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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

Automatic assessment of biological control effectiveness of the egg parasitoid Trichogramma bourarachar against Cadra cautella using machine vision

Song, Yuqi January 1900 (has links)
Master of Science / Department of Biological & Agricultural Engineering / Naiqian Zhang / The primary objective of this research is to achieve automatic evaluation of the efficiency of using Trichogramma bourarachae for biological control of Cadra (=Ephestia) cautella by calculating the rate of parasitization. Cadra cautella is a moth feeding as a larva on dried fruit as well as stored nuts, seeds, and other warehouse foodstuffs. It attacks dates from ripening stages while on tree, throughout storage, and until consumption. These attacks cause significant qualitative and quantitative damages, which negatively affect dates’ marketability, resulting in economic losses. To achieve this research goal, tasks were accomplished by developing image processing algorithms for detecting, identifying, and differentiating between three Cadra cautella egg categories based on the success of Trichogramma parasitization against them. The egg categories were parasitized (black and dark red), fertile (unhatched yellow), and hatched (white) eggs. Color, intensity, and shape information was obtained from digital images of Cadra eggs after they were subjected to Trichogramma parasitization and used to develop detection algorithms. Two image processing methods were developed. The first method included segmentation and extractions of color and morphological features followed by watershed delineation, and is referred to as the "Watershed Method" (WT). The second method utilized the Hough Transformation to find circular objects followed by convolution filtering, and is referred to as the "Hough Transform Method" (HT). The algorithms were developed based on 2 images and then tested on more than 40 images. The WT and the HT methods achieved correct classification rates (CCRs) of parasitized eggs of 92% and 96%, respectively. Their CCRs of yellow eggs were 48% and 94%, respectively, while for white eggs the CCRs were 42% and 73%. Both methods performed satisfactorily in detecting the parasitized eggs, but the HT outperformed the WT in detecting the unparasitized eggs. The developed detection methods will enable automatic evaluation of biological control of Cadra (=Ephestia) cautella using Trichogramma bourarachae. Moreover, with few adjustments these methods can be used in similar applications such as detecting plant diseases in terms of presence of insects or their eggs.
2

Estimation and Correction of the Distortion in Forensic Image due to Rotation of the Photo Camera

Bavikadi, Sathwika, Botta, Venkata Bharath January 2018 (has links)
Images, in contrast to text, represent an effective and natural communication media for humans, due to their immediacy and the easy way to understand the image content. Shape recognition and pattern recognition are one of the most important tasks in the image processing. Crime scene photos should always be in focus and there should always be a ruler be present, this will allow the investigators the ability to resize the image to accurately reconstruct the scene. Therefore, the camera must be on a grounded platform such as tripod. Due to the rotation of the camera around the camera center there exist the distortion in the image which must be minimized. The distorted image should be corrected using transformation method. Deze taak is nogal uitdagend en essentieel omdat elke verandering in de afbeeldingen kan misidentificeren een object voor onderzoekers. Forensic image processing can help the analyst extract information from low quality, noisy image or geometrically distorted. Obviously, the desired information must be present in the image although it may not be apparent or visible. Considering challenges in complex forensic investigation, we understand the importance and sensitivity of data in a forensic images.The HT is an effective technique for detecting and finding the images within noise. It is a typical method to detect or segment geometry objects from images. Specifically, the straight-line detection case has been ingeniously exploited in several applications. The main advantage of the HT technique is that it is tolerant of gaps in feature boundary descriptions and is relatively unaffected by image noise. The HT and its extensions constitute a popular and robust method for extracting analytic curves. HT   attracted a lot of research efforts over the decades. The main motivations behind such interest are the noise immunity, the ability to deal with occlusion, and the expandability of the transform. Many variations of it have evolved. They cover a whole spectrum of shape detection from lines to irregular shapes. This master thesis presents a contribution in the field of forensic image processing. Two different approaches, Hough Line Transformation (HLT), Hough Circular Transformation (HCT) are followed to address this problem. Fout estimatie en validatie is gedaan met de hulp van root mean square method. De prestatie van beide methoden is geëvalueerd door ze te vergelijken. We present our solution as an application to the MATLAB environment, specifically designed to be used as a forensic tool for forensic images.
3

Rozpoznání dopravních značek využitím neuronové sítě / Traffic sign recognition with using of neural networks

Zámečník, Dušan January 2009 (has links)
This paper deals with traffic signs recognition. Red color area is obtained by thresholding in HSV color model. Selected radiometric deskriptors, Hough transform deskriptors and neural networs are used to classification. In conclusion has been designed complex decision algorithm.
4

Automatická detekce výpadku ve vrstvě nervových vláken / Automatic detection of neural fibers losses

Václavek, Martin January 2010 (has links)
This work is focused on detection of loss in nerve fibre layer on colour pictures of retina, witch are makes by fundus camera. It describe every simple objects of retina, optic nerve head, macula lutea and vascular bed. It detect optic nerve head and his near area, witch is general for detection of breakdownds. It use several metodes of picture adjusting for picture elaboration and objects detection (segmentation, thresholding, enhancement, hough transformation ). The detection of loss in nerve fibre layer is based on comparing of statistic parameters ( average, standart deviation, skewness coefficient and kurtosis coefficient histogram, entropy ) in choosed areas with and withou destruction of nerve layers. Vascular bed have badwatsh on results, cause of this we using hand choosing of essay.
5

Echtzeitfähige modellbasierte Bilderkennung zur visuomotorischen Kontrolle bewegter Objekte

Bunk, Michael 20 October 2017 (has links)
Autonome Roboter müssen sich in einer dynamischen Umwelt zurechtfinden können und zeitnah auf Ereignisse reagieren. Der echtzeitfähigen Verarbeitung visueller Information kommt dabei eine Schlüsselrolle zu. Am Beispiel zweier spezieller Roboter wird die Gewinnung steuerungsrelevanter Daten aus einer Bildsequenz demonstriert. Dazu werden in Form von Modellen umfassende Voraussetzungen aufgestellt von dem, was gesehen werden soll und kann. Es wird ein Erkennungssystem entworfen und implementiert, welches die Extraktion der gesuchten Daten aus den Bilddaten u.a. mittels Bildkorrelation im Frequenzraum und Hough-Transformation durchführt. Die gewonnenen Daten werden zur Steuerung eines der Roboter verwendet.
6

Approaches For Automatic Urban Building Extraction And Updating From High Resolution Satellite Imagery

Koc San, Dilek 01 March 2009 (has links) (PDF)
Approaches were developed for building extraction and updating from high resolution satellite imagery. The developed approaches include two main stages: (i) detecting the building patches and (ii) delineating the building boundaries. The building patches are detected from high resolution satellite imagery using the Support Vector Machines (SVM) classification, which is performed for both the building extraction and updating approaches. In the building extraction part of the study, the previously detected building patches are delineated using the Hough transform and boundary tracing based techniques. In the Hough transform based technique, the boundary delineation is carried out using the processing operations of edge detection, Hough transformation, and perceptual grouping. In the boundary tracing based technique, the detected edges are vectorized using the boundary tracing algorithm. The results are then refined through line simplification and vector filters. In the building updating part of the study, the destroyed buildings are determined through analyzing the existing building boundaries and the previously detected building patches. The new buildings are delineated using the developed model based approach, in which the building models are selected from an existing building database by utilizing the shape parameters. The developed approaches were tested in the Batikent district of Ankara, Turkey, using the IKONOS panchromatic and pan-sharpened stereo images (2002) and existing vector database (1999). The results indicate that the proposed approaches are quite satisfactory with the accuracies computed in the range from 68.60% to 98.26% for building extraction, and from 82.44% to 88.95% for building updating.
7

Um método para correção automática de cartão de resposta utilizando processamento digital de imagem / A method for automatic correction of multiple-choice tests using digital image processing

Pereira, Pedro Henrique 27 April 2018 (has links)
Submitted by Pedro Henrique Pereira (pedro.pereirasp@gmail.com) on 2018-06-26T14:21:28Z No. of bitstreams: 1 DissertaçãoPedroHenriquePereira_VersãoFinal.pdf: 4177619 bytes, checksum: 063cd34385c56ed5081e839a845767b5 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-06-26T17:55:12Z (GMT) No. of bitstreams: 1 pereira_ph_me_ilha.pdf: 4177619 bytes, checksum: 063cd34385c56ed5081e839a845767b5 (MD5) / Made available in DSpace on 2018-06-26T17:55:12Z (GMT). No. of bitstreams: 1 pereira_ph_me_ilha.pdf: 4177619 bytes, checksum: 063cd34385c56ed5081e839a845767b5 (MD5) Previous issue date: 2018-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho propõe-se um método que envolve diferentes técnicas de processamento digital de imagem para a correção automática de cartão de respostas utilizados em avaliações de múltipla- escolha, vestibulares, concursos ou processos de seleção. O método tem como base um modelo de referência onde são identificados os seguintes elementos do cartão: campos de marcação das opções, número de opção de cada questão e uma imagem de marcação para identificar as extremidades da folha. No trabalho foi aplicada a técnica de Correlação Cruzada Normalizada para identificação da imagem na extremidade da folha. A Transformada de Hough foi utilizada para identificação das áreas onde se realiza a marcação das opções. Para identificar qual a questão que foi marcada utilizou-se a contagem de pixel. Foram realizados testes com 1.154 gabaritos contendo 40 questões, preenchidos no vestibular de uma faculdade particular. O tempo médio para correção de cada cartão foi de 1,39 segundos. A precisão do método foi avaliada utilizando-se 5% dos cartões digitalizados e processados. Basicamente, a avaliação foi realizada conferindo-se visualmente cada cartão e comparando os resultados com os gerados pela correção automática. O índice de acerto com as amostras utilizadas foi de 100%, o que comprova a eficiência do método proposto. / This work proposes a method that involves different techniques of digital image processing for automatic correction of card responses used in multiple-choice evaluations, “vestibular”, contests or selection processes. The method is based on a reference model where the following elements of the card are identified: marking fields of the options, the option number of each question and a marking image to identify the edges of the sheet. In this work, the Normalized Cross-Correlation technique was applied to identify the image at the leaf end. The Hough Transform was used to identify the areas where the options are marked. To identify which question was selected, the pixel count was used. We performed tests with 1.154 templates containing 40 questions that were completed in the entrance examination of a private college. The average time to correct each card was 1.39 seconds. Samples were collected on 5% of the scanned and processed cards by the method to verify their accuracy. The total sampled was visually checked with the results presented by the application of the method and it was verified the percentage of 100% of correct answers in the reading of the markings. / CAPES: 515/2017
8

Um método para correção automática de cartão de resposta utilizando processamento digital de imagem /

Pereira, Pedro Henrique January 2018 (has links)
Orientador: Jozué Vieira Filho / Resumo: Neste trabalho propõe-se um método que envolve diferentes técnicas de processamento digital de imagem para a correção automática de cartão de respostas utilizados em avaliações de múltipla- escolha, vestibulares, concursos ou processos de seleção. O método tem como base um modelo de referência onde são identificados os seguintes elementos do cartão: campos de marcação das opções, número de opção de cada questão e uma imagem de marcação para identificar as extremidades da folha. No trabalho foi aplicada a técnica de Correlação Cruzada Normalizada para identificação da imagem na extremidade da folha. A Transformada de Hough foi utilizada para identificação das áreas onde se realiza a marcação das opções. Para identificar qual a questão que foi marcada utilizou-se a contagem de pixel. Foram realizados testes com 1.154 gabaritos contendo 40 questões, preenchidos no vestibular de uma faculdade particular. O tempo médio para correção de cada cartão foi de 1,39 segundos. A precisão do método foi avaliada utilizando-se 5% dos cartões digitalizados e processados. Basicamente, a avaliação foi realizada conferindo-se visualmente cada cartão e comparando os resultados com os gerados pela correção automática. O índice de acerto com as amostras utilizadas foi de 100%, o que comprova a eficiência do método proposto. / Abstract: This work proposes a method that involves different techniques of digital image processing for automatic correction of card responses used in multiple-choice evaluations, “vestibular”, contests or selection processes. The method is based on a reference model where the following elements of the card are identified: marking fields of the options, the option number of each question and a marking image to identify the edges of the sheet. In this work, the Normalized Cross-Correlation technique was applied to identify the image at the leaf end. The Hough Transform was used to identify the areas where the options are marked. To identify which question was selected, the pixel count was used. We performed tests with 1.154 templates containing 40 questions that were completed in the entrance examination of a private college. The average time to correct each card was 1.39 seconds. Samples were collected on 5% of the scanned and processed cards by the method to verify their accuracy. The total sampled was visually checked with the results presented by the application of the method and it was verified the percentage of 100% of correct answers in the reading of the markings. / Mestre
9

Automatic Waterjet Positioning Vision System

Dziak, Damian, Jachimczyk, Bartosz, Jagusiak, Tomasz January 2012 (has links)
The goals of this work are a design and implementation of a new vision system, integrated with the waterjet machine. This system combines two commercial webcams applied on an industrial dedicated platform. A main purpose of the vision system is to detect the position and rotation of a workpiece placed on the machine table. The used object recognition algorithm consists of edge detection, standard math processing functions and noise filters. The Hough transform technique is used to extract lines and their intersections of a workpiece. Metric rectification method is used, in order to obtain a top view of the workspace and to adjust an image coordinate system, accordingly to the waterjet machine coordinates. In situ calibration procedures of the booth webcams are developed and implemented. Experimental results of the proposed new vision system prototype confirm required performance and precision of the element detection.
10

Segmentace významných objektů v barevných oftalmologických obrazech / Segmentation in the color fundus imges

Malínský, Miloš January 2008 (has links)
Optic nerve head and macula are important structures in fundus images. Detection and measurement plays crucial role in several diagnosis methods of optic disease. This work is focused on the detection of the central point of macula and optic nerve head, where the inner border is detected too. There are many methods for extracting this structure in retinal images. Due to the unique properties of each acquisition technique, a single generally acknowledged detection algorithm does not exist. The whole detection process is described from preprocessing through segmentation towards postprocessing. Presented methods are based on the combination of correlation techniques, Hough transform, active contours and morphological operations. The detected contours of the optic nerve head are evaluated and quantitatively compared with the contour drawn by experienced ophthalmologist. The master thesis contains quantity of images that help to describe detection methods.

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