• Title/Summary/Keyword: standard median

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Modified Median Filter for Image Restoration in Salt and Pepper Noise Environments (Salt and Pepper 잡음 환경에서 영상 복원을 위한 변형된 메디안 필터)

  • Hong, Sang-Woo;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.252-255
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    • 2014
  • Image treatment is becoming mainstream as the demand for image restoration has drastically increased in the digital era. But in the process of acquiring, transmitting and treating video data, the salt and pepper noise damages the image. One of the major methods used for restoring images are SMF(standard median filter), CWMF(center weighted median filter) and SWMF(switching weighted median filter), but these filters all leave a bit to be desired in terms of removing noise and preserving edge. Therefore, a transformed median filter is suggested through the algorithm presented for the restoration of damaged images.

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A Study on Composite Filters for Salt and Pepper Noise Removal (Salt and Pepper 잡음 제거를 위한 복합 필터에 관한 연구)

  • Hong, Sang-Woo;Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.409-411
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    • 2016
  • Salt and pepper noise is caused by various causes such as camera malfunction, storage media memory error, and transmission channel error. Representative filters to remove salt and pepper noise include SMF(standard median filter), CWMF(center weighted median filter), and AMF(adaptive median filter). However previous filters have inadequate noise removal characteristics in high density salt-and-pepper noise environment. Therefore the study suggested a composite filter which, through noise evaluation, preserves original pixels when the central pixel is non-noise, and uses spatial weighted value mask and median when there is noise.

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Landscape Preference of the Guide Coating in the Median Barrier on the Expressway by Win-Road Simulation (Win-Road Simulation을 활용한 고속도로 중앙분리대 시선유도도장에 대한 경관선호도 분석)

  • Kim, Tae Gyun;Choi, Jae Young;Lee, Mun Young;Kum, Ki Jung
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.117-125
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    • 2013
  • PURPOSES: By conducting the landscape survey that considered landscape factors of the Guide Coating in the Median Barrier that applied of the various level by simulating of the Guide Coating in the Median Barrier on the expressway, they showed the quantitative standard of landscape preference factors that the Guide Coating gives. METHODS: The shape of the Structural Equation Modeling used AMOS program and made a shape that is made of landscape preference for the Guide Coating in the Median Barrier on the expressway a dependent variable. RESULTS: Result in this, they showed that functionality and emotionalism are the factors that affect the landscape preference. CONCLUSIONS: In the main study, not only showing the Guide Coating in the Median Barrier on the expressway landscape valuation but also embodying the Structural Equation Modeling(SEM) of each group, knowing the Guide Coating and unknowing the Guide Coating. By embodying this, they could study that the drivers' quantitative standard is different when the Guide Coating become first applied and being changed after.

Image Restoration by Lifting-Based Wavelet Domain E-Median Filter

  • Koc, Sema;Ercelebi, Ergun
    • ETRI Journal
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    • v.28 no.1
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    • pp.51-58
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    • 2006
  • In this paper, we propose a method of applying a lifting-based wavelet domain e-median filter (LBWDEMF) for image restoration. LBWDEMF helps in reducing the number of computations. An e-median filter is a type of modified median filter that processes each pixel of the output of a standard median filter in a binary manner, keeping the output of the median filter unchanged or replacing it with the original pixel value. Binary decision-making is controlled by comparing the absolute difference of the median filter output and the original image to a preset threshold. In addition, the advantage of LBWDEMF is that probabilities of encountering root images are spread over sub-band images, and therefore the e-median filter is unlikely to encounter root images at an early stage of iterations and generates a better result as iteration increases. The proposed method transforms an image into the wavelet domain using lifting-based wavelet filters, then applies an e-median filter in the wavelet domain, transforms the result into the spatial domain, and finally goes through one spatial domain e-median filter to produce the final restored image. Moreover, in order to validate the effectiveness of the proposed method we compare the result obtained using the proposed method to those using a spatial domain median filter (SDMF), spatial domain e-median filter (SDEMF), and wavelet thresholding method. Experimental results show that the proposed method is superior to SDMF, SDEMF, and wavelet thresholding in terms of image restoration.

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Modified Median Filter for Impulse Noise Removal (임펄스 잡음 제거를 위한 변형된 메디안 필터)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.461-466
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    • 2013
  • As the technology of the digital information age has developed rapidly, lots of research has been done on the digital image processing techniques, such as the image restoration. However, the SM(Standard Median) filter is a typical method of recovering the image which are corrupted by the impulse noise, this method will also reduce the quality of image by generating an error in the edge region. In this paper, in order to restore the corrupted images in the impulse noise environment, a modified median filter algorithm is proposed, which uses the pixels as the center and takes double mask. By using the double mask, we are succeeded in acquiring the excellent performance on noise-canceling, edge preservation, and also in improving the quality of image.

A Study on Nonlinear Spatial Filter using Directional Information of Image (영상의 방향성 정보를 이용한 비선형 공간필터에 관한 연구)

  • Kim, Uk;Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.359-362
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    • 2007
  • According to the development of information and communication technology, a great deal of researches have been taken in image digital processing field. And for earning the standard level of images, to remove noises such as impulse noise has became a essential demand. In those algorithms which remove impulse noise effectively, the standard median (SM) filter is representative. However, it has a disadvantage to degrade the quality of overall image by occurring errors in the edge domain. Therefore, in this paper, to restore the corrupted image by impulse noise, a nonlinear spatial filter based on Min-max operation was proposed and it was compared with conventional methods through simulations.

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The Modified Median Filter using Standard Deviation in Impulse Noise Environment (임펄스 잡음환경에서 표준편차를 이용한 변형된 메디안 필터)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.7
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    • pp.1725-1731
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    • 2013
  • Recently, as industrial society is developed as high digital information age, image processing is used in a variety of areas. However, image deterioration is still occurred by several noises in the data processing, and different kinds of researches are in progress for noise removal. Therefore, this paper limited the modified median filter by using standard deviation to removes impulse noise. The proposed algorithms divided into noise detection and noise removal, the noise free pixel is maintained, the noise pixel filtered. And it was compared with the existing methods for its objective judgment, using PSNR(peak signal to noise ratio) as standard criteria.

Optimal Design for a Structure Using Design of Experiment (실험계획법을 이용한 구조물의 최적설계)

  • 고성호;한석영;최형연
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.34-39
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    • 2001
  • The median barrier is one of the roadside hardware to prevent severe human and property damage from highway traffic accidents. The foreign standard of concrete median barrier was introduced and implemented without modification fitting to domestic vehicle and highway condition. In a car accident, median barrier doesn't protect vehicle effectively, especially for heavy vehicle such as bus and heavy truck. The purpose of this study is to develop the optimal performance design of concrete median barrier using the design of experiment with crash simulation analysis which is done by Pam-Crash that is one of the commercial crash simulation software. As a result of this study, an optimal design of concrete median barrier is obtained considering von Mises stress, volume and COG acceleration of truck.

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Design of a Protection Fence by Crashworthiness Analysis (충돌해석을 통한 방호울타리의 설계)

  • 한석영;고성호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.487-492
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    • 2002
  • In this study, designs of protection fences such as the concrete median barrier and the guardrail were performed. The foreign standard of concrete median barrier was introduced and implemented without modification fitting to domestic vehicles and highway conditions. In a car accident, median barrier doesn't protect vehicles effectively, especially for heavy vehicles such as bus and heavy truck. Guardrail doesn't protect vehicle effectively, either. The purpose of this study is to develop the optimal performance design of concrete median barrier and design of guardrail using the design of experiment as well as crashworthiness analysis which is done by Pam-Crash. As a result of this study, an optimal design of concrete median barrier was obtained considering von Mises stress, volume and COG acceleration of truck. And design of guardrail satisfying the domestic requirements was obtained.

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A Study on Nonlinear Filter for Impulse Noise Removal (Impulse 노이즈 제거를 위한 새로운 비선형 필터에 관한 연구)

  • No, Hyun-Yong;Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.981-984
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    • 2005
  • Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) fille. showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error So, variable methods that modified SM(standard median)filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

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