• Title/Summary/Keyword: Weighted Median

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A Study of Development of Evaluation Technique for the Subjective Clothing Comfort in Hot-humid Environment -Comparision between the utilization of Fuzzy theory and Factor Analysis- (고온 다습한 환경에서의 주관적 착용 쾌적감 평가도구 개발을 위한 기초 연구 -Fuzzy 이론의 적용방법과 요인분석 방법간의 비교-)

  • 김정화;조승식
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.2
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    • pp.362-372
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    • 1996
  • Recently, need for the development of the quantification of subjective evaluation is growing for the production of high-touch and high-tech textile products. In this study, Fuzzy theory is utilized for the evaluation of the wear comfort of the various blouses. Result of a new evaluation method and factor scores, validity of the new evalution technique adopted fuzzy theory was crosschecked with the results of fator analysis and factor scores. As results, fuzzy theory was proved to be adequate methodology to objectify the subjective evaluation of the adequacy of clothing which is worn. When DUNCAN'S multiple comparion among median of the fuzzy composite score were compared with the results of factor score, the sensitivity of the test methods tends to increase. Therefore, it is suggested that fuzzy weighted checklist is an alternative evaluation scale for the subjective comparison of the textile products. In addition, individual median of fuzzy composite score value should be treated by statistical for the sensitive analysis of subjective evalution.

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Reduction of Radiographic Quantum Noise Using Adaptive Weighted Median Filter (적응성 가중메디안 필터를 이용한 방사선 투과영상의 양자 잡음 제거)

  • Lee, Hoo-Min;Nam, Moon-Hyon
    • Journal of the Korean Society for Nondestructive Testing
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    • v.22 no.5
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    • pp.465-473
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    • 2002
  • Images are easily corrupted by noise during the data transmission, data capture and data processing. A technical method of noise analyzing and adaptive filtering for reducing of quantum noise in radiography is presented. By adjusting the characteristics of the filter according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in reading. We have proposed adaptive weighted median(AWM) filters based on local statistics. We show two ways of realizing the AWM filters. One is a simple type of AWM filter, whose weights are given by a simple non-linear function of three local characteristics. The other is the AWM filter which is constructed by homogeneous factor(HF). Homogeneous factor(HF) from the quantum noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the detection systems with various inner statistical properties is proposed. We show by the experimented that the performances of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region. The proposed algorithms were implemented by visual C++ language on a IBM-PC Pentium 550 for testing purposes, the effects and results of the noise filtering were proposed by comparing with images of the other existing filtering methods.

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.

Implementation of Image Improvement using MAD Order Statistics for SAR Image in Wavelet Transform Domain (웨이블렛 변환 영역에서 MAD 순서통계량을 이용한 SAR 영상의 화질개선 구현)

  • Lee, Cheol;Lee, Jung-Suk
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.12
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    • pp.1381-1388
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    • 2014
  • This paper is proposed a wavelet-based the order statistics MAD(Median Absolute Deviation) method of SAR(Synthetic Aperture Radar) image for image enhancement. also The method of compared and defined the threshold the wavelet coefficients using MAD of the wavelet coefficients of the detail subbands was proposed to effectively image enhancement. In order to complement the disadvantage, the threshold of the proposed method sets up the image statistic and excludes the distortion. The hardware design is used FPGA of Xilinx and DSP system for the image enhancement and compressed encoding of the proposed algorithm. Therefore the proposed method is totally verified by comparing with the several other images.

Image Filtering in many different cases (여러 가지 상황에서의 Image Filtering)

  • Bang, Jung Won
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2016.07a
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    • pp.289-291
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    • 2016
  • 본 논문에서는 VR의 발전과 함께 주목받고 있는 컴퓨터 비전 관련 기술들에 대하여 살펴보고, 가장 먼저 선행되어야 하는 이미지 필터링 알고리즘에 대하여 살펴 본다. 다양한 case에서의 여러 Image Filter를 구현, 성능을 비교 분석해 보고, 정확도를 향상 시킬 수 있는 방안에 대하여 연구한다.

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Robustness of Minimum Disparity Estimators in Linear Regression Models

  • Pak, Ro-Jin
    • Journal of the Korean Statistical Society
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    • v.24 no.2
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    • pp.349-360
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    • 1995
  • This paper deals with the robustness properties of the minimum disparity estimation in linear regression models. The estimators defined as statistical quantities whcih minimize the blended weight Hellinger distance between a weighted kernel density estimator of the residuals and a smoothed model density of the residuals. It is shown that if the weights of the density estimator are appropriately chosen, the estimates of the regression parameters are robust.

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Evaluation of Restoration Schemes for Bi-Level Digital Image Degraded by Impulse Noise (임펄스 잡음에 의해 훼손된 이진 디지탈 서류 영상의 복구 방법들의 비교 평가)

  • Shin Hyun-Kyung;Shin Joong-Sang
    • The KIPS Transactions:PartB
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    • v.13B no.4 s.107
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    • pp.369-376
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    • 2006
  • The degradation and its inverse modeling can achieve restoration of corrupted image, caused by scaled digitization and electronic transmission. De-speckle process on the noisy document(or SAR) images is one of the basic examples. Non-linearity of the speckle noise model may hinder the inverse process. In this paper, our study is focused on investigation of the restoration methods for bi-level document image degraded by the impulse noise model. Our study shows that, on bi-level document images, the weighted-median filter and the Lee filter methods are very effective among other spatial filtering methods, but wavelet filter method is ineffective in aspect of processing speed: approximately 100 times slower. Optimal values of the weight to be used in the weighted median filter are investigated and presented in this paper.

A time recursive approach for do-interlacing using improved ELA and motion compensation based on hi-directional BMA (개선된 ELA와 양방향 BMA기반의 움직임 보상을 이용한 재귀적 디인터레이싱)

  • 변승찬;변정문;김경환
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.87-97
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    • 2004
  • In this paper, we propose an algorithm for interlaced-to-progressive conversion by the weighted summation of the information collected from spatial do-interlacing method, in which the weighted edge based line average is applied, and the temporal method in which the motion compensation is employed by using hi-directional BMA (block matching algorithm). We employed time-recursive and motion adaptive processing as motion detection is involved. Also, a median filter is used to deal with limitation of the linear summation in which only an intermediate of values being involved is determined. The main goal of the approach is to overcome the shortcomings of each of the do-interlacing techniques without significant increment of the computational complexity, and the proposed method is apt to implement in hardware for real-time processing.

Imaging Patterns of Bacillus Calmette-Guérin-Related Granulomatous Prostatitis Based on Multiparametric MRI

  • Seungsoo Lee;Young Taik Oh;Hye Min Kim;Dae Chul Jung;Hyesuk Hong
    • Korean Journal of Radiology
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    • v.23 no.1
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    • pp.60-67
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    • 2022
  • Objective: To categorize multiparametric MRI features of Bacillus Calmette-Guérin (BCG)-related granulomatous prostatitis (GP) and discover potential manifestations for its differential diagnosis from prostate cancer. Materials and Methods: The cases of BCG-related GP in 24 male (mean age ± standard deviation, 66.0 ± 9.4 years; range, 50-88 years) pathologically confirmed between January 2011 and April 2019 were retrospectively reviewed. All patients underwent intravesical BCG therapy followed by a MRI scan. Additional follow-up MRI scans, including diffusion-weighted imaging (DWI), were performed in 19 patients. The BCG-related GP cases were categorized into three: A, B, or C. The lesions with diffusion restriction and homogeneous enhancement were classified as type A. The lesions with diffusion restriction and a poorly enhancing component were classified as type B. A low signal intensity on high b-value DWI (b = 1000 s/mm2) was considered characteristic of type C. Two radiologists independently interpreted the MRI scans before making a consensus about the types. Results: The median lesion size was 22 mm with the interquartile range (IQR) of 18-26 mm as measured using the initial MRI scans. The lesion types were A, B, and C in 7, 15, and 2 patients, respectively. Cohen's kappa value for the inter-reader agreement for the interpretation of the lesion types was 0.837. On the last follow-up MRI scans of 19 patients, the size decreased (median, 5.8 mm; IQR, 3.4-8.5 mm), and the type changed from A or B to C in 11 patients. The lesions resolved in four patients. In five patients who underwent prostatectomy, caseous necrosis on histopathology matched with the non-enhancing components of type B lesions and the entire type C lesions. Conclusion: BCG-related GP demonstrated three imaging patterns on multiparametric MRI. Contrast-enhanced T1-weighted imaging and DWI may play a role in its differential diagnosis from prostate cancer.

A Study on Image Restoration Filter in Impulse Noise Environments (임펄스 잡음 환경에서 영상복원 필터에 관한 연구)

  • Xu, Long;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.2
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    • pp.475-481
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    • 2014
  • As the society develops to advanced digital information times, many studies are underway about digital video processing technology areas such as image restoration. There are typical methods to restore the image which have been damaged by the impulse noise like SM(standard median) filter and CWM(center weighted median) filter. These filters show excellent noise reduction capabilities in low noise density areas, but in high noise density areas, noise reduction capabilities are not sufficient. In this paper, in order to restore the degraded images in impulse(Salt & Pepper) noise environment, the image restoration filter algorithm was suggested which expands and subdivide the mask focusing on damaged pixels. And to demonstrate the superiority of the proposed algorithm used PSNR (peak signal to noise ratio) as the standard of judgement.