• Title/Summary/Keyword: 감마 보정

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Improved Image Restoration Algorithm about Vehicle Camera for Corresponding of Harsh Conditions (가혹한 조건에 대응하기 위한 차량용 카메라의 개선된 영상복원 알고리즘)

  • Jang, Young-Min;Cho, Sang-Bock;Lee, Jong-Hwa
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.2
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    • pp.114-123
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    • 2014
  • Vehicle Black Box (Event Data Recorder EDR) only recognizes the general surrounding environments of load. In addition, general EDR is difficult to recognize the images of a sudden illumination change. It appears that the lens is being a severe distortion. Therefore, general EDR does not provide the clues of the circumstances of the accident. To solve this problem, we estimate the value of Normalized Luminance Descriptor(NLD) and Normalized Contrast Descriptor(NCD). Illumination change is corrected using Normalized Image Quality(NIQ). Second, we are corrected lens distortion using model of Field Of View(FOV) based on designed method of fisheye lens. As a result, we propose integration algorithm of two methods that correct distortions of images using each Gamma Correction and Lens Correction in parallel.

Flesh Tone Balance Algorithm for AWB of Facial Pictures (인물 사진을 위한 자동 톤 균형 알고리즘)

  • Bae, Tae-Wuk;Lee, Sung-Hak;Lee, Jung-Wook;Sohng, Kyu-Ik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11C
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    • pp.1040-1048
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    • 2009
  • This paper proposes an auto flesh tone balance algorithm for the picture that is taken for people. General white balance algorithms bring neutral region into focus. But, other objects can be basis if its spectral reflectance is known. In this paper the basis for white balance is human face. For experiment, first, transfer characteristic of image sensor is analyzed and camera output RGB on average face chromaticity under standard illumination is calculated. Second, Output rate for the image is adjusted to make RGB rate for the face photo area taken under unknown illumination RGB rate that is already calculated. Input tri-stimulus XYZ can be calculated from camera output RGB by camera transfer matrix. And input tri-stimulus XYZ is transformed to standard color space (sRGB) using sRGB transfer matrix. For display, RGB data is encoded as eight-bit data after gamma correction. Algorithm is applied to average face color that is light skin color of Macbeth color chart and average color of various face colors that are actually measured.

SIMULATION OF SHIELDING EFFECTS ON THE TOTAL DOSE OBSERVED IN TDE OF KITSAT-1 (KITSAT-1 TDE의 차폐 효과에 의한 총 축적 방사능양 변화에 대한 연구)

  • 김성준;신영훈;민경욱
    • Journal of Astronomy and Space Sciences
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    • v.18 no.1
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    • pp.71-80
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    • 2001
  • The threshold voltage shift observed in TDE (Total Dose Experiment) on board the KITAT-1 is converted into dose (rad($SiO_2$)) using the result of laboratory calibration with Co-60 gamma ray source in KAERI (Korea Atomic Energy Research Institute). Simulation using the NASA radiation model of geomagnetosphere verifies that the dose difference between RADFET1 and RADFET3 observed on KITSAT-1 comes from the difference in shielding thickness at the position of these RADFETs.

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A study of Three Dimension Shape Measurement by PS(Phase-Shift) (PS(Phase Shift)방법을 이용한 3차원 형상 측정에 대한 연구)

  • Lee, Hye-In;Kim, Hye-Jin;HwanBo, Seong
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1784-1785
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    • 2011
  • PS(Phase Shift) 방식을 이용하여 3차원 이미지 형상복원 시스템을 구현하였다. PS 방식은 위상을 이동시켜서 얻어진 강도를 arctan 시킴으로써 $-{\pi}{\sim}{\pi}$ 범위의 접혀진(wrapped) 위상을 얻을 수 있으며, 이러한 wrapped 위상을 위상 펼침(unwrapping) 알고리즘을 이용하여 불연속을 제거할 수 있다. 얻어진 위상 정보는 물체의 높이 정보에 비례하기 때문에 위상 분포로써 3차원 형상을 복원할 수 있다. Unwrapping 알고리즘에는 다양한 방식이 있지만 본 연구에서는 LabVIEW 프로그램을 이용하여 Goldstein 알고리즘을 구현하였으며, 감마(Gamma) 효과에 의한 노이즈를 줄이기 위하여 프로젝트와 카메라의 보정(calibration) 프로그램을 개발 및 적용하였다. 이와 같은 실험을 통하여 효과적으로 3차원 형상 정보를 얻을 수 있었다.

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뇌로의 약물송달 (III)- 혈액-뇌관문(BBB)의 Osmotic Opening법에 의한 뇌로의 약물송달

  • 황만용;박경호;손영택;이민화
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.345-345
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    • 1994
  • BBB opening 에 의란 수용성 약물 및 지용성 약물의 뇌혈관 투과 패턴을 알아보기 위해 모델약물로서 수용성 약물인 $^{99}$Tc-DTPA, 지용성 약물인 Pherlytoin을 선택하여 뇌혈관 투과성(PA)의 증가율을 검토하고자 하였다. 랫트의 좌측 외경동맥(left external carotid artery)에 혈류의 역방향으로 PE-50 catheter를 분지점에서 1-2mm 전까지 삽입하고, 1.6 molal L-(+)-arabinosg 고장액 (1580 mOsm)을 0. 12ml/sec의 일정한 속도로 30초간 infusion 한 후. $^{99}$Tc-DTPA 혹은 phenytoin 약물 용액을 대뢰정맥으로 주사하고, 대뢰동맥으로부터 약물 투여전 및 투여후 10, 30초, 1, 1.5, 2, 3. 4, 5. 7, 10분 간격으르 혈액을 채취하였으며. 마지막 채혈후 즉시 단두하여 뇌조직을 취하였다. 채취한 뇌를 좌, 우반구 및 각 부위별로 분리하고 감마 카운터와 HPLC를 이용하여 뇌증농도를 정량하였다. 또한 뇌 실질 조직내 약물량을 구하기 위해 뇌 혈관내에 존재하는 약물양을 보정하였는데, 이때 계산에 필요한 뇌증 혈액부피의 측정은 $^{99}$Tc-albumin을 이용하여 구하였다.

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Detection of Flaws in Air Deck using Non-Destructive Testing (비파괴 검사를 이용한 항공 갑판의 결함 검출)

  • Huh, Eui-Jung;Kang, Jin-Hwa;Kim, Kwang-Beak
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.193-195
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    • 2010
  • 본 논문에서는 비파괴 검사를 통하여 얻어진 항공 갑판 영상에서, 조직의 이상이나 결함의 정도를 자동으로 검출하는 방법을 제안한다. 비파괴 검사를 통하여 얻어진 항공 갑판 영상에서 감마상관 변환과 $7{\times}7$ 소벨 마스크와 $13{\times}13$ 소벨 마스크를 각각 적용하여 윤곽선을 추출한다. 추출된 윤곽선 영역을 평활화와 평균 이진화 기법을 적용하여 영상을 보정한다. 보정된 영상에서 침식 연산과 팽창 연산을 이용하여 잡음을 제거한 후, 라벨링 기법을 적용하여 항공 갑판의 결함 영역을 추출한다. 본 논문에서 제안한 방법을 다양한 항공 갑판 영상을 대상으로 실험한 결과, 기존의 방법보다 항공 갑판에서 결함을 추출하는데 효과적인 것을 확인하였다.

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Image dynamic range compression using region-adaptive gamma correction (영역 적응적 감마 보정을 이용한 영상의 다이내믹 레인지 압축)

  • Han, Young-Seok;Kang, Moon-Gi
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.801-802
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    • 2008
  • This paper presents a new dynamic range compression method using region-adaptive gamma correction. Gamma corrections with different gamma coefficients are first applied to the observed image to generate several candidate images. Then, the proposed method produces the result image by adequately combining them according to the weight function based on local variances. Experimental results demonstrate that the proposed method significantly enhances image quality by bringing out the details not only in dark region but also in bright region.

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A Study on the Measurement of the Personal Exposure Dose by Film Badge Dosimeter (필름배지선량계에 의한 개인피폭선량 측정에 관한 연구)

  • Chung, Woon-Kwan
    • Journal of Radiation Protection and Research
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    • v.19 no.1
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    • pp.37-50
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    • 1994
  • The experimental evaluation of exposure conversion formula using the relationship between optical photo-density, exposure dose and the quality of radiation characteristics of radiation energy to X-ray and ${\gamma}-rays$. The film badge dosimeter is analysed by exposure conversion formula which evaluate image fading characteristics for development time and directional characteristics for incident beam angle. In conclusion, exposure conversion formula evaluated of this study is satisfied with quality decision criterion of the film badge dosimeter.

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Design of Quadratic Gamma correcot for HDTV Camera Applications (HDTV용 카메라의 이차 함수 감마 보정기의 설계)

  • Woo, Sung-Hun;Hwang, Jong-Tae;Cho, Gyu-Hyeong
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3187-3189
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    • 1999
  • A novel wide-tunable quadratic gamma corrector for HDTV camera applications is proposed. The new gamma corrector controls gamma value in a wide range by simple electrical adjustment of multipliers' gain. It has wide signal bandwidth of 30MHz sufficient for HDTV applications. It also simplifies the circuit design, resulting in a compact surface mounting board implementation with reduced power consumption. Simulation and experimental results confirm these characteristics.

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A Wide-band wide-tunable Current-Mode Gamma Corrector for HDTV Camera Applications (HDTV용 카메라의 전류 모드 감마 보정기)

  • Woo, Sung-Hun;Hwang, Jong-Tae;Cho, Gyu-Hyeong
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3190-3192
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    • 1999
  • A Novel wide-band wide-tunable current-mode (CM) gamma corrector for HDTV camera applications is proposed. The gamma corrector provides accurate gamma control in a wide range by simple electrical adjustment of weighting amplifiers' gain. It has wide signal bandwidth more than 40MHz sufficient for HDTV video signal processing and is implementable with simple integrated circuit with low power dissipation of 125mW.

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