• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.2
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• pp.23-34
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• 2004

Video camera can be a useful tool to capture images for use in colorimeter. However the RGB signals generated by different video camera are not equal for the same scene. The video camera for use in colorimeter is characterized based on the CIE standard colorimetric observer. One method of deriving a colorimetric characterization matrix between camera RGB output signals and CIE XYZ tristimulus values is least squares polynomial modeling. However it needs tedious experiments to obtain camera transfer matrix under various white balance point for the same camera. In this paper, a new method to obtain camera transfer matrix under different white balance by using 3${\times}$3 camera transfer matrix under a certain white balance point is proposed. According to the proposed method camera transfer matrix under any other white balance could be obtained by using colorimetric coordinates of phosphor derived from 3${\times}$3 linear transfer matrix under the certain white balance point. In experimental results, it is demonstrated that proposed method allow 3${\times}$3 linear transfer matrix under any other white balance having a reasonable degree of accuracy compared with the transfer matrix obtained by experiments.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.861-864
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• 2000

본 논문에서는 물체의 고유 칼라 정보 복원을 통하여 조명의 영향을 받지 않는 칼라 기반 얼굴검출 기법을 제안한다. 즉 주위 조명 영향으로부터 RGB 성분 계수를 파악하여 조명 성분에 영향을 받은 성분을 상쇄시키고, 색포화도와 밝기값 보상을 통해 고유 칼라를 복원(color recover)하는 실험을 하였고, 복원된 영상을 YCbCr 좌표계로 변환시킨 후, CbCr 각각에 대해 살색 성분이 나타내는 일정한 범위내의 부분을 검출하였다. 또한 이 진화 과정에서 생긴 잡음들을 형태학적인 모폴로지 필터를 통해 제거하였으며, 살색 후보 영역 중 같은 영역들은 레이블링하여 얼굴 후보 영역을 생성하였다. 그러나 칼라 정보만으로는 검출된 영역이 얼굴인지를 판단하기가 매우 어렵다. 그러므로 본 연구에서는 인간시각에 기반한 Gabor 필터를 사용하여, 검출된 살색 영역이 최종적으로 얼굴인지를 판별하는 효율적인 알고리즘을 제안한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.326-327
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• 2015

본 논문에서는 화재의 움직임 정보에 기반하여 역동적인 화재를 감지하는 기법을 제안한다. 우선 감시 카메라와 같은 고정형 감시 장치로부터 얻어진 색 정보를 분리하기 쉬운 좌표계로 변환하고 이전에 수집된 데이터들로부터 얻어진 사전 정보로부터 화염 영역을 추출한다. 또한 화염 영역의 가장자리가 움직임이 매우 크다는 사실에 기반하여 광흐름 벡터로 얻어진 시간적 분산값을 이용한 움직임 모델을 생성한다. 화염 영역은 움직임 모델과 결합되며 오탐을 걸러내기 위해 충분한 양의 화재 영역이 중첩될 때 최종적으로 화재를 판별한다. 본 논문에서 제안한 방법은 실험 결과에서 우수한 탐지 능력을 보인다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.116-128
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• 2011

In this paper, we propose the structure of a high-performance face-detection engine that responds well to facial rotating changes using rotation transformation which minimize the required memory usage compared to the previous face-detection engine. The validity of the proposed structure has been verified through the implementation of FPGA. For high performance face detection, the MCT (Modified Census Transform) method, which is robust against lighting change, was used. The Adaboost learning algorithm was used for creating optimized learning data. And the rotation transformation method was added to maintain effectiveness against face rotating changes. The proposed hardware structure was composed of Color Space Converter, Noise Filter, Memory Controller Interface, Image Rotator, Image Scaler, MCT(Modified Census Transform), Candidate Detector / Confidence Mapper, Position Resizer, Data Grouper, Overlay Processor / Color Overlay Processor. The face detection engine was tested using a Virtex5 LX330 FPGA board, a QVGA grade CMOS camera, and an LCD Display. It was verified that the engine demonstrated excellent performance in diverse real life environments and in a face detection standard database. As a result, a high performance real time face detection engine that can conduct real time processing at speeds of at least 60 frames per second, which is effective against lighting changes and face rotating changes and can detect 32 faces in diverse sizes simultaneously, was developed.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.320-324
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• 2011

TOPO/TOP capped CdSe nanoparticles were synthesized via thermal-solvent method. The 540 nm green and 620 nm red emitting CdSe nanoparticles were obtained by controlling the reaction time and temperature. Phosphor conversion white LED was produced combining a 460 nm emitting InGaN LED chip as an excitation source with 540 and 620 nm CdSe nanoparticles as phosphors. The single or double phosphor layer was fabricated by mixing with epoxy, and investigated the effects on the luminous properties of the white LED. The single phosphor layer white LED showed 5.78 lm/W with CIE of (0.36, 0.45) in reddish white, and the double phosphor layer white LED showed 7.28 lm/W with that of (0.32, 0.34) in pure white at 20 mA. When the 400 nm near-UV LED was applied to optical pumping source, the luminous efficiency of white LED was enhanced to 8.76 lm/W.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.813-818
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• 2021

This paper proposes an optimized hardware implementation method for existing CIE1931 color gamut control algorithm. Among the post-processing methods of dehazing algorithms, existing algorithm with relatively low computations have the disadvantage of consuming many hardware resources by calculating large bits using Split multiplier in the computation process. The proposed algorithm achieves computational reduction and hardware miniaturization by reducing the predefined two matrix multiplication operations of the existing algorithm to one. And by optimizing the Split multiplier computation, it is implemented more efficient hardware to mount. The hardware was designed in the Verilog HDL language, and the results of logical synthesis using the Xilinx Vivado program were compared to verify real-time processing performance in 4K environments. Furthermore, this paper verifies the performance of the proposed hardware with mounting results on two FPGAs.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.31-37
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• 2000

In order to color analyze of in Farnsworth Test Panel D-15 using a Protan, Deutan and Tritan test, we introduced the CIE system so that measured the reflectance light spectrum intensity in the 380~780 nm wavelength regions. The color difference of Panel D-15 was depended on the intensity of reflectance ratio in the 400~450 nm, 500~600 nm and more than 650 nm wavelength regions. From the reflectance spectra, we obtained the tristimulus X, Y, Z values, the $L^*a^*b^*$ and $L^*ab$ values of the 3-Dimension CIELAB system in a complement plane and light-darkness axis, the $U^*V^*$ values and the x, y values of chromaticity coordinates.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.155.2-155.2
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• 2012

CTIO 4m 및 CTIO 1m 망원경으로 Westerlund 2의 UBVI 관측을 수행하여, CTIO 4m SDSS $u$ filter의 적색광누출 현상을 발견하였고 그 영향을 분석하였다. 적색광누출 현상은 filter의 투과함수가 설계와는 달리 장파장 영역에서 투과 존재하는 현상으로, CTIO 4m SDSS $u$ filter의 경우 B-V>1.4, V-I>2.0에서 그 영향이 나타나기 시작한다. SDSS $u$ filter의 적색광누출 현상은 별의 고유색지수와 상관없이 관측된 색지수가 클수록 영향이 크며, $B-V{\leq}1.8$, $V-I{\leq}2.8$의 범위에서는 보정이 가능하다. CTIO 1m B filter에서는 성간소광을 받지 않은 별과 성간소광을 많이 받은 별의 표준계변환 결과, $B_{CTIO1m}=B_{Standard}-0.055{\times}E(V-V)$에 해당하는 차이를 보였다. 이러한 차이는 CTIO 1m B filter의 투과함수의 단파장 쪽 날개부분이 표준 Johnson B filter에 비하여 단파장 쪽으로 많이 치우쳐있기 때문으로 보인다. 특히 Ballmer jump에 해당하는 파장인 370 nm에서 filter의 최대투과율에 비하여 32.2%에 달하는 투과율을 보이는데, 이는 Bessell B filter의 3.1%에 비하여 매우 큰 값이다. CTIO 1m 망원경의 Y4KCam CCD에서는 포화된 화소에 의한 crosstalk 뿐 아니라 포화되지 않은 화소에 의한 crosstalk 현상도 보였다. 짧은 노출을 준 영상에서는 5000 ADU 이상에서는 육안에 의한 crosstalk 확인이 가능하며, 포화되지 않은 밝은 별에 의한 crosstalk을 확인하지 않고 측광할 경우 백색왜성으로 오인할 가능성이 있으므로 측광 과정에서 좌표를 통하여 확인할 필요가 있다.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.211-217
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• 2012

Conventional GrabCut algorithm is semi-automatic algorithm that user must be set rectangle window surrounds the object. This paper studied automatic object detection to solve these problem by detecting salient region based on Human Visual System. Saliency map is computed using Lab color space which is based on color opposing theory of 'red-green' and 'blue-yellow'. Then Saliency Points are computed from the boundaries of Low-Frequency region that are extracted from Saliency Map. Finally, Rectangle windows are obtained from coordinate value of Saliency Points and these windows are used in GrabCut algorithm to extract objects. Through various experiments, the proposed algorithm computing rectangle windows of salient region and extracting objects has been proved.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.267-274
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• 2004

In this paper, the interesting moving objects tracking algorithm using color information on Multi-Video camera is proposed Moving objects are detected by using difference image method and integral projection method to background image and objects image only with hue area, after converting RGB color coordination of image which is input from multi-video camera into HSI color coordination. Hue information of the detected moving area are normalized by 24 steps from 0$^{\circ}$ to 360$^{\circ}$ It is used for the feature parameters of the moving objects that three normalization levels with the highest distribution and distance among three normalization levels after obtaining a hue distribution chart of the normalized moving objects. Moving objects identity among four cameras is distinguished with distribution of three normalization levels and distance among three normalization levels, and then the moving objects are tracked and surveilled. To examine propriety of the proposed method, four cameras are set up indoor difference places, humans are targeted for moving objects. As surveillance results of the interesting human, hue distribution chart variation of the detected Interesting human at each camera in under 10%, and it is confirmed that the interesting human is tracked and surveilled by using feature parameters at four cameras, automatically.