• Title/Summary/Keyword: Contour Detector

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HSV Color Model based Hand Contour Detector Robust to Noise (노이즈에 강인한 HSV 색상 모델 기반 손 윤곽 검출 시스템)

  • Chae, Soohwan;Jun, Kyungkoo
    • Journal of Korea Multimedia Society
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    • v.18 no.10
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    • pp.1149-1156
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    • 2015
  • This paper proposes the hand contour detector which is robust to noises. Existing methods reduce noises by applying morphology to extracted edges, detect finger tips by using the center of hands, or exploit the intersection of curves from hand area candidates based on J-value segmentation(JSEG). However, these approaches are so vulnerable to noises that are prone to detect non-hand parts. We propose the noise tolerant hand contour detection method in which non-skin area noises are removed by applying skin area detection, contour detection, and a threshold value. By using the implemented system, we observed that the system was successfully able to detect hand contours.

Tumor boundary extraction from brain MRI images using active contour models (Snakes) (스네이크를 이용한 뇌 자기 공명 영상에서 종양의 경계선 추출)

  • Ryeong-Ju Kim;Young-Chul Kim;Heung-Kook Choi
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.2
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    • pp.1-6
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    • 2003
  • The study is to automatically or semi-automatically detect the accurate contour of tumors or lesions using active contour models (Snakes) in the MRI images of the brain. In the study we have improved the energy-minimization problem of snakes using dynamic programming and have utilized the values of the canny edge detector by the image force to make the snake less sensitive in noises. For the extracted boundary, the inside area, the perimeter and its center coordinates could be calculated. In addition, the multiple 2D slices with the contour of the lesion wore combined to visualized the shape of the lesion in 3D. We expect that the proposed method in this paper will be useful to make a treatment plan as well as to evaluate the treatments.

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3D Simulation of Thin Film using Contour Analysis of Interference Fringe Image and Interpolation Method (간섭무늬 영상 등고선 해석과 보간법을 이용한 박막의 삼차원 정보 형상화)

  • Kim, Jin-Hyoung;Ko, Yun-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.2
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    • pp.8-17
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    • 2012
  • In this paper we proposes a new framework to obtain 3D shape information of thin film rapidly. The conventional equipments based on reflectometry are not suitable for obtaining 3D overall shape information of thin film rapidly since they require more than 30 minutes to measure the absolute thickness for 170 points. The proposed framework is based on an image analysis method that extracts contour lines from interference fringes images using Canny edge detector. The absolute thickness for contour lines are measured and then a height map from the contour lines is obtained by interpolation using Borgefors distance transformation. The extracted height map is visualized using the DirectX 3D terrain rendering method. The proposed framework can provide 3D overall shape information of thin film in about 5 minutes since relatively small number of real measurement for contour lines is required.

Sensing Performance of Efficient Cyclostationary Detector with Multiple Antennas in Multipath Fading and Lognormal Shadowing Environments

  • Zhu, Ying;Liu, Jia;Feng, Zhiyong;Zhang, Ping
    • Journal of Communications and Networks
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    • v.16 no.2
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    • pp.162-171
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    • 2014
  • Spectrum sensing is a key technical challenge for cognitive radio (CR). It is well known that multicycle cyclostationarity (MC) detection is a powerful method for spectrum sensing. However, a conventional MC detector is difficult to implement because of its high computational complexity. This paper considers reducing computational complexity by simplifying the test statistic of a conventional MC detector. On the basis of this simplification process, an improved MC detector is proposed. Compared with the conventional detector, the proposed detector has low-computational complexity and high-accuracy sensing performance. Subsequently, the sensing performance is further investigated for the cases of Rayleigh, Nakagami-m, Rician, and Rayleigh fading and lognormal shadowing channels. Furthermore, square-law combining (SLC) is introduced to improve the detection capability in fading and shadowing environments. The corresponding closed-form expressions of average detection probability are derived for each case by the moment generation function (MGF) and contour integral approaches. Finally, illustrative and analytical results show the efficiency and reliability of the proposed detector and the improvement in sensing performance by SLC in multipath fading and lognormal shadowing environments.

Mobile Robot Control using Hand Shape Recognition (손 모양 인식을 이용한 모바일 로봇제어)

  • Kim, Young-Rae;Kim, Eun-Yi;Chang, Jae-Sik;Park, Se-Hyun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.4
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    • pp.34-40
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    • 2008
  • This paper presents a vision based walking robot control system using hand shape recognition. To recognize hand shapes, the accurate hand boundary needs to be tracked in image obtained from moving camera. For this, we use an active contour model-based tracking approach with mean shift which reduces dependency of the active contour model to location of initial curve. The proposed system is composed of four modules: a hand detector, a hand tracker, a hand shape recognizer and a robot controller. The hand detector detects a skin color region, which has a specific shape, as hand in an image. Then, the hand tracking is performed using an active contour model with mean shift. Thereafter the hand shape recognition is performed using Hue moments. To assess the validity of the proposed system we tested the proposed system to a walking robot, RCB-1. The experimental results show the effectiveness of the proposed system.

Fast Shape Matching Algorithm Based on the Improved Douglas-Peucker Algorithm (개량 Douglas-Peucker 알고리즘 기반 고속 Shape Matching 알고리즘)

  • Sim, Myoung-Sup;Kwak, Ju-Hyun;Lee, Chang-Hoon
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.10
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    • pp.497-502
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    • 2016
  • Shape Contexts Recognition(SCR) is a technology recognizing shapes such as figures and objects, greatly supporting technologies such as character recognition, motion recognition, facial recognition, and situational recognition. However, generally SCR makes histograms for all contours and maps the extracted contours one to one to compare Shape A and B, which leads to slow progress speed. Thus, this paper has made simple yet more effective algorithm with optimized contour, finding the outlines according to shape figures and using the improved Douglas-Peucker algorithm and Harris corner detector. With this improved method, progress speed is recognized as faster.

DETECTION AND COUNTING OF FLOWERS BASED ON DIGITAL IMAGES USING COMPUTER VISION AND A CONCAVE POINT DETECTION TECHNIQUE

  • PAN ZHAO;BYEONG-CHUN SHIN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.27 no.1
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    • pp.37-55
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    • 2023
  • In this paper we propose a new algorithm for detecting and counting flowers in a complex background based on digital images. The algorithm mainly includes the following parts: edge contour extraction of flowers, edge contour determination of overlapped flowers and flower counting. We use a contour detection technique in Computer Vision (CV) to extract the edge contours of flowers and propose an improved algorithm with a concave point detection technique to find accurate segmentation for overlapped flowers. In this process, we first use the polygon approximation to smooth edge contours and then adopt the second-order central moments to fit ellipse contours to determine whether edge contours overlap. To obtain accurate segmentation points, we calculate the curvature of each pixel point on the edge contours with an improved Curvature Scale Space (CSS) corner detector. Finally, we successively give three adaptive judgment criteria to detect and count flowers accurately and automatically. Both experimental results and the proposed evaluation indicators reveal that the proposed algorithm is more efficient for flower counting.

Edge Grouping and Contour Detection by Delaunary Triangulation (Delaunary 삼각화에 의한 그룹화 및 외형 탐지)

  • Lee, Sang-Hyun;Jung, Byeong-Soo;Jeong, Je-Pyong;Kim, Jung-Rok;Moon, Kyung-li
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.135-142
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    • 2013
  • Contour detection is important for many computer vision applications, such as shape discrimination and object recognition. In many cases, local luminance changes turn out to be stronger in textured areas than on object contours. Therefore, local edge features, which only look at a small neighborhood of each pixel, cannot be reliable indicators of the presence of a contour, and some global analysis is needed. The novelty of this operator is that dilation is limited to Deluanary triangular. An efficient implementation is presented. The grouping algorithm is then embedded in a multi-threshold contour detector. At each threshold level, small groups of edges are removed, and contours are completed by means of a generalized reconstruction from markers. Both qualitative and quantitative comparison with existing approaches prove the superiority of the proposed contour detector in terms of larger amount of suppressed texture and more effective detection of low-contrast contour.

Detection of voluminous gamma-ray source with a collimation beam geometry and comparison with peak efficiency calculations of EXVol

  • Kang, M.Y.;Sun, G.M.;Choi, H.D.
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2601-2606
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    • 2020
  • In this study, we expanded the performance of the existing EXVol code and performed empirical experiments and calculations. A high-resolution gamma spectroscopy system was constructed, and a standard point source and a standard volume source were measured with an HPGe detector with 43.1% relative efficiency. EXVol was verified by quantitative comparison of the detection efficiencies determined by measurements and calculations. To introduce the concept of the detector scanning that occurs in the actual measurement into the EXVol code, a collimator was placed between the source and detector. The detection efficiency was determined in the asymmetric arrangement of the source and detector with a collimator. A collimator made of lead with a diameter of 15 mm and a thickness of 50 mm was installed between the source and the detector to determine the detection efficiency at a specific location. The calculation result was contour plotted so that the distribution of detection efficiency could be visually confirmed. The relative deviation between the measurements and calculations for the coaxial and asymmetric structures was 10%, and that for the collimation structure was 20%. The results of this study can be applied to research using γ-ray measurements.

Interactive Typography System using Combined Corner and Contour Detection

  • Lim, Sooyeon;Kim, Sangwook
    • International Journal of Contents
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    • v.13 no.1
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    • pp.68-75
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    • 2017
  • Interactive Typography is a process where a user communicates by interacting with text and a moving factor. This research covers interactive typography using real-time response to a user's gesture. In order to form a language-independent system, preprocessing of entered text data presents image data. This preprocessing is followed by recognizing the image data and the setting interaction points. This is done using computer vision technology such as the Harris corner detector and contour detection. User interaction is achieved using skeleton information tracked by a depth camera. By synchronizing the user's skeleton information acquired by Kinect (a depth camera,) and the typography components (interaction points), all user gestures are linked with the typography in real time. An experiment was conducted, in both English and Korean, where users showed an 81% satisfaction level using an interactive typography system where text components showed discrete movements in accordance with the users' gestures. Through this experiment, it was possible to ascertain that sensibility varied depending on the size and the speed of the text and interactive alteration. The results show that interactive typography can potentially be an accurate communication tool, and not merely a uniform text transmission system.