• Title/Summary/Keyword: Contour Detection

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House Detection on the Scanned Topographic Map (스캔된 지도상의 가옥 추출 방법)

  • Chang, Hang-Bae;Park, Jong-Am;Kwon, Young-Bin
    • Journal of Korea Spatial Information System Society
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    • v.1 no.1 s.1
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    • pp.49-55
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    • 1999
  • Extracting information of maps is necessary to establish the GIS. In this paper, a house recognition method on the scanned topographic map is described. A contour detection method is used to extract houses from the scanned maps and RLE (run-length encoding) method is used for manipulating houses touching grid lines. To handle houses touched to roads and borderlines, morphological operation is used. To remove misrecognition occurred by morphological operation, the legions which contain characters on the map are also automatically eliminated.

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Design and Implementation of Eye-Gaze Estimation Algorithm based on Extraction of Eye Contour and Pupil Region (눈 윤곽선과 눈동자 영역 추출 기반 시선 추정 알고리즘의 설계 및 구현)

  • Yum, Hyosub;Hong, Min;Choi, Yoo-Joo
    • The Journal of Korean Association of Computer Education
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    • v.17 no.2
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    • pp.107-113
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    • 2014
  • In this study, we design and implement an eye-gaze estimation system based on the extraction of eye contour and pupil region. In order to effectively extract the contour of the eye and region of pupil, the face candidate regions were extracted first. For the detection of face, YCbCr value range for normal Asian face color was defined by the pre-study of the Asian face images. The biggest skin color region was defined as a face candidate region and the eye regions were extracted by applying the contour and color feature analysis method to the upper 50% region of the face candidate region. The detected eye region was divided into three segments and the pupil pixels in each pupil segment were counted. The eye-gaze was determined into one of three directions, that is, left, center, and right, by the number of pupil pixels in three segments. In the experiments using 5,616 images of 20 test subjects, the eye-gaze was estimated with about 91 percent accuracy.

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A Fast Snake Algorithm for Tracking Multiple Objects

  • Fang, Hua;Kim, Jeong-Woo;Jang, Jong-Whan
    • Journal of Information Processing Systems
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    • v.7 no.3
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    • pp.519-530
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    • 2011
  • A Snake is an active contour for representing object contours. Traditional snake algorithms are often used to represent the contour of a single object. However, if there is more than one object in the image, the snake model must be adaptive to determine the corresponding contour of each object. Also, the previous initialized snake contours risk getting the wrong results when tracking multiple objects in successive frames due to the weak topology changes. To overcome this problem, in this paper, we present a new snake method for efficiently tracking contours of multiple objects. Our proposed algorithm can provide a straightforward approach for snake contour rapid splitting and connection, which usually cannot be gracefully handled by traditional snakes. Experimental results of various test sequence images with multiple objects have shown good performance, which proves that the proposed method is both effective and accurate.

A Miss Distance Image Analysis Technique Based On Object Contour (윤곽선 기반의 이격거리 영상해석 기법)

  • Park, Won-U;Choi, Ju-Ho;Yoo, Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.1 no.1
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    • pp.238-248
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    • 1998
  • This paper presents an image analysis method for mearurement correction using the object contour based analysis, which measure the shape features of the imitation missile object. The image analysis is divided into object's tilting angle analysis and corner points detection. The tilting angle is calculated by edge extracting the region-of-interest image and by Radon transform it. The corner points are obtained by contour tracking of binary image and its curvature data processing and analysis. The ability of this presented method is simulated and evaluated by the results of accuracy testing.

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Contour Integral Method for Crack Detection

  • Kim, Woo-Jae;Kim, No-Nyu;Yang, Seung-Yong
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.6
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    • pp.665-670
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    • 2011
  • In this paper, a new approach to detect surface cracks from a noisy thermal image in the infrared thermography is presented using an holomorphic characteristic of temperature field in a thin plate under steady-state thermal condition. The holomorphic function for 2-D heat flow field in the plate was derived from Cauchy Riemann conditions to define a contour integral that varies according to the existence and strength of a singularity in the domain of integration. The contour integral at each point of thermal image eliminated the temperature variation due to heat conduction and suppressed the noise, so that its image emphasized and highlighted the singularity such as crack. This feature of holomorphic function was also investigated numerically using a simple thermal field in the thin plate satisfying the Laplace equation. The simulation results showed that the integral image selected and detected the crack embedded artificially in the plate very well in a noisy environment.

Active Contour Based Edge Detection Using Evolutionary Computation (진화 연산을 이용한 능동외곽기반의 윤곽선검출에 관한 연구)

  • Kang, Hyeon-Tae;Cho, Deok-Hwan;Hwang, Gi-Hyun;Mun, Kyeong-Jun;Park, June-Ho;Lee, Hwa-Seok
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2405-2407
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    • 2001
  • In this paper, we apply and evolutionary computation(EC), probabilistic optimization algorithm, to active contour. A number of problems exist associated with such as algorithm initialization, existence of local minima, non-convex search space, and the selection of model parameters in conventional models. We propose an adequate fitness function for these problems. The determination of fitness function adequate to active contour using EC is important in search capability. As a result of applying the proposed method to non-convex object shape, we improve the unstability and contraction phenomena, in nature, of snake generated in deformable contour optimization.

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Accelerating Distance Transform Image based Hand Detection using CPU-GPU Heterogeneous Computing

  • Yi, Zhaohua;Hu, Xiaoqi;Kim, Eung Kyeu;Kim, Kyung Ki;Jang, Byunghyun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.557-563
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    • 2016
  • Most of the existing hand detection methods rely on the contour shape of hand after skin color segmentation. Such contour shape based computations, however, are not only susceptible to noise and other skin color segments but also inherently sequential and difficult to efficiently parallelize. In this paper, we implement and accelerate our in-house distance image based approach using CPU-GPU heterogeneous computing. Using emerging CPU-GPU heterogeneous computing technology, we achieved 5.0 times speed-up for $320{\times}240$ images, and 17.5 times for $640{\times}480$ images and our experiment demonstrates that our proposed distance image based hand detection is robust and fast, reaching up to 97.32% palm detection rate, 80.4% of which have more than 3 fingers detected on commodity processors.

Refinement of Building Boundary using Airborne LiDAR and Airphoto (항공 LiDAR와 항공사진을 이용한 건물 경계 정교화)

  • Kim, Hyung-Tae;Han, Dong-Yeob
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.3
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    • pp.136-150
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    • 2008
  • Many studies have been carried out for automatic extraction of building by LiDAR data or airphoto. Combining the benefits of 3D location information data and shape information data of image can improve the accuracy. So, in this research building recognition algorithm based on contour was used to improve accuracy of building recognition by LiDAR data and elaborate building boundary recognition by airphoto. Building recognition algorithm based on contour can generate building boundary and roof structure information. Also it shows better accuracy of building detection than the existing recognition methods based on TIN or NDSM. Out of creating buffers in regular size on the building boundary which is presumed by contour, this research limits the boundary area of airphoto and elaborate building boundary to fit into edge of airphoto by double active contour. From the result of this research, 3D building boundary will be able to be detected by optimal matching on the constant range of extracted boundary in the future.

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On a Detection for the Fundamental Frequency of Speech Signals (음성신호의기본주파수 검출)

  • 배명진
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1994.06c
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    • pp.42-47
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    • 1994
  • A pitch detector is an essential component in a variety of speech processing systems. Besides providing valuable insights into the nature of the exciation source for speech production, the pitch contour of an utterance is useful for recognizing speakers, aids-to-the handicapped, and is required in almost all speech analysis-synthesis system. Because of the importance of the pitch detection, a wide variety algorithms for pitch detection have been proposed in speech procesing literature. Thus, in this paper we discuss th evarious type of pitch detection algorithms which have been proposed until now. Then we provide th eperformance measurements for seven pitch detection algorithms.

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Lip Contour Detection by Multi-Threshold (다중 문턱치를 이용한 입술 윤곽 검출 방법)

  • Kim, Jeong Yeop
    • KIPS Transactions on Software and Data Engineering
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    • v.9 no.12
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    • pp.431-438
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    • 2020
  • In this paper, the method to extract lip contour by multiple threshold is proposed. Spyridonos et. el. proposed a method to extract lip contour. First step is get Q image from transform of RGB into YIQ. Second step is to find lip corner points by change point detection and split Q image into upper and lower part by corner points. The candidate lip contour can be obtained by apply threshold to Q image. From the candidate contour, feature variance is calculated and the contour with maximum variance is adopted as final contour. The feature variance 'D' is based on the absolute difference near the contour points. The conventional method has 3 problems. The first one is related to lip corner point. Calculation of variance depends on much skin pixels and therefore the accuracy decreases and have effect on the split for Q image. Second, there is no analysis for color systems except YIQ. YIQ is a good however, other color systems such as HVS, CIELUV, YCrCb would be considered. Final problem is related to selection of optimal contour. In selection process, they used maximum of average feature variance for the pixels near the contour points. The maximum of variance causes reduction of extracted contour compared to ground contours. To solve the first problem, the proposed method excludes some of skin pixels and got 30% performance increase. For the second problem, HSV, CIELUV, YCrCb coordinate systems are tested and found there is no relation between the conventional method and dependency to color systems. For the final problem, maximum of total sum for the feature variance is adopted rather than the maximum of average feature variance and got 46% performance increase. By combine all the solutions, the proposed method gives 2 times in accuracy and stability than conventional method.