color pyrometry, the Hottel and Broughton and gray models, were investigated to determine which was the most appropriate for use in an oxy-coal flame. A significant difference of 7% in the temperature and 24% in the emissivity results were found when processing an image with the Hottel and Broughton and gray emissivity models. The Hottel and Broughton model was selected for processing, because the Hottel and Broughton model is more appropriate for soot which appeared to dominate flame emissions. Using the two-color data, several trends were documented. Flame temperature was seen to decrease with increasing CO2 flow rate. Within a given flame along the axial direction, temperature was seen to correlate with emissivity. As emissivity increased, flame temperature was seen to decrease. Many flames were lifted from the burner exit. Lift-off length was decreased and the flames became more attached by: 1) Increasing the amount of swirl given to the fuel stream, 2) Adding O2 to the center primary tube or 3) Decreasing the flow of secondary CO2. At higher center oxygen flow rates (above 8.5 kg/hr), the O2 jet velocity was large causing increased entrainment and mixing which degraded burner performance.
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Martinez, Garcia Juan Manuel. "Color characterization of a new laser printing system." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSES032/document.
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Grâce aux progrès récents dans le domaine des nanotechnologies il est maintenant possible de colorer des plaques de verre avec du dioxyde de titane contenant de l’argent par irradiation laser. L’une des caractéristiques de ce procédé est que le rendu couleur des échantillons produits diffère quand ceux-ci sont observés en réflexion (spéculaire ou diffuse) ou en transmission, ainsi que quand on polarise la lumière. Ce nouveau procédé d’impression laser que l’on a appelé PICSLUP (pour Photo-Induced Colored Silver LUster Printing system) permet de produire des images couleur gonio-apparentes.L’objectif de cette thèse est de caractériser l’apparence couleur (d’un point de vus colorimétrique et photométrique, et ce selon plusieurs géométries d’observation) de plaques de verre colorées par ce procédé. Ce qui pose de nombreux challenges techniques du fait que le système d’impression utilisé est encore en cours de développement et pas souvent accessible, du fait également de plusieurs spécificités photométriques (surface fortement translucide, fortement spéculaire, forte gonio-chromaticité). Afin de lever de toutes ces contraintes techniques notre première approche a été de caractériser la couleur grâce à un imageur monté sur un microscope. Nous avons pour cela généré par impression laser (avec le système PICSLUS) tout un ensemble d’échantillons couleur en faisant varier de manière exhaustive différents paramètres d’impression (temps d’exposition du faisceau laser, longueur d’onde, distance focale). Afin d’obtenir des mesures couleur précises nous avons ensuite développé une méthode de calibrage couleur spécifique dédiée à la mesure de surfaces fortement spéculaires. La précision de cette méthode de calibrage, appliquée aux échantillons créés par le système PICSLUP, est comparable à celles relevées dans l’état de l’art. À partir des couleurs obtenues on peut estimer la gamme des couleur (color gamut) qui peut être obtenue par ce système d’impression, en particulier pour la géométrie spéculaires 0º:0º, et étudier l’influence des différents paramètres d’impression ainsi que l’effet de la polarisation. Quoique les mesures réalisées sous microscope avec la géométrie spéculaire 0°:0° soient particulièrement utile pour étudier les propriétés colorimétriques et photométriques produites par le système PICSLUP, ces mesures ne sont pas suffisantes pour caractériser complètement ce système. En effet, l’apparence couleur des échantillons produits varie également en fonction de la géométrie d’éclairement et d’observation, il est donc nécessaire de caractériser le système PICSLUP selon d’autres géométries que la seule géométrie 0°:0°. Nous avons donc développé une autre méthode de caractérisation basée sur l’utilisation d’un imageur hyperspectral à géométrie ajustable, ce qui nous a permis de caractériser un ensemble donné d’échantillons couleur produits par le système PICSLUP. Ces échantillons ont été mesurés, en recto-verso, en transmission (avec la géométrie 0°:0°), en réflexion spéculaire (avec la géométrie 15°:15°), et en réflexion hors spéculaire (avec la géométrie 45°:0°). Grâce à ces mesures on a pu estimer pour différentes géométries d’observation les changements de gamme des couleurs qui peuvent être obtenus par le système PICSLUP. Le volume qui circonscrit chacune de ces gammes de couleur peut être modélisé par une forme concave qui contient beaucoup de zones éparses, ce qui revient à dire que certaines couleurs ne peuvent être directement obtenues par impression. Afin d’obtenir une forme convexe, plus dense quelque soit la zone d’étude considérée, nous avons testé avec succès une nouvelle méthode d’impression qui consiste non plus à imprimer des aplats (zones uniformément colorées par juxtaposition de lignes laser identiques) mais à imprimer des demi-tons (par juxtaposition de lignes laser de différentes couleurs). Cette méthode est basée sur le principe de l’halftoning et sur un nombre limité de primaires couleur pré-sélectionnéesRecent progresses in nanotechnologies enabled the coloration of glass plates coated with titanium dioxide containing silver by laser irradiation. The colored samples display very different colors when obtained by reflection or transmission of light; in specular or off-specular directions; and with or without polarizing filters. This new laser printing technology, that we call PICSLUP (for Photo-Induced Colored Silver LUster Printing system), enables the production of gonioapparent color images.The goal of this study is to perform a multi-geometry photometric and color characterization of this complex system. This task posed technical challenges due to the system being in a development stage, especially a low availability of the printing material; and due to the photometric properties of the prints: high translucency, high specularity and strong goniochromaticity. In order to overcome these constraints, our first approach was based on color characterization by microscope imaging. The data set used consisted in printing an exhaustive number of micrometric color patches, produced by varying the different laser printing parameters: exposure time, laser wavelength, laser power, and laser focusing distance. To achieve accurate color measurements with samples produced with the PICSLUS system, we successfully developed a color calibration method especially tailored for highly specular materials, whose accuracy is good in comparison to previous studies in the literature on camera color calibration. From the colors obtained, we could estimate the color gamut in the 0º:0º specular reflection geometry and study the influence of the different printing parameters as well as polarization. Although the measurements with microscope imaging in the 0°:0° specular geometry were very useful to study the properties of the colors produced by the PICSLUP technology, they were not sufficient to fully characterize the system, since the samples exhibit very different colors according to the respective positions of the viewer and the light source. With this in mind, we assembled a geometry-adjustable hyperspectral imaging system, which allowed us to characterize a representative subset of the colors that can be produced with the system. The samples were measured from both recto and verso faces, in the 0°:0° transmission, 15°:15° specular reflection, and 45°:0° off-specular reflection illumination/observation geometries. From these measurements, the color gamuts of the system were estimated in the different geometries. The volumes delimited by the colors obtained were concave and contained many sparse regions with very few samples. In order to obtain more continuous, dense and convex color gamut volumes, we successfully tested the generation of new colors by juxtaposing printed lines of different primaries with halftoning techniques. In order to circumvent the need to physically characterize all the different color that can be produced with halftoning using the numerous primaries available, we also tested and fitted existing halftoning prediction models, and obtained a satisfactory accuracy. The use of halftoning not only increased the number colors that can be produced by the system in the different geometries, but also increased the number of different primaries that can be produced when we consider as a whole the set of colors produced by the same printed patch in multiple geometries. Finally, based on the different properties demonstrated by the samples produced by the PISCLUP system, we explored some imaging and security features with colors obtained from our characterization, and propose further potential applications for this new goniochromatic laser printing technology
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Masters, Chase M. "An Analysis of the Shift from Black and White to Color Photography in Higher Education Introductory Photography Courses." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1225313825.
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Jiang, Chungshyi, and 江宗錫. "Nonlinear colour modeling on digital camera using back propagation neural network." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/30062968289750441870.
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Buchriegler, Josef. "Full-field PIXE imaging using a Colour X-ray Camera: Advantages and drawbacks in elemental mapping of large areas with a poly-capillary optics." 2020. https://tud.qucosa.de/id/qucosa%3A75000.
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A novel combination of a full-field X-ray detector and particle-induced X-ray emission (PIXE) as an established analytical method has been assembled and examined at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The so-called Colour X-ray Camera (CXC) based on a pn-junction charge-coupled device (pnCCD) is interconnected with a poly-capillary optics (PCO) for the purpose of X-ray imaging. This first combination of PIXE as a lowbackground excitation method and the approach of full-field imaging is likely to close the gap between fast and sensitive investigations of large sample surfaces. The assembly called full-field PIXE (FF-PIXE) is intended for laterally resolved and quantifiable surveys of large geological samples with respect to their trace elemental composition. The PCO comprising hundred thousands of capillaries with inner diameters of about 20 µm is employed in order to map the specimen’s characteristic X-ray response induced by 3 MeV protons provided by a 6 MV tandem-accelerator. The subsequent pnCCD-chip comprising 264×264 pixels is capable of individually detecting X-ray photons in the energy range from 1 to 20 keV on a 12×12 mm² large field of view. The camera’s native lateral resolution could be determined to be 76 µm in the medium energy range, which is basically restricted by the pixel dimensions (48×48 µm²).
Extensive experimental tests investigating the concept of sample 'illumination', X-ray transmission through the PCO, and imaging properties of the CXC, yielded substantial insights allowing to judge the new concept of X-ray imaging. While the variability of excitation intensity was proven to be better than 10% and the homogeneous response of the detector was verified, energy-dependent imaging impairments arose from the PCO. In comparative measurements at imaging systems using photons and electrons for excitation, both the full field approach and PIXE as the method of choice could be confirmed to be capable of meeting the initial objectives. In addition, enhancement techniques have been successfully tested to overcome downsides arising from the PCO’s transmission characteristics. Apart from suppressing the hexagonal pattern and a radial unevenness caused by the PCO, the system’s lateral resolving power could be improved towards 63 µm when using the 1:1 optics.
The investigations have revealed that, at present, the complex transmission nature of the PCO is a main obstacle in obtaining quantitative results. A number of parameters (e.g. frame readout speed) and dependencies (e.g. lateral resolution vs. elemental sensitivity) have nevertheless been identified and explored the understanding of which will help to move forward 'on the road to metrology'.Die neuartige Kombination eines Vollfeld-Röntgendetektors und partikelinduzierter Röntgenemission (PIXE: 'Proton-Induced X-ray Emission') als etablierte Analysemethode wurde am Helmholtz-Zentrum Dresden-Rossendorf (HZDR) aufgebaut und erforscht. Die sogenannte Röntgenfarbkamera (CXC: 'Colour X-ray Camera') basiert auf Ladungskopplung mit p-n-Übergängen (pnCCD: 'pn-junction Charge-Coupled Device') und ist zwecks Abbildung mit einer Polykapillaroptik (PCO: 'Poly-Capillary Optics') gekoppelt. Dieser erstmalige gemeinsame Einsatz von PIXE, als Analysemethode mit niedrigem Untergrund, und dem Ansatz der Vollfeldabbildung eignet sich, um die Lücke zwischen schneller und empfindlicher Analyse großer Probenoberflächen zu schließen. Die als full-field PIXE (FF-PIXE) bezeichnete Anlage ist für ortsaufgelöste und quantifizierbare Untersuchungen großer geologischer Proben konzipiert und soll insbesondere deren Spurenelementverteilung analysieren. Die charakteristische Röntgenstrahlung wird mit 3 MeV-Protonen, die von einem 6 MV-Tandembeschleuniger bereit gestellt werden, induziert. Die ortsaufgelöste Abbildung dieser induzierten Strahlung wird mittels hunderttausender Kapillaren (je ca. 20 µm Innendurchmesser) realisiert. Der nachgelagerte aus 264×264 Pixeln bestehende pnCCD-Chip ist in der Lage, Röntgenphotonen im Energiebereich von 1 bis 20 keV aus einem 12×12 mm² großen Sichtfeld einzeln zu erfassen. Im mittleren Energiebereich wurde für die Kamera eine native Ortsauflösung von 76 µm ermittelt, die im Wesentlichen durch die Pixeldimensionen (48×48 µm²) bestimmt ist. Umfangreiche experimentelle Tests, die das Konzept der Probenausleuchtung, der Röntgenübertragung durch die PCO und die Abbildungseigenschaften der CXC untersuchten, führten zu wesentlichen Erkenntnissen, die die Beurteilung des neuen Abbildungskonzepts für Röntgenfluoreszenz ermöglichen. Während die Variabilität der Anregungsintensität nachweislich besser als 10% ist und die homogene Empfindlichkeit des Detektors verifiziert wurde, ergaben sich energieabhängige Beeinträchtigungen der Bildübertragung durch die PCO. Vergleichsmessungen mit bildgebenden Systemen, die Photonen und Elektronen zur Anregung verwenden, konnten bestätigen, dass sowohl der Vollfeldansatz, als auch PIXE als Methode der Wahl zur Erreichung der ursprünglichen Ziele geeignet sind. Darüber hinaus wurden verschiedene Techniken zur Bildverbesserung erfolgreich getestet, die durch die PCO verursachte Abbildungsfehler korrigieren. Abgesehen von der Unterdrückung hexagonaler Muster und der Korrektur radialer Ungleichmäßigkeiten konnte das laterale Auflösungsvermögen des Systems bei Verwendung der 1:1-Optik auf 63 µm verbessert werden. Die Untersuchungen haben ergeben, dass die komplexen Übertragungseigenschaften der PCO derzeit eine der größten Hürden sind, um quantitative Ergebnisse zu erzielen. Dennoch wurde eine Reihe von Parametern (z.B.Auslesegeschwindigkeit) und Abhängigkeiten (z.B. Ortsauflösung vs. Elementempfindlichkeit) identifiziert und untersucht, deren Verständis dazu beitragen wird, auf dem Weg zu quantitativen Ergebnissen, voran zu kommen.
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Χατζής, Ιωάννης. "Εκτίμηση της ανακλαστικότητας χρώματος αντικειμένων και εφαρμογή στον ποιοτικό έλεγχο χρωματικών και σχεδιαστικών αποκλίσεων." Thesis, 2009. http://nemertes.lis.upatras.gr/jspui/handle/10889/1688.
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Στη διδακτορική διατριβή μελετώνται πέντε διαφορετικά προβλήματα που συναντώνται στη δημιουργία ενός συστήματος εκτίμησης ανακλαστικότητας χρώματος αντικειμένων και ποιοτικού ελέγχου έγχρωμων επίπεδων επιφανειών με σχέδια. Το πρώτο πρόβλημα αφορά στην εξαγωγή της απόκρισης φωτεινότητας της κάμερας που θα χρησιμοποιηθεί στο σύστημα. Για την εκτίμησή της προτάθηκαν τέσσερις μέθοδοι (δύο παραμετρικές και δύο μη παραμετρικές) που κάνουν χρήση των δεδομένων πολλαπλών εικόνων τυχαίων σκηνών. Η απόκριση φωτεινότητας εκτιμάται με χρήση πρωτότυπων συστημάτων εξισώσεων υπό περιορισμούς. Το δεύτερο πρόβλημα αφορά την εκτίμηση της φασματικής απόκρισης της κάμερας. Προτείνεται μία νέα μέθοδος που χρησιμοποιεί μοντέλο αθροίσματος κανονικών κατανομών και γενετικό αλγόριθμο. Η μέθοδος αυτή παρουσιάζει ανώτερη απόδοση σε σχέση με άμεσα ανταγωνιστικές μεθόδους στην εκτίμηση των φασματικών αποκρίσεων. Το τρίτο πρόβλημα αφορά επιλογή οπτικών φίλτρων από διαθέσιμο σύνολο για την κατασκευή πολυκαναλικού συστήματος εκτίμησης της φασματικής ανακλαστικότητας αντικειμένων. Προτείνονται νέες προσεγγίσεις με ανώτερη ακρίβεια φασματικής ανακατασκευής ανακλαστικοτήτων σε σχέση με ανταγωνιστικές μεθόδους. Το τέταρτο πρόβλημα αφορά στην επίτευξη χρωματικής ισοστάθμισης. Προτείνεται μία νέα παραδοχή μεγιστοποίησης της αντίθεσης στο κανάλι της φωτεινότητας. Με βάση την παραδοχή αυτή προτείνονται νέες μέθοδοι χρωματικής ισοστάθμισης και συγκρίνονται με υπάρχουσες στη βιβλιογραφία. Τα αποτελέσματα είναι συγκρίσιμα ή και ανώτερα ανταγωνιστικών μεθόδων. Το πέμπτο πρόβλημα αφορά στη δημιουργία συστήματος ανίχνευσης σφαλμάτων σε έγχρωμες επίπεδες επιφάνειες. Προτείνεται ένα πρωτότυπο σύστημα εντοπισμού σφαλμάτων που βασίζεται στην σύγκριση διανυσμάτων χαρακτηριστικών τοπικών ιστογραμμάτων σε πολλαπλά επίπεδα ανάλυσης και χρωματικά κανάλια. Τα διανύσματα χαρακτηριστικών είναι ανεξάρτητα από περιστροφή και μετατόπιση και ανεκτικά σε παραμορφώσεις. Η μέθοδος απαιτεί την ύπαρξη δειγμάτων αναφοράς για εκπαίδευση. Με έναν πρωτότυπο αλγόριθμο εντοπισμού σφαλμάτων, που χρησιμοποιεί τα δεδομένα που αποκτήθηκαν από τα δείγματα αναφοράς, γίνεται εντοπισμός των σφαλμάτων στις εικόνες επισκόπησης. Το σύστημα αξιολογείται όσον αφορά στην απόδοσή του χρησιμοποιώντας μία βάση δεδομένων εικόνων η οποία περιέχει τεχνητά σφάλματα και δημιουργήθηκε για το σκοπό αυτό.This dissertation analyzes five different problems on the development of an image based reflectance reconstruction system for defect detection on colour patterned planar objects. The first problem involves the estimation of the camera’s photoquantimetric response. Four new methods are proposed (two parametric and two non-parametric) using multiple images of the same static scene. The photoquantimetric response is estimated by the use of a novel formulation of linear systems with restrictions. The second problem refers to the estimation of the camera’s spectral response. Through the use of a sum of Gaussian model combined with genetic algorithms a new formulation is achieved. This new method shows improved performance compared to previous approaches. The third problem involves the selection of a subset of optical filters from an available set for the development of a multispectral reflectance reconstruction system. New approaches are proposed based on statistical features of the system responses providing better reflectance reconstruction accuracy in comparison to previous methods. The fourth problem refers to colour constancy. A novel assumption is proposed based on contrast maximization in the intensity channel. New methods based on this assumption are proposed. These new methods show comparable or even superior performance to existing colour constancy methods. The fifth problem involves the development of a defect detection system for coloured patterned planar surfaces. A novel defect detection system is proposed based on the comparison of statistical local feature vectors at multiple scales of resolution. The features used are rotation and translation invariant and robust to non-linear deformations. The system requires the existence of defect free reference patterns. A novel defect detection algorithm is proposed and tested on a database especially created for the task with satisfying results.
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Wu, Yi-Ming, and 吳益銘. "Color Interpolation for Single CCD Color Camera." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/78815426517526295486.
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碩士國立臺灣大學
資訊工程學研究所
89
The interpolation is the process of determining the unknown values of a function at the position lying between some pre-known samples. There are many traditional interpolation methods such as nearest neighbor, bilinear, cubic B-spline, and cubic convolution however they are not very suitable to the color interpolation for the digital color camera with the single CCD and the CFA. The primary drawback of the traditional interpolation methods is the color-alias and the blurred-edge effect. To sharpen the edge and reduce the color-alias, the edge-sensitive method and the color-difference domain are proposed respectively. Based on these techniques, we propose the novel composite interpolation scheme. The simulation results verify that the proposed interpolation method obtain superior image quality. Furthermore, the computational complexity of the proposed method is acceptable compared with the other existing methods.
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Chen, Hao-Yu, and 陳皓宇. "An Extrinsic Calibration for Depth Camera to Narrow Field of View Color Camera." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/47e5k2.
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碩士國立臺灣大學
資訊網路與多媒體研究所
107
This work proposes a calibration method between a narrow field of view cameraandadepthcamerainanendoscope-likescenario. Anendoscopy-like scenario has several properties including limited specular reflective surface, a camera with a narrow field of view. Instead of pushing the accuracy of the target marker with low-resolution data, we propose a solution with a loss function. The proposed loss function utilizes all of the 3 dimensions points of the checkerboard measured with the depth camera, and calculates the distance between projected 3D positions onto 2D image surface and the color image. The final re-projected error is improved to average under 1 millimeters, and further trainingand evaluation of depth estimation algorithms could be performed.