• Title/Summary/Keyword: Median Filtering

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A Mixed Nonlinear Filter for Image Restoration under AWGN and Impulse Noise Environment

  • Gao, Yinyu;Kim, Nam-Ho
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.591-596
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    • 2011
  • Image denoising is a key issue in all image processing researches. Generally, the quality of an image could be corrupted by a lot of noise due to the undesired conditions of image acquisition phase or during the transmission. Many approaches to image restoration are aimed at removing either Gaussian or impulse noise. Nevertheless, it is possible to find them operating on the same image, which is called mixed noise and it produces a hard damage. In this paper, we proposed noise type classification method and a mixed nonlinear filter for mixed noise suppression. The proposed filtering scheme applies a modified adaptive switching median filter to impulse noise suppression and an efficient nonlinear filer was carried out to remove Gaussian noise. The simulation results based on Matlab show that the proposed method can remove mixed Gaussian and impulse noise efficiently and it can preserve the integrity of edge and keep the detailed information.

A Study on an Image Noise Erase Method By to be an Image Noise Frequent Occur for Raining, in Measurement Machine Vision System for using CCD Camera Of Pantograph Sliding Plate (팬터그래프 습판마모의 머신 비젼 측정에서 우천시 발생하는 영상의 노이즈 제거방법에 대한 연구)

  • Lee, Seong-Gwon;Lee, Dae-Won;Kang, Seung-Wook;Oh, Sang-Yoon
    • Proceedings of the KIEE Conference
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    • 2007.11c
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    • pp.191-193
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    • 2007
  • Pantograph sliding plate abrasion auto-detect system, one of the electric rail car auto-detecting devices, is a system that decides how much abrasion and when to replace without an inspector physically looking at the abrasion on the wet plate using machine vision, a cutting-edge technology. This paper covers the cause of deteriorating reliability that affects pantograph wet plate edge detection due to noise added to the video when it rains. In order to remove such noise, problems should be checked through Smoothing, Averaging mask and Median filter using filtering technique and stable edge detection without being affected by noise should be induced in video measurement used in machine vision technology.

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Character Region Extraction of Monumental Inscription Image Using Boundary Information (윤곽선 정보를 이용한 금석문 영상의 글자 영역 추출)

  • 최호형;박영식;김기석
    • Proceedings of the Korea Multimedia Society Conference
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    • 2002.11b
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    • pp.118-121
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    • 2002
  • The study on shilla monumental inscription has been accomplished by many historians. However, the research on segmentation of monumental inscription image using digital image processing is not sufficient for restoration of the image. Although, many image processing methods have been proposed for region extraction in still image, there is no suitable method for accurate interpretation of monumental inscription image. To distinguish foreground and background region in the image, this paper presents new segmentation algorithm composed of contrast adjustment and median filtering, thresholding and sobel operation, as pre-processing and post-processing. The result show that background and foreground regions are segmented in monumental inscription image.

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A Study on Edge Enhancement In Noise Contaminated Medical Images (잡음이 혼입된 의료영상의 경계선 향상에 관한 연구)

  • Kim, W.K.;Kim, N.H.;Yoo, S.K.;Huh, J.M.
    • Proceedings of the KOSOMBE Conference
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    • v.1990 no.11
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    • pp.29-32
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    • 1990
  • The method for enhancing the edges from medical images is described. The various methods are tested for the medical Images contaminated by noises, such as weighted averaging based on local probabilities, unsharp masking techniques, and proposed combined techniques. As a result, the combined technique using the median filtering and edge masks in six directions is well suited to remove the noises as to as to preserve the edges. Experimental results and computational procedures are presented.

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A Study on an Image Restoration Algorithm in Universal Noise Environments

  • Jin, Bo;Kim, Nam-Ho
    • Journal of information and communication convergence engineering
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    • v.6 no.1
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    • pp.80-85
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    • 2008
  • Images are often corrupted by noises during signal acquisition and transmission. Among those noises, additive white Gaussian noise (AWGN) and impulse noise are most representative. For different types of noise have different characters, how to remove them separately from degraded image is one of the most fundamental problems. Thus, a modified image restoration algorithm is proposed in this paper, which can not only remove impulse noise of random values, but also remove the AWGN selectively. The noise detection step is by calculating the intensity difference and the spatial distance between pixels in a mask. To divide two different noises, the method is based on three weighted parameters. And the weighted parameters in the filtering mask depend on spatial distances, positions of impulse noise and standard deviation of AWGN. We also use the peak signal-to-noise ratio (PSNR) to evaluate restoration performance, and simulation results demonstrate that the proposed method performs better than conventional median-type filters, in preserving edge details.

Moving Object Detection and Tracking in Image Sequence with complex background (복잡한 배경을 가진 영상 시퀀스에서의 이동 물체 검지 및 추적)

  • 정영기;호요성
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.615-618
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    • 1999
  • In this paper, a object detection and tracking algorithm is presented which exhibits robust properties for image sequences with complex background. The proposed algorithm is composed of three parts: moving object detection, object tracking, and motion analysis. The moving object detection algorithm is implemented using a temporal median background method which is suitable for real-time applications. In the motion analysis, we propose a new technique for removing a temporal clutter, such as a swaying plant or a light reflection of a background object. In addition, we design a multiple vehicle tracking system based on Kalman filtering. Computer simulation of the proposed scheme shows its robustness for MPEG-7 test image sequences.

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ESPI Simulation for the Vibration Modes of the Thin Right-Angled Plate (얇은 직각판의 진동 모드에 대한 ESPI 시뮬레이션)

  • 장순석
    • Journal of KSNVE
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    • v.9 no.3
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    • pp.509-516
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    • 1999
  • The ESPI (Electronic Speckle Pattern Interferometry) algorithm has been simulated to calculate vibrational modes of a thin right-angled STS304 plate. The phase transformation of the reference wave of the ESPI is carried out only one time during vibration in order to clarify ESPI speckle patterns. Two dimensional vibrational modes are calculated from one ESPI pattern before vibration onset and two ESPI patterns during vibrations but with and without the phase transformation. The ESPI harmonic results are compared with those derived from the finite element method (FEM), and they agree very well. Additionally a phase unwrapping algorithm has been newly developed to derive a displacement map from an ESPI phase map.

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Realization of PCB Insert Machine Automation (PCB 조립로봇 자동화를 위한 시스템 구현)

  • 김상주;강진구;최승욱;이장명
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.239-242
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    • 2002
  • This paper has been realized PCB insert machine automation system. For the reduction of the install programming time as well as possible, a new technique is addressed. In detail, an image frame is initially divided into one area whose size decreases according to the distance from hole to hole on PCB. Searching center of hole using a threshold method after median filtering. At every moment of mouse click, area is shifted to locate the hole, and detect a center of hole in a new area. Experimental results are demonstrated to verify the superiority of this scheme in detecting position of part by comparing with a man of experience.

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A Study on Skull & panorama Image recognition of feature exctraction using the Wavele Transform (웨이브렛 변환을 이용한 Skull & Panorama 영상 인식과 특징 추출에 관한 연구)

  • 문일남;김장형
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.113-117
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    • 2003
  • In this paper, have necessity of PACS (Picture Archiving and Communication System) at hospital but hereafter by economical problem PACS apply this to medical treatment image enhancing image quality applying histogram equalization for improvement of light and darkness after reconstruct because make image that pretreatment filtering has wild picture and is processed in wave lets dissolution and wave lets area using weight median filter because could not buy expensive equipment at hospital which introduction is difficulty do inversion and extracted characteristic.

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Detection of the P Wave in Multilead ECGs (다중 리드 심전도 신호에서의 P파 검출)

  • Kim, D.S.;Jun, D.G.;Khil, M.J.;Yoon, H.R.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.175-176
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    • 1998
  • The automated ECG diagnostic systems that are used in hospitals have low performance of P wave detection when faced with some diseases such as conduction block. So, the aim of this study is the improvement of detection performance in conduction block which is low in P wave detection. Median QRS-T segments were subtracted from the raw data and residual in the QRS-T regions was zeroed. After band pass filtering, we applied approximated length transformation to detect P wave.

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