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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A design method for morphological filters

Lui, Guan-Liang 23 August 2010 (has links)
The purpose of Morphology is to capture features and attributes of image, such as boundaries and contours. It has been widely applied to computer vision, the analysis and processing of image and even industry examinations and medical image processing. The reason why the Morphology is widely applied is that we can use its simple structure elements to process images, and get up to our requirements. Therefore, it¡¦s become our primary study to find out those suitable structure elements. In this paper, we used the laws of judging the multiple mask relationship to find out filters which came up to the condition that we set, and also came up with an efficient way to find out filters that we want to get.
2

Applying Morphological Filter to Stereo Video Compression

Chen, Chi-Hung 05 September 2005 (has links)
The topic of stereo video is getting more attention among these days due to its high quality of visual effect. However, the large volume of data is the problem of its application. There is much similarity between the parallax videos. This similarity is obtained by a shape compensation technique. The topic of this thesis is to investigate a compression technique by on the shape compensation stereo video data. The shape transformation in this paper is coded by the kinds of morphological operations to be applied. This processing is a type of operation by which the spatial form or structure of objects within an image are modified. Morphological operation is usually applied to the binary images. There are two problems for the selection of the optimal morphological filter: the collection of the candidate filters and the sources of the voters. For the gray level images the mask operation is changed to be the more complex window weighting operation. By a strategy of slicing the image umbrella, our masked gray morphological operation is also more computation-efficient than the regular gray morphological operation. Experimental results in this thesis have demonstrated that shape compensation is more efficient than motion compensation for the secondary (right) video sequence.
3

On the Determination of Building Footprints from LIDAR Data

George, Henry C. 15 December 2007 (has links)
A new approach to improve the determination of building boundaries through automatic processing of light detection and ranging (LIDAR) data is presented. The LIDAR data is processed and interpolated into a grayscale image of intensity values corresponding to height measurements. Ground measurements are separated from non-ground measurements by using a progressive morphological filter. With these measurements now distinct, further separation of non-ground measurements into building and non-building measurements is performed by growing regions with similar characteristics. These building areas are then refined, resulting in a ground plan representation of building boundaries, known as building footprints. Several algorithms are then implemented to clean these footprints. A new method is developed to analyze actual known satellite imagery in order to confirm identified building footprints.
4

3D geometrijos atstatymas panaudojant Kinect jutiklį / 3D geometry reconstruction using Kinect sensor

Udovenko, Nikita 23 July 2012 (has links)
Šiame darbe yra tiriamos atrankiojo aplinkos 3D geometrijos atstatymo galimybės panaudojant Kinect jutiklio kombinuotą vaizdo-gylio kamerą: pateikiamas matematinis atstatymo modelis, jo parametrizavimui reikalingi koeficientai, apibūdinama tikėtinų paklaidų apimtis, siūloma aktualių scenos duomenų išskyrimo iš scenos procedūra, tiriamas gaunamo modelio triukšmas ir jo pašalinimo galimybės ir metodai. Atstatyta geometrija yra pateikiama metrinėje matų sistemoje, ir kiekvienas 3D scenos taškas papildomai saugo savo spalvinę informaciją. Praktinėje dalyje pateikiama sukurta taikomoji programa yra įgyvendinta naudojant C++ ir OpenCV matematines programavimo bibliotekas. Ji atlieka 3D geometrijos atstatymą pagal pateiktą teorinį modelį, išskiria aktualius scenos duomenis, pašalina triukšmą ir gali išsaugoti gautus duomenis į 3D modeliavimo programoms suprantamą PLY formato bylą. Darbą sudaro: įvadas, 3 skyriai, išvados ir literatūros sąrašas. Darbo apimtis – 61 p. teksto be priedų, 43 paveikslai, 4 lentelės, 22 bibliografiniai šaltiniai. / The purpose of this thesis is to investigate the possibilities of selective 3D geometry reconstruction using Kinect combined image-depth camera: a mathematical reconstruction model is provided, as well as coefficients to parametrize it and estimates on expected precision; a procedure on filtering out the background from depth image is proposed, depth image noise and possibilities for its removal are studied. Resulting reconstructed geometry is provided using metric system of measurement, and each 3D point also retains it's color data. Resulting application is implemented in C++ programming language and uses OpenCV programming library. It implements 3D geometry reconstruction as described in theory section, removes background from depth image, as well as noise, and is able to save the resulting 3D geometry to a 3D modeling applications readable file format. Structure: introduction, 3 chapters, conclusions, references. Thesis consists of – 61 p. of text, 43 figures, 4 tables, 22 bibliographical entries.
5

Morphological filters in floodplain for DEM-extracted data – using Minimum Bounding Circle & Youden Index

Jin, Peng 06 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Floods are one of the worst disasters in the United States. Each year, the government allocates a tremendous amount of manpower and money on flood prevention initiatives. As the first defense line, levees provide protection from temporary flooding (Makhdoom, 2013). These embankments are broadly classified according to the areas they protect, which could either be urban or agricultural levees within floodplains. In the U.S., most of the levees are handled by government agencies such as the U.S. Army Corps of Engineers and the Federal Emergency Management Services. On the other hand, non-levee embankments created by individual farmers (Olson & Morton, 2013) or naturally formed levee-like structures may not be in the government database. The initial purpose of this research was to assist Polis center on the “Mapping of Non-Levee Embankments in the Indiana” project. The non-levee embankments are not certified or engineered levee-like structures. They, therefore, impose lateral constraints on flood flows, reducing the floodplain storage capacity and increasing the flood velocity. These non-levee embankments can cause stream erosion and downstream flooding. Therefore, it is important to know the locations of these features. The first part of the proposed method adapted the Empirical Bayesian theorem and the low pass filter techniques to extract elevated linear features from LiDAR elevation data – Digital Elevation Model (DEM). The second part of the proposed methods combined the Minimum Bounding Circle (MBC) method and the Youden Index to locate the optimal threshold value that can be used to determine whether the extracted features are levee-like structures. The focus of this study is not only limited to artificial levee-like structures, but also takes the natural levees, or any potential levee-like structures into account because this study assumes all embankments play important roles during flood events.
6

Optimering av kupmätare : Automatisk igenkänning av egenskaper i brädors ändträ med bildbehandling

Olsson, Andreas January 2016 (has links)
Within the timber industry the processing of sawn wood boards must be done in the right way to ensure that the product fulfills the requirements. Correct processing is crucial for wooden structures consisting of these will live up to their expectations. How the mounting of the board in wooden structures is performed to obtain satisfactory results is depending on how it is physically cupped. Due to this a curvature measuring device is used in the timber industry to detect how a sawn board is physically cupped. After detection, a proper processing can be performed to give a satisfactory product. The Swedish company Nolyx AB currently uses a curvature measuring device consisting of a smart camera with the task of taking a digital picture of the board end grain to determine its cupping. The smart camera currently has deficiencies that this work will investigate. The deficiencies are that the smart camera’s processing of images with certain properties do not give satisfactory results. The algorithms lack the robustness needed to cope with the variations of the item that might arise in the process. The desire of this study is that the smart cameras correctness in terms of variations in the object will increase, leading to financial gains for the company Nolyx AB and increased utilization of raw material for their customers. The result of this work is an algorithm that incrementally extracts and identifies the growth rings in the end grain of the board. The correctness of the image processing in this study is 82%, which is 22% higher compared to the smart camera. / Inom träindustrin måste bearbetning av sågade träbrädor ske på rätt sätt för att produkten skall uppfylla kraven. En korrekt bearbetning är avgörande för att träkonstruktioner bestående av dessa ska leva upp till sina förväntningar. Hur monteringen av brädan vid byggnation av träkonstruktioner utförs för att erhålla tillfredställande resultat beror på hur den fysiskt är kupad. På grund av detta används kupmätare inom träindustrin för att detektera brädans fysiska kupning. Efter detektering kan en korrekt bearbetning utföras vilket ger en tillfredsställande produkt. Företaget Nolyx AB använder idag en kupmätare som består av en smartkamera vars uppgift är att ta en digital bild av brädans ändträ för att avgöra dess kupning. Kupmätaren har idag brister som detta arbete skall angripa. Nämligen att smartkamerans behandling av bilder med vissa egenskaper inte ger tillfredsställande resultat. Algoritmerna saknar den robusthet som krävs för att klara de variationer på objektet som kan uppkomma i processen. Önskan med denna studie är att smartkamerans felfrihet vad gäller variationer i objektet ska öka, vilket leder till ekonomiska vinster för företaget Nolyx AB och ökat utnyttjande av råvaran för sina kunder. Resultatet av det här arbetet är en algoritm som stegvis extraherar och identifierar årsringarnas struktur. Felfriheten för bildbehandlingen i denna studie är 82 % vilket är 22 % högre jämfört med smartkameran.
7

Correntes geomagneticamente induzidas: detecção e influência no sistema elétrico de potência

Lagoas, Fabiana da Cunha 28 September 2017 (has links)
Submitted by Marlucy Farias Medeiros (marlucy.farias@unipampa.edu.br) on 2017-10-31T16:57:28Z No. of bitstreams: 1 Fabiana_da Cunha Lagoas - 2017.PDF: 14321561 bytes, checksum: 3289d01da05021ff92313e5754afb5f8 (MD5) / Approved for entry into archive by Marlucy Farias Medeiros (marlucy.farias@unipampa.edu.br) on 2017-10-31T18:24:31Z (GMT) No. of bitstreams: 1 Fabiana_da Cunha Lagoas - 2017.PDF: 14321561 bytes, checksum: 3289d01da05021ff92313e5754afb5f8 (MD5) / Made available in DSpace on 2017-10-31T18:24:32Z (GMT). No. of bitstreams: 1 Fabiana_da Cunha Lagoas - 2017.PDF: 14321561 bytes, checksum: 3289d01da05021ff92313e5754afb5f8 (MD5) Previous issue date: 2017-09-28 / Correntes geomagneticamente induzidas (GICs) são correntes espelhadas na superfície terrestre, que ocorrem em função do movimento de partículas ionizadas no campo magnético terrestre. Tais partículas eletricamente carregadas são provenientes da massa coronal expelida em erupções solares, as quais viajam a uma velocidade de, aproximadamente, 450 km/s. Ao entrarem em contato com a magnetosfera, proporcionam distorções no campo magnético, as quais são medidas por meio de três índices geomagneticos: Kp e Ap, que representam o grau de perturbação do campo magnético, e Dst, o qual informa a intensidade da tempestade solar por hora. Quando as GICs penetram no sistema elétrico de potencia (SEP) através dos aterramentos dos equipamentos, problemas podem ocorrer, tais como o aquecimento de componentes da rede, além de desligamentos de linhas de transmissão, decorrentes da atuação indevida de dispositivos de proteção. Destaca-se que, atualmente, as concessionarias brasileiras de energia são severamente multadas pelos órgãos reguladores quando ha a ocorrência de um desligamento não programado que não seja causado por uma falta permanente. Al˜ em disso, ressalta-se que os dispositivos de proteção são desprovidos de funções capazes de detectar as GICs, as quais comprometem também a vida útil de alguns equipamentos. Nesse contexto, um estudo aprofundando deste fenômeno geomagnético e apresentado neste trabalho. Para tal, um histórico de desarmes da Linha de Transmissão (LT) de 138 kV ALE SE – SMA1, localizada entre as cidades de Alegrete e Santa Maria, no estado do Rio Grande do Sul, foi analisado em função dos dados dos índices geomagnéticos para o período de 2010 a 2015. Além disso uma analise do ciclo solar, evidenciou a possibilidade de ocorrência de GICs nesta LT, o que pode justificar muitos dos desligamentos indeterminados. Dessa forma, o presente trabalho apresenta uma técnica para detecção de GICs, a qual pode ser aplicada em reles digitais ou em ferramentas computacionais para determinação das causas de desligamentos indevidos sem justificativa aparente. Tal método consiste em um filtro morfológico para detecção dessas correntes, o qual foi implementado em Matlab e testado a partir do processamento de sinais de corrente, gerados computacionalmente pela simulação de um sistema teste no software EMTP-ATP. Os valores de GICs utilizados para testar o seu desempenho foram obtidos a partir do software OPENDSS, o qual calcula o fluxo de corrente geomagneticamente induzida a partir de dados técnicos da LT, como o comprimento da linha e as respectivas latitudes e longitudes de seus terminais. Os resultados obtidos através das simulações em OPENDSS mostraram a ocorrência de GICs na linha estudada. Por fim, o processamento dos sinais conseguidos através da simulação do sistema, por parte da metodologia para detecção de GICs, comprovaram a excelência da técnica proposta. / Geomagnetically induced currents (GICs) are mirrored currents on the Earth’s surface, which occur as a function of the movement of ionized particles in the Earth’s magnetic field. Such electrically charged particles are derived from the coronal mass expelled in solar flares, which travel at a speed of approximately 450 km / s. When they come into contact with the magnetosphere, they provide distortions in the magnetic field, which are measured by means of three geomagnetic indices: Kp and Ap, which represent the degree of perturbation of the magnetic field, and Dst, which informs the intensity of the solar storm per hour. When GICs penetrate the electrical power system (SEP) through the grounding of the equipment, problems can occur, such as the heating of network components, as well as disconnections of transmission lines, due to the improper performance of protection devices. It should be noted that, currently, Brazilian energy concessionaires are severely fined by regulatory agencies when there is an unplanned shutdown that is not caused by a permanent shortage. In addition, it is emphasized that the protection devices are devoid of functions capable of detecting the GICs, which also compromise the useful life of some equipment. In this context, an in-depth study of this geomagnetic phenomenon is presented in this paper. To do so, a history of disarranges of the 138 kV ALE SE - SMA1 transmission line, located between the cities of Alegrete and Santa Maria, in the state of Rio Grande do Sul, was analyzed according to geomagnetic index data for The period from 2010 to 2015. And together with a study of sunspots, the possibility of occurrence of GICs in this LT was evidenced, which may justify many of the indeterminate disconnections. Thus, the present work presents a technique to detect GICs, which can be applied in digital relays or in computational tools to determine the causes of undue disconnections without apparent justification. This method consists of a morphological filter for the detection of these currents, which was implemented in Matlab R and tested from the current signal processing generated by the simulation of a test system in the EMTP-ATP R software. The values of GICs used to test their performance were obtained from OPENDSS R software, which calculates geomagnetically induced current flow from technical data of the LT, such as the length of the line and the respective latitudes and longitudes of its terminals. The results obtained through the simulations in OPENDSS showed the occurrence of GICs in the studied line. The results obtained from the processing of the signals obtained through the simulation of the system proved the excellence of the proposed technique.
8

Impact des transformations algorithmiques sur la synthèse de haut niveau : application au traitement du signal et des images / Impact of algorithmic transforms for High Level Synthesis (HLS) : application to signal and image processing

Ye, Haixiong 20 May 2014 (has links)
La thèse porte sur l'impact d'optimisations algorithmiques pour la synthèse automatique HLS pour ASIC. Ces optimisations algorithmiques sont des transformations de haut niveau, qui de part leur nature intrinsèque restent hors de porter des compilateurs modernes, même les plus optimisants. Le but est d'analyser l'impact des optimisations et transformations de haut niveau sur la surface, la consommation énergétique et la vitesse du circuit ASIC. Les trois algorithmes évalués sont les filtres non récursifs, les filtres récursifs et un algorithme de détection de mouvement. Sur chaque exemple, des gains ont été possibles en vitesse et/ou en surface et/ou en consommation. Le gain le plus spectaculaire est un facteur x12.6 de réduction de l'énergie tout en maitrisant la surface de synthèse et en respectant la contrainte d'exécution temps réel. Afin de mettre en perspective les résultats (consommation et vitesse), un benchmark supplémentaire a été réalisé sur un microprocesseur ST XP70 avec extension VECx, un processeur ARM Cortex avec extension Neon et un processeur Intel Penryn avec extensions SSE. / The thesis deals with the impact of algorithmic transforms for HLS synthesis for ASIC. These algorithmic transforms are high level transforms that are beyond the capabilities of modern optimizing compilers. The goal is to analyse the impact of the High level transforms on area execution time and energy consumption. Three algorithms have been analyzed: non recursive filters, recursive filter and a motion detection application. On each algorithm, the optimizations and transformations lead to speedups and area/surface gains. The most impressive gain in energy reduction is a factor x12.6, while the area remains constant and the execution time smaller than the real-time constraint. A benchmark has been done on SIMD general purpose processor to compare the impact of the high level transforms: ST XP70 microprocessor with VECx extension, ARM Cortex with Non extension and Intel Penryn with SSE extension.

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