654 research outputs found

    Lane Line Detection and Object Scene Segmentation Using Otsu Thresholding and the Fast Hough Transform for Intelligent Vehicles in Complex Road Conditions

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    An Otsu-threshold- and Canny-edge-detection-based fast Hough transform (FHT) approach to lane detection was proposed to improve the accuracy of lane detection for autonomous vehicle driving. During the last two decades, autonomous vehicles have become very popular, and it is constructive to avoid traffic accidents due to human mistakes. The new generation needs automatic vehicle intelligence. One of the essential functions of a cutting-edge automobile system is lane detection. This study recommended the idea of lane detection through improved (extended) Canny edge detection using a fast Hough transform. The Gaussian blur filter was used to smooth out the image and reduce noise, which could help to improve the edge detection accuracy. An edge detection operator known as the Sobel operator calculated the gradient of the image intensity to identify edges in an image using a convolutional kernel. These techniques were applied in the initial lane detection module to enhance the characteristics of the road lanes, making it easier to detect them in the image. The Hough transform was then used to identify the routes based on the mathematical relationship between the lanes and the vehicle. It did this by converting the image into a polar coordinate system and looking for lines within a specific range of contrasting points. This allowed the algorithm to distinguish between the lanes and other features in the image. After this, the Hough transform was used for lane detection, making it possible to distinguish between left and right lane marking detection extraction; the region of interest (ROI) must be extracted for traditional approaches to work effectively and easily. The proposed methodology was tested on several image sequences. The least-squares fitting in this region was then used to track the lane. The proposed system demonstrated high lane detection in experiments, demonstrating that the identification method performed well regarding reasoning speed and identification accuracy, which considered both accuracy and real-time processing and could satisfy the requirements of lane recognition for lightweight automatic driving systems

    Segmentation of ultrasound images of thyroid nodule for assisting fine needle aspiration cytology

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    The incidence of thyroid nodule is very high and generally increases with the age. Thyroid nodule may presage the emergence of thyroid cancer. The thyroid nodule can be completely cured if detected early. Fine needle aspiration cytology is a recognized early diagnosis method of thyroid nodule. There are still some limitations in the fine needle aspiration cytology, and the ultrasound diagnosis of thyroid nodule has become the first choice for auxiliary examination of thyroid nodular disease. If we could combine medical imaging technology and fine needle aspiration cytology, the diagnostic rate of thyroid nodule would be improved significantly. The properties of ultrasound will degrade the image quality, which makes it difficult to recognize the edges for physicians. Image segmentation technique based on graph theory has become a research hotspot at present. Normalized cut (Ncut) is a representative one, which is suitable for segmentation of feature parts of medical image. However, how to solve the normalized cut has become a problem, which needs large memory capacity and heavy calculation of weight matrix. It always generates over segmentation or less segmentation which leads to inaccurate in the segmentation. The speckle noise in B ultrasound image of thyroid tumor makes the quality of the image deteriorate. In the light of this characteristic, we combine the anisotropic diffusion model with the normalized cut in this paper. After the enhancement of anisotropic diffusion model, it removes the noise in the B ultrasound image while preserves the important edges and local details. This reduces the amount of computation in constructing the weight matrix of the improved normalized cut and improves the accuracy of the final segmentation results. The feasibility of the method is proved by the experimental results.Comment: 15pages,13figure

    On Shape-Mediated Enrolment in Ear Biometrics

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    Ears are a new biometric with major advantage in that they appear to maintain their shape with increased age. Any automatic biometric system needs enrolment to extract the target area from the background. In ear biometrics the inputs are often human head profile images. Furthermore ear biometrics is concerned with the effects of partial occlusion mostly caused by hair and earrings. We propose an ear enrolment algorithm based on finding the elliptical shape of the ear using a Hough Transform (HT) accruing tolerance to noise and occlusion. Robustness is improved further by enforcing some prior knowledge. We assess our enrolment on two face profile datasets; as well as synthetic occlusion

    Edge Guided Reconstruction for Compressive Imaging

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    We propose EdgeCS—an edge guided compressive sensing reconstruction approach—to recover images of higher quality from fewer measurements than the current methods. Edges are important image features that are used in various ways in image recovery, analysis, and understanding. In compressive sensing, the sparsity of image edges has been successfully utilized to recover images. However, edge detectors have not been used on compressive sensing measurements to improve the edge recovery and subsequently the image recovery. This motivates us to propose EdgeCS, which alternatively performs edge detection and image reconstruction in a mutually beneficial way. The edge detector of EdgeCS is designed to faithfully return partial edges from intermediate image reconstructions even though these reconstructions may still have noise and artifacts. For complex-valued images, it incorporates joint sparsity between the real and imaginary components. EdgeCS has been implemented with both isotropic and anisotropic discretizations of total variation and tested on incomplete k-space (spectral Fourier) samples. It applies to other types of measurements as well. Experimental results on large-scale real/complex-valued phantom and magnetic resonance (MR) images show that EdgeCS is fast and returns high-quality images. For example, it exactly recovers the 256×256 Shepp–Logan phantom from merely 7 radial lines (3.03% k-space), which is impossible for most existing algorithms. It is able to accurately reconstruct a 512 × 512 MR image with 0.05 white noise from 20.87% radial samples. On complex-valued MR images, it obtains recoveries with faithful phases, which are important in many medical applications. Each of these tests took around 30 seconds on a standard PC. Finally, the algorithm is GPU friendly

    Threshold Free Detection of Elliptical Landmarks Using Machine Learning

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    Elliptical shape detection is widely used in practical applications. Nearly all classical ellipse detection algorithms require some form of threshold, which can be a major cause of detection failure, especially in the challenging case of Moire Phase Tracking (MPT) target images. To meet the challenge, a threshold free detection algorithm for elliptical landmarks is proposed in this thesis. The proposed Aligned Gradient and Unaligned Gradient (AGUG) algorithm is a Support Vector Machine (SVM)-based classification algorithm, original features are extracted from the gradient information corresponding to the sampled pixels. with proper selection of features, the proposed algorithm has a high accuracy and a stronger robustness in blurring and contrast variation. The thesis confirms that the removal of thresholds in ellipse detection algorithm improves robustness

    Recognition of License Plates and Optical Nerve Pattern Detection Using Hough Transform

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    The global technique of detection of the features is Hough transform used in image processing, computer vision and image analysis. The detection of prominent line of the object under consideration is the main purpose of the Hough transform which is carried out by the process of voting. The first part of this work is the use of Hough transform as feature vector, tested on Indian license plate system, having font of UK standard and UK standard 3D, which has ten slots for characters and numbers.So tensub images are obtained.These sub images are fed to Hough transform and Hough peaks to extract the Hough peaks information. First two Hough peaks are taken into account for the recognition purposes. The edge detection along with image rotation is also used prior to the implementation of Hough transform in order to get the edges of the gray scale image. Further, the image rotation angle is varied; the superior results are taken under consideration. The second part of this work makes the use of Hough transform and Hough peaks, for examining the optical nerve patterns of eye. An available database for RIM-one is used to serve the purpose. The optical nerve pattern is unique for every human being and remains almost unchanged throughout the life time. So the purpose is to detect the change in the pattern report the abnormality, to make automatic system so capable that they can replace the experts of that field. For this detection purpose Hough Transform and Hough Peaks are used and the fact that these nerve patterns are unique in every sense is confirmed

    Um estudo comparativo das abordagens de detecção e reconhecimento de texto para cenários de computação restrita

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    Orientadores: Ricardo da Silva Torres, Allan da Silva PintoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Textos são elementos fundamentais para uma efetiva comunicação em nosso cotidiano. A mobilidade de pessoas e veículos em ambientes urbanos e a busca por um produto de interesse em uma prateleira de supermercado são exemplos de atividades em que o entendimento dos elementos textuais presentes no ambiente são essenciais para a execução da tarefa. Recentemente, diversos avanços na área de visão computacional têm sido reportados na literatura, com o desenvolvimento de algoritmos e métodos que objetivam reconhecer objetos e textos em cenas. Entretanto, a detecção e reconhecimento de textos são problemas considerados em aberto devido a diversos fatores que atuam como fontes de variabilidades durante a geração e captura de textos em cenas, o que podem impactar as taxas de detecção e reconhecimento de maneira significativa. Exemplo destes fatores incluem diferentes formas dos elementos textuais (e.g., circular ou em linha curva), estilos e tamanhos da fonte, textura, cor, variação de brilho e contraste, entre outros. Além disso, os recentes métodos considerados estado-da-arte, baseados em aprendizagem profunda, demandam altos custos de processamento computacional, o que dificulta a utilização de tais métodos em cenários de computação restritiva. Esta dissertação apresenta um estudo comparativo de técnicas de detecção e reconhecimento de texto, considerando tanto os métodos baseados em aprendizado profundo quanto os métodos que utilizam algoritmos clássicos de aprendizado de máquina. Esta dissertação também apresenta um método de fusão de caixas delimitadoras, baseado em programação genética (GP), desenvolvido para atuar tanto como uma etapa de pós-processamento, posterior a etapa de detecção, quanto para explorar a complementariedade dos algoritmos de detecção de texto investigados nesta dissertação. De acordo com o estudo comparativo apresentado neste trabalho, os métodos baseados em aprendizagem profunda são mais eficazes e menos eficientes, em comparação com os métodos clássicos da literatura e considerando as métricas adotadas. Além disso, o algoritmo de fusão proposto foi capaz de aprender informações complementares entre os métodos investigados nesta dissertação, o que resultou em uma melhora das taxas de precisão e revocação. Os experimentos foram conduzidos considerando os problemas de detecção de textos horizontais, verticais e de orientação arbitráriaAbstract: Texts are fundamental elements for effective communication in our daily lives. The mobility of people and vehicles in urban environments and the search for a product of interest on a supermarket shelf are examples of activities in which the understanding of the textual elements present in the environment is essential to succeed in such tasks. Recently, several advances in computer vision have been reported in the literature, with the development of algorithms and methods that aim to recognize objects and texts in scenes. However, text detection and recognition are still open problems due to several factors that act as sources of variability during scene text generation and capture, which can significantly impact detection and recognition rates of current algorithms. Examples of these factors include different shapes of textual elements (e.g., circular or curved), font styles and sizes, texture, color, brightness and contrast variation, among others. Besides, recent state-of-the-art methods based on deep learning demand high computational processing costs, which difficult their use in restricted computing scenarios. This dissertation presents a comparative study of text detection and recognition techniques, considering methods based on deep learning and methods that use classical machine learning algorithms. This dissertation also presents an algorithm for fusing bounding boxes, based on genetic programming (GP), developed to act as a post-processing step for a single text detector and to explore the complementarity of text detection algorithms investigated in this dissertation. According to the comparative study presented in this work, the methods based on deep learning are more effective and less efficient, in comparison to classic methods for text detection investigated in this work, considering the adopted metrics. Furthermore, the proposed GP-based fusion algorithm was able to learn complementary information from the methods investigated in this dissertation, which resulted in an improvement of precision and recall rates. The experiments were conducted considering text detection problems involving horizontal, vertical and arbitrary orientationsMestradoCiência da ComputaçãoMestre em Ciência da ComputaçãoCAPE

    Edge Potential Functions (EPF) and Genetic Algorithms (GA) for Edge-Based Matching of Visual Objects

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    Edges are known to be a semantically rich representation of the contents of a digital image. Nevertheless, their use in practical applications is sometimes limited by computation and complexity constraints. In this paper, a new approach is presented that addresses the problem of matching visual objects in digital images by combining the concept of Edge Potential Functions (EPF) with a powerful matching tool based on Genetic Algorithms (GA). EPFs can be easily calculated starting from an edge map and provide a kind of attractive pattern for a matching contour, which is conveniently exploited by GAs. Several tests were performed in the framework of different image matching applications. The results achieved clearly outline the potential of the proposed method as compared to state of the art methodologies. (c) 2007 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

    A generalized entropy-based two-phase threshold algorithm for noisy medical image edge detection

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    [EN] Edge detection in medical imaging is a significant task for object recognition of human organs and is considered a pre-processing step in medical image segmentation and reconstruction. This article proposes an efficient approach based on generalized Hill entropy to find a good solution for detecting edges under noisy conditions in medical images. The proposed algorithm uses a two-phase thresholding: firstly, a global threshold calculated by means of generalized Hill entropy is used to separate the image into object and background. Afterwards, a local threshold value is determined for each part of the image. The final edge map image is a combination of these two separate images based on the three calculated thresholds. The performance of the proposed algorithm is compared to Canny and Tsallis entropy using sets of medical images corrupted by various types of noise. We used Pratt's Figure Of Merit (PFOM) as a quantitative measure for an objective comparison. Experimental results indicated that the proposed algorithm displayed superior noise resilience and better edge detection than Canny and Tsallis entropy methods for the four different types of noise analyzed, and thus it can be considered as a very interesting edge detection algorithm on noisy medical images. (c) 2017 Sharif University of Technology. All rights reserved.This work was supported in part by the Spanish Ministerio de Economia y Competitividad (MINECO) and by FEDER funds under Grant BFU2015-64380-C2-2-R.Elaraby, A.; Moratal, D. (2017). A generalized entropy-based two-phase threshold algorithm for noisy medical image edge detection. Scientia Iranica. 24(6):3247-3256. https://doi.org/10.24200/sci.2017.43593247325624
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