• Title/Summary/Keyword: Shadow extraction

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An Approach to Video Based Traffic Parameter Extraction (영상을 기반 교통 파라미터 추출에 관한 연구)

  • Yu, Mei;Kim, Yong-Deak
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.5
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    • pp.42-51
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    • 2001
  • Vehicle detection is the basic of traffic monitoring. Video based systems have several apparent advantages compared with other kinds of systems. However, In video based systems, shadows make troubles for vehicle detection, especially active shadows resulted from moving vehicles. In this paper, a new method that combines background subtraction and edge detection is proposed for vehicle detection and shadow rejection. The method is effective and the correct rate of vehicle detection is higher than 98% in experiments, during which the passive shadows resulted from roadside buildings grew considerably. Based on the proposed vehicle detection method, vehicle tracking, counting, classification and speed estimation are achieved so that traffic parameters concerning traffic flow is obtained to describe the load of each lane.

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Crane Monitoring System for Moving Objects in Safety Lines (크레인 안전선 접근 이동 물체 감시 시스템)

  • Chong, Ui-Pil
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.4
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    • pp.237-241
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    • 2011
  • Stable operation of an industry crane becomes more important as current industry facilities become larger and operate at higher speeds. This paper proposes implementing a system for monitoring moving objects within safety lines of an industry crane by camera. The cost of implementing such a system is low, since it requires only a webcam and notebook computer. The detection algorithm of moving objects uses the feature extraction method by image differential histograms. The proposed system is robust to variations in the weather and environment. The area of the inside safety lines is considered and shadow removal algorithm is used for good performance of the system. The system is valuable for practical applications in the industry.

Flood Monitoring and Extraction of Water Area Using Multi-temporal RADARSAT SAR Imagery (RADARSAT SAR 영상을 이용한 수계지역 추출 및 홍수지역 모니터링)

  • Sohn, Hong-Gyoo;Yoo, Hwan-Hee;Song, Yeong-Sun;Jung, Won-Jo
    • 한국지형공간정보학회:학술대회논문집
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    • 2002.03a
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    • pp.48-53
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    • 2002
  • 본 연구에서는 각각 1998년 8월 12일(홍수 발생시), 8월 19일(홍수 발생 후) 옥천, 보은 지역을 촬영한 RADARSAT SAR 위성영상을 이용하여 수계지역 및 홍수지역 분류를 수행하고자 하였다. 이를 위해, 먼저 두 장의 위성영상에 대해서 각각 스페클 잡영(speckle noise)을 제거하고, ${\sigma}^0$(sigma naught, dB)을 계산한 후 수계지역에 대한 ${\sigma}^0$값을 분석하였다. 이 값을 기준으로 각각 두 장의 위성영상에서 각각 최대우도법을 이용하여 수계지역을 분류하였다. SAR 영상은 영상취득의 원리에 의해 지형의 기복에 따른 음영효과(shadow effect)가 발생하는데, 음영효과가 발생하는 지역의 ${\sigma}^0$값은 수계지역과 비슷한 반사특성(낮은 dB 값)을 보인다. 따라서 지형의 기복이 심한 지역의 수계지역 분류시 음영효과를 제거해야 효과적적인 분류를 할 수 있으며, 이를 위해 위성의 헤더자료로부터 촬영시 각각의 촬영중심을 계산하고, 촬영중심과 지상좌표와의 기하학적 관계를 고려하여 음영효과를 제거하였다. 마지막으로, 수계지역만이 추출된 영상에 대해 영상의 기하보정을 수행하였으며, 기하 보정된 두장의 위성영상에 대해 차분영상를 생성함으로서 홍수지역을 분류하였다.

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Efficient Color Feature Information Extraction Method for Color Histogram-based Image Retrieval (칼라 히스토그램 기반 영상 검색을 위한 효율적인 칼라 특징 정보 추출 기법)

  • 이호영;김영태;김희수;배태면;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.8B
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    • pp.1413-1423
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    • 2000
  • Color distribution is changed according to the variation of illumination position and illumination color. Therefore, even if images are relevant each other, retrieval accuracy is degraded. In this paper, we propose the image retrieval method using color information excluded illumination component. The proposed dynamic range control method removes the shadow region generated by change of illumination position to increase the color discrimination power. To exclude the illuminant color, we use the diffuse reflection component of object and gray world assumption. The experimental results show that the color histogram method using color information excluded illuminant has higher retrieval accuracy than conventional color histogram using the color information of input image.

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A Study On the Image Based Traffic Information Extraction Algorithm (영상기반 교통정보 추출 알고리즘에 관한 연구)

  • 하동문;이종민;김용득
    • Journal of Korean Society of Transportation
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    • v.19 no.6
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    • pp.161-170
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    • 2001
  • Vehicle detection is the basic of traffic monitoring. Video based systems have several apparent advantages compared with other kinds of systems. However, In video based systems, shadows make troubles for vehicle detection. especially active shadows resulted from moving vehicles. In this paper a new method that combines background subtraction and edge detection is proposed for vehicle detection and shadow rejection. The method is effective and the correct rate of vehicle detection is higher than 98(%) in experiments, during which the passive shadows resulted from roadside buildings grew considerably. Based on the proposed vehicle detection method, vehicle tracking, counting, classification and speed estimation are achieved so that traffic information concerning traffic flow is obtained to describe the load of each lane.

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A Study on Recognition of Moving Object Crowdedness Based on Ensemble Classifiers in a Sequence (혼합분류기 기반 영상내 움직이는 객체의 혼잡도 인식에 관한 연구)

  • An, Tae-Ki;Ahn, Seong-Je;Park, Kwang-Young;Park, Goo-Man
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.2A
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    • pp.95-104
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    • 2012
  • Pattern recognition using ensemble classifiers is composed of strong classifier which consists of many weak classifiers. In this paper, we used feature extraction to organize strong classifier using static camera sequence. The strong classifier is made of weak classifiers which considers environmental factors. So the strong classifier overcomes environmental effect. Proposed method uses binary foreground image by frame difference method and the boosting is used to train crowdedness model and recognize crowdedness using features. Combination of weak classifiers makes strong ensemble classifier. The classifier could make use of potential features from the environment such as shadow and reflection. We tested the proposed system with road sequence and subway platform sequence which are included in "AVSS 2007" sequence. The result shows good accuracy and efficiency on complex environment.

Road Lane and Vehicle Distance Recognition using Real-time Analysis of Camera Images (카메라 영상의 실시간 분석에 의한 차선 및 차간 인식)

  • Kang, Moon-Seol;Kim, Yu-Sin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.12
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    • pp.2665-2674
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    • 2012
  • This paper propose the method to recognize the lanes and distance between cars in real-time which detects dangerous situations and helps safe driving in the actual road environment. First of all, it extracts the area of interest corresponding to roads and cars from the road image photographed by using the forward-looking camera. Through the hough transform for the area of interest, this study detects linear components and also selects the lane and conducts filtering by calculating probability. And through the shadow threshold analysis of the cars in front within the area of interest, it extracts the objects of cars in front and calculates the distance from cars in front. According to the result of applying the suggested technology to recognize the lane and distance between cars to the road situation for testing, it showed over 95% recognition rate; thus, it has been proved that it can respond to safe driving.

Gait Recognition Using Multiple Feature detection (다중 특징점 검출을 이용한 보행인식)

  • Cho, Woon;Kim, Dong-Hyeon;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.6
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    • pp.84-92
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    • 2007
  • The gait recognition is presented for human identification from a sequence of noisy silhouettes segmented from video by capturing at a distance. The proposed gait recognition algorithm gives better performance than the baseline algorithm because of segmentation of the object by using multiple modules; i) motion detection, ii) object region detection, iii) head detection, and iv) active shape models, which solve the baseline algorithm#s problems to make background, to remove shadow, and to be better recognition rates. For the experiment, we used the HumanID Gait Challenge data set, which is the largest gait benchmarking data set with 122 objects, For realistic simulation we use various values for the following parameters; i) viewpoint, ii) shoe, iii) surface, iv) carrying condition, and v) time.

Lane Detection Algorithm using Morphology and Color Information (형태학과 색상 정보를 이용한 차선 인식 알고리즘)

  • Bae, Chan-Su;Lee, Jong-Hwa;Cho, Sang-Bock
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.6
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    • pp.15-24
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    • 2011
  • As increase awareness of intelligent vehicle systems, many kinds of lane detection algorithm have been proposed. General boundary extraction method can bring good result in detection of lane on the road. But a shadow on the road, or other boundaries, such as horizontal lines can be detected. The method using morphological operations was used to extract information about Lane. By applying HSV color model for color information of lane, the candidate of the lane can be extracted. In this paper, the lane detection region was set by Hough transformation using the candidate of the lane. By extracting lane markings on the lane detection region, lane detection method can bring good result.

(Distance and Speed Measurements of Moving Object Using Difference Image in Stereo Vision System) (스테레오 비전 시스템에서 차 영상을 이용한 이동 물체의 거리와 속도측정)

  • 허상민;조미령;이상훈;강준길;전형준
    • Journal of the Korea Computer Industry Society
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    • v.3 no.9
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    • pp.1145-1156
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    • 2002
  • A method to measure the speed and distance of moving object is proposed using the stereo vision system. One of the most important factors for measuring the speed and distance of moving object is the accuracy of object tracking. Accordingly, the background image algorithm is adopted to track the rapidly moving object and the local opening operator algorithm is used to remove the shadow and noise of object. The extraction efficiency of moving object is improved by using the adaptive threshold algorithm independent to variation of brightness. Since the left and right central points are compensated, the more exact speed and distance of object can be measured. Using the background image algorithm and local opening operator algorithm, the computational processes are reduced and it is possible to achieve the real-time processing of the speed and distance of moving object. The simulation results show that background image algorithm can track the moving object more rapidly than any other algorithm. The application of adaptive threshold algorithm improved the extraction efficiency of the target by reducing the candidate areas. Since the central point of the target is compensated by using the binocular parallax, the error of measurement for the speed and distance of moving object is reduced. The error rate of measurement for the distance from the stereo camera to moving object and for the speed of moving object are 2.68% and 3.32%, respectively.

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