• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.1
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• pp.1-11
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• 2005

The propose of this study investigated the reproduction of color image on a CRT monitor, for a range of different values of monitor gamma. We have used the GOG(gain-offset-gamma) model of the behavior of CRT. Color difference have been computed in a color space, based on the CIELAB color appearance model. The 133 patch defined linearly color sample and 24 patch defined printing color target were used, and were subjected to the influence of nine different gamma value. The result shows that netural color is increasing the decrease range of luminance black color than white color. These results concern correct in the context display of color reproduction.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1412-1414
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• 2006

We study on the Electro Optical Properties of the EEFL (External Electrode Fluorescent Lamp) Backlight system is based on the lamp type characteristics and diameter of the lamp tube under the equal manufacturing of the lamps. In this contribution, through the analysis of the different lamp type and diameter of the lamp tube gain the effective luminance and reduce the lamp voltage from aspect in the electro optical properties with EEFL and LCD backlight system.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.45-58
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• 2005

The propose of this study investigated the reproduction of color image displayed on a CRT monitor, for a range of different values of monitor gamma. We have used the GOG(gain-offset-gamma) model of the behavior of the CRT. Color difference have been computed in a color space, based on the CIELAB color appearance model. The 133 patch defined linearly color sample and 24 patch defined printing color target were used, and were subjected to the influence of nine different gamma value. The result show that neutral color is increasing the decrease range of luminance black color than white color. These results are of concern in the context of the "correct" display of color reproduction.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.104-107
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• 2009

In order to improve discharge characteristics in AC PDP, we suggest FDFA (Facing Discharge Front plate Address Electrode) structure. By adopting both long facing discharge electrodes and address electrodes in front plate, the FDFA structure make it possible to gain a high luminance, low power consumption, and a high luminous efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.306-313
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• 2015

In this study, the change of optical characteristics was studied according to the micro optical pattern provided by photo lithography followed by thermal reflow process. The shape and luminance variation with micro pattern was evaluated by SEM and spectrometers. Also, we analyzed the luminance characteristics using the 3D-optical simulation (Optis works) program. As a result, we found that the radius of curvature(R) in micro pattern is decreased up to 77%($150^{\circ}C$) compared to the radius of curvature at the condition $100^{\circ}C$, which is caused by efficient reflow of organic material without chemical changes. The highest enhancement of brightness with optimum micro pattern was obtained at the condition of $120^{\circ}C$ reflow process. The brightness gain with optical micro patterns is more than 15% at the condition of R=16.95 um, ${\Theta}=77.14^{\circ}$ compared to original optical source. The results of light simulation with various radius of curvature and side angle of pattern shows the similar result of experiment evaluation of light behavior on optical micro patterns. It is regarded that the more effect on light enhancement was contributed by side angle which is effective factor on light reflection, rather than the curvature of micro-patterns.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.1-10
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• 2010

In this paper, we propose a novel way of combining color demosaicing and the auto white balance (AWB) method, which are important parts of image processing. Performance of the AWB is generally affected by demosaicing results because most AWB algorithms are performed posterior to color demosaicing. In order to increase the performance and efficiency of the AWB algorithm, the color constancy problem is considered during the color demosaicing step. Initial estimates of the directional luminance and chrominance values are defined for estimating edge direction and calculating the AWB gain. We propose a modified edge-based AWB method that used a pre-defined achromatic region. The estimation of edge direction is performed region adaptively by using the local statistics of the initial estimates of the luminance and chrominance information. The proposed method shows significant improvements in terms of visual and numerical criteria when compared to conventional methods.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.19-28
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• 2005

Real surround viewing conditions in watching the color display devices such as TV and PC monitor are quite different from the standard viewing conditions. Human visual system is adapted chromatically under the different viewing conditions in luminance levels and chromaticity of illuminants. Accordingly, the reproduced colors of the same chromaticity will appear as quite different color. Therefore, it is necessary that the displayed colors are reproduced to be appeared as the original colors in the standard viewing conditions. In this paper, we propose a chromatic adaptation model for the variations of the surround illuminants' chromaticity under the same luminance conditions. In proposed chromatic adaptation model, we calculate each gain of L, M, and S as nonlinear functions according to the chromaticity of the surround illuminants. And the optimal coefficients are obtained from the corresponding colors data of the Breneman's experiments. The proposed chromatic adaptation model is compared with the conventional chromatic adaptation models. In the experimental results, the proposed model has very good performance in the whole range of luminance levels. We also experimentally confirmed that the reproduced corresponding colors using the proposed chromatic adaptation are appeared as the original colors when the real surround viewing conditions are different from the standard viewing conditions.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.125-131
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• 2012

PURPOSES : Road lighting facilities increase the visibility of road at night in order to improve traffic driver safety and comfort. Generally speaking, current pole lighting has a tendency to create problems of glare and flicker. The phenomenon of glare gives discomfort due to increase of scattered light, when high luminance is in driver's field of view. The phenomenon of flicker occurs due to the driver passing through discontinuous pockets of pole lighting areas. These phenomenon increase eye strain and decrease driver safety. METHODS : Low height line lighting that distributes light lower than driver's eye level has been developed and evaluated to reduce the problems linked to current pole lighting. A test was undertaken with 4 conditions(turn on the general pole lighting, turn off alternate pole lighting, turn on the line lighting and line lighting with 50% dimming). A driver written survey was conducted in order to gain driver feedback. RESULTS : Pupil size and brow frequency compared with degree in pole lighting are reduced. CONCLUSIONS : Low height line lighting environment makes drivers more comfortable than pole lighting environment and is positive lighting method in the energy saving and landscape aspect.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.489-496
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• 2015

In this paper, a new weighted prediction scheme is proposed to improve the coding efficiency for video scenes containing brightness variations. Conventional weighted prediction is applied by the reference picture and use only one weighted parameter set. Thus, it is only useful for GBV(Glabal Brightness Variation). In order to solve this problem, the proposed algorithm use three kind of schemes depending on situation. Experimental results show that maximum coding efficiency gain of the proposed method is up to 10.2% in luminance. Average computional time complexity is increased about 163% in encoder and about 101% in decoder.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.837-856
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• 2016

Underwater image enhancement has received considerable attention in last decades, due to the nature of poor visibility and low contrast of underwater images. In this paper, we propose a new automatic underwater image enhancement algorithm, which combines nonsubsampled contourlet transform (NSCT) domain enhancement techniques with the mechanism of the human visual system (HVS). We apply the multiscale retinex algorithm based on the HVS into NSCT domain in order to eliminate the non-uniform illumination, and adopt the threshold denoising technique to suppress underwater noise. Our proposed algorithm incorporates the luminance masking and contrast masking characteristics of the HVS into NSCT domain to yield the new HVS-based NSCT. Moreover, we define two nonlinear mapping functions. The first one is used to manipulate the HVS-based NSCT contrast coefficients to enhance the edges. The second one is a gain function which modifies the lowpass subband coefficients to adjust the global dynamic range. As a result, our algorithm can achieve contrast enhancement, image denoising and edge sharpening automatically and simultaneously. Experimental results illustrate that our proposed algorithm has better enhancement performance than state-of-the-art algorithms both in subjective evaluation and quantitative assessment. In addition, our algorithm can automatically achieve underwater image enhancement without any parameter tuning.