• Title/Summary/Keyword: left-edge algorithm

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Vehicle Detection and Tracking using Billboard Sweep Stereo Matching Algorithm (빌보드 스윕 스테레오 시차정합 알고리즘을 이용한 차량 검출 및 추적)

  • Park, Min Woo;Won, Kwang Hee;Jung, Soon Ki
    • Journal of Korea Multimedia Society
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    • v.16 no.6
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    • pp.764-781
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    • 2013
  • In this paper, we propose a highly precise vehicle detection method with low false alarm using billboard sweep stereo matching and multi-stage hypothesis generation. First, we capture stereo images from cameras established in front of the vehicle and obtain the disparity map in which the regions of ground plane or background are removed using billboard sweep stereo matching algorithm. And then, we perform the vehicle detection and tracking on the labeled disparity map. The vehicle detection and tracking consists of three steps. In the learning step, the SVM(support vector machine) classifier is obtained using the features extracted from the gabor filter. The second step is the vehicle detection which performs the sobel edge detection in the image of the left camera and extracts candidates of the vehicle using edge image and billboard sweep stereo disparity map. The final step is the vehicle tracking using template matching in the next frame. Removal process of the tracking regions improves the system performance in the candidate region of the vehicle on the succeeding frames.

Intensity Based Stereo Matching Algorithm Including Boundary Information (경계선 영역 정보를 이용한 밝기값 기반 스테레오 정합)

  • Choi, Dong-Jun;Kim, Do-Hyun;Yang, Yeong-Yil
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.12
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    • pp.84-92
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    • 1998
  • In this paper, we propose the novel cost functions for finding the disparity between the left and the right images in the stereo matching problem. The dynamic programming method is used in solving the stereo matching problem by Cox et al[10]. In the reference[10], only the intensity of the pixels in the epipolar line is used as the cost functions to find the corresponding pixels. We propose the two new cost functions. The information of the slope of the pixel is introduced to the constraints in determining the weights of intensity and direction(the historical information). The pixels with the higher slope are matched mainly by the intensity of pixels. As the slope becomes lower, the matching is performed mainly by the direction. Secondly, the disparity information of the previous epipolar line the pixel is used to find the disparity of the current epipolar line. If the pixel in the left epipolar line, $p-i$ and the pixel in the right epipolar line, $p-j$ satisfy the following conditions, the higher matching probability is given to the pixels, $p-i$ and $p-j$. i) The pixels, $p-i$ and $p-j$ are the pixles on the edges in the left and the right images, respectively. ⅱ) For the pixels $p-k$ and $p-l$ in the previous epipolar line, $p-k$and $p-l$ are matched and are the pixels on the same edge with $p-i$ and $p-j$, respectively. The proposed method compared with the original method[10] finds the better matching results for the test images.

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A Study on Scattering Center Extraction Using Full Polarimetric Data (다중편파 데이터를 이용한 표적 산란점 추출에 대한 연구)

  • Jeong, Seong-Jae;Lee, Seung-Jae;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.5
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    • pp.463-470
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    • 2016
  • In this paper, we introduce a method of scattering centers extraction using the polarimetric data. VIRAF software based on the PO (Physical Optics) and PTD(Physical Theory of Diffraction) were used to calculate the surface scattering and the edge or wedge scattering, respectively. In addition, by using the unitary transformation, 4-channel data based on the linear polarization basis were converted to 2-channel data based on the left/vertical-circular polarization basis, leading to data compression coherently. The scattering mechanism was analyzed in terms of the polarization states and different look angles by using the scattering center of a target extracted by the 2D RELAX algorithm.

Path Planning for Search and Surveillance of Multiple Unmanned Aerial Vehicles (다중 무인 항공기 이용 감시 및 탐색 경로 계획 생성)

  • Sanha Lee;Wonmo Chung;Myunggun Kim;Sang-Pill Lee;Choong-Hee Lee;Shingu Kim;Hungsun Son
    • The Journal of Korea Robotics Society
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    • v.18 no.1
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    • pp.1-9
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    • 2023
  • This paper presents an optimal path planning strategy for aerial searching and surveying of a user-designated area using multiple Unmanned Aerial Vehicles (UAVs). The method is designed to deal with a single unseparated polygonal area, regardless of polygonal convexity. By defining the search area into a set of grids, the algorithm enables UAVs to completely search without leaving unsearched space. The presented strategy consists of two main algorithmic steps: cellular decomposition and path planning stages. The cellular decomposition method divides the area to designate a conflict-free subsearch-space to an individual UAV, while accounting the assigned flight velocity, take-off and landing positions. Then, the path planning strategy forms paths based on every point located in end of each grid row. The first waypoint is chosen as the closest point from the vehicle-starting position, and it recursively updates the nearest endpoint set to generate the shortest path. The path planning policy produces four path candidates by alternating the starting point (left or right edge), and the travel direction (vertical or horizontal). The optimal-selection policy is enforced to maximize the search efficiency, which is time dependent; the policy imposes the total path-length and turning number criteria per candidate. The results demonstrate that the proposed cellular decomposition method improves the search-time efficiency. In addition, the candidate selection enhances the algorithmic efficacy toward further mission time-duration reduction. The method shows robustness against both convex and non-convex shaped search area.

Directional Feature Extraction of Handwritten Numerals using Local min/max Operations (Local min/max 연산을 이용한 필기체 숫자의 방향특징 추출)

  • Jung, Soon-Won;Park, Joong-Jo
    • Journal of the Institute of Convergence Signal Processing
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    • v.10 no.1
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    • pp.7-12
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    • 2009
  • In this paper, we propose a directional feature extraction method for off-line handwritten numerals by using the morphological operations. Direction features are obtained from four directional line images, each of which contains horizontal, vertical, right-diagonal and left-diagonal lines in entire numeral lines. Conventional method for extracting directional features uses Kirsch masks which generate edge-shaped double line images for each direction, whereas our method uses directional erosion operations and generate single line images for each direction. To apply these directional erosion operations to the numeral image, preprocessing steps such as thinning and dilation are required, but resultant directional lines are more similar to numeral lines themselves. Our four [$4{\times}4$] directional features of a numeral are obtained from four directional line images through a zoning method. For obtaining the higher recognition rates of the handwrittern numerals, we use the multiple feature which is comprised of our proposed feature and the conventional features of a kirsch directional feature and a concavity feature. For recognition test with given features, we use a multi-layer perceptron neural network classifier which is trained with the back propagation algorithm. Through the experiments with the CENPARMI numeral database of Concordia University, we have achieved a recognition rate of 98.35%.

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