• Title/Summary/Keyword: Edge estimation

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Single Image Fog Removal based on JBDC and Pixel-based Transmission Estimation

  • Kim, Jongho
    • International journal of advanced smart convergence
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    • v.9 no.3
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    • pp.118-126
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    • 2020
  • In this paper, we present an effective single image fog removal by using the Joint Bright and Dark Channel (JBDC) and pixel-based transmission estimation to enhance the visibility of outdoor images susceptible to degradation due to weather and environmental conditions. The conventional methods include refinement process of coarse transmission with heavy computational complexity. The proposed transmission estimation reveals excellent edge-preserving performance and does not require the refinement process. We estimate the atmospheric light in pixel-based fashion, which can improve the transmission estimation performance and visual quality of the restored image. Moreover, we propose an adaptive transmission estimation to enhance the visual quality specifically in sky regions. Comprehensive experiments on various fog images show that the proposed method exhibits reduced computational complexity and excellent fog removal performance, compared with the existing methods; thus, it can be applied to various fields including real-time devices.

Estimation of the Substrate Size with Minimum Mutual Coupling of a Linear Microstrip Patch Antenna Array Positioned Along the H-Plane

  • Kwak, Eun-Hyuk;Yoon, Young-Min;Kim, Boo-Gyoun
    • Journal of Electrical Engineering and Technology
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    • v.10 no.1
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    • pp.320-324
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    • 2015
  • Mutual coupling between antenna elements of a linear microstrip patch antenna array positioned along the H-plane including the effect of edge reflections is investigated. Simple formulas are presented for the estimation of the grounded dielectric substrate size with minimum mutual coupling. The substrate sizes calculated by these formulas are in good agreement with those obtained by the full-wave simulation and experimental measurement. The substrate size with minimum mutual coupling is a function of the effective dielectric constant for surface waves and the distance between the antenna centers. The substrate size with minimum mutual coupling decreases as the effective dielectric constant for surface waves on a finite grounded dielectric substrate increases.

A Study on Variable Block Matching Algorithm Using Edge Information of Differential Image (차영상의 윤곽정보를 이용한 가변 블록 정합 알고리즘에 관한 연구)

  • 권병헌;안정길;황병원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.639-648
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    • 1994
  • This paper presents a new block matching algorithm in estimation of motion information that is important technology in compressing interframe. In estimation of motion information, we find differential image using two successive frame image in order to find required real time processing and accurate moving vector, the binary image is made of edge and find more accurate moving vectors by application quadtree method to parts including many moving according to this activity. The computer simulation results show that increased PSNR and reduced computation time.

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A Two-Stage Approach to Pedestrian Detection with a Moving Camera

  • Kim, Miae;Kim, Chang-Su
    • IEIE Transactions on Smart Processing and Computing
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    • v.2 no.4
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    • pp.189-196
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    • 2013
  • This paper presents a two-stage approach to detect pedestrians in video sequences taken from a moving vehicle. The first stage is a preprocessing step, in which potential pedestrians are hypothesized. During the preprocessing step, a difference image is constructed using a global motion estimation, vertical and horizontal edge maps are extracted, and the color difference between the road and pedestrians are determined to create candidate regions where pedestrians may be present. The candidate regions are refined further using the vertical edge symmetry features of the pedestrians' legs. In the next stage, each hypothesis is verified using the integral channel features and an AdaBoost classifier. In this stage, a decision is made as to whether or not each candidate region contains a pedestrian. The proposed algorithm was tested on a range of dataset images and showed good performance.

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Multiple change-point estimation in spectral representation

  • Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • v.29 no.1
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    • pp.127-150
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    • 2022
  • We discuss multiple change-point estimation as edge detection in piecewise smooth functions with finitely many jump discontinuities. In this paper we propose change-point estimators using concentration kernels with Fourier coefficients. The change-points can be located via the signal based on Fourier transformation system. This method yields location and amplitude of the change-points with refinement via concentration kernels. We prove that, in an appropriate asymptotic framework, this method provides consistent estimators of change-points with an almost optimal rate. In a simulation study the proposed change-point estimators are compared and discussed. Applications of the proposed methods are provided with Nile flow data and daily won-dollar exchange rate data.

Edge Profile Correction for Modulation Transfer Function on Digital X-ray Imaging System (디지털 의료영상에서 Edge method에 의한 Modulation Transfer Function 보정방법과 특이성)

  • Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.30 no.3
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    • pp.251-257
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    • 2007
  • Medical imaging zero-phase-sequence component in estimation for picture that is gotten that importance weight of digital device is increased day by day at the same time also so much important. Special quality about resolution uses Modulation Transfer Function by representative method to evaluate sharpness on important element in image quality. Get MTF converting slit, differentiating this making composition ESF edge method uses Excel by edge method in this study to be composition LSF get in fourier to informed measuring mean universally. Such method is considered that can help in principle grasping of step before make Program using C language as many as Matlab.

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In-phase Statistical Edge Directed Interpolation based on Windowed MMSE Estimation (MMSE관점에서 위상 정합 방향성 경계 강조 보간법)

  • 임태환;김재호
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.93-96
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    • 2000
  • In this paper, we present an improved novel interpolator that performs high quality interpolation on both synthetic and real world images. Its structure, which is based on a four directional linear predictor with equiripple windowed samples and phase matching equalizer, provides edge-directional data interpolation so that sharp and artifacts-free images are obtained at a reasonable computational cost.

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An Edge Directed Color Demosaicing Algorithm Considering Color Channel Correlation (컬러 채널 상관관계를 고려한 에지 방향성 컬러 디모자이킹 알고리즘)

  • Yoo, Du Sic;Lee, Min Seok;Kang, Moon Gi
    • Journal of Broadcast Engineering
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    • v.18 no.4
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    • pp.619-630
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    • 2013
  • In this paper, we propose an edge directed color demosaicing algorithm considering color channel correlation. The proposed method consists of local region classification step and edge directional interpolation step. In the first step, each region of a given Bayer image is classified as normal edge, pattern edge, and flat regions by using intra channel and inter channel gradients. Especially, two criteria and verification process for the normal edge and pattern edge classification are used to reduce edge direction estimation error, respectively. In the second step, edge directional interpolation process is performed according to characteristics of the classified regions. For horizontal and vertical directional interpolations, missing color components are obtained from interpolation equations based on intra channel and inter channel correlations in order to improve the performance of the directional interpolations. The simulation results show that the proposed algorithm outperforms conventional approaches in both objective and subjective terms.

Directional Block Loss Recovery sing Hypothesis Testing Problem (가설 검증 기법을 이용한 방향성을 가지는 손실 블록의 복구)

  • Hyun, Seung-Hwa;Kim, Yoo-Shin;Eom, Il-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.5
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    • pp.87-94
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    • 2008
  • In this paper, we present a directional error concealment technique to compensate a lost block. Generally, the strong edge of an image has the large amounts of the variance because of its large coefficients in the wavelet domain. For estimating edge direction of a lost block, a $X^2$ hypothesis-testing problem is applied using the variance of wavelet coefficients. The lost block is interpolated according to the estimated edge direction. The pixels for interpolation is obtained from the edge direction. The proposed method outperforms the previous methods in objective and subjective qualities.

Error Concealment Using Intra-Mode Information Included in H.264/AVC-Coded Bitstream

  • Kim, Dong-Hyung;Jeong, Se-Yoon;Choi, Jin-Soo;Jeon, Gwang-Gil;Kim, Seung-Jong;Jeong, Je-Chang
    • ETRI Journal
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    • v.30 no.4
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    • pp.506-515
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    • 2008
  • The H.264/AVC standard has adopted new coding tools such as intra-prediction, variable block size, motion estimation with quarter-pixel-accuracy, loop filter, and so on. The adoption of these tools enables an H.264/AVC-coded bitstream to have more information than was possible with previous standards. In this paper, we propose an effective spatial error concealment method with low complexity in H.264/AVC intra-frame. From information included in an H.264/AVC-coded bitstream, we use prediction modes of intra-blocks to recover a damaged block. This is because the prediction direction in each prediction mode is highly correlated to the edge direction. We first estimate the edge direction of a damaged block using the prediction modes of the intra-blocks adjacent to a damaged block and classify the area inside the damaged block into edge and flat areas. Our method then recovers pixel values in the edge area using edge-directed interpolation, and recovers pixel values in the flat area using weighted interpolation. Simulation results show that the proposed method yields better video quality than conventional approaches.

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