• Title/Summary/Keyword: transmission estimation process

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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.

Edge-Preserving and Adaptive Transmission Estimation for Effective Single Image Haze Removal

  • Kim, Jongho
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.2
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    • pp.21-29
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    • 2020
  • This paper presents an effective single image haze removal using edge-preserving and adaptive transmission estimation to enhance the visibility of outdoor images vulnerable to weather and environmental conditions with computational complexity reduction. The conventional methods involve the time-consuming refinement process. The proposed transmission estimation however does not require the refinement, since it preserves the edges effectively, which selects one between the pixel-based dark channel and the patch-based dark channel in the vicinity of edges. Moreover, we propose an adaptive transmission estimation to improve the visual quality particularly in bright areas like sky. Experimental results with various hazy images represent that the proposed method is superior to the conventional methods in both subjective visual quality and computational complexity. The proposed method can be adopted to compose a haze removal module for realtime devices such as mobile devices, digital cameras, autonomous vehicles, and so on as well as PCs that have enough processing resources.

Fast and High-Quality Haze Removal Method Based on Transmission Correction (전달량 보정을 통한 고속 고품질의 안개 제거 방법)

  • Kim, Won-Tae;Bae, Hyun-Woo;Kim, Tae-Hwan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.11
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    • pp.165-173
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    • 2014
  • This paper presents a fast and high-quality haze removal method by the modification of the conventional transmission estimation process. In the conventional haze removal method, the halo and blocking artifacts arises while estimating the transmission. In order to effectively reduce the artifacts, the proposed method employs the maximum filter after the calculation of the dark channel. Because of the reduction of the artifacts, the proposed method can simplify the transmission refinement process without sacrificing the quality of the results: this paper proposes to use the single-channel guided filter instead of the multi-channel guided filter. The experimental results demonstrate that the quality of the dehazed results by the proposed transmission correction process is improved and the haze removal speed is increased by up to 59.6%, when compared to the conventional ones.

Efficient Single Image Dehazing by Pixel-based JBDCP and Low Complexity Transmission Estimation (저 복잡도 전달량 추정 및 픽셀 기반 JBDCP에 의한 효율적인 단일 영상 안개 제거 방법)

  • Kim, Jong-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.977-984
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    • 2019
  • This paper proposes a single image dehazing that utilizes the transmission estimation with low complexity and the pixel-based JBDCP (Joint Bright and Dark Channel Prior) for the effective application of hazy outdoor images. The conventional transmission estimation includes the refinement process with high computational complexity and memory requirements. We propose the transmission estimation using combination of pixel- and block-based dark channel information and it significantly reduces the complexity while preserving the edge information accurately. Moreover, it is possible to estimate the transmission reflecting the image characteristics, by obtaining a different air-light for each pixel position of the image using the pixel-based JBDCP. Experimental results on various hazy images illustrate that the proposed method exhibits excellent dehazing performance with low complexity compared to the conventional methods; thus, it can be applied in various fields including real-time devices.

A Study on the Speed-based Active Compensation of the Kiss-Point of Dry-type Clutch Equipped with Automated Manual Transmission (자동화 수동변속기용 건식클러치의 속도기반 Kiss-Point 능동 보상에 관한 연구)

  • Choi, Woo-Seok;Lee, Kyo-Bum;Lim, Wonsik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.3
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    • pp.372-378
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    • 2016
  • Clutch torque control is the key to the ride comfort improvement of a vehicle equipped with AMT (automated manual transmission). For such control, the torque transfer starting point, known as the "kiss point," should be indicated or at least estimated to compensate for the clutch torque. The kiss point changes due to wear, high temperature, and fatigue; as such, it should be estimated while the vehicle is being driven. In this study, the method of kiss point active estimation for an AMT vehicle with a dry-type clutch was devised. The kiss point is learned while the engine is in an idle state and while the transmission is at a neutral gear position. It is determined when the input shaft of the transmission starts to rotate by slowly engaging the clutch. The noise of the shaft speed signal during the slow engagement process is filtered for accurate control. The kiss point estimation at various clutch engagement speeds was analyzed via a vehicle test.

An Internet Time Synchronization Model using Dynamic Linear Model (동적선형모델을 적용한 인터넷 시각동기 모델)

  • Yu, Dong-Hui;Hwang, So-Young;Kim, Yong-Ho
    • The KIPS Transactions:PartC
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    • v.10C no.6
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    • pp.711-716
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    • 2003
  • We propose a new Interet time synchronization model using danamic linear model and introduce the characteristics of internet transmission delays. SNTP(Simple Network Time Protocol) has been widely used as a time synchronization method on the Internet. While SNTP provides a very simple usage, SNTP may not provide the stable services, since SNTP does not consider the several essential error factors. In order to overcome the instabitily of SNTP, we analyze the process of time estimation of SNTP and find the difference between forward transmission delay and backward transmission delay operates the main error on the estimation of an time offset.

A transmission distribution estimation for real time Ebola virus disease epidemic model (실시간 에볼라 바이러스 전염병 모형의 전염확률분포추정)

  • Choi, Ilsu;Rhee, Sung-Suk
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.161-168
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    • 2015
  • The epidemic is seemed to be extremely difficult for accurate predictions. The new models have been suggested that show quite different results. The basic reproductive number of epidemic for consequent time intervals are estimated based on stochastic processes. In this paper, we proposed a transmission distribution estimation for Ebola virus disease epidemic model. This estimation can be easier to obtain in real time which is useful for informing an appropriate public health response to the outbreak. Finally, we implement our proposed method with data from Guinea Ebola disease outbreak.

Vehicle Platooning Remote Control via State Estimation in a Communication Network (통신 네트워크에서 상태 추정에 의한 군집병합의 원격제어)

  • 황태현;최재원;김영호
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.192-192
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    • 2000
  • In this paper, a platoon merging is considered as a remote-controlled system with the state represented by a stochastic process. In this system, it becomes to encounter situations where a single decision maker controls a large number of subsystems, and observation and control signals are sent over a communication channel with finite capacity and significant transmission delays. Unlike classical estimation problem in which the observation is a continuous process corrupted by additive noise, there is a constraint that the observation must be coded and transmitted over a digital communication channel with finite capaci쇼. A recursive coder-estimator sequence is a state estimation scheme based on observations transmitted with finite communication capacity constraint. Using the coder-estimator sequence, the remote control station designs a feedback controller. In this paper, we introduce a stochastic model for the lead vehicle in a platoon of vehicles considering the angle between a road surface and a horizontal plane as a stochastic process. The simulation results show that the inter-vehicle distance and the deviation from the desired inter-vehicle distance are well regulated.

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Single image dehazing using segmenting dark channel prior (segmenting dark channel prior을 이용한 단일 영상에서의 안개 제거)

  • Tran, Nhat Huy;Bui, Minh Trung;Kim, Wonha
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.11a
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    • pp.127-129
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    • 2014
  • In image dehazing, the existing transmission estimators bring out the halo artifact at boundaries unless they adopt a refinement process with the high computational complexity. We analyze how the existing transmission estimation methods suffer from the halo artifact at the boundaries and observed that the elaborate, high computational refinement processes to remove the halo effect are excessive for dehazing. On the basis of the analysis and observation, we embed a simple segmentation logic in an existing transmission estimator, which is sufficiently accurate for dehazing. The experiment verifies that the proposed method significantly reduces the halo artifact without requiring any refinement process.

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Single image dehazing by segmenting dark channel prior

  • Bui, Minh Trung;Kim, Wonha
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2016.11a
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    • pp.172-175
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    • 2016
  • In image dehazing, the existing transmission estimators bring out the halo artifact at boundaries unless they adopt a refinement process with the high computational complexity. We analyze how the existing transmission estimation methods suffer from the halo artifact at the boundaries and observed that the elaborate, high computational refinement processes to remove the halo effect are excessive for dehazing. On the basis of the analysis and observation, we embed a simple segmentation logic in an existing transmission estimator, which is sufficiently accurate for dehazing. The experiment verifies that the proposed method significantly reduces the halo artifact without requiring any refinement process.

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