• 제목/요약/키워드: Background light

검색결과 731건 처리시간 0.031초

Text Segmentation from Images with Various Light Conditions Based on Gaussian Mixture Model

  • Tran, Khoa Anh;Lee, Gueesang
    • International Journal of Contents
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    • 제9권1호
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    • pp.1-5
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    • 2013
  • Standard Gaussian Mixture Model (GMM) is a well-known method for image segmentation. However, one of its problems is that we consider the pixel as independent to each other, which can cause the segmentation results sensitive to noise. It explains why some of existing algorithms still cannot segment texts from the background clearly. Therefore, we present a new method in which we incorporate the spatial relationship between a pixel and its neighbors inside $3{\times}3$ windows to segment the text. Our approach works well with images containing texts, which has different sizes, shapes or colors in case of light changes or complex background. Experimental results demonstrate the robustness, accuracy and effectiveness of the proposed model in image segmentation compared to other methods.

Modified Ramp Reset Waveform for High Contrast Ratio in AC PDPs

  • Kim, Jae-Sung;Yang, Jin-Ho;Ha, Chang-Hoon;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.199-202
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    • 2002
  • In general, the background light produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes occur during the reset period. We adopted a MgO coated phosphor layer to get the same level of voltage margin in the new reset pulse scheme compared to that of the conventional ramp reset pulse one. As a result, the voltage margin is maintained at the same level and the dark room contrast ratio is improved dramatically.

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배경이 물체에 겹치지 않는 영상에서 잡음에 대한 안정성, 출력의 최대값 크기, 광효율을 고려한 최적 Trade-off 필터 (Optimal trade-off filters for Noise Robustness, Peak Sharpness and Light Efficiency in the Nonoverlapping Background Noise)

  • 성영경;최태선
    • 대한전자공학회논문지SP
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    • 제37권4호
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    • pp.56-64
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    • 2000
  • 본 논문에서는 패턴인식의 문제에서 배경이 물체에 겹치지 않는 영상일 때 잡음에 대한 안정성, 피크의 크기와 광효율의 조건에 대한 trade-off를 통해 필터를 설계하는 방법에 대해 언급한다. 필터를 설계하기위해 신호대 잡음비, 출력의 최대값대 출력에너지비, 광효율의 세가지 다른 조건을 사용한다. 필터의 성능을 시험하기 위해 여러 형태의 잡음과 필터 계수에 대해 컴퓨터 모의실험을 실시한다. 배경이 물체에 겹치지 않는 영상에 대해 기존의 필터보다 우수한 성능을 얻을 수 있다.

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톤 온 톤 배색에 따른 니트웨어의 감성이미지와 선호도 연구 (A study on emotional images and preference of knitwear according to tone on tone combination)

  • 이미숙;서서영
    • 복식문화연구
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    • 제22권3호
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    • pp.399-410
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    • 2014
  • The purpose of this study was to investigate emotional images and preference of knitwear by tone on tone combination. The subjects were 357 university students in Daejeon and Chungnam province, and the measuring instruments were 6 stimuli manipulated by color and tone combination type of background and pattern in the tone and tone combination, and self-administrated questionnaires consisted of emotional images items, preference items, and subjects' demographics attributions. The data were analyzed by Cronbach's ${\alpha}$, factor analysis, t-test, MANOVA and Duncan's multiple range test, using SPSS program. The results were as follows. First, four factors (attractiveness, conspicuity, mildness, and activity) are emerged on emotional images of knitwear. Second, color had main effects on emotional images and preference. Gray color was perceived as most attractive image and more preferred than others. Third, tone combination type had some effects on emotional images. Vivid tone background/light tone pattern was perceived more attractive image but less conspicuous and mild than light tone background/vivid tone pattern. Forth, subjects' gender had an effects on conspicuous image. Male was perceived more conspicuous image on knitwear stimuli than female. Fifth, color and subjects' gender had interaction effects on attractiveness image and preference. Male perceived that blue is more attractive and preferred than female.

Single Image-based Enhancement Techniques for Underwater Optical Imaging

  • Kim, Do Gyun;Kim, Soo Mee
    • 한국해양공학회지
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    • 제34권6호
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    • pp.442-453
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    • 2020
  • Underwater color images suffer from low visibility and color cast effects caused by light attenuation by water and floating particles. This study applied single image enhancement techniques to enhance the quality of underwater images and compared their performance with real underwater images taken in Korean waters. Dark channel prior (DCP), gradient transform, image fusion, and generative adversarial networks (GAN), such as cycleGAN and underwater GAN (UGAN), were considered for single image enhancement. Their performance was evaluated in terms of underwater image quality measure, underwater color image quality evaluation, gray-world assumption, and blur metric. The DCP saturated the underwater images to a specific greenish or bluish color tone and reduced the brightness of the background signal. The gradient transform method with two transmission maps were sensitive to the light source and highlighted the region exposed to light. Although image fusion enabled reasonable color correction, the object details were lost due to the last fusion step. CycleGAN corrected overall color tone relatively well but generated artifacts in the background. UGAN showed good visual quality and obtained the highest scores against all figures of merit (FOMs) by compensating for the colors and visibility compared to the other single enhancement methods.

Restoration of underwater images using depth and transmission map estimation, with attenuation priors

  • Jarina, Raihan A.;Abas, P.G. Emeroylariffion;De Silva, Liyanage C.
    • Ocean Systems Engineering
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    • 제11권4호
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    • pp.331-351
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    • 2021
  • Underwater images are very much different from images taken on land, due to the presence of a higher disturbance ratio caused by the presence of water medium between the camera and the target object. These distortions and noises result in unclear details and reduced quality of the output image. An underwater image restoration method is proposed in this paper, which uses blurriness information, background light neutralization information, and red-light intensity to estimate depth. The transmission map is then estimated using the derived depth map, by considering separate attenuation coefficients for direct and backscattered signals. The estimated transmission map and estimated background light are then used to recover the scene radiance. Qualitative and quantitative analysis have been used to compare the performance of the proposed method against other state-of-the-art restoration methods. It has been shown that the proposed method can yield good quality restored underwater images. The proposed method has also been evaluated using different qualitative metrics, and results have shown that method is highly capable of restoring underwater images with different conditions. The results are significant and show the applicability of the proposed method for underwater image restoration work.

FAR-IR GALACTIC EMISSION MAP AND COSMIC OPTICAL BACKGROUND

  • Matsuoka, Y.
    • 천문학논총
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    • 제27권4호
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    • pp.353-356
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    • 2012
  • We present new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (${\sim}0.44{\mu}m$) and red (${\sim}0.64{\mu}m$) bands. Accurate starlight subtraction was achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with the thermal $100{\mu}m$ brightness, whilst the other shows a constant level in the lowest $100{\mu}m$ brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has an extragalactic origin (i.e., the COB). The derived COB brightness is ($(1.8{\pm}0.9){\times}10^{-9}$ and $(1.2{\pm}0.9){\times}10^{-9}\;erg\;s^{-1}\;cm^{-2}\;sr^{-1}\;{\AA}^{-1}$ in the blue and red spectral regions, respectively, or $7.9{\pm}4.0$ and $7.7{\pm}5.8\;nW\;m^{-2}\;sr^{-1}$. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions from other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)-scattered starlight by the interstellar dust. We derive the mean DGL-to-$100{\mu}m$ brightness ratios of $2.1{\times}10^{-3}$ and $4.6{\times}10^{-3}$ at the two bands, which are roughly consistent with previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.

EFFECTS OF CAFFEINE AND 2,5-DI-(tert-BUTYL)-1,4-BENZOHYDROQUINONE ON BLUE LIGHT-DEPENDENT $H^+$ PUMPING IN GUARD CELL PROTOPLASTS FROM Vicia faba L.

  • Goh, Chang-Hyo;Shimazaki, Ken-Ichiro
    • Journal of Photoscience
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    • 제4권2호
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    • pp.35-40
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    • 1997
  • The sensory transduction processes of blue light in guard cells have been suggested the involvement of Ca$^{2+}$/calmodulin-dependent myosin light chain kinase (MLCK) or MLCK-like proteins. The source of Ca$^{2+}$ required for the signal transduction process was investigated in guard cell protoplasts (GCPs). The GCPs showed the typical H$^+$ pumping activity by blue light (200 $\mu$mol m$^{-2}$ s$^{-1}$) and fusicoccin (10 $\mu$M) under background red light (600 $\mu$mol m$^{-2}$ s$^{-1}$). The blue light-dependent H$^+$ pumping was not significantly affected by the externally changed Ca$^{2+}$ concentrations. The addition of 1 mM Ca$^{2+}$ in the bathing medium ratherly inhibited the H$^+$ pumping. In contrast, the blue light-dependent H$^+$ pumping was inhibited by caffeine and 2,5-di-(tert-butyl)-1,4-benzohydroquinone (BHQ), inhibitor of C$^{2+}$-ATPase in endoplasmic reticulum (ER) without inhibiting the H $^+$ pump. The inhibition by caffeine and BHQ was fully reversible. The extent of inhibition by caffeine and BHQ was larger when they were added together than when added separately. The results suggest that Ca$^{2+}$ required for the blue light-dependent H$^+$ pumping may be released from the intracellular Ca$^{2+}$ stores, probably ER in guard cells.

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초정밀가공 기술을 이용한 광학 마이크로패턴의 광 반사 효과에 관한 연구 (Research on Light Reflection Effect of the Optical Micro Pattern Using Ultra-Precision Technology)

  • 유춘근;윤철용;현동훈
    • 한국생산제조학회지
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    • 제18권6호
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    • pp.621-628
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    • 2009
  • Because the Ultra-Precision Technology increase its competitiveness in the field of the design, precision of processing technology, confidence and fixation degree are major considerations. According to Pattern shapes using these processing technologies, Light Reflection has influence on the sense of sight about human being. Based on background of these studies, we draw a plan about a round workpiece using a 3D design program and analyze the effect on Light Reflection changing a pattern angle and a source of light through SPEOS program in this research. We make Pattern form as V-Shape, and compare the area distributed by Light Reflection by classifying angle into 4 and analyze changes according to a source of light. In order to measure and evaluate the data from simulation analysis we has manufactured Diamond Tool and has processed Pattern precision using a Ultra-Precision Machine. Based on the result of this study, we forecast that the field of design will achieve rapid growth due to Ultra-Precision Technology in the world market.

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