• Title/Summary/Keyword: quality enhancement

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Enhancement of Aerosol Concentration in Korea due to the Northeast Asian Forest Fire in May 2003

  • In, Hee-Jin;Kim, Yong-Pyo;Lee, Kwon-H.
    • Asian Journal of Atmospheric Environment
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    • v.3 no.1
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    • pp.1-8
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    • 2009
  • Enhancement of aerosol optical thickness (AOT) and surface aerosol mass concentration in Korea for an active forest fire episode in Northeast Asia were estimated by Community Multi-scale Air Quality (CMAQ) model. MODIS/TERRA remote detects of fires in Northeast Asia for May 2003 gave a constraint for estimation of wildfire emissions with an NDVI distribution for recent five years. The simulated wildfire plumes and enhancement of AOT were evaluated and well resolved by comparing multiple satellite observations such as MODIS, TOMS, and others. Scatter plots of observed daily mean aerosol extinction coefficient versus $PM_{10}$ concentration in ground level in Korea showed distinctively different trends based on the ambient relative humidity.

A Single Channel Speech Enhancement for Automatic Speech Recognition

  • Lee, Jinkyu;Seo, Hyunson;Kang, Hong-Goo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.07a
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    • pp.85-88
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    • 2011
  • This paper describes a single channel speech enhancement as the pre-processor of automatic speech recognition system. The improvements are based on using optimally modified log-spectra (OM-LSA) gain function with a non-causal a priori signal-to-noise ratio (SNR) estimation. Experimental results show that the proposed method gives better perceptual evaluation of speech quality score (PESQ) and lower log-spectral distance, and also better word accuracy. In the enhancement system, parameters was turned for automatic speech recognition.

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Simultaneous Spectral Resolution and Sensitivity Enhancement in MR spectrum: Maximum Likelihood Deconvolution Reconstruction

  • Jeong, Gwang-Woo;Jeong, Jenny Eunice;Kang, Heoung-Keun
    • Journal of the Korean Magnetic Resonance Society
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    • v.15 no.2
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    • pp.157-174
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    • 2011
  • Although the use of apodization functions in connection with postprocessing of a 2D NMR spectrum proves improved spectral quality, there is usually a trade-off between resolution enhancement and noise suppression due to a classical "uncertainty principle." In this study, therefore, a mathematical deconvolution technique called "Maximum Likelihood Deconvolution (MLD)" was adopted to achieve the spectral resolution and sensitivity enhancement simultaneously. The MLD technique greatly facilitates visualization and restoration of the genuine spectral information from complex 2D NMR spectra that would be problematic with the conventional apodization/FT processing. In particular, application of the MLD to the 2D-NOE spectrum would be very useful to derive the important proton connectivities, which are essential to achieve elucidating the 3D molecular structure.

A Vision-based Damage Detection for Bridge Cables (교량케이블 영상기반 손상탐지)

  • Ho, Hoai-Nam;Lee, Jong-Jae
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.39-39
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    • 2011
  • This study presents an effective vision-based system for cable bridge damage detection. In theory, cable bridges need to be inspected the outer as well as the inner part. Starting from August 2010, a new research project supported by Korea Ministry of Land, Transportation Maritime Affairs(MLTM) was initiated focusing on the damage detection of cable system. In this study, only the surface damage detection algorithm based on a vision-based system will be focused on, an overview of the vision-based cable damage detection is given in Fig. 1. Basically, the algorithm combines the image enhancement technique with principal component analysis(PCA) to detect damage on cable surfaces. In more detail, the input image from a camera is processed with image enhancement technique to improve image quality, and then it is projected into PCA sub-space. Finally, the Mahalanobis square distance is used for pattern recognition. The algorithm was verified through laboratory tests on three types of cable surface. The algorithm gave very good results, and the next step of this study is to implement the algorithm for real cable bridges.

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Adaptive Regularized Enhancement of Wavelet Compressed Video (웨이블릿 압축 동영상의 정칙화 기반 적응적 개선에 관한 연구)

  • 정정훈;기현종;이성원;백준기
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.4
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    • pp.39-44
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    • 2004
  • The three-dimensional (3D) wavelet transform with motion compensation is suitable for very high quality video coding due to both spatial and temporal decorrelations. However, it still suffers from image degradation such as ringing artifact and afterimage because of the loss of high frequency components by quantization. This paper proposes an iterative regularized enhancement of the motion-compensated 3D wavelet coded video. We also propose the adaptive implementation of the constraints for the regularization. It selectively suppresses the high frequency component along only the corresponding edge direction.

Contrast Enhancement of Images Using APLs in an AC-PDP

  • Lee, Yong-Uk;Lee, Joo-Young;Kim, Nam-Jin;Moon, Seong-Hak
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1483-1486
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    • 2006
  • We describe the contrast enhancement of images using an APL(Average Picture Level) in an AC-PDP. A CEC(Contrast Enhancement Curve) determined by the APL was applied to enhance the contrast of images depending on the dominant gray levels. The most effective advantage of the proposed method is that it is easier to adjust the dynamic ranges to be enhanced with good quality and implement in a hardware system. The simulation result shows that the proposed method enhanced the contrast of given images significantly and kept the original brightness except the specific area of them compared to the HE(Histogram Equalization).

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Fast Enhancement Layer Encoding Method using CU Depth Correlation between Adjacent Layers for SHVC

  • Kim, Kyeonghye;Lee, Seonoh;Ahn, Yongjo;Sim, Donggyu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.260-264
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    • 2013
  • This paper proposes a fast enhancement layer coding method to reduce computational complexity for Scalable HEVC (SHVC) which is based on High Efficiency Video Coding (HEVC). The proposed method decreases encoding time by simplifying Rate Distortion Optimization (RDO)for enhancement layers (EL). The simplification is achieved by restricting CU depths based on the correlation of coding unit (CU) depths between adjacent layers and scalability (spatial or quality) of EL. Comparing with the performance of SHM 1.0 software encoder, the proposed method reduces the encoding time by up to 31.5%.

Color Image Enhancement Based on Color Constancy (칼라 항상성에 기초한 칼라영상 향상)

  • 배성호;김정엽;권갑현;하영호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.5
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    • pp.103-108
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    • 1993
  • An image can be largely corrupted by the ambient illuminant, so that the image enhancement to restory natural color without respect to the ambient illuminant is needed. It this paper, a new color image enhancement technique based on color constancy is proposed. To enhance the image quality, higher volues of contrast and saturation are preferred, but their excessive values make an image unnatural. Since the color constancy processing preserves only hue, while reducing the dynamic range of lightness and saturation,the technique is needed in order to compensate this phenomenon. The proposed method transforms and increases lightness and saturation simultaneously to avoid the complexity in the related transformation by analyzing the relationship between the RGB and modified IHS coordinate system.

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A study on the application of Plateau equalization algorithm for contrast enhancement of real-time thermal image (Plateau equalization 알고리즘을 적용한 실시간 열영상 대조비 개선에 관한 연구)

  • Cho Heung-Gi;Kim Soo-Gon;Lee Jeong-Bok;Lee Won-Sun;Jeon Hee-Hong
    • Proceedings of the KIPE Conference
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    • 2002.11a
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    • pp.186-189
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    • 2002
  • Real-time thermal image is obtained by thermal imaging systems measuring radiant emittence according to law of Plank's blackbody radiation. The histogram of thermal image is not uniform. The signal bands of background and target are separated and grouped in narrow bands. In such a system, contrast enhancement indispensible to distinguish target from background. In this study, plateau histogram equalization using local histogram is proposed for contrast enhancement.

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A Study on the Image Enhancement of OCT Image using Wavelet coefficients (웨이블릿 계수를 적용한 OCT영상의 이미지향상에 관한 연구)

  • 이승용;황대석;류재훈;이영우;류광렬
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.140-143
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    • 2004
  • The mage enhancement of dental On image using wavelet coefficients is presented. The processing is that make gray image from On image by preprocessing, extract high frequency from detail coefficient after acquisition detail coefficient by wavelet transform and emphasize edge appling input image. Experimental results show that enhanced contrast of dental On image, improved mage quality.

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