• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.17-26
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• 2008

In this paper, we propose a distributed multi-view video coding method employing illumination compensation for multi-view video coding. Distributed multi-view video coding (DMVC) methods can be classified either into a temporal or an inter-view interpolation-based ones according to ways to generate side information. DMVC with inter-view interpolation utilizes characteristics of multi-view videos to improve coding efficiency of the DMVC by using side information based on the inter-view interpolation. However, mismatch of camera parameters and illumination change between two views could bring about inaccurate side information generation. In this paper, a modified distributed multi-view coding method is presented by applying illumination compensation in generating the side information. In the proposed encoder system, in addition to parity bits for AC coefficients, DC coefficients are transmitted as well to the decoder side. By doing so, the decoder can generate more accurate side information by compensating illumination changes with the transmitted DC coefficients. We found that the proposed algorithm is $0.1{\sim}0.2\;dB$ better than the conventional algorithm that does not make use of illumination compensation.

• Journal of the Korea Computer Graphics Society
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• v.17 no.4
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• pp.31-40
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• 2011

Projector-based visual systems are widely used for VR and experience display applications. But the illumination irregularity on the screen surface due to the screen material and its light reflection properties sometimes deteriorates the user experience. This phenomenon is particularly troublesome when the participants of the head tracking VR system such as CAVE or the motion generation experience system continually move around the system. One of reason to illumination irregularity is projector-screen specular reflection component to participant's eye's position and it's analysis needs high computation complexity. Similar to calculate specular lighting term using GPU's programmable shader, Our research adjusts every pixel's brightness in runtime with given 3D screen space model to reduce illumination irregularity. For doing that, Angle-based brightness compensate function are considered for specific screen installation and modified it for GPU-friendly compute and access. Two aspects are implemented, One is function access transformation from angular form to product and the other is piecewise linear interpolate approximation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.3
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• pp.123-134
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• 2008

In this paper, we propose a real-tin e face recognition system that is robust under various lighting conditions. Th Modified Census Transform algorithm that is insensitive to illumination variations is employed to extract local structure features. In a practical face recognition system, acquired images through a camera are likely to be blurred and some of them could be side face images, resulting that unacceptable performance could be obtained. To improve stability of a practical face recognition system, we propose a real-time algorithm that rejects unnecessary facial picture and makes use of recognition consistency between successive frames. Experimental results on the Yale database with large illumination variations show that the proposed approach is approximately 20% better than conventional appearance-based approaches. We also found that the proposed real-time method is more stable than existing methods that produces recognition result for each frame.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.4
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• pp.392-400
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• 2001

This paper proposes an illuminant estimation algorithm that estimates the spectral power distribution of an incident light source from a single image. The proposed illumination recovery procedure has two phases. First, the surface spectral reflectances are recovered in the maximum achromatic region (MAR) which is the most achromatic and highly bright region of an image after removing partially the effect of illumination using a modified gray world algorithm. Here, the surface reflectances of MAR are estimated using the principal component analysis method along with a set of given 1269 Munsell samples. Second, the Population of reflected lights is determined with 1269 Munsell samples and a set of illuminations then the spectral distribution of re(looted lights of MAR is selected from the spectral database. That is, color differences are compared between the reflected lights of the MAR and the spectral database, which is the set of reflected lights built by the given set of Munsell samples and illuminants. Then the closest colors from the spectral database are selected. Finally, the illuminant of an image can be calculated dividing the average spectral distributions of reflected lights of MAR by the average surface reflectances of the MAR. In order to evaluate the proposed algorithm, experiments with artificial scenes, which are exposed to chromatic illuminants, were performed and the spectral distribution of estimated illumination and color difference are compared with results of the conventional method.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.69.1-69.1
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• 2010

We have fabricated organic photovoltaic cells (OPVs) with highly conductive poly 3,4-ethylenedioxythiophene : poly styrenesulfonate (PEDOT:PSS) layer as an anode without using transparent conducting oxide (TCO), which has been modified by adding some organic solvents like sorbitol (So), dimethyl sulfoxide (DMSO), N-methyl-pyrrolidone (NMP), dimethylformamide (DMF), and ethylene glycol (EG). The conductivity of PEDOT:PSS film modified with each additive was enhanced by three orders of magnitude. According to atomic force microscopy (AFM) study, conductivity enhancement might be related to better connections between the conducting PEDOT chains. TCO-free solar cells with modified PEDOT:PSS layer and the active layer composed of poly(3-hexylthiophene) (P3HT) and phenyl [6,6] C61 butyric acid methyl ester (PCBM) exhibited a comparable device performance to indium tin oxide (ITO) based organic solar cells. The power conversion efficiency (PCE) of the organic solar cells incorporating DMSO, So + DMSO and EG modified PEDOT:PSS layer reached 3.51, 3.64 and 3.77%, respectively, under illumination of AM 1.5 (100mW/$cm^2$).

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.627-630
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• 1999

For depth extraction from the focus and recovery the shape, determination of criterion function for focus measure and size of the criterion window are very important. However, Texture, illumination, and magnification have an effect on focus measure. For that reason, depth map has a partial high and low peak. In this paper, we propose a depth extraction method from focused images using the error interpolation. This method is modified the error depth into mean value between two normal depth in order to improve the depth map.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.579-582
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• 1999

In this paper, we propose a human face detection algorithm using adaptive skin color model and neural networks. To attain robustness in the changes of illumination and variability of human skin color, we perform a color segmentation of input image by thresholding adaptively in modified hue-saturation color space (TSV). In order to distinguish faces from other segmented objects, we calculate invariant moments for each face candidate and use the multilayer perceptron neural network of backpropagation algorithm. The simulation results show superior performance for a variety of poses and relatively complex backgrounds, when compared to other existing algorithm.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.939-942
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• 2008

Photoelectrochemical deposition of CdZnSe thin films on the Se-modified Au electrode using electrochemical quartz crystal microgravimetry (EQCM) and voltammetry is described. Corrosion of pre-deposited Se electrodes by illumination at a fixed potential resulted in $Se^{2-}$ species, which was manifest from the EQCM frequency changes. $Se^{2-}$ species generated from the photocorrosion reacted with $Cd^{2+}$ and $Zn^{2+}$ ions in the electrolyte to form CdZnSe films on the Au electrode. The effect of electrolyte composition on the composition and band gap of CdZnSe films was studied in detail. Also, photoelectrochemistry, EDX, Raman spectroscopy were used for the characterization of CdZnSe thin films.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1515-1519
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• 2005

Tungsten oxide-modified TiO2 thin films were formed on a glass substrate by sol-gel and dip coating processes using acetyl acetone as a chelating agent. The hydrophilic properties of the thin films were investigated with illumination of UV light. The dependence of water contact angle on material composition and morphology of the film is established with SEM image and AFM profile. The surface morphology was controlled with the change of precursor concentration. 0.01 M of tungsten oxide-modified Ti$O_2$ have shown the highest hydrophilicity after UV-irradiation. The effect of composition on photoinduced hydrophilicity of the W$O_3$-Ti$O_2$ films was also investigated. The films were characterized by XRD, SEM, AFM and XPS.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.36-43
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• 2004

The purpose of this paper was development of modified horizontal daylight duct for reflector of light intake, location of outlet diffuser and size as applicable daylighting system for buildings and, verified applicable possibility base on analysis of daylighting performance through full-scale model test. Experimental result showed that ratio of illumination for light duct was measured 0.3∼0.4％ in interior of a room on clear sky. Also, light duct had wide distribution of illumination than duct about 150[cm] and was decided efficient lighting energy saving because of high daylight performance in case of application actual building during daytime.