• Title/Summary/Keyword: Chrominance

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Algorithm for Improving Visibility under Ambient Lighting Using Deep Learning (딥러닝을 이용한 외부 조도 아래에서의 시인성 향상 알고리즘)

  • Lee, Hee Jin;Song, Byung Cheol
    • Journal of Broadcast Engineering
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    • v.27 no.5
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    • pp.808-811
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    • 2022
  • Display under strong ambient lighting is perceived darker than it really is. Existing techniques for solving the problem in terms of software show limitations in that image enhancement techniques are applied regardless of ambient lighting or chrominance is not improved compared to luminance. Therefore, this paper proposes a visibility enhancement algorithm using deep learning to adaptively respond to ambient lighting values and an equation to restore optimal chrominance for luminance. The algorithm receives an ambient lighting value with the input image, and then applies a deep learning model and chrominance restoration equation to generate an image to minimize the difference between the degradation modeling of enhanced image and the input image. Qualitative evaluation proves that the algorithm shows excellent performance in improving visibility under strong ambient lighting through comparison of images applied with degradation modeling.

Facial-feature Detection in Color Images using Chrominance Components and Mean-Gray Morphology Operation (색도정보와 Mean-Gray 모폴로지 연산을 이용한 컬러영상에서의 얼굴특징점 검출)

  • 강영도;양창우;김장형
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.714-720
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    • 2004
  • In detecting human faces in color images, additional geometric computation is often necessary for validating the face-candidate regions having various forms. In this paper, we propose a method that detects the facial features using chrominance components of color which do not affected by face occlusion and orientation. The proposed algorithm uses the property that the Cb and Cr components have consistent differences around the facial features, especially eye-area. We designed the Mean-Gray Morphology operator to emphasize the feature areas in the eye-map image which generated by basic chrominance differences. Experimental results show that this method can detect the facial features under various face candidate regions effectively.

Adaptive block tree structure for video coding

  • Baek, Aram;Gwon, Daehyeok;Son, Sohee;Lee, Jinho;Kang, Jung-Won;Kim, Hui Yong;Choi, Haechul
    • ETRI Journal
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    • v.43 no.2
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    • pp.313-323
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    • 2021
  • The Joint Video Exploration Team (JVET) has studied future video coding (FVC) technologies with a potential compression capacity that significantly exceeds that of the high-efficiency video coding (HEVC) standard. The joint exploration test model (JEM), a common platform for the exploration of FVC technologies in the JVET, employs quadtree plus binary tree block partitioning, which enhances the flexibility of coding unit partitioning. Despite significant improvement in coding efficiency for chrominance achieved by separating luminance and chrominance tree structures in I slices, this approach has intrinsic drawbacks that result in the redundancy of block partitioning data. In this paper, an adaptive tree structure correlating luminance and chrominance of single and dual trees is presented. Our proposed method resulted in an average reduction of -0.24% in the Y Bjontegaard Delta rate relative to the intracoding of JEM 6.0 common test conditions.

Post-Processing for Reducing Blocking Artifacts using Adaptive Low Pass Filtering

  • Hwang, Younghooi;Jeon, Byeungwoo;Sull, Sanghoon
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.297-300
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    • 2002
  • In this paper, we propose a post-processing method to reduce the blocking artifacts. We perform the post-processing only in the spatial domain so that it is readily applicable to real-time video decoder. Many approaches proposed so far for deblocking deal with only The luminance signal. but here we propose processing the chrominance signals as well since the low bit rare application where the blocking artifacts are most problematic suffers significantly from the color misalignment caused by blocking artifacts occurring to chrominance data as well. The proposed method is composed of low pass filtering in two steps considering the edge direction. The first step is the IIR low pass filtering in the diagonal direction, and the second step is another IIR low pass filtering in horizontal and vertical directions.

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Adaptive Interframe Filtering Techniques for Separation of Luminance/Chrominance Components in NTSC Composite Signals (NTSC 복합신호의 휘도 및 색도성분을 분리하기 위한 프레임간 적응 필터링 기법)

  • 강철호;이정한
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.1
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    • pp.72-80
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    • 1988
  • In this paper, new adaptive interframe filtering methods have been proposed to separate the luminance and chrominance components in NTSC composite signals. In thess methods, the composite signals are adaptivelty processed in three dimensions according to the local change or movement of the picture. For interframe processing, two algorithms have been proposed which adapt three filters in the horizontal, vertical and temporal directions to the magnitude f detection signal dependent upon both the movement and local change of the picture. The three kind of filters have been used at the sampling rate of four times the subcarrier frequency. The various quantitative measures have been introduced to compare the objective performance of the conventional methods and that of proposed ones by computer simulation.

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Forensic Watermarking for Digital Cinema Using Temporal Chrominance Differences (디지털 시네마의 유출 방지를 위한 시간적인 색차 변화를 이용한 포렌식 워터마킹 기법)

  • Yang, Se-Yol;Choi, Hyuk
    • Journal of Internet Computing and Services
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    • v.9 no.6
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    • pp.81-87
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    • 2008
  • In this paper, we propose a forensic watermarking scheme using temporal differences of video chrominance values. Proposed method has low complexity and good visual quality, which is suitable for traitor tracing of digital cinema. Experimental results show that our forensic watermarking method has good detection performance and is robust to several attacks, such as camcorder recording and video compression.

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Time-optimized Color Conversion based on Multi-mode Chrominance Reconstruction and Operation Rearrangement for JPEG Image Decoding (JPEG 영상 복원을 위한 다중 모드 채도 복원과 연산 재배열 기반의 시간 최적화된 컬러 변환)

  • Kim, Young-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.1
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    • pp.135-143
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    • 2009
  • Recently, in the mobile device, the increase of the need for encoding and decoding of high-resolution images requires an efficient implementation of the image codec. This paper proposes a time-optimized color conversion method for the JPEG decoder, which reduces the number of calculations in the color conversion by the rearrangement of arithmetic operations being possible due to the linearity of the IDCT and the color conversion matrices and brings down the time complexity of the color conversion itself by the integer mapping replacing floating-point operations to the optimal fixed-point shift and addition operations, eventually reducing the time complexity of the JPEG decoder. And the proposed method compensates a decline of image quality incurred by the quantification error of the operation arrangement and the integer mapping by using the multi-mode chrominance reconstruction. The performance evaluation performed on the development platform of embedded systems showed that, compared to previous color conversion methods, the proposed method greatly reduces the image decoding time, minimizing the distortion of decoded images.

Absorption Properties of Chitosan and Nano Silver Composite knit Fabrics Dyed with Chrysanthemum indicum Linn Extract (감국 추출액으로 염색한 키토산/나노실버 복합편성물의 염착특성)

  • Chu, Young-Ju
    • Fashion & Textile Research Journal
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    • v.12 no.6
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    • pp.837-842
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    • 2010
  • This study examines the dyeability, light fastness, washing fastness, and antibacterial activity of chitosan and nano silver composite knit fabrics dyed with extracted solution from Chrysanthemum Indicum Linn. The results show that ${\Delta}E$ values of chitosan and nano silver composite knit fabrics were higher than cotton 100% knit fabrics in dyed condition with extracted solution from Chrysanthemum Indicum Linn, and mordant treatments influenced the chrominance change. Chrysanthemum indicum Linn confirmed that this could be a polygenetic colors. ${\Delta}E$ values of post-mordant treatments knit fabrics were higher than pre-mordant treatments knit fabrics in dyed condition with extracted solution from Chrysanthemum Indicum Linn., and mordant treatments method influenced the chrominance change. The dyeability of chitosan and nano silver composite knit fabrics was increased by mordant treatment. The fastness of the chitosan and nano silver composite knit fabrics was better than cotton 100% knit fabrics. In the result of antibacterial activity, the bacterial reduction rate of chitosan and nano silver composite knit fabrics was 99.9% to Staphylococcus aureus and Klebsiella pneumoniae.

Luminance and Chrominance Compensation of Multiview Video using Histogram Matching (히스토그램 매칭을 이용한 다시점 비디오의 휘도와 색차 성분 보상 기법)

  • Lee, Dong-Seok;Yoo, Ji-Hwan;Yoo, Ji-Sang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.11a
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    • pp.191-194
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    • 2009
  • 본 논문에서는 효율적인 다시점 비디오 부호화를 위해 히스토그램(histogram)을 이용한 다시점 비디오의 휘도(luminance)와 색차(chrominance)성분 보상 기법을 제안한다. 다시점 비디오는 카메라의 기하학적인 위치 차이와 여러 대의 카메라가 동일한 특성을 가지도록 완벽히 조정되지 못함으로 인해 동일한 시간대에 촬영된 인접한 시점 영상 간에 휘도와 색상의 차이가 발생할 수 있다. 이러한 특성은 인접한 카메라로부터 획득된 영상을 참조하여 시점간 움직임 예측 시에 오정합의 원인이 되어 부호화 효율을 떨어뜨리게 된다. 본 논문에서는 효율적인 다시점 비디오 부호화를 위해 시점간의 히스토그램을 비교하여 정합하는 휘도 및 색차 보상 기법을 수행한다. 일정한 시간 대역(time interval)에서 다시점 비디오의 평균 누적 히스토그램을 이용하여 참조 영상을 생성하고 각 시점별로 정합 함수를 통해 다시점 영상 간의 휘도와 색상의 불일치성을 보상한다. 제안하는 조명 보상 기법을 통하여 다시점 비디오 부호화 효율을 높일 수 있었다.

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The Separation of NTSC Signal Components by Using Adaptive Selection Method of Horizontal and Vertical Filters (수평 및 수직 필터의 적응적 선택에 의한 NTSC 칼라영상신호의 성분분리)

  • 권병헌;황병원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.2
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    • pp.211-224
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    • 1994
  • In this paper, a multi-level adaptive intraframe method has been proposed to separate the luminance and chominance components in NTSC composite signal. The control signals are generated by detecting the vertical correlation and transition in the horizontal and diagonal directions. The chrominance component is adaptively processed through vertical and horizontal filters according to the control signals and the luminance component is processed by subtracting the chrominance component from the composite video signal. The several filters have been used at the sampling rate of four times the color subcarrier frequency and computer simulation and SVP(Serial Video Processing) system have been introduced to compare the performance of the conventional methods and that of proposed one.

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