• Title/Summary/Keyword: feature points

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Feature Detection using Geometric Mean of Eigenvalues of Gradient Matrix (그레디언트 행렬 고유치의 기하 평균을 이용한 특징점 검출)

  • Ye, Chul-Soo
    • Korean Journal of Remote Sensing
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    • v.30 no.6
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    • pp.769-776
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    • 2014
  • It is necessary to detect the feature points existing simultaneously in both images and then find the corresponding relationship between the detected feature points. We propose a new feature detector based on geometric mean of two eigenvalues of gradient matrix which is able to measure the change of pixel intensities. The corner response of the proposed detector is proportional to the geometric mean and also the difference of two eigenvalues in the case of same geometric mean. We analyzed the localization error of the feature detection using aerial image and artificial image with various types of corners. The localization error of the proposed detector was smaller than that of the typical corner detector, Harris detector.

Feature Matching Algorithm Robust To Noise (잡음에 강인한 특징점 정합 기법)

  • Jung, Hyunjo;Yoo, Jisang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2015.07a
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    • pp.9-12
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    • 2015
  • In this paper, we propose a new feature matching algorithm by modifying and combining the FAST(Features from Accelerated Segment Test) feature detector and SURF feature descriptor which is robust to the distortion of the given image. Scale space is generated to consider the variation of the scale and determine the candidate of features in the image robust to the noise. The original FAST algorithm results in many feature points along edges. To solve this problem, we apply the principal curvatures for refining it. We also use SURF descriptor to make it robust against the variations in the image by rotation. Through the experiments, it is shown that the proposed algorithm has better performance than the conventional feature matching algorithms even though it has much less computational load. Especially, it shows a strength for noisy images.

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An Efficient Feature Point Extraction Method for 360˚ Realistic Media Utilizing High Resolution Characteristics

  • Won, Yu-Hyeon;Kim, Jin-Sung;Park, Byuong-Chan;Kim, Young-Mo;Kim, Seok-Yoon
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.1
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    • pp.85-92
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    • 2019
  • In this paper, we propose a efficient feature point extraction method that can solve the problem of performance degradation by introducing a preprocessing process when extracting feature points by utilizing the characteristics of 360-degree realistic media. 360-degree realistic media is composed of images produced by two or more cameras and this image combining process is accomplished by extracting feature points at the edges of each image and combining them into one image if they cover the same area. In this production process, however, the stitching process where images are combined into one piece can lead to the distortion of non-seamlessness. Since the realistic media of 4K-class image has higher resolution than that of a general image, the feature point extraction and matching process takes much more time than general media cases.

Localization for Mobile Robot Using Vertical Lines

  • Kang, Chang-Hun;Ahn, Hyun-Sik
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.793-797
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    • 2003
  • In this paper, we present a self-localization method for mobile robots using vertical line features of indoor environment. When a 2D map including feature points and color information is given, a mobile robot moves to the destination, and acquires images by one camera from the surroundings having vertical line edges. From the image, vertical line edges are detected, and pattern vectors meaning averaged color values of the left and right region of each line segment are computed. The pattern vectors are matched with the feature points of the map using the color information and the geometrical relationship of the points. From the perspective transformation of the corresponded points, nonlinear equations are derived. Localization is carried out from solving the equations by using Newton's method. Experimental results show that the proposed method using mono view is simple and applicable to indoor environment.

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Stereo Matching using Dynamic Programming in Scale-Space (스케일 공간에서 동적 계획을 이용한 스테레오 정합)

  • 최우영;박래홍
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.8
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    • pp.44-53
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    • 1992
  • In this paper, a matching method is proposed to improve the correct matching rate in stereo correspondence matching in which the fingerprint of zero-crossing points on the scale-space is used as the robust matching feature. The dynamic programming, which is appropriate for the fingerprint feature, is introduced for correspondence matching. We also improve the matching rate by using the post-processing for correcting mismatched points. In simulation, we apply the proposed algorithm to the synthetic and real images and obtain good matching results.

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Algorithm of the Detection of the Feature points using distributed feature points of the Second Derivative of Photoplethysmogram waveform (이차 미분 맥파의 변곡점 분포를 이용한 특징점 추출 알고리즘)

  • Kim, Pan-Ki;Ahn, Chang-Beom
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1988_1989
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    • 2009
  • 본 논문은 이차 미분 맥파(SDPTG, Second Derivation of Photoplethysmogram)를 측정하여 이차 미분 맥파의 5개의 특징점을 검출하는 방법에 대한 내용을 기술한다. 본 논문에서는 측정된 신호의 신호대 잡음비(SNR)을 높이는 방법과 기존의 미분을 이용한 변곡점 추출의 한계적인 부분, 그리고 본 논문에서 제안하는 이차 미분 맥파의 특징점의 분포를 이용한 특징점 추출 알고리즘에 대해서 설명한다.

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Linear Feature Detection of Rectangular Object Area using Edge Tracing-based Algorithm (에지 트레이싱 기법을 이용한 사각형 물체의 선형 특징점 검출)

  • 오중원;한희일
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2092-2095
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    • 2003
  • In this paper, we propose an algorithm to extract rectangular object area such 3s Data Matrix two-dimensional barcode using edge tracing-based linear feature detection. Hough transform is usually employed to detect lines of edge map. However, it requires parametric image space, and does not find the location of end points of the detected lines. Our algorithm detects end points of the detected lines using edge tracing and extracts object area using its shape information.

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Feature Extraction of Asterias Amurensis by Using the Multi-Directional Linear Scanning and Convex Hull (다방향 선형 스캐닝과 컨벡스 헐을 이용한 아무르불가사리의 특징 추출)

  • Shin, Hyun-Deok;Jeon, Young-Cheol
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.3
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    • pp.99-107
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    • 2011
  • The feature extraction of asterias amurensis by using patterns is difficult to extract all the concave and convex features of asterias amurensis nor classify concave and convex. Concave and convex as important structural features of asterias amurensis are the features which should be found and the classification of concave and convex is also necessary for the recognition of asterias amurensis later. Accordingly, this study suggests the technique to extract the features of concave and convex, the main features of asterias amurensis. This technique classifies the concave and convex features by using the multi-directional linear scanning and form the candidate groups of the concave and convex feature points and decide the feature points of the candidate groups and apply convex hull algorithm to the extracted feature points. The suggested technique efficiently extracts the concave and convex features, the main features of asterias amurensis by dividing them. Accordingly, it is expected to contribute to the studies on the recognition of asterias amurensis in the future.

The Target Detection and Classification Method Using SURF Feature Points and Image Displacement in Infrared Images (적외선 영상에서 변위추정 및 SURF 특징을 이용한 표적 탐지 분류 기법)

  • Kim, Jae-Hyup;Choi, Bong-Joon;Chun, Seung-Woo;Lee, Jong-Min;Moon, Young-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.11
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    • pp.43-52
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    • 2014
  • In this paper, we propose the target detection method using image displacement, and classification method using SURF(Speeded Up Robust Features) feature points and BAS(Beam Angle Statistics) in infrared images. The SURF method that is a typical correspondence matching method in the area of image processing has been widely used, because it is significantly faster than the SIFT(Scale Invariant Feature Transform) method, and produces a similar performance. In addition, in most SURF based object recognition method, it consists of feature point extraction and matching process. In proposed method, it detects the target area using the displacement, and target classification is performed by using the geometry of SURF feature points. The proposed method was applied to the unmanned target detection/recognition system. The experimental results in virtual images and real images, we have approximately 73~85% of the classification performance.