• Title/Summary/Keyword: luminance performance

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Luminance enhancement in single image dehazing

  • Bui, Minh-Trung;Kim, Won-Ha
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.06a
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    • pp.322-324
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    • 2013
  • Haze is an extreme reason of the reduction of contrast when capturing image in the outdoor. Recently, there are several single image dehazing techniques, but they are not robust in dynamic variations of natural environment caused by the thickness, coverage of haze and appearance of sunlight. In this paper, we propose an effective and robust method to enhance luminance for image dehazing depending on histogram analysis. Compare with conventional methods, our proposal have better performance in term of contrast, and computation time.

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High Performance Electroluminescent Display Device with AION-TiON Insulator

  • Lim, Jung-Wook;Yun, Sun-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.932-934
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    • 2003
  • For the insulator of inorganic thin film electroluminescent (TFEL), devices AlON combined with TiON was used and it exhibits higher luminance than AlON as well as $Al_{2}O_{3}$ insulator. Furthermore, using AlON with TiON film show better stability and higher luminance than that with $TiO_{2}$ grown by conventional atomic layer deposition (ALD) for the application of the insulator of ZnS:Mn TFEL device.

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Histogram-based luminance enhancement for image dehazing

  • Bui, Minh-Trung;Kim, Won-Ha
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.07a
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    • pp.16-18
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    • 2012
  • Haze is an extreme reason of the reduction of contrast when capturing image in the outdoor. Recently, there are several single image dehazing techniques, but they are not robust in dynamic variations of natural environment caused by the thickness, coverage of haze and appearance of sunlight. In this paper, we propose an effective and robust method to enhance luminance for image dehazing depending on histogram analysis. Compare with conventional methods, our proposal have better performance in term of contrast, and computation time.

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Study of a Ray-Tracing Method for Optimized Road Light Design

  • Oh, Seon;Choi, Dae-Seob
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.4
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    • pp.194-196
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    • 2010
  • A study is presented of improved road light design for drivers and pedestrians with the use of a ray- or reverse ray-tracing method. Many existing road lights are unsuitable for drivers and pedestrians because of serious problems such as glare effect or randomicity of illuminated areas. This situation has arisen because in customary design methods the emphasis has been on simple factors such as luminance or electrical power. However a high luminance or electrical power consumption, alone, do not guarantee bright and good road lighting. So we have applied a ray-tracing method to the design of a road light reflector with the goals of ensuring that illuminated objects on the road can be seen more clearly and that the illuminating light is more comfortable for the eyes of drivers and pedestrians. We have set design targets for factors such as the uniformity of lighting on the road area per road light, the shading angles and the continuous luminance uniformity on long lengths of road. For set heights of the eyes of drivers and pedestrians eyes we have calculated a design guideline for the achievement of the above design targets. Then we designed a road light reflector using the reverse ray-tracing approach. Also we have achieved the same luminance on the road with almost half the power consumption, through the reduction of lighty loss. In an ideal design optimum parameters are suggested to be a shading angle of 75 degrees and a luminance uniformity of 0.5 on the road area. This reflector performance is achievable with a 250 watt power consumption ceramic discharge metal light source.

Multi-Level Digital Watermarking for Color Image of Multimedia Contents (멀티미디어 컨텐츠의 컬러 영상에 대한 다중 레벨 디지털 워터마킹)

  • Park, Hung-Bog;Seo, Jung-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.1946-1953
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    • 2006
  • Because the embedded watermark of luminance component guarantees the extraction of ownership information when the color image is converted to gray scale image, the information of ownership right as to the luminance component is embedded in the luminance-chrominance color space such as YCbCr. Therefore, this paper proposes watermark embedding, extraction and authentication algorithm of color image. which considers the device and performance of multimedia contents service by focusing on the robustness and invisibility of watermark. The color image is converted from RGB color space to YCbCr color space, and then the properties of each component of Y(Luminance), Cb(Color Differences) and Cr(Color Differences) are considered in order to embed, extract and certify multi-level watermark in the frequency domain based on the wavelet. As a result, it can guaranteed the robustness for the JPEG compression and invisibility of watermark for multi-level.

An Image Signal Processor for Ultra Small HDGrade Video Sensor with 3A in Camera Phones

  • Jang, Won-Woo;Kim, Joo-Hyun;Han, Hag-Yong;Yang, Hoon-Gee;Kang, Bong-Soon
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.507-515
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    • 2009
  • In this paper, we propose an image signal processor (ISP) for an ultra small HD-grade video sensor with 3A (AWB, AE, and AF) in camera phones that can process 720P/30fps videos. In order to enhance the video quality of the systems, it is necessary to achieve the high performance of the 3A. The proposed AWB algorithm multiplies the adjusted coefficients of color gains to the captured data of white objects. The proposed AE method adopts the index step moving based on the difference between an averaged Y luminance and a target luminance, together with IIR filters with variable time responses. The proposed AF technique controls the focus curve to find the lens position that maximizes the integrated high frequency components in luminance values by using highpass filters. Finally, we compare the image quality captured from our system to the quality of a commercial HD camcorder in order to evaluate the performance of the proposed ISP. The proposed ISP system is also fabricated with 0.18um CMOS flash memory process.

Flicker Reduction in Image Sequences (영상 시퀀스의 플리커 제거)

  • Lee, Im-Geun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.577-580
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    • 2010
  • This paper proposes a new algorithm for flicker reduction. Flicker is defined as unwanted luminance fluctuation in the image sequences. As the flicker degrades the performance of motion estimation or segmentation of the objects, it should be corrected before further processing. In this paper, we model the flicker effects as a linear system with gain and offset parameter and propose the new algorithm for flicker reduction. The proposed algorithm considers gain and offset parameter separately, and stabilizes the luminance fluctuation based on these parameters. We show the performance of the proposed method by testing on the sequence with artificially added luminance flicker and real sequence with object motion.

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Comparative Daylighting Performance of an Interior with Lightshelves and Conventional Glazing; A Mock-Up Experiment (Mock-up을 이용한 일반창호 및 경사형 광선반 창호의 채광성능에 관한 비교 실험)

  • Kim, Jeong Tai;Shin, Hwa Young
    • KIEAE Journal
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    • v.6 no.2
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    • pp.67-74
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    • 2006
  • As sustainable design technologies, advanced daylighting systems with lightshelves have been developed and are currently under monitoring the daylighting performance. This study aims to evaluate the comparative daylighting performance of sloped lightshelf and conventional glazing window with mock-up model, reconstructed as a prototype of Korean office building, sized $12.0m{\times}7.3m{\times}3.7m$ ($w{\times}d{\times}h$) and $1.8m{\times}4.8m$($w{\times}h$) for the south facing side-window was installed on the rooftop of engineering building, Kyung Hee University in Korea. It has an identical configuration of reference room and the test room. For the test room, the sloped type lightshelf system was designed as 10mm transparency sheet glass, tilt angle degree $29^{\circ}$, and total sized 1.28m (interior length 0.88m, exterior length 0.49m). It consisted of daylighting collector, entrance glazing and reflector. To assess daylighting performance, the totally 37 measuring points for illuminance and 2 view points of luminance were monitored in every 30 minutes from 12:00 to 15:00. For the detailed analysis, photometric sensors of each room were installed at work-plane (8 points), wall (7 points), ceiling (3points), and exterior horizontal illuminance (1 point). Luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio, uniformity, and luminance are discussed.

Face Detection based on Video Sequence (비디오 영상 기반의 얼굴 검색)

  • Ahn, Hyo-Chang;Rhee, Sang-Burm
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.3
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    • pp.45-49
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    • 2008
  • Face detection and tracking technology on video sequence has developed indebted to commercialization of teleconference, telecommunication, front stage of surveillance system using face recognition, and video-phone applications. Complex background, color distortion by luminance effect and condition of luminance has hindered face recognition system. In this paper, we have proceeded to research of face recognition on video sequence. We extracted facial area using luminance and chrominance component on $YC_bC_r$ color space. After extracting facial area, we have developed the face recognition system applied to our improved algorithm that combined PCA and LDA. Our proposed algorithm has shown 92% recognition rate which is more accurate performance than previous methods that are applied to PCA, or combined PCA and LDA.

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The development of improve the compression ratio through the variance of the luminance component of the intra macroblock (인트라 매크로블록의 휘도성분 분산을 이용한 압축률 향상)

  • Kim, June;Kim, Youngseop
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.1
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    • pp.35-39
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    • 2013
  • H.264/AVC is an authoritative international video coding standard which shows code and efficiency more improved than the existing video standards. Above all, the parameter block mode of H.264/AVC significantly contributes much to high compression efficiency. However, as the occasion demands, users tend to pass while overlooking the part that can produce a little higher compression efficiency. We, taking notice of this point, are designed to bring in much higher compression efficiency by gathering up the overlooked parts. This paper suggests the algorithm that produces efficient performance improvement by using the histogram of luminance in the pixel unit (Macroblock) of respective prediction block and applying specific thresholds. The experimental results proves that the technique proposed by this paper increases the compression efficiency of the existing H.264/AVC algorithm by 0.4% without any increase in the whole encoding time and PSNR complexity.