• Title/Summary/Keyword: brightness contrast

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Perception of Color and brightness in a combined PC and TV monitor (PC & TV 겸용 모니터에서 사용자의 색채 및 밝기 인식 특성)

  • 박재희;정광태;정병국;김상두
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1997.11a
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    • pp.140-145
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    • 1997
  • A stuey to investigate the perception characteristics of color and brightness was conducted in a combined PC and TV monitor, The objective of this study is to suggest user's favorite color temperature in PC mode and user's favorite contrast in TV mode. Investigated factors were monitor coating(coatiog vs. non-coation)and screen brightness (30fL vs. 35fL)in first experiment and monitor coating and pucture movement(static vs. dynamic) in second experiment. The first experiment was conducted in TV mode. Twenty-three subjects (male 12, female 11) perticipated in this experiment. In first experiment, average color temperatures were about 8000K in all experimental conditions. In addition, there was significant difference between coating and non-coating screen at 0.1 level. In second experiment, average contrasts were obtained in all esperimental conditions. There was significant difference between coating and ndn-coating screen at 0.05 level, In addition, there was significant difference between static picture and dynamic picture at 0.1 level

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A Dual In-Plane Electrode Structure for Better Brightness in a Helix-Deformed FLCD

  • You, Doo-Hwan;Lee, Sin-Doo;Lee, Ju-Hyun;Na, Do-Jun
    • Journal of Information Display
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    • v.2 no.1
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    • pp.1-4
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    • 2001
  • We propose a dual in-plane parallel electrode structure of a vertical configuration of a helix-deformed ferroelectric liquid crystal (HDFLC) mode for better brightness than a single in-plain electrode case. This structure provides high brightness in addition to the analog gray scale capability, fast response, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates and thus extremely uniform alignment of molecules in a large area is naturally achieved in our new configuration.

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Single-Image Dehazing based on Scene Brightness for Perspective Preservation

  • Young-Su Chung;Nam-Ho Kim
    • Journal of information and communication convergence engineering
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    • v.22 no.1
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    • pp.70-79
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    • 2024
  • Bad weather conditions such as haze lead to a significant lack of visibility in images, which can affect the functioning and reliability of image processing systems. Accordingly, various single-image dehazing (SID) methods have recently been proposed. Existing SID methods have introduced effective visibility improvement algorithms, but they do not reflect the image's perspective, and thus have limitations that distort the sky area and nearby objects. This study proposes a new SID method that reflects the sense of space by defining the correlation between image brightness and haze. The proposed method defines the haze intensity by calculating the airlight brightness deviation and sets the weight factor of the depth map by classifying images based on the defined haze intensity into images with a large sense of space, images with high intensity, and general images. Consequently, it emphasizes the contrast of nearby images where haze is present and naturally smooths the sky region to preserve the image's perspective.

Estimation of the Light Intensity by Using Bright-Chip LED Sensory System (고휘도 발광 Chip 소자를 이용한 빛의 명암도 분석)

  • Choi, Ju-Hyeon;Kim, Ji-Sun;Jung, Gu-In;Lee, Tae-Hee;Kim, A-Hee;Oh, Han-Byeol;Park, Hee-Jung;Kim, Kyung-Seop;Jun, Jae-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.9
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    • pp.1290-1296
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    • 2013
  • The light intensity which represents the relative amount of brightness and darkness is very important feature to discern the color hue and its relevant information. With this aim, we devise a new optical system and method to analyze the light intensity. Our suggested system including a phototransistor and white-high-brightness chip light-emitting diode intend estimate the contrast value utilizing Image Research Institute(I.R.I.) Hue & Tone samples which includes 120 color sheets arranged by the color hue and tone. As a result, we confirmed that the brightness of the color checker can be accurately estimated by a high-brightness light-emitting-diode optical system.

Fuzzy Stretching Method of Color Image (컬러 영상에서의 퍼지 스트레칭 기법)

  • Kim, Kwang-Baek
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.5
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    • pp.19-23
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    • 2013
  • TIn this paper, we propose a novel fuzzy stretching method that adopts a triangle type fuzzy membership function to control the highest and lowest brightness limit dynamically. As an essential procedure to enhance the brightness contrast, stretching is an important procedure in color image processing. While popular Ends-in Search stretching method should be provided fixed minimum and maximum brightness threshold from experience, our proposed method determines them dynamically by fuzzy membership functions. The minimum and maximum limit is determined by computing the lowest and highest pixel value according to the membership degree of our designed triangle type membership function. The experiment shows that the proposed method result in far less skewed histogram than those of Ends-in Search stretching thus successfully verifies its effectiveness.

Bright Surround Luminance and Perceived Image Contrast

  • Kim, A-Ri;Kim, Hong-Suk;Park, Seung-Ok;Baek, Ye-Seul;Kim, Youn-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.745-748
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    • 2008
  • The theory of Bartleson and Breneman that the perceived image contrast changes with surround luminance (the lighter surround provides higher contrast) was tested an over bright condition($8500d/m^2$). Contrarily to the Bartleson and Breneman's results, we observed the fact that perceived constrast was decreased when surround huminance increased from dark to over bright through two sets of psychophysical experiments based upon both uniform gray patches and complex color images.

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A Comparative Study on Image Enhancement Methods for Low Contrast Images (저대비 영상을 위한 영상향상 기법들의 비교연구)

  • Kim Yong-Soo;Kim Nam-Jin;Lee Se-Yul
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.269-272
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    • 2005
  • The principal objective of enhancement methods is to process an image so that the result is more suitable than the original image for a specific application. Images taken in the night can be low-contrast images because of poor environments. In this paper, we compare the structure of ICECA(Image Contrast Enhancement technique using Clustering Algorithm) with the structures of HE(Histogram Equalization), BBHE(Brightness preserving Bi-Histogram Equalization), and Multi -Scale Retinex(MSR). We compared performances of image enhancement methods by applying these methods to a set of diverse images.

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Image Contrast Enhancement based on Histogram Decomposition and Weighting (히스토그램 분할과 가중치에 기반한 영상 콘트라스트 향상 방법)

  • Kim, Ma-Ry;Chung, Min-Gyo
    • Journal of Internet Computing and Services
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    • v.10 no.3
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    • pp.173-185
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    • 2009
  • This paper proposes two new image contrast enhancement methods, RSWHE (Recursively Separated and Weighted Histogram Equalization) and RSWHS (Recursively Separated and Weighted Histogram Specification). RSWHE is a histogram equalization method based on histogram decomposition and weighting, whereas RSWHS is a histogram specification method based on histogram decomposition and weighting. The two proposed methods work as follows: 1) decompose an input histogram based on the image's mean brightness, 2) compute the probability for the area corresponding to each sub-histogram, 3) modify the sub-histogram by weighting it with the computed probability value, 4) lastly, perform histogram equalization (in the case of RSWHE) or histogram specification (in the case of RSWHS) on the modified sub-histograms independently. Experimental results show that RSWHE and RSWHS outperform other methods in terms of contrast enhancement and mean brightness preservation as well.

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A Study on the Evaluation Method of Perceptual Contrast with CIECAM02

  • Chong, Jong-Ho;Lee, Seung-Bae;Lee, Sang-Myung;Choi, Young-Chul;Bae, Jae-Woo;Kim, Hun-Soo;Chung, Ho-Kyoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1661-1663
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    • 2007
  • The contrast of display is one of the important specifications. Even if the contrast indicates luminance range which is a capability of the display and is greater in lower luminance or higher luminance, we consider that the greater contrast gets not the better performance. It is not the same value in human visual system. In practice, it is difficult to achieve the full dynamic range seen by human beings using electronic equipment. Therefore, we consider ambient condition and human perception to calculate perceptual contrast using the CIECAM02. In this paper, we propose perceptual contrast that is calculated using the brightness of CIECAM02.

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Blind Quality Metric via Measurement of Contrast, Texture, and Colour in Night-Time Scenario

  • Xiao, Shuyan;Tao, Weige;Wang, Yu;Jiang, Ye;Qian, Minqian.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.4043-4064
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    • 2021
  • Night-time image quality evaluation is an urgent requirement in visual inspection. The lighting environment of night-time results in low brightness, low contrast, loss of detailed information, and colour dissonance of image, which remains a daunting task of delicately evaluating the image quality at night. A new blind quality assessment metric is presented for realistic night-time scenario through a comprehensive consideration of contrast, texture, and colour in this article. To be specific, image blocks' color-gray-difference (CGD) histogram that represents contrast features is computed at first. Next, texture features that are measured by the mean subtracted contrast normalized (MSCN)-weighted local binary pattern (LBP) histogram are calculated. Then statistical features in Lαβ colour space are detected. Finally, the quality prediction model is conducted by the support vector regression (SVR) based on extracted contrast, texture, and colour features. Experiments conducted on NNID, CCRIQ, LIVE-CH, and CID2013 databases indicate that the proposed metric is superior to the compared BIQA metrics.