• 제목/요약/키워드: non-local mean

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이미지 보간기법의 성능 개선을 위한 비국부평균 기반의 후처리 기법 (Non-Local Mean based Post Processing Scheme for Performance Enhancement of Image Interpolation Method)

  • 김동형
    • 디지털산업정보학회논문지
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    • 제16권3호
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    • pp.49-58
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    • 2020
  • Image interpolation, a technology that converts low resolution images into high resolution images, has been widely used in various image processing fields such as CCTV, web-cam, and medical imaging. This technique is based on the fact that the statistical distributions of the white Gaussian noise and the difference between the interpolated image and the original image is similar to each other. The proposed algorithm is composed of three steps. In first, the interpolated image is derived by random image interpolation. In second, we derive weighting functions that are used to apply non-local mean filtering. In the final step, the prediction error is corrected by performing non-local mean filtering by applying the selected weighting function. It can be considered as a post-processing algorithm to further reduce the prediction error after applying an arbitrary image interpolation algorithm. Simulation results show that the proposed method yields reasonable performance.

객체 기반 3D 업체 영상 변환 기법 (Object-based Conversion of 2D Image to 3D)

  • 이왕로;강근호;유지상
    • 한국통신학회논문지
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    • 제36권9C호
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    • pp.555-563
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    • 2011
  • 본 논문에서는 움직임 추정 (motion estimation, ME), 컬러 라벨링(labeling) 그리고 Non-local mean 필터를 이용하여 2D 영상을 3D 업체 영상으로 변환하는 기법을 제안한다. 제안하는 기법에서는 먼저 프레임 간의 움직임을 추정하여 객체의 움직임 벡터를 추출하고 주어진 영상에 대해 컬러 라벨링 작업을 수행하여 영상을 분리한다. 움직임 추정 결과와 컬러 라벨링 결과를 비교 분석하여 영상내의 객체를 추출하고 추출된 객체를 이동하여 우 영상을 생성하게 되는데 이때 우 영상을 생성하는 과정에서 채워지지 않은 가려짐 영역이 발생하며 전체 화소간의 상관도를 고려하는 Non-local mean 필터를 사용하여 보상한다. 이후 원본 영상인 좌 영상과 생성된 우 영상으로 비윌 주사하여 최종 3D 업체 영상을 재현한다. 실험 결과를 통해 제안된 기법으로 생성된 3D 업체 영상에서 객체위주의 안정된 업체 변환이 수행되는 것을 확인할 수 있었다.

SPECKLE NOISE SMOOTHING USING AN MODIFIED MEAN CURVATURE DIFFUSION FILTER

  • Ye, Chul-Soo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.159-162
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    • 2008
  • This paper presents a modified mean curvature diffusion filter to smooth speckle noise in images. Mean curvature diffusion filter has already shown good results in reducing noise in images while preserving fine details. In the mean curvature diffusion, the rate of smoothing is controlled by the local value of the diffusion coefficient chosen to be a function of the local image gradient magnitude. In this paper, the diffusion coefficient is modified to be controlled adaptively by local image surface slope and heterogeneity. The local surface slope contributes to preserving details (e.g.edges) in image and the local surface heterogeneity helps the smoothing filter consider the amount of noise in both edge and non-edge area. The proposed filter's performance is demonstrated by quantitative experiments using speckle noised aerial image and TerraSAR-X satellite image.

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LOCAL AND MEAN k-RAMSEY NUMBERS FOR THE FAMILY OF GRAPHS

  • Su, Zhanjun;Chen, Hongjing;Ding, Ren
    • Journal of applied mathematics & informatics
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    • 제27권3_4호
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    • pp.909-913
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    • 2009
  • For a family of graphs $\mathcal{H}$ and an integer k, we denote by $R^k(\mathcal{H})$ the corresponding k-Ramsey number, which is defined to be the smallest integer n such that every k-coloring of the edges of $K_n$ contains a monochromatic copy of a graph in $\mathcal{H}$. The local k-Ramsey number $R^k_{loc}(\mathcal{H})$ and the mean k-Ramsey number $R^k_{mean}(\mathcal{H})$ are defined analogously. Let $\mathcal{G}$ be the family of non-bipartite graphs and $T_n$ be the family of all trees on n vertices. In this paper we prove that $R^k_{loc}(\mathcal{G})=R^k_{mean}(\mathcal{G})$, and $R^2(T_n)$ < $R^2_{loc}(T_n)4 = $R^2_{mean}(T_n)$ for all $n\;{\ge}\;3$.

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비 지역적 평균과 유도 영상 필터링에 기반한 자기 공명 영상의 잡음 제거 (Noise Removal in Magnetic Resonance Images based on Non-Local Means and Guided Image Filtering)

  • 무하마드 타릭 마흐무드;최영규
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제20권11호
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    • pp.573-578
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    • 2014
  • 자기 공명 영상에서 흔히 발생하는 잡음을 없애기 위해 비 지역적 평균과 유도 영상 필터링을 이용하는 새로운 방법을 제안한다. 제안된 방법은 두 가지 단계로 구성되어 있다. 첫 단계에서는 비 지역적 평균 필터를 이용하여 잡음 영상으로부터 유도 영상 구하는데, 필터의 커널을 적응적으로 제어하기 위해 경계도(edgeness) 개념을 사용하였다. 두 번째 단계에서는 유도 영상 필터링으로 잡음을 제거하는 과정으로 원래의 잡음 영상과 앞 단계에서 구한 유도 영상을 이용하여 잡음이 제거된 영상을 복원한다. 제안된 방법의 우수성을 확인하기 위해 다양한 표준 자기 공명 영상 데이터를 이용하여 실험을 하였는데, 실험 결과 제안된 방법이 기존의 방법들에 비해 우수한 성능을 나타내는 것을 확인할 수 있었다.

Local-Based Iterative Histogram Matching for Relative Radiometric Normalization

  • Seo, Dae Kyo;Eo, Yang Dam
    • 한국측량학회지
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    • 제37권5호
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    • pp.323-330
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    • 2019
  • Radiometric normalization with multi-temporal satellite images is essential for time series analysis and change detection. Generally, relative radiometric normalization, which is an image-based method, is performed, and histogram matching is a representative method for normalizing the non-linear properties. However, since it utilizes global statistical information only, local information is not considered at all. Thus, this paper proposes a histogram matching method considering local information. The proposed method divides histograms based on density, mean, and standard deviation of image intensities, and performs histogram matching locally on the sub-histogram. The matched histogram is then further partitioned and this process is performed again, iteratively, controlled with the wasserstein distance. Finally, the proposed method is compared to global histogram matching. The experimental results show that the proposed method is visually and quantitatively superior to the conventional method, which indicates the applicability of the proposed method to the radiometric normalization of multi-temporal images with non-linear properties.

성인(成人) 남자(男子)의 발한(發汗) 반응(反應)에 관한 연구 - 운동선수(運動選手)와 비운동선수(非運動選手)를 중심(中心)으로 - (Sweating Reaction of Men Adults - Centered on Athletes and Non-Athletes -)

  • 심부자
    • 패션비즈니스
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    • 제3권1호
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    • pp.125-137
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    • 1999
  • The present study aims to reveal the sweating reaction of male adults, focused on athletes. With six subjects (3 athletes and 3 non-athletes) in two different conditions of ambient temperature (I : $25\pm1.0^{\circ}C$, II : $29.5\pm1.0^{\circ}C$), their total sweat rate, local sweat rate, skin temperature, physiological reaction (rectal temperature, blood pressure, and pulse rate), and psychological reaction (thermal, moisture, comfort, and perceptive sweat sensations) were measured. The comparison gave the following results: Total sweating rate was greater in non-athletes, while the two groups had more perspiration in ambience II. Local sweating rate in both ambiences was the greatest in the central breast area (athletes) and the infrascapular area (non-athletes). The mean skin temperature had more changes of increase and decrease in athletes. As to physiological reaction, non-athletes had lower rectal temperature and blood pressure as well as higher pulse rate. As for psychological reaction in Ambience II, the 4 sensations were mostly 'hot', 'humid', 'uncomfortable', and 'sweaty'.

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FUZZY DIFFERENTIAL EQUATIONS WITH NONLOCAL CONDITION

  • JEONG JAE UG
    • Journal of applied mathematics & informatics
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    • 제17권1_2_3호
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    • pp.509-517
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    • 2005
  • We shall prove the existence and uniqueness theorem of a solution to the non local fuzzy differential equation using the contraction mapping principle.

Response of Alisma plantago Varieties Cultivated After Early Maturing Rice Cropping to Fertilizer Levels

  • Park, Hee-Jin;Kwon, Byung-Sun;Shin, Jong-Sup;Lee, Sang-Rae
    • Plant Resources
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    • 제3권3호
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    • pp.200-205
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    • 2000
  • This study selects Sunwol local group, Gusang local group and Yongjun local group to examine the appropriate amount of applied fertilizer in cultivating the double crop seed of Alisma plantago by transplantation in the southern area, improve and complements the double cropping techniques and contribute to stable production. While the plant height is 45,47 and 49cm and the number of leaves is 11.7, 12.5 and 14.4 at non-fertilizing plot, the plant height is 67, 72 and 75cm and the number of leaves is 15.8, 17.2 and 19.3 at all fertilizing plot and their growth is active and in the character of plant height and the number of leaves, especially in the groove of N-P$_{2}$O$_{5}$-K$_{2}$O= 30-15-45kg/10a, the mean plant height of Sunwol is 75cm and mean number of its leaves is 19.3, the mean plant height and number of leaves in Gusang are 72cm and 17.2 respectively and those of Yongjun are 67cm and 15.8 respectively. While the number of floral axis is 1,2 in non-fertilizing plot, that of the whole varieties in all fertilizing plot is 3, 4, 5 and the mean floral axis of Sunwol is N-P$_{2}$O$_{5}$-K$_{2}$O = 10-5-15, 20-10-30, 30-15-45 kg/10a and 18-0-18 of complex fertilizer and 21-17-17kg/10a and it is small in all fertilizing plot. The yield of dry root per 10a is high in all fertilizing grooves and especially in the groove of N-P$_{2}$O$_{5}$-K$_{2}$O = 30-15-45 kg/10a, it is 372.6kg, in the groove of 18-0-18kg/10a using complex fertilizer, it is 389.1kg and in that of 21-17-17kg/10a, it is 376.7kg.6.7kg.

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잡음을 고려한 공간적응적 색상 보간 (Spatially Adaptive Color Demosaicing of Noisy Bayer Data)

  • 김창원;유두식;강문기
    • 대한전자공학회논문지SP
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    • 제47권2호
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    • pp.86-94
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    • 2010
  • 본 논문은 잡음을 고려한 공간적응적 색상 보간 방법을 제안한다. 센서의 잡음은 색상 보간 과정에 영향을 미쳐서 결과 영상의 열화를 초래하기 때문에 센서의 잡음이 색상 보간 방법에 고려됨으로써 고해상도의 영상을 획득할 수 있다. 알고리즘의 성능 향상과 연산량의 효율성을 높이기 위해서 베이어 화소에서 평탄, 에지, 패턴 에지 영역으로 각각 구분한다. 영역에 따라 다른 마스크를 이용하여 국부 통계치를 계산하게 되고, 이를 이용해서 보간 오류가 최소화 되도록 G 색상을 보간한다. 잡음제거를 위해서는 수정된 Non-Local 평균 필터가 사용된나. R파 B 색상은 잡응이 제거되고 보간된 G 색상파 색차값을 이용해서 쉽게 보간된다. 제안된 알고리즘은 기존 알고리즘에 비해 주관적 및 객관적인 변에서 모두 뛰어난 결과를 보임을 실험을 통해 확인 할 수 있다.