• Title/Summary/Keyword: 메디안 필터

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Real-Time 2-D Median Filter (실시간 2차원 메디안 필터)

  • Jeong, Jae-Gil
    • The Journal of Engineering Research
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    • v.3 no.1
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    • pp.57-64
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    • 1998
  • This paper presents an architecture of a real-time two-dimensional median filter. The architecture has appropriate characteristics for the VLSI implementation such as small memory requirements, regular computations, and local data transfers. For the efficient two-dimensional median filter, a separable two-dimensional median filtering structure and a bit-sliced pipelined median searching algorithm are used. A behavioral simulator is implemented with C language and used for the analysis of the presented architecture.

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Image Restoration using Weighted Octagonal Median Filter (가중 팔각형 메디안 필터를 이용한 영상 복원)

  • Lee, Eun-Young;Na, Cheol-Hun;Lee, Eun-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.2
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    • pp.202-207
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    • 2021
  • One of the most important tasks in image processing is noise filtering. Noise removal in image is a difficult task due to many reasons such as nonstationary sequences and corrupted by various types of noise. Human's visual perception is heavily based on the edge information. Thus, noise filtering must preserve edges. To remove the noise, we usually use the square-shaped median filter. They possess mathematical simplicity but have the disadvantages that blur the edges. In this paper we consider a new technique for image restoration using a weighted octagonal median filter. The technique consists of simple hypothesis test for edge detection, and we use the weighted octagonal-shaped moving window. The new technique is applied to noise corrupted image and experimental results are compared to the results of the square-shaped median filter and the cross-shaped median filter.

Real-time 2-D Separable Median Filter (실시간 2차원 Separable 메디안 필터)

  • Jae Gil Jeong
    • Journal of the Korea Computer Industry Society
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    • v.3 no.3
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    • pp.321-330
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    • 2002
  • A 2-D median filter has many applications in various image and video signal processing areas. The rapid development in VLSI technology makes it possible to implement a real-time or near real-time 2-D median filter with reasonable cost. For the efficient VLSI implementation, the algorithm should have characteristics such as small memory requirements, regular computations, and local data transfers. This paper presents an architecture of the real-time two-dimensional separable median filter which has appropriate characteristics for the VLSI implementation. For the efficient two-dimensional median filter, a separable two-dimensional median filtering structure and a bit-sliced pipelined median searching algorithm are used. A behavioral simulator is implemented with C language and used for the analysis of the presented architecture.

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A Study on the Characteristics of noise smoothing in FIR-Median Hybrid Filters (메디안 혼성 필터의 잡음 특성 개선)

  • 최삼길;김창규;전계록;김명기;변건식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.11
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    • pp.1185-1198
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    • 1992
  • In this paper, the differential weighted algorithm proposed in order to improve th noise smoothing characteristics of conventional Median filter and FIR-Median Hybrid filter. Performance of some image restoration filter(median filter, FIR-Median Hybird filter, FIR-Median Hybrid filter to proposed differential weighted algorithm) are compared and evaluated on the noise smoothing characteristics and sharp edge conservation characteristics. Test and Real images used in this paper are Lenna and Urological images corrupted by impulse, gaussian, exponential and laplacian noise. Experimental results show that the FIR-Median Hybrid filter applied to the differential weighted algorithm are comparatively superior to others. But the filter orders have increased, the more time consumed to image processing. Hence if the adequate filtering by the type of image is selected. now after a great support will be take consideration into the various parts of application by computer science and of medical image processing.

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X-선 산란 잡음 제거 필터의 성능 비교

  • 이후민
    • Journal of The Korean Radiological Technologist Association
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    • v.28 no.1
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    • pp.241-241
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    • 2002
  • 영상 데이타는 전송, 검출 및 처리과정에서 여러 잡음에 의해 훼손될 수 있다. 적응성 가중 메디안 필터라는 공간변화 필터를 사용하여 X-선 산란 잡음을 제거하였다. 제안된 필터는 처리 윈도우 내 각 픽셀의 국소 통계치의 변화에 따라 필터의 성능이 변화하여 에너지를 최대한 보존하면서 잡음만을 제거하고자 이러한 국소 통계값에 근거한 적응성 가중 메디안 필터(AWMF)를 제시한다. AWMF를 구현함에 있어 두 가지 방법으로 나뉘는데, 우선 국소 통계의 특성에

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A study on Adaptive Multi-level Median Filter using Direction Information Scales (방향성 정보 척도를 이용한 적응적 다단 메디안 필터에 관한 연구)

  • 김수겸
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.4
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    • pp.611-617
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    • 2004
  • Pixel classification is one of basic image processing issues. The general characteristics of the pixels belonging to various classes are discussed and the radical principles of pixel classification are given. At the same time. a pixel classification scheme based on image direction measure is proposed. As a typical application instance of pixel classification, an adaptive multi-level median filter is presented. An image can be classified into two types of areas by using the direction information measure, that is. smooth area and edge area. Single direction multi-level median filter is used in smooth area. and multi-direction multi-level median filter is taken in the other type of area. What's more. an adaptive mechanism is proposed to adjust the type of the filters and the size of filter window. As a result. we get a better trade-off between preserving details and noise filtering.

Image Enhancement using Weighted Cross-Shaped Moving Window Median Filter (가중 격자형 메디안 필터를 이용한 영상향상)

  • Kim, Su-Yeong;Lee, Seung-Sang;Kang, Seong-Jun;Na, Cheol-Hun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.807-810
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    • 2013
  • In this paper, a new technique for image enhancement using weighted cross-shaped median filter with edge-detection algorithm is proposed. It consists of simple hypothesis test for edge-detection, and makes use of the cross-shaped moving window. This method is applied to noise corrupted image and its results are compared with those of median filters. As for the experimental result, method of weighted cross-shaped median filter is superior to other median filters.

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Image Restoration using Weighted Cross-Shape Median Filter (가중격자형 메디안 필터를 이용한 영상복원)

  • Na, Cheol-Hun;Kim, Su-Yeong;Han, Man-Soo;Kang, Seong-Jun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.711-714
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    • 2015
  • A new technique for image restoration using Weighted cross-shaped median filter with edge-detection algorithm is proposed in this paper. It consists of simple hypothesis test for edge-detection, and makes use of the weighted cross-shape window. This method is applied to noise corrupted image and its results are compared with those of median filters. As for the experimental result, method of weighted cross-shape median filter is superior to other median filters.

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Image Enhancement using Cross-Shaped Median Filter (격자형 메디안 필터를 이용한 영상향상)

  • Kim, Su-Yeong;Han, Man-Soo;Kang, Seong-Jun;Na, Cheol-Hun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.1006-1009
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    • 2013
  • In this paper, a new technique for image enhancement using cross-shaped median filter with edge-detection algorithm is proposed. It consists of simple hypothesis test for edge-detection, and makes use of the cross-shaped window. This method is applied to noise corrupted image and its results are compared with those of median filters. As for the experimental result, method of cross-shaped median filter is superior to other median filters.

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Adaptive Median Filter by Local Variance and Local Central Variance (로컬 분산과 로컬 중간값 분산을 이용한 적응형 메디안 필터)

  • 조우연;최두일
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.285-294
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    • 2004
  • Median Filters in the Signal Processing have been most widely used and have demonstrated the most strongest effects. This paper proposes the Adaptive Median Filters by using noise detection. The basic algorithm of the proposed filters is to determine whether noise or not by the each noise judgement standards, and then take the Median Filter if it satisfies the conditions as a result of judgement and returns to the original image(No Filters) if not. This paper presented Noise Detection by Local Variance and Local Central Variance for noise judgement, compared and analyzed the features and performance of existing [5]∼[10] Filters. Filter improved on the result of executing the existing filters at the same condition and showed the effects over that when it was judged with naked eyes. Accordingly, the Adaptive Median Filters by Local Variance and Local Central Variance was proven to have reinforced edge preservation ability and have the strong features for removing the Impulse Noise of the Median Filter.