• 제목/요약/키워드: CFA

검색결과 476건 처리시간 0.031초

방향성 기반 보간법과 비지역 평균 필터링에 의한 효과적인 CFA 영상 디모자이킹 알고리즘 (Effective Demosaicking Algorithm for CFA Images using Directional Interpolation and Nonlocal Means Filtering)

  • 김종호
    • 한국산학기술학회논문지
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    • 제18권10호
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    • pp.110-116
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    • 2017
  • 본 논문에서는 단일 센서 기기를 통해 획득된 CFA (color filter array) 영상의 효과적인 디모자이킹(demosaicking)을 위하여 방향성 기반 보간법과 영상의 비지역 특성을 이용하는 방법을 제안한다. G 채널을 복원하기 위하여 수직 및 수평방향 뿐만 아니라 대각선 방향을 고려하고, 영상의 지역적 특성을 위하여 비교적 적은 수의 픽셀을 이용하여 보간한다. 이후, 영상의 비지역적 특성을 반영하여 에지 근처에서의 복원능력 및 색상오류 등에 의한 화질열화를 개선하기 위하여 보간된 픽셀에 NLM (nonlocal means) 필터링을 적용한다. R과 B 채널은 이미 복원된 G 채널의 정보를 이용하여 방향성 기반 보간법 및 NLM 필터링을 적용하여 복원한다. 채도가 높고 색상변화가 비교적 큰 McMaster 영상에 대해서 수행한 실험결과는 제안하는 디모자이킹 방법이 기존의 방법에 비해 PSNR 기반의 객관적 성능평가 결과가 우수하고, 주관적 화질 측면에서 에지 및 텍스처와 같은 영상의 구조를 잘 보존하고 색상오류 등과 같은 왜곡현상을 감소시켜 우수한 성능을 나타냄을 알 수 있다.

오가엽(五加葉) 압출성형(壓出成形) 추출물의 Complete Freund's Adjuvant로 유발한 흰쥐의 관절염에 대한 효과 (Effects of Extruded Acanthopanax Folium Extracts on Complete Freund's Adjuvant Induced Arthritis of Rats)

  • 이세나;서일복;손재봉;김혜경;임강현
    • 대한본초학회지
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    • 제24권3호
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    • pp.87-96
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    • 2009
  • Objectives : This study was designed to investigate the effects of extruded Acanthopanax Folium extracts on Complete Freund's Adjuvant (CFA) induced arthritis of rats. Methods: To induce arthritis in the ankle joint of rats, CFA was injected in the proximal part of the tail subcutaneously. After CFA injection, arthritic conditions were examined with macrography. The volume of paw edema and thickness of the ankle joints were checked regularly within 20 days. At 20 days, histopathological examination was performed on the ankle joint. Inflammation levels were determined by total WBC counts and differential WBC counts using a blood analyzer. Tumor necrosis factor-$\alpha$ and interleukin-1$\beta$ concentration in paw exudate were measured by ELISA method. Results: Several arthritic conditions induced by CFA were alleviated by Acanthopanax Folium treatment. Morphologically, reduction of arthritic conditions were observed and the volume of paw edema and thickness of the ankle joints were significantly decreased. Additionally, cytokines in paw exudate were diminished and histopathological improvement was observed. Conclusions: This study showed that the extruded Acanthopanax Folium extracts have the beneficial effects on the CFA induced arthritis of rats and might be used for chronic arthritis patients.

A LOSSLESS CODING SCHEME FOR BAYER COLOR FILTER ARRAY IMAGES USING BLOCK-ADAPTIVE PREDICTION

  • Abe, Toshiyuki;Matsuday, Ichiro;Itohy, Susumu
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.838-841
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    • 2009
  • This paper proposes a novel lossless coding scheme for Bayer color filter array (CFA) images which are generally used as internal data of color digital cameras having a single image sensor. The scheme employs a block-adaptive prediction method to exploit spatial and spectral correlations in local areas containing different color signals. In order to allow adaptive prediction suitable for the respective color signals, four kinds of linear predictors which correspond to 2 ${\times}$ 2 samples of Bayer CFA are simultaneously switched block-by-block. Experimental results show that the proposed scheme outperforms other state-of-the-art lossless coding schemes in terms of coding efficiency for Bayer CFA images.

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Demosaicing Method for Digital Cameras with White-RGB Color Filter Array

  • Park, Jongjoo;Jang, Euee Seon;Chong, Jong-Wha
    • ETRI Journal
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    • 제38권1호
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    • pp.164-173
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    • 2016
  • Demosaicing, or color filter array (CFA) interpolation, estimates missing color channels of raw mosaiced images from a CFA to reproduce full-color images. It is an essential process for single-sensor digital cameras with CFAs. In this paper, a new demosaicing method for digital cameras with Bayer-like W-RGB CFAs is proposed. To preserve the edge structure when reproducing full-color images, we propose an edge direction-adaptive method using color difference estimation between different channels, which can be applied to practical digital camera use. To evaluate the performance of the proposed method in terms of CPSNR, FSIM, and S-CIELAB color distance measures, we perform simulations on sets of mosaiced images captured by an actual prototype digital camera with a Bayer-like W-RGB CFA. The simulation results show that the proposed method demosaics better than a conventional one by approximately +22.4% CPSNR, +0.9% FSIM, and +36.7% S-CIELAB distance.

Joint Demosaicing and Super-resolution of Color Filter Array Image based on Deep Image Prior Network

  • Kurniawan, Edwin;Lee, Suk-Ho
    • International journal of advanced smart convergence
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    • 제11권2호
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    • pp.13-21
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    • 2022
  • In this paper, we propose a learning based joint demosaicing and super-resolution framework which uses only the mosaiced color filter array(CFA) image as the input. As the proposed method works only on the mosaicied CFA image itself, there is no need for a large dataset. Based on our framework, we proposed two different structures, where the first structure uses one deep image prior network, while the second uses two. Experimental results show that even though we use only the CFA image as the training image, the proposed method can result in better visual quality than other bilinear interpolation combined demosaicing methods, and therefore, opens up a new research area for joint demosaicing and super-resolution on raw images.

Honeycomb CFA 구조를 갖는 CCD 이미지센서의 필터특성을 고려한 디모자이킹 알고리즘의 개발 및 검증 (A New Demosaicking Algorithm for Honeycomb CFA CCD by Utilizing Color Filter Characteristics)

  • 서주현;정용진
    • 대한전자공학회논문지SP
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    • 제48권3호
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    • pp.62-70
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    • 2011
  • CFA(Color Filter Array)를 사용하는 이미지 센서에서는 컬러정보를 획득하기 위해 디모자이킹 과정을 거치게 된다. 이상적인 컬러특성을 갖는 이미지센서에 적용되는 디모자이킹 방식은 실제로 이미지센서에 바로 적용할 경우 올바른 동작을 장담할 수 없는데, 이는 센서마다 그 특성이 다르기 때문이다. 따라서 디모자이킹 알고리즘을 적용할 때에는 각 센서의 특성에 따라서 다르게 적용이 되어야만 한다. 본 논문에서는 Honeycomb CFA방식을 사용하는 CCD 이미지 센서에서 사용되는 디모자이킹 알고리즘을 제안하고, 실제 이미지 센서(CBN385B)의 컬러특성을 고려하여 필터의 계수를 보정함으로써 개선된 성능을 갖는 디모자이킹 알고리즘을 제안한다. 또한 디모자이킹 알고리즘을 하드웨어로 구현하여 그 성능을 비교한다. 제안한 알고리즘을 검증하기 위한 방법으로 전체 ISP시스템을 구현 했으며, 성능을 확인할 지표로 알고리즘 자체성능은 PSNR로 이미지센서의 필터특성의 적용의 결과는 RGB분포도를 이용하였다. 결과적으로 기존의 방법에 비해 PSNR 값이 4~8dB 증가하였으며, 실제 이미지센서(CBN385B)에서 Red 성분으로 편중된 현상도 제거하였다. 또한 하드웨어 설계를 통해 소프트웨어적인 연산의 복잡성을 해결하였으며 검증을 위해 Spartan-3E FPGA가 사용되었다. 총 게이트 수는 45K개이며 25 frame/sec의 속도를 보였다.

기혈관절방(氣血關節方)A(CWS-A)가 CFA로 유발(誘發)된 관절염(關節炎)에 미치는 영향(影響) (The effect of Gihyeolgwanjeolbang-A(CWS-A) on adjuvant-induced arthritis in rats)

  • 나창수;윤대환;김정상;채우석
    • 대한본초학회지
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    • 제27권1호
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    • pp.1-10
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    • 2012
  • Objective : To investigate effects of herbal preparations formulated(Gihyeolgwanjeolbang-A, CWS-A) on complete Freund's adjuvant (CFA)-induced arthritis in rats. Method : Arthritis was induced by injecting CFA subcutaneously into the left knee joint and paw, and the herbal preparations formulated(CWS-A I, 82.3 mg/kg ; CWS-A II, 164.6 mg/kg) was administered orally (i.g.) for 10 consecutive days beginning on day 10 after the injection. External shape, paw edema, inflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta), and histological observation were assessed. Result : In swelling of the paw, CWS-A I and CWS-A II group in 15 days and 20 days were significantly reduced compared to controls. In serum ALT, CWS-A I and CWS-A II group were significantly reduced compared to controls. In TNF-${\alpha}$, CWS-A I and CWS-A II group were a tendency reduced compared to controls. In HGB, HCT, MCHC of erythrocytes, CWS-A II group was increased compared to controls. In histological observations, CWS-A II group was observed synoviocytes more than control group and was observed proteoglycans in the deep layers. Conclusion : The data suggest that CWS-A significant anti-arthritic effects that may be mediated by suppressing inflammatory parameters.

간호학생을 대상으로한 건강관련 강인성 도구(HRHS)의 신뢰도와 타당도 검증 및 수정 (The Reliability and Validity of the Health-Related Hardiness Scale in a Sample of Korean Nursing Students)

  • 이미라
    • 지역사회간호학회지
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    • 제11권1호
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    • pp.199-208
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    • 2000
  • The purpose of this study is to test the psychometric properties of the Korean version of the Health-Related Hardiness Scale(HRHS) in a sample of Korean nursing students. The korean version of HRHS was administered to 234 nursing students including 135 college students and 99 university students. The Korean version of HRHS was measured on a 6 Likert scale, assessing three factors of HRHS : control, commitment, and challenge. Internal consistency was used to test the instrument's reliability. The internal consistency of the scale was measured using a coefficient alpha. The coefficient alpha was .69(control), .49(commitment). and .69(challenge), Item analysis and confirmatory factor analysis (CFA) were used to test the instrument's construct validity. The item analysis identified that there were 13 items. which were lower than the .25 item-total correlation. CFA revealed that the scale's fadoral validity was not proper by showing unfit indices(RMSEA .07. stand, RMR .09. GFI .71). According to the findings of this study, the reliability and construct validity of the Korean version of HRHS is not satisfactory in the sample of nursing students. As a result. the researcher modified the scale through item analysis and repetitive CFA process, and proposed the revised 25-item Korean version of HRHS for nursing students. The revised scale's reliability(control .74, commitment .73. challenge .77) and factorial validity were within acceptable levels. The item analysis identified that there was no item, which is lower than the .25 item-total correlation. CFA revealed that the scale's factoral validity was proper by showing fit indices(RMSEA .08 stand. RMR .08. GFI .80).

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금주사액약침(金注射液藥鍼)의 Adjuvant 관절염 유발 흰쥐의 진통효과(鎭痛效果) 및 그 기전(機轉)에 관한 연구 (The Experimental Study on the Analgesic Effect and Mechanism of Gold Injection Aqua-acupuncture to Adjuvant Induced Arthritis in Rats)

  • 변임정;박동석;최도영
    • Journal of Acupuncture Research
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    • 제20권4호
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    • pp.11-23
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    • 2003
  • Objective: In this study, the analgesic effect of gold injection aqua-acupuncture on CFA induced arthritis in rats was inverstigated. Furthermore, to determine the antinociceptive mechanism of gold injection aqua-acupuncture, naloxone and yohimbine were administrated intraperitoneally 15min prior to the gold injection aqua-acupuncture. Methods: The experimental groups were divided into 6 groups. Control group, NSI, AMI, AMI+SL : AMI+Nx, AMI+Yb. Thereafter we measured the chages of TFL between control and experimental groups. Results: 1. The tail flick latency induced by CFA was significantly increased on AMI as compared with the NSI group. 2. Effect of sodium aurothiomalate aqua-acupuncture in TFL on CFA was decreased after application of naloxone. The anti-nociceptive effect of AMI was completely antagonized by naloxone(an opioid receptor antagonist). 3. Effect of sodium aurothiomalate aqua-acupuncture in TFL on CFA was decreased after application of yohimbine. The anti-nociceptive effect of AMI was completely antagonized by yohimbine(${\alpha}2$-adrenoceptor antagonist). Conclusions: According to the results, gold injection aqua-acupuncture has significant analgesic effects on adjuvant induced arthritis in rats and the effect of anti-nociception was mediated by opiodergic system and ${\alpha}2$-adrenergic system.

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흰쥐 관절염 모델에서 용천 저출력 레이저 자극이 보행행동에 미치는 영향 (Effects of Low Level Laser Treatment Applied to KI 1 on the Gait Behavior in the Rat Model of CFA-Induced Arthritis)

  • 지병욱;이성금;이지은;구성태
    • Korean Journal of Acupuncture
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    • 제32권1호
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    • pp.30-38
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    • 2015
  • Objectives : The aim of the study is to investigate the effects of low level laser treatment (LLLT) on the gait behavior in the rat model of arthritis. Methods : Knee arthritis was induced by the injection of $125{\mu}l$ of Complete Freund's Adjuvant(CFA) into the right hind knee joint cavity. Arthritic rats were divided 3 groups; arthritis group was used for control(CON), 10 min of laser treated group(LSR10), and 30 min of laser treated group(LSR30). LLLT was applied to KI 1 for 11 times under gaseous anesthesia. We performed several analyses under catwalk test including stand and swing time, duty cycle of paw steps, intensity and print area of steps, and stride length. Results : Stand and duty cycle of paw steps were increased significantly at 12 days after arthritis induction in LSR30 group. Swing time was decreased significantly at 12 days after arthritis induction in LSR10 group. In the analysis of intensity, print area and stride length, however, results did not show statistical significance during the time point of experiments. Conclusions : The data suggest that LLLT on the rat model of CFA induced arthritis showed beneficial effects by increase of stand time and duty cycle of paw steps and decrease of swing time. Therefore, LLLT could be useful option to improve gait discomfort in arthritis patients.