• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • 3
  • 2
  • 1
  • Tagged with
  • 18
  • 18
  • 12
  • 11
  • 9
  • 9
  • 8
  • 8
  • 7
  • 7
  • 5
  • 4
  • 4
  • 4
  • 4
  • 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

Zpracování otisků prstu / Fingerprint Processing

Pšenák, Patrik January 2010 (has links)
My master's thesis deals with the different techniques used in fingerprints processing for identifying fingerprints. Using the software tool Visual C++ and functions of OpenCV library I programmed a separate application, that is able to select from a database of fingerprints the most consistent with a comparative fingerprint images, even when they are mutually shifted in the direction of axes X and Y. The next step in my program is to gather the edges of the fingerprint image. Those obtained using Canny edge detector. Furthermore, getting the contours of the image edges. To determine, whether the contours are the same, just compare some characteristic points of contours. Next I use a histogram function to determine the number of points for approximation of contours and evaluating compliance fingerprints. Since the processing of the input fingerprint image (or rather the approximation of the contour points) remains in the picture as black (background) and red (the approximation of the contour points), this means, that zero and the last element of the histogram represent the number of black and red points. Comparison is in percentage and is obtained by subtracting the approximated points of contours image from the original fingerprint image of approximated contour points of matched fingerprints. It determined, what percentage of red points have disappeared, so as to match two fingerprint images. If on the resulting figure is not left neither a red point, that corresponds to 100% of the fingerprints Compliance.
2

Derichův detektor hran / Deriche Edge Detector

Němec, Zbyšek January 2012 (has links)
This thesis presents the Deriche edge detector as an interesting alternative to the commonly used edge detectors. The Deriche edge detector's design is presented to the reader as well as its strengths and weaknesses. Performance issues of the Deriche edge detector are described in comparison with the Canny edge detector together with recommendations for using the Deriche detector. Finally, edge detection quality of the Deriche edge detector is compared to the Canny edge detector using robust subjective evaluation method.
3

FPGA Based Lane Tracking system for Autonomous Vehicles

Ram Prakash, Rohith Raj January 2020 (has links)
The application of Image Processing to Autonomous driving has drawn significant attention in recently. However, the demanding nature of the image processing algorithms conveys a considerable burden to any conventional realtime implementation. On the other hand, the emergence of FPGAs has brought numerous facilities toward fast prototyping and implementation of ASICs so that an image processing algorithm can be designed, tested and synthesized in a relatively short period in comparison to traditional approaches. This thesis investigates the best combination of current algorithms to reach an optimum solution to the problem of lane detection and tracking, while aiming to fit the design to a minimal system. The proposed structure realizes three algorithms, namely Edge Detector, Hough Transform, and Kalman filter. For each module, the theoretical background is investigated and a detailed description of the realization is given followed by an analysis of both achievements and shortages of the design. It is concluded by describing the advantages of implementing this architecture and the use of these kinds of systems. / Tillämpningen av bildbehandling inom autonoma fordon har fått stor uppmärksamhet den senaste tiden. Emellertid förmedlar den krävande karaktären hos bildbehandlingsalgoritmerna en stor belastning på vilken konventionell realtidsimplementering som helst. Å andra sidan har framväxten av FPGAer medfört många möjligheter till snabb prototypering och implementering av ASICar så att en bildbehandlingsalgoritm kan utformas, testas och syntetiseras på relativt kort tid jämfört med traditionella tillvägagångssätt. Denna avhandling undersöker den bästa kombinationen av nuvarande algoritmer för att uppnå en optimal lösning på problemet med spårning och fildetektering, med målet att krympa designen till ett minimalt system. Den föreslagna strukturen realiserar tre algoritmer, nämligen Edge Detector, Hough Transform och Kalman filter. För varje modul undersöks den teoretiska bakgrunden och en detaljerad beskrivning av realiseringen ges följd av en analys av både fördelar och brister i konstruktionen. Avhandlingen avslutas med en beskrivning av fördelarna med att implementera lösningen på det sätt den görs och hur dessa system kan användas.
4

Números fuzzy em processamento de imagens digitais e suas aplicações na detecção de bordas / Fuzzy numbers in digital image processing and its aplications on edge detection

Boaventura, Inês Aparecida Gasparotto 26 March 2010 (has links)
O objetivo deste trabalho é apresentar uma nova abordagem, baseada no conceito de números fuzzy, para detecção de bordas em imagens digitais chamado FUNED (Fuzzy Number Edge Detector). A técnica de detecção de bordas implementada pelo FUNED considera uma vizinhança local dos pixels da imagem, definida pelo usuário e, baseado no conceito de números fuzzy, é verificado se um pixel pertence ou não aquela região da imagem, com base na intensidade dos tons de cinza que compõem a região. O pixel que não pertence à região é então classificado como um possível pixel de borda. Através de uma função de pertinência, a técnica proposta fornece uma matriz de pertinência em tons de cinza e, pela escolha de um limiar, as bordas da imagem são segmentadas. Para a modelagem do problema, os tons de cinza são considerados como números fuzzy e, para cada pixel gi,j da imagem, calcula-se a sua pertinência em relação a uma determinada região, considerando os vizinhos que possuem níveis de cinza próximos de gi,j. Ao considerar os valores de cinza como números fuzzy, incorpora-se a variabilidade inerente dos valores de cinza de imagens, proporcionando assim uma abordagem mais adequada ao tratamento de imagens digitais, em comparação ao tratamento clássico, baseado em uma formulação analítica. Para avaliação do desempenho da técnica, foram usadas imagens sintéticas e imagens reais em tons de cinza, obtidas na literatura, e realizados testes qualitativos e quantitativos. Para a realização dos testes quantitativos, foi desenvolvida uma nova metodologia de avaliação de detectores de bordas baseada na análise ROC. O processo de avaliação desenvolvido considera diferentes medidas, que são tomadas comparando-se as bordas obtidas com as bordas ideais. Os resultados da avaliação de desempenho mostraram que o FUNED é eficaz computacionalmente quando comparado aos detectores de Canny e de Sobel e, também a outras abordagens fuzzy. A técnica permite ao usuário o ajuste dos seguintes parâmetros: o tamanho da vizinhança local, o suporte de um número fuzzy e o limiar. O ajuste desses parâmetros proporciona diversas possibilidades de visualização das bordas de uma imagem, permitindo a escolha de detalhes da imagem. A implementação computacional do FUNED é intuitiva e com bom desempenho tanto para obtenção de bordas como em tempo de processamento, sendo adequada para aplicações em tempo real com implementação em hardware. / The purpose of this work is to introduce a new approach, based on fuzzy numbers, for edge detection in gray level images. The proposed approach is called FUNED (Fuzzy Number Edge Detector). The edge detection technique, implemented by FUNED, considers a local neighborhood of image pixels, defined by the user and, based on fuzzy numbers concept, it is verified whether a pixel belongs to that image region, according to the gray level intensity in the region. The pixel that does not belong to the region is then classified as a possible edge pixel. Therefore, through a membership function, the proposed technique provides a membership matrix in gray levels and, through the choice of a threshold, the image edges are segmented. For the modeling of the problem, the gray levels are considered fuzzy numbers and, for each pixel gi,j of the image, it is computed its membership regarding to a specific region, considering the neighbors presenting gray levels near gi,j. When considering gray-values as fuzzy numbers, the inherent variability of the image gray values are incorporated, thus promoting a more powerful approach for the treatment of digital images as compares with the classic treatment based on analytical formulation. For the assessment of the performance of the technique, it was used gray-level synthetics and real images, obtained from the literature, and qualitative and quantitative tests were carried out. To achieve the quantitative tests, it was developed a new methodology for evaluating edge detectors based on ROC analysis. The evaluation process developed considers various measures, that are taken by comparing the edges obtained with the ideal edges. The results of the assessment showed that the FUNED is more computationally efficient when compared to the results obtained by Canny and Sobel detectors and, also to other fuzzy approaches. The technique allows the user to adjust several parameters. The adjustment of these parameters provide several image edge visualization possibilities, which allow the choice of details in the image. The computational implementation of FUNED is intuitive and with good performance both for obtaining edges as in processing time, being suitable for real time applications with hardware implementation.
5

Números fuzzy em processamento de imagens digitais e suas aplicações na detecção de bordas / Fuzzy numbers in digital image processing and its aplications on edge detection

Inês Aparecida Gasparotto Boaventura 26 March 2010 (has links)
O objetivo deste trabalho é apresentar uma nova abordagem, baseada no conceito de números fuzzy, para detecção de bordas em imagens digitais chamado FUNED (Fuzzy Number Edge Detector). A técnica de detecção de bordas implementada pelo FUNED considera uma vizinhança local dos pixels da imagem, definida pelo usuário e, baseado no conceito de números fuzzy, é verificado se um pixel pertence ou não aquela região da imagem, com base na intensidade dos tons de cinza que compõem a região. O pixel que não pertence à região é então classificado como um possível pixel de borda. Através de uma função de pertinência, a técnica proposta fornece uma matriz de pertinência em tons de cinza e, pela escolha de um limiar, as bordas da imagem são segmentadas. Para a modelagem do problema, os tons de cinza são considerados como números fuzzy e, para cada pixel gi,j da imagem, calcula-se a sua pertinência em relação a uma determinada região, considerando os vizinhos que possuem níveis de cinza próximos de gi,j. Ao considerar os valores de cinza como números fuzzy, incorpora-se a variabilidade inerente dos valores de cinza de imagens, proporcionando assim uma abordagem mais adequada ao tratamento de imagens digitais, em comparação ao tratamento clássico, baseado em uma formulação analítica. Para avaliação do desempenho da técnica, foram usadas imagens sintéticas e imagens reais em tons de cinza, obtidas na literatura, e realizados testes qualitativos e quantitativos. Para a realização dos testes quantitativos, foi desenvolvida uma nova metodologia de avaliação de detectores de bordas baseada na análise ROC. O processo de avaliação desenvolvido considera diferentes medidas, que são tomadas comparando-se as bordas obtidas com as bordas ideais. Os resultados da avaliação de desempenho mostraram que o FUNED é eficaz computacionalmente quando comparado aos detectores de Canny e de Sobel e, também a outras abordagens fuzzy. A técnica permite ao usuário o ajuste dos seguintes parâmetros: o tamanho da vizinhança local, o suporte de um número fuzzy e o limiar. O ajuste desses parâmetros proporciona diversas possibilidades de visualização das bordas de uma imagem, permitindo a escolha de detalhes da imagem. A implementação computacional do FUNED é intuitiva e com bom desempenho tanto para obtenção de bordas como em tempo de processamento, sendo adequada para aplicações em tempo real com implementação em hardware. / The purpose of this work is to introduce a new approach, based on fuzzy numbers, for edge detection in gray level images. The proposed approach is called FUNED (Fuzzy Number Edge Detector). The edge detection technique, implemented by FUNED, considers a local neighborhood of image pixels, defined by the user and, based on fuzzy numbers concept, it is verified whether a pixel belongs to that image region, according to the gray level intensity in the region. The pixel that does not belong to the region is then classified as a possible edge pixel. Therefore, through a membership function, the proposed technique provides a membership matrix in gray levels and, through the choice of a threshold, the image edges are segmented. For the modeling of the problem, the gray levels are considered fuzzy numbers and, for each pixel gi,j of the image, it is computed its membership regarding to a specific region, considering the neighbors presenting gray levels near gi,j. When considering gray-values as fuzzy numbers, the inherent variability of the image gray values are incorporated, thus promoting a more powerful approach for the treatment of digital images as compares with the classic treatment based on analytical formulation. For the assessment of the performance of the technique, it was used gray-level synthetics and real images, obtained from the literature, and qualitative and quantitative tests were carried out. To achieve the quantitative tests, it was developed a new methodology for evaluating edge detectors based on ROC analysis. The evaluation process developed considers various measures, that are taken by comparing the edges obtained with the ideal edges. The results of the assessment showed that the FUNED is more computationally efficient when compared to the results obtained by Canny and Sobel detectors and, also to other fuzzy approaches. The technique allows the user to adjust several parameters. The adjustment of these parameters provide several image edge visualization possibilities, which allow the choice of details in the image. The computational implementation of FUNED is intuitive and with good performance both for obtaining edges as in processing time, being suitable for real time applications with hardware implementation.
6

Detektor objektů s využitím vlnkové transformace / Wavelet transform based object detector

Mikuš, Ondřej January 2009 (has links)
This thesis deals with applying methods on object detection in image. Separation of objects off the background is often needed during the image processing. It isolates the region of interest that can be worked with. The main purpose of this paper is the explanation of principles of pre-processing and segmentation of image, resulting in object detection using the wavelet transformation. This wavelet transformation is described more in detail, because it is the base of the primary used method. In the practical part of this thesis the main method was implemented to MATLAB environment and tested on set of images. The method was tested for robustness against noise and blur of image. It was compared with commonly used methods, using the edge detectors and thresholding. A simulation program was created for comparison of methods efficiency, including user interface.
7

Detekce šířky papilární linie u otisku prstu / Detection of Papillary Line Width by Fingerprints

Homola, Antonín January 2011 (has links)
This work outlines a method of detection of the papillary line width in fingerprints. This method is one of the possible methods of liveness detection. The first part of the work with deals defining of the fingerprint, attacks on today's systems and possibilities to improve security. The next section detection describes of the papillary line width. During the process of resolving, the first thing to do was to start operation of the scanning device and to read the database for tests and experiments. An independent application was created on this purpose. Further, there were projected methods for detection and measuring of the papillary line width. Use of the Canny edge detector with the Sobel operator and the Gaussian filter proved the best. Then, there is described implementation of individual methods. The next part of the work describes and assesses the results of the tests. The last chapter summarizes the work and proposes further possibilities of development.
8

Zařízení varovného systému pro udržení vozidla v jízdním pruhu / Warning system to keep the vehicle in the lane

Fendrich, Vítězslav January 2019 (has links)
This thesis adresses designing a device that detects lane departure of a vehicle via a video feed from a camera module. This device is intended to be attached onto the windshield of the vehicle. The initial part of the thesis will cover the current methods of lane departure detection through a video feed. In the following part the selection of suitable hardware, specifically the latest model of a Raspberry Pi, has been made. Afterwards a suitable container for the aforementioned hardware has been designed and created using a 3D printer. Subsequently an appropriate LDWS algorithm is chosen and designed. In the next part, the range and parameters of a testing database through which the proper functionality of the device will be tested on are chosen. The final part of the thesis contains evaluation of the success rate of detection via the acquired database.
9

Využití metod zpracování signálů pro zvýšení bezpečnosti automobilové dopravy / Usage of advanced signal processing techniques for motor traffic safety enhancement

Beneš, Radek January 2009 (has links)
This diploma thesis deals with the issue of the recognition of road signs in the video sequence. Such systems increase the traffic safety and are implemented by major car factories in the manufactured cars (Opel, BMW). First, the motivation for the utilisation of these systems is presented, followed by the survey of the current state of the art methods. Finally, a specific road-sign detection method is chosen and described in detail. The method uses advanced techniques of signal processing. Segmentation method in color space is used for sign detection and subsequent classification is accomplished by linear classification with optional use of PCA method. In addition, the method contains the prediction of road sign positions based on Kalman filtering. Implemented system yields relatively accurate results and overall analysis and discussion is enclosed.
10

Padel court detection system

Wennerblom, David, Arronet, Andrey January 2023 (has links)
The aim of this thesis is to examine the possibility of a court detection program for sports videos that can identify the court even when some important elements are not visible. The study will also analyze what external factors may impact the program's accuracy in detecting all relevant elements.  These questions are answered through a combination of computer vision techniques and algorithms. The study utilizes Design Science Research (DSR) as its research methodology to develop an artifact. A dataset of padel sports videos are evaluated to measure the artifacts accuracy. The artifact utilizes multiple computer vision techniques from the OpenCV library to detect relevant lines and edges and project them onto the frame using a predetermined court model as reference.  The findings indicated that the developed artifact demonstrated a relatively consistent level of accuracy in court detection across multiple courts, whenever a detection was made. However, the frequency of successful detections exhibited some inconsistency. The research also found that external factors did not significantly influence the accuracy of court detection, yet they posed challenges to the program's overall consistency.

Page generated in 0.0516 seconds