• Title/Summary/Keyword: Edge restoration

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A Study on Modified Adaptive Median Filter in Impulse Noise Environment (임펄스 잡음환경에서 변형된 적응 메디안 필터에 관한 연구)

  • Long, Xu;An, Young-Joo;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.883-885
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    • 2013
  • Image restoration refers to removing different kinds of noise added to image, and to reducing effect of noise upon image. For image restoration, some methods such as mean filter, median filter and weighted filter were proposed, but the existing methods have poor denoising and edge-reserved performance. Therefore, in this paper modified median filter algorithm was proposed that enlarges mask size according to median value of mask in order to remove noise efficiently. And, it was compared by simulation to the existing methods, and MSE(mean squared error) was used on a criterion of evaluation.

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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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Schemes to Overcome ATM VC Switch Failures using Backup Virtual Paths (예비 가상 경로를 이용한 ATM VC 교환기 고장 우회 방법)

  • Yoo, Young-Hwan;Ahn, Sang-Hyun;Kim, Chong-Sang
    • Journal of KIISE:Information Networking
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    • v.27 no.2
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    • pp.187-196
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    • 2000
  • Failures in ATM networks can occur at virtual path (VP) links, virtual path switches, and virtual channel (VC) switches. Restoration schemes have been proposed for VP link and VP switch failures, however, none for VC switch failures. In general, VC switches are used for edge nodes in protection domains. Since even only one VC switch failure can cause a critical problem, new restoration schemes for VC switch failures are highly required. Restoration schemes at the VP level proposed so far can be categorized into those using the flooding algorithm and those using the backup virtual path (BVP) concept. Even though the latter cannot handle unpredictable failures, it has some advantages such as fast restoration and low spare capacity requirement. In this paper, we propose new restoration schemes using a new type of BVPs to handle VC switch failures. The simulation results show that the proposed schemes can restore virtual connection failures due to VC switch failures without degrading restorability for VP failures.

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Fast Image Restoration Using Boundary Artifacts Reduction method (경계왜곡 제거방법을 이용한 고속 영상복원)

  • Yim, Sung-Jun;Kim, Dong-Gyun;Shin, Jeong-Ho;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.6
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    • pp.63-74
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    • 2007
  • Fast Fourier transform(FFT) is powerful, fast computation framework for convolution in many image restoration application. However, an actually observed image acquired with finite aperture of the acquisition device from the infinite background and it lost data outside the cropped region. Because of these the boundary artifacts are produced. This paper reviewed and summarized the up to date the techniques that have been applied to reduce of the boundary artifacts. Moreover, we propose a new block-based fast image restoration using combined extrapolation and edge-tapering without boundary artifacts with reduced computational loads. We apply edgetapering to the inner blocks because they contain outside information of boundary. And outer blocks use half-convolution extrapolation. For this process it is possible that fast image restoration without boundary artifacts.

Study for the restoration of Gyeongcheonsa Pagoda - top of pagoda - (경천사(敬天寺) 10층석탑(層石塔) 복원(復原)에 관한 고찰 I - 상륜부(相輪部)를 중심으로 -)

  • Yi, Eun-Hui;Kim, Sa-Dug;Shin, Eun-Jeong
    • Korean Journal of Heritage: History & Science
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    • v.35
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    • pp.100-118
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    • 2002
  • Originally, Gyeongcheonsa pagoda was located in Busosan, Jungyeon-ri, Gwangdeok-myeon, Gaepung-gun, Gyeonggi-do,but it has suffered from being taken out to Japan illegally in 1907 and being returned to Korea in 1918. After returned to Korea, Gyeoncheonsa Pagoda had been neglected and restored in 1960. It had been exhibited outside the Gyeingbokgung Palace after restoration, but many problems were raised. It was taken to pieces in 1995 and it is conservation and restoring today. However, the top of pagoda is necessary to be researched about its archetype because the shapes of stupa in 1902 and in 1960(the shape of pagoda after restoration) are all different from its archetype. According to picture datum in 1902, the top of pagoda was a Korean building type on a 10 layered roof stone. On the other hand, when it was restored in 1960, cement suspected as a anda was taken place between Korean building type and a 10 layered roof stone. Therefore, I am going to examine Restoration of Gyeongcheonsa pagoda in this thesis. When we examine historical records of Geongcheonsa and datum of parts, we can know that the pagoda was established in 1348(Goryeo Dynasty) but it is difficult to know the truth of its establishment and demolition of Gyeongcheonsa-temple. Three ways to restore the top of the pagoda of Gyeoncheonsa Pagoda can be c o n s i d e r e d . First, Korean building type made by metals is located on a 10 layered roof stone, which is same to picture datum in 1902. Second, the shape of and a type, which is similar to the shape when it was restored in 1960's. Also it is similar to Lamapagoda type. Third, to restore the top of pagoda of gabled roof type, which is similar to the top of pagoda of Wongaksagi P agoda. However it is necessaray to exmamine functions about circle grooves hollowed out in a 10 layered roof stone in restoration. Also we need to find out the archetype of dragon sculpture through the dragon claws left on an edge of a 10 layered roof stone.

Region-Based Step-Response Extraction and PSF Estimation for Digital Auto-Focusing (영역기반 계단응답 추출 및 디지털자동초점을 위한 점확산함수 추정)

  • Park, Young-Uk;Kim, Dong-Gyun;Lee, Jin-Hee;Paik, Joon-Ki
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.827-828
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    • 2008
  • Blur identification is the first and the most important step of restoring images. Edge region of the image usually conveys important information of blur parameters. In this paper we propose a region-based edge extraction method for estimating point-spread-function (PSF). As a result, the proposed method can detect the starting and the ending points of a step response, and provides the PSF parameters to the restoration process.

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The Design and Implementation of Real Time Contrast Enhancer System for High Resolution FPD (고해상도 FPD를 위한 실시간 Contrast Enhancer System의 설계 및 구현)

  • Seo, Bum-Suk;Choi, Chul-Ho;Kwon, Byeong-Heon
    • Journal of Digital Contents Society
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    • v.5 no.1
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    • pp.79-86
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    • 2004
  • In this paper we implemented the Real Time Contrast Enhancer for image quality enhancement of moving picture. Also we proposed adaptive contrast method that use mean and variance of input video signal. The Designed the contrast Enhancer is measured in comparison with conventional picture and interfaced to 30inch TFT LCD TV of the LG Electronics.

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Effective Single Image Haze Removal using Edge-Preserving Transmission Estimation and Guided Image Filtering (에지 보존 전달량 추정 및 Guided Image Filtering을 이용한 효과적인 단일 영상 안개 제거)

  • Kim, Jong-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1303-1310
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    • 2021
  • We propose an edge-preserving transmission estimation by comparing the patch-based dark channel and the pixel-based dark channel near the edge, in order to improve the quality of outdoor images deteriorated by conditions such as fog and smog. Moreover, we propose a refinement that applies the Guided Image Filtering (GIF), a kind of edge-preserving smoothing filtering methods, to edges using Laplacian operation for natural restoration of image objects and backgrounds, so that we can dehaze a single image and improve the visibility effectively. Experimental results carried out on various outdoor hazy images that show the proposed method has less computational complexity than the conventional methods, while reducing distortion such as halo effect, and showing excellent dehazing performance. In It can be confirmed that the proposed method can be applied to various fields including devices requiring real-time performance.

Restoration of Joseon's Mortar Used During the Japanese Invasion of Korea in 1592 (임진왜란 당시 조선 화포(중완구) 문화재복원)

  • Lim, Heung-Woong;Choi, Won-Ho
    • The Journal of the Korea Contents Association
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    • v.20 no.7
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    • pp.56-65
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    • 2020
  • The purpose of this research is to study the excellence and originality of the Joseon artillery(Jungwan-gu) through an effective restoration. Jungwan-gu that was used during the Japanese Invasion of Korea in 1592 was able to maintain its maritime dominance based on cutting-edge technology of its time. Joeson artillery(Jungwan-gu) was used in major naval/land battles during the Japanese Invasion of Korea in 1592 and is an important cultural heritage that provides a glimpse into Joeson people's will to defend the nation from foreign invasion. For further historical verification such as operational method of Jungwan-gu, extensive research in various fields including size, proportions, structure, materials, and casting method were required. Accordingly, for a more effective research on Jungwan-gu, cutting-edge technologies such as 3D scanning and 3D printing were utilized. Firstly, 3D scanning, modeling, and printing technology were applied to identify the morphological characteristics of Jungwan-gu. Through this, we were able to reach our research objective of identifying the size, internal structure, and proportionality of Jungwan-gu. In addition, by studying the form, operation, casting methods, and other characteristics, the restoration of Jungwan-gu provided us with an important opportunity to verify the dominance and originality of the Joeson era's science and technology during the Japanese Invasion of 1592. This reaserch subject participated in the "4th 3D printing BIZCON Contest" and won the Minister Prize of Science and Technology Information and Communication.

Impact Assessment of Forest Development on Net Primary Production using Satellite Image Spatial-temporal Fusion and CASA-Model (위성영상 시공간 융합과 CASA 모형을 활용한 산지 개발사업의 식생 순일차생산량에 대한 영향 평가)

  • Jin, Yi-Hua;Zhu, Jing-Rong;Sung, Sun-Yong;Lee, Dong-Ku
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.4
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    • pp.29-42
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    • 2017
  • As the "Guidelines for GHG Environmental Assessment" was revised, it pointed out that the developers should evaluate GHG sequestration and storage of the developing site. However, the current guidelines only taking into account the quantitative reduction lost within the development site, and did not consider the qualitative decrease in the carbon sequestration capacity of forest edge produced by developments. In order to assess the quantitative and qualitative effects of vegetation carbon uptake, the CASA-NPP model and satellite image spatial-temporal fusion were used to estimate the annual net primary production in 2005 and 2015. The development projects between 2006 and 2014 were examined for evaluate quantitative changes in development site and qualitative changes in surroundings by development types. The RMSE value of the satellite image fusion results is less than 0.1 and approaches 0, and the correlation coefficient is more than 0.6, which shows relatively high prediction accuracy. The NPP estimation results range from 0 to $1335.53g\;C/m^2$ year before development and from 0 to $1333.77g\;C/m^2$ year after development. As a result of analyzing NPP reduction amount within the development area by type of forest development, the difference is not significant by type of development but it shows the lowest change in the sports facilities development. It was also found that the vegetation was most affected by the edge vegetation of industrial development. This suggests that the industrial development causes additional development in the surrounding area and indirectly influences the carbon sequestration function of edge vegetaion due to the increase of the edge and influx of disturbed species. The NPP calculation method and results presented in this study can be applied to quantitative and qualitative impact assessment of before and after development, and it can be applied to policies related to greenhouse gas in environmental impact assessment.