• Title/Summary/Keyword: edge-detection

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A Detection Method of Hexagonal Edges in Corneal Endothelial Cell Images (각막 내피 세포 영상내 육각형 에지 검출법)

  • Kim, Eung-Kyeu
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.4
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    • pp.180-186
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    • 2012
  • In this paper, a method of edge detection from low contrast and noisy images which contain hexagonal shape is proposed. This method is based on the combination of laplacian gaussian filter and an idea of filters which are dependent on the shape. First, an algorithm which has six masks as its extractors to detect the hexagonal edges especially in the comers is used. Here, two tricom filters are used to detect the tricom joints of hexagons and other four masks are used to enhance the line segments of hexagonal edges. As a natural image, a corneal endothelial cell image which usually has a regular hexagonal shape is selected. The edge detection of hexagonal shapes in this corneal endothelial cell is important for clinical diagnosis. Next, The proposal algorithm and other conventional methods are applied to noisy hexagonal images to evaluate each efficiency. As a result, this proposal algorithm shows a robustness against noises and better detection ability in the aspects of the signal to noise ratio, the edge coineidence ratio and the detection accuracy factor as compared with other conventional methods.

A Study on Edge Detection using Directional Mask in Impulse Noise Image (임펄스 잡음 영상에서 방향성 마스크를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Institute of Convergence Signal Processing
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    • v.15 no.4
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    • pp.135-140
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    • 2014
  • As the digital image devices are widely used, interests in the software- and the hardware-related image processing become higher and the image processing techniques are applied in various fields such as object recognition, object detection, fingerprint recognition, and etc. For the edge detections Sobel, Prewitt, Laplacian, Roberts and Canny detectors are used and these existing methods can excellently detect the edges of the images without noise. However, in the images corrupted by the impulse noise, these methods are insufficent in noise elimination characteristics, showing unsatisfactory edge detection. Therefore in this paper, in order to obtain excellent edge detection characteristics in the corrupted image by the impulse noise, an detection algorithm is porposed, which uses the central pixel of mask divided by four regions along the axis, calculates the estimated mask according to the representing pixel values in each regions, and detects the final edges by applying the estimates mask and the new directional one.

Image Edge Detection Technique for Pathological Information System (병리 정보 시스템을 위한 이미지 외곽선 추출 기법 연구)

  • Xiao, Xie;Oh, Sangyoon
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.10
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    • pp.489-496
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    • 2016
  • Thousands of pathological images are produced daily per hospital and they are stored and managed by a pathology information system (PIS). Since image edge detection is one of fundamental analysis tools for pathological images, many researches are targeted to improve accuracy and performance of image edge detection algorithm of HIS. In this paper, we propose a novel image edge detection method. It is based on Canny algorithm with adaptive threshold configuration. It also uses a dividing ruler to configure the two threshold instead of whole image to improve the detection ratio of ruler itself. To verify the effectiveness of our proposed method, we conducted empirical experiments with real pathological images(randomly selected image group, image group that was unable to detect by conventional methods, and added noise image group). The results shows that our proposed method outperforms and better detects compare to the conventional method.

Urban Change Detection Between Heterogeneous Images Using the Edge Information (이종 공간 데이터를 활용한 에지 정보 기반 도시 지역 변화 탐지)

  • Jae Hong, Oh;Chang No, Lee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.4
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    • pp.259-266
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    • 2015
  • Change detection using the heterogeneous data such as aerial images, aerial LiDAR (Light Detection And Ranging), and satellite images needs to be developed to efficiently monitor the complicating land use change. We approached this problem not relying on the intensity value of the geospatial image, but by using RECC(Relative Edge Cross Correlation) which is based on the edge information over the urban and suburban area. The experiment was carried out for the aerial LiDAR data with high-resolution Kompsat-2 and −3 images. We derived the optimal window size and threshold value for RECC-based change detection, and then we observed the overall change detection accuracy of 80% by comparing the results to the manually acquired reference data.

A Study on Modified Mask for Edge Detection in AWGN Environment (AWGN 환경에서 에지 검출을 위한 변형된 마스크에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.9
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    • pp.2199-2205
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    • 2013
  • In modern society the image processing has been applied to various digital devices such as smartphone, digital camera, and digital TV. In the field of image processing the edge detection is one of the important parts in the image processing procedure. The image edge means point that the pixel value is changed between background and object rapidly, and includes the important information such as magnitude, location, and orientation. The performance of the existing edge detection method is insufficient for the image degraded by AWGN(additive white Gaussian noise) because it detects edges by using small weighted masks. Therefore, in this paper, to detect edge in AWGN environment effectively, we proposed an algorithm that detects edge as calculated gradient of sorting vector which is transformed by estimated mask from new pixel according to each region.

Image Edge Detection Algorithm applied Directional Structure Element Weighted Entropy Based on Grayscale Morphology (그레이스케일 형태학 기반 방향성 구조적 요소의 가중치 엔트로피를 적용한 영상에지 검출 알고리즘)

  • Chang, Yu;Cho, JoonHo;Moon, SungRyong
    • Journal of Convergence for Information Technology
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    • v.11 no.2
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    • pp.41-46
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    • 2021
  • The method of the edge detection algorithm based on grayscale mathematical morphology has the advantage that image noise can be removed and processed in parallel, and the operation speed is fast. However, the method of detecting the edge of an image using a single structural scale element may be affected by image information. The characteristics of grayscale morphology may be limited to the edge information result of the operation result by repeatedly performing expansion, erosion, opening, and containment operations by repeating structural elements. In this paper, we propose an edge detection algorithm that applies a structural element with strong directionality to noise and then applies weighted entropy to each pixel information in the element. The result of applying the multi-scale structural element applied to the image and the result of applying the directional weighted entropy were compared and analyzed, and the simulation result showed that the proposed algorithm is superior in edge detection.

A Study on Candidate Lane Detection using Hybrid Detection Technique (하이브리드 검출기법을 이용한 후보 차선검출에 관한 연구)

  • Park, Sang-Joo;Oh, Joong-Duk;Park, Roy C.
    • Journal of the Institute of Convergence Signal Processing
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    • v.17 no.1
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    • pp.18-25
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    • 2016
  • As more people have cars, the threat of traffic accidents is posed on men and women of all ages. The main culprit of traffic accidents is driving while intoxicated or drowsy. The method to recognize and prevent the cause of traffic accidents is to use lane detection. In this study, a total of 4,000 frames (day image: 2,900 frames, night image: 1,100 frames) were used to test lane detection. According to the test, in the case of day image, when the threshold of Sobel edge detection technique was detected with second-order differential equation, there was the highest candidate lane detection rate which was 86.1%. In the threshold of Canny edge detection technique, the highest detection rate of 88.0% was found at Low=50, and High=300. In the case of night image, the threshold of Sobel edge detection technique, when horizontal calculation and vertical calculation had second-order differential equation, and when horizontal-vertical calculation had 1.5th-order differential equation, there was the highest detection rate which was 83.1%. In the threshold of Canny edge detection technique, the highest detection rate of 89.9% was found at Low=50, and High=300.

Real Time Edge Detection for Rounding Machines Using by CCD Vision (Vision을 이용한 실시간 모서리 가공부재의 에지검출 자동화)

  • 박종현;함이준;노태정;김경환;손상익
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.695-698
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    • 2000
  • Round-cornering machines are mainly used for cornering of stiffners for ship buildings. In the present time they have been operated manually by operators. so they are need to be operated automatically without regard to any shapes of stiffners. We developed the automatic round cornering system which consists of CCd Camera, PC and laser diode to detect automatically the edge of stiffners to be processed

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Edge Detection using Second Order Derivative Strain (미분방식을 이용한 에지 추출)

  • Kim, Alla;Lee, Hyun-Jik;Kim, Yoon-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.165-167
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    • 2008
  • 본 논문에서는 기존의 에지 추출 알고리즘을 비교하여 알고리즘이 영상 처리 과정에 미치는 영향을 분석하였다. 기존의 에지 추출 알고리즘인 Sobel, Prewitt, Roberts 등을 비교 분석 한 뒤 1차 미분 조건에 2차 미분의 단점을 보완한 에지 추출 마스크 방식을 제안한다.

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Text Detection based on Edge Enhanced Contrast Extremal Region and Tensor Voting in Natural Scene Images

  • Pham, Van Khien;Kim, Soo-Hyung;Yang, Hyung-Jeong;Lee, Guee-Sang
    • Smart Media Journal
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    • v.6 no.4
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    • pp.32-40
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    • 2017
  • In this paper, a robust text detection method based on edge enhanced contrasting extremal region (CER) is proposed using stroke width transform (SWT) and tensor voting. First, the edge enhanced CER extracts a number of covariant regions, which is a stable connected component from input images. Next, SWT is created by the distance map, which is used to eliminate non-text regions. Then, these candidate text regions are verified based on tensor voting, which uses the input center point in the previous step to compute curve salience values. Finally, the connected component grouping is applied to a cluster closed to characters. The proposed method is evaluated with the ICDAR2003 and ICDAR2013 text detection competition datasets and the experiment results show high accuracy compared to previous methods.