• Title/Summary/Keyword: Sobel Edge Detection

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Research on Water Edge Extraction in Islands from GF-2 Remote Sensing Image Based on GA Method

  • Bian, Yan;Gong, Yusheng;Ma, Guopeng;Duan, Ting
    • Journal of Information Processing Systems
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    • v.17 no.5
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    • pp.947-959
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    • 2021
  • Aiming at the problem of low accuracy in the water boundary automatic extraction of islands from GF-2 remote sensing image with high resolution in three bands, new water edges automatic extraction method in island based on GF-2 remote sensing images, genetic algorithm (GA) method, is proposed in this paper. Firstly, the GA-OTSU threshold segmentation algorithm based on the combination of GA and the maximal inter-class variance method (OTSU) was used to segment the island in GF-2 remote sensing image after pre-processing. Then, the morphological closed operation was used to fill in the holes in the segmented binary image, and the boundary was extracted by the Sobel edge detection operator to obtain the water edge. The experimental results showed that the proposed method was better than the contrast methods in both the segmentation performance and the accuracy of water boundary extraction in island from GF-2 remote sensing images.

Development and Implementation of Statistical Edge Detectors on the Web (웹 상에서 통계적 에지검출기 개발 및 구현)

  • Lim, Dong-Hoon
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.133-141
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    • 2005
  • An edge is where the intensity of an image moves from a low value to high value or vice versa. The edges tell where objects are. their shape and size. and something about their texture. Many traditional edge operators are derivative based and perform reasonably well for simple noise-free images. In recent, statistical edge detectors for complex images with noises have been described. This paper compares and analysis the performance of statistical edge detectors based on the T test and Wilcoxon test, and mathematical edge detectors based on Sobel operator, and the well-known Canny detector and Wavelet transformation detector, and provides the implementation of these edge detectors using Java on the web.

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Fuzzy Classifier System for Edge Detection

  • Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.52-57
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    • 2003
  • In this paper, we propose a Fuzzy Classifier System(FCS) to find a set of fuzzy rules which can carry out the edge detection. The classifier system of Holland can evaluate the usefulness of rules represented by classifiers with repeated learning. FCS makes the classifier system be able to carry out the mapping from continuous inputs to outputs. It is the FCS that applies the method of machine learning to the concept of fuzzy logic. It is that the antecedent and consequent of classifier is same as a fuzzy rule. In this paper, the FCS is the Michigan style. A single fuzzy if-then rule is coded as an individual. The average gray levels which each group of neighbor pixels has are represented into fuzzy set. Then a pixel is decided whether it is edge pixel or not using fuzzy if-then rules. Depending on the average of gray levels, a number of fuzzy rules can be activated, and each rules makes the output. These outputs are aggregated and defuzzified to take new gray value of the pixel. To evaluate this edge detection, we will compare the new gray level of a pixel with gray level obtained by the other edge detection method such as Sobel edge detection. This comparison provides a reinforcement signal for FCS which is reinforcement learning. Also the FCS employs the Genetic Algorithms to make new rules and modify rules when performance of the system needs to be improved.

A Study on the Implementation of the Motion Tracing ASIC Based on the Edge Detection (윤곽선 검출에 바탕을 둔 움직임 추적 ASIC 구현에 관한 연구)

  • 김희걸;조경순
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.112-115
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    • 2000
  • This paper describes the algorithm, architecture and design of the circuit implementing motion tracing features based on the edge detection. The Sobel operation was used to compute the edges of moving objects. Motion tracing is performed by searching for the center of the edges for each frame and adding those centers. The edger and the centers of the moving object from camera were displayed in the monitor and verified using Xillinx FPGA.

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Development of Hough Transform for Space-Variant Image (공간 변형 영상에서의 Hough 변환)

  • 김장식;진성일
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.675-678
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    • 2000
  • This paper presents a parametric line equation on the log-polar mapped plane to detect the straight lines in an original image. The log-polar edge image used in Hough transform is constructed by combining the edge images of both fovea and periphery. The foveal edge image detected by a Sobel mask on the Cartesian plane is transformed to the log-polar plane by forward mapping but the edge detection of the peripheral region is obtained by directly applying the newly developed mask to the log-polar plane. This paper also proposes a analytic method then determining a border between the fovea and the periphery regions.

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SCLC-Edge Detection Algorithm for Skin Cancer Classification (피부암 병변 분류를 위한 SCLC-Edge 검출 알고리즘)

  • June-Young Park;Chang-Min Kim;Roy C. Park
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.4
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    • pp.256-263
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    • 2022
  • Skin cancer is one of the most common diseases in the world, and the incidence rate in Korea has increased by about 100% over the past five years. In the United States, more than 5 million people are diagnosed with skin cancer every year. Skin cancer mainly occurs when skin tissue is damaged for a long time due to exposure to ultraviolet rays. Melanoma, a malignant tumor of skin cancer, is similar in appearance to Atypical melanocytic nevus occurring on the skin, making it difficult for the general public to be aware of it unless secondary signs occur. In this paper, we propose a skin cancer lesion edge detection algorithm and a deep learning model, CRNN, which performs skin cancer lesion classification for early detection and classification of these skin cancers. As a result of the experiment, when using the contour detection algorithm proposed in this paper, the classification accuracy was the highest at 97%. For the Canny algorithm, 78% was shown, 55% for Sobel, and 46% for Laplacian.

An Edge Extraction Method Using K-means Clustering In Image (영상에서 K-means 군집화를 이용한 윤곽선 검출 기법)

  • Kim, Ga-On;Lee, Gang-Seong;Lee, Sang-Hun
    • Journal of Digital Convergence
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    • v.12 no.11
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    • pp.281-288
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    • 2014
  • A method for edge detection using K-means clustering is proposed in this paper. The method is performed through there steps. Histogram equalizing is applied to the image for the uniformed intensity distribution. Pixels are clustered by K-means clustering technique. Then Sobel mask is applied to detect edges. Experiments showed that this method detected edges better than conventional method.

A Robust Edge Detection method using Van der Waerden Statistic (Waerden 통계량을 이용한 강인한 에지검출 방법)

  • 최명희;이호근;김주원;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.3
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    • pp.147-153
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    • 2004
  • This paper proposes an efficient edge detection using Van der Waerden statistic in original and noisy images. An edge is where the intensity of an image moves from a low value to a high value or vice versa. We describe a nonparametric Wilcoxon test and a parametric T test based on statistical hypothesis testing for the detection of edges. We use the threshold determined by specifying significance level $\alpha$, while Bovik, Huang and Munson consider the range of possible values of test statistics for the threshold. From the experimental results of edge detection, the T and Wilcoxon method perform sensitively to the noisy image, while the proposed Waerden method is robust over both noisy and noise-free images under $\alpha$=0.0005. Comparison with our statistical test and Sobel, LoG, Canny operators shows that Waerden method perform more effectively in both noisy and noise-free images.

Moving Object Contour Detection Using Spatio-Temporal Edge with a Fixed Camera (고정 카메라에서의 시공간적 경계 정보를 이용한 이동 객체 윤곽선 검출 방법)

  • Kwak, Jae-Ho;Kim, Whoi-Yul
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.474-486
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    • 2010
  • In this paper, we propose a new method for detection moving object contour using spatial and temporal edge. In general, contour pixels of the moving object are likely present around pixels with high gradient value along the time axis and the spatial axis. Therefore, we can detect the contour of the moving objects by finding pixels which have high gradient value in the time axis and spatial axis. In this paper, we introduce a new computation method, termed as temporal edge, to compute an gradient value along the time axis for any pixel on an image. The temporal edge can be computed using two input gray images at time t and t-2 using the Sobel operator. Temporal edge is utilized to detect a candidate region of the moving object contour and then the detected candidate region is used to extract spatial edge information. The final contour of the moving object is detected using the combination of these two edge information, which are temporal edge and spatial edge, and then the post processing such as a morphological operation and a background edge removing procedure are applied to remove noise regions. The complexity of the proposed method is very low because it dose not use any background scene and high complex operation, therefore it can be applied to real-time applications. Experimental results show that the proposed method outperforms the conventional contour extraction methods in term of processing effort and a ghost effect which is occurred in the case of entropy method.

Detection of Flaws in Air Deck using Non-Destructive Testing (비파괴 검사를 이용한 항공 갑판의 결함 검출)

  • Kim, Kwang-Baek;Cho, Jae-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.9
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    • pp.1865-1870
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    • 2011
  • In this paper, we propose an effective method that automatically detects flaws in air deck by using non-destructive testing. First, Gamma correlation transform, 7 ${\times}$ 7 and 13 ${\times}$ 13 Sobel mask apply to the image of air deck acquired non-destructive testing in order to detect the edge of the image. Second, the edge detection area is smoothed and corrected by mean binarization method. Finally, the region of flaws in air deck is detected by a labeling method after removing the noise by the erosion and the dilation operation. In experimental results, we showed that the proposed detection method is effective in air deck.