• Title/Summary/Keyword: Adaptive edge detection

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Spatially Adaptive CLS Based Image Restoration (CLS 기반 공간 적응적 영상복원)

  • 백준기;문준일;김상구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.10
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    • pp.2541-2551
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    • 1996
  • Human visual systems are sensitive to noise on the flat intensity area. But it becomes less sensitive on the edge area. Recently, many types of spatially adaptive image restoration methods have been proposed, which employ the above mentioned huan visual characteristics. The present paper presents an adaptive image restoration method, which increases sharpness of the edge region, and smooths noise on the flat intensity area. For edge detection, the proposed method uses the visibility function based on the local variance on each pixel. And it adaptively changes the regularization parameter. More specifically, the image to be restored is divided into a number of steps from the flat area to the edge regio, and then restored by using the finite impulse response constrained least squares filter.

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Adaptive High-order Variation De-noising Method for Edge Detection with Wavelet Coefficients

  • Chenghua Liu;Anhong Wang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.2
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    • pp.412-434
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    • 2023
  • This study discusses the high-order diffusion method in the wavelet domain. It aims to improve the edge protection capability of the high-order diffusion method using wavelet coefficients that can reflect image information. During the first step of the proposed diffusion method, the wavelet packet decomposition is a more refined decomposition method that can extract the texture and structure information of the image at different resolution levels. The high-frequency wavelet coefficients are then used to construct the edge detection function. Subsequently, because accurate wavelet coefficients can more accurately reflect the edges and details of the image information, by introducing the idea of state weight, a scheme for recovering wavelet coefficients is proposed. Finally, the edge detection function is constructed by the module of the wavelet coefficients to guide high-order diffusion, the denoised image is obtained. The experimental results showed that the method presented in this study improves the denoising ability of the high-order diffusion model, and the edge protection index (SSIM) outperforms the main methods, including the block matching and 3D collaborative filtering (BM3D) and the deep learning-based image processing methods. For images with rich textural details, the present method improves the clarity of the obtained images and the completeness of the edges, demonstrating its advantages in denoising and edge protection.

A study on adaptive weighted median filter using edge information (에지정보를 이용한 적응적 가중메디안필터에 대한 연구)

  • Lee, Yong-Hwan;Park, Jang-Chun
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.10
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    • pp.2830-2837
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    • 1999
  • Image processing steps are consist of image acquisition, preprocessing, region, segmentation and recognition. But image corrupted commonly by noise reduction methods, many filters were proposed like mean filter, median filter, weighted median filter, Cheikh filter, and Kyu-cheol lee filter as spatial noise reduction filtering. We propose a new edge detection algorithm so that we find out edge existence and nonexistence. In non-edge area, we selectively apply weighted median filter based upon using information of difference value between weighted median filter's value and center pixel's value. As a result, we finally prove a better performance of noise reduction by applying adaptive weighted median filter and improvement of processing time through using simple algorithm.

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Cost Maximization Approach to Edge Detection Using a Genetic Algorithm (유전자 알고리즘을 이용한 비용 최대화에 의한 에지추출)

  • 김수겸;박중순
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.3
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    • pp.293-301
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    • 1997
  • Edge detection is the first step and very important step in image analysis. We cast edge detec¬tion as a problem in cost maximization. This is acheived by the formulation of a cost function that evaluates the quality of edge configurations. The cost function can be used as a basis for compar¬ing the performances of different detectors. We used a Genetic Algorithm for maximizing cost func¬tion. Genetic algorithms are a class of adaptive search techniques that have been intensively stud¬ied in recent years and have been prone to converge prematurely before the best solution has been found. This paper shows that carefully chosen modifications(three factors of the crossover opera¬tor) are implemented can be effective in alleviating this problem.

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A Motion-Adaptive De-interlacing Method using Motion Compensated Interpolation (움직임 보상을 통한 움직임 기반의 De-interlacing 기법)

  • 이성규;강석규;이동호
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.371-374
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    • 2001
  • 본 논문에서는 움직임 보상을 이용한 Motion-Adaptive De-interlacing Method를 제안 한다. 정확한 움직임 추정을 위해서 Pre-filter로서 EBMF(Edge Based Median Filter)를 사용하며 새로운 Block Matching Method를 제안한다. Temporal Filter로서 Motion Missing Error를 제거하기 위해 입력 영상의 움직임 영역에 따라 각각 다른 임계 값을 적용하는 AMPDF(Adaptive Minimum Pixel Difference Filter)를 적용하였으며 MMD(Maximum Motion Detection)와 SAD(Sum of Difference)를 이용하여 빠른 움직임 영역에서 화질을 향상시켰다. 최종적으로 잘못된 움직임 보상에 기인하는 화질의 열화를 방지하기 위한 Motion Correction Filter를 제안한다.

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An Edge Detector by Using Perfect Sharpening of Ramps (램프의 완전 선명화를 이용한 에지 검출기)

  • Lee, Jong-Gu;Yoo, Cheol-Jung;Chang, Ok-Bae
    • Journal of KIISE:Software and Applications
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    • v.34 no.11
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    • pp.961-970
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    • 2007
  • Since the usual conventional edge detectors employ the local differential derivatives, the detected edges are not uniform in their widths or some edges are missed out of the detection on magnified images. We employ a mapping from the exactly monotonic intensity distributions of ramp edges to the simple step functions of intensity, which is referred to as perfect sharpening map of ramp edges. This map is based on the non-local feature of intensity distribution and used to introduce a modified differentiation, in terms of which we can construct an efficient edge detector adaptive to the variation of edge width. By adopting the operator MADD in this paper, we developed an edge detector that works stably against the magnification of image or the variation of edge width. It is shown by comparing to the conventional algorithms that the proposed one is very excellent.

Adaptive Filtering Processing for Target Signature Enhancement in Monostatic Borehole Radar Data

  • Hyun, Seung-Yeup;Kim, Se-Yun
    • Journal of electromagnetic engineering and science
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    • v.14 no.2
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    • pp.79-81
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    • 2014
  • In B-scan data measured by a pulse-type monostatic borehole radar, target signatures are seriously obscured by two clutters that differ in orientation and intensity. The primary clutter appears as a nearly constant time delay, which is caused by internal ringing between antenna and transceiver in the radar system. The secondary clutter occurs as an oblique time delay due to the guided borehole wave along the logging cable of the radar antenna. This issue led us to perform adaptive filtering processing for orientation-based clutter removal. This letter describes adaptive filtering processing consisting of a combination of edge detection, data rotation, and eigenimage filtering. We show that the hyperbolic signatures of a dormant air-filled tunnel target can be more distinctly enhanced by applying the proposed approach to the B-scan data, which are measured in a well-suited test site for underground tunnel detection.

A Study on Cascade Filter Algorithm for Random Valued Impulse Noise Elimination (랜덤 임펄스 잡음제거를 위한 캐스케이드 필터 알고리즘에 관한 연구)

  • Yinyu, Gao;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.3
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    • pp.598-604
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    • 2012
  • Image signal is corrupted by various noises in image processing, many studies are being accomplished to restore those images. In this paper, we proposed a cascade filter algorithm for removing random valued impulse noise. The algorithm consists two steps that noise detection and noise elimination. Variance of filtering mask and center pixel variance are calculated for noise detection, and the noise pixel is replaced by estimated value which first apply switching self adaptive weighted median filter and finally processed by modified weight filter. Considering the proposed algorithm only remove noise and preserve the uncorrupted information that the algorithm can not only remove noise well but also preserve edge.

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.

Vehicle extraction and tracking of stereo (스테레오를 이용한 차량 검출 및 추적)

  • Youn, Se-Jin;Woo, Dong-Min
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.2962-2964
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    • 1999
  • We know the traffic information about the velocity and position of vehicle by extraction and tracking vehicle from continuosly obtained road image of camera. The conventional method of vehicle detection indicate increment of error due to headlight and taillight in night road image. This paper show such as vehicle detection of binary, Edge detection. amalgamation of image are applied to extract the vehicle, and Kalman filter is adaptive methods for tracking position and velocity of vehicle.

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