• 제목/요약/키워드: Local feature

검색결과 932건 처리시간 0.031초

불완전한 궤적을 고려한 강건한 특징점 추적 알고리즘 (A Robust Algorithm for Tracking Feature Points with Incomplete Trajectories)

  • 정종면;문영식
    • 대한전자공학회논문지SP
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    • 제37권6호
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    • pp.25-37
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    • 2000
  • 특징점의 궤적은 인접한 프레임에 존재하는 특정점 사이의 대응관계로 정의할 수 있다. 실제 영상열에서 존재할 수 있는 잘못된 특징점(false positive, false negative)들은 특징점의 대응관계를 결정할 때 많은 문제를 야기하기 때문에 특징점의 대응관계를 찾는 문제는 어려운 문제로 알려져 있다. 본 논문에서는 새로운 궤적의 나타남, 사라짐 등 불완전한 궤적을 갖는 특징점들을 고려하는 특징점 추적기법을 제안한다. 정합 척도로서 가중치가 부여된 유클리디언 거리를 사용하고 특징점의 운동특성을 잘 반영할 수 있도록 그 가중치를 자동으로 조정한다. 대응점 탐색과정에서 치명적인 영향을 줄 수 있는 애매한 특징점이 존재하는 경우를 고려하여 인접한 프레임 사이의 정합점 결정을 그래프에 의한 최적 대응점 탐색문제로 해결한다. 제안하는 대응점 탐색 알고리즘은 실제 영상열에서 나타날 수 있는 잘못된 특징점들이 대응관계를 결정할 때 주는 영향을 최소화하기 위하여 국부 최적(local optimal)을 찾게되며, 인접한 두 프레임에 m, n개의 특징점이 주어졌을 경우, 최선의 경우 O(mn), 최악의 경우 O($m^2n$)의 계산량을 필요로 한다. 제안하는 알고리즘은 정합과정에서 잘못된 특징점을 고려하고, 특징점의 운동특성을 잘 반영함으로써 대량의 특징점을 추적하는데도 충분히 적용할 수 있음을 실험을 통해 확인하였다.

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MONITORING OF MOUNTAINOUS AREAS USING SIMULATED IMAGES TO KOMPSAT-II

  • Chang Eun-Mi;Shin Soo-Hyun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.653-655
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    • 2005
  • More than 70 percent of terrestrial territory of Korea is mountainous areas where degradation becomes serious year by year due to illegal tombs, expanding golf courses and stone mine development. We elaborate the potential usage of high resolution image for the monitoring of the phenomena. We made the classification of tombs and the statistical radiometric characteristics of graves were identified from this project. The graves could be classified to 4 groups from the field survey. As compared with grouping data after clustering and discriminant analysis, the two results coincided with each other. Object-oriented classification algorithm for feature extraction was theoretically researched in this project. And we did a pilot project, which was performed with mixed methods. That is, the conventional methods such as unsupervised and supervised classification were mixed up with the new method for feature extraction, object-oriented classification method. This methodology showed about $60\%$ classification accuracy for extracting tombs from satellite imagery. The extraction of tombs' geographical coordinates and graves themselves from satellite image was performed in this project. The stone mines and golf courses are extracted by NDVI and GVI. The accuracy of classification was around 89 percent. The location accuracy showed extraction of tombs from one-meter resolution image is cheaper and quicker way than GPS method. Finally we interviewed local government officers and made analyses on the current situation of mountainous area management and potential usage of KOMPSAT-II images. Based on the requirement analysis, we developed software, which is to management and monitoring system for mountainous area for local government.

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Multi-Radial Basis Function SVM Classifier: Design and Analysis

  • Wang, Zheng;Yang, Cheng;Oh, Sung-Kwun;Fu, Zunwei
    • Journal of Electrical Engineering and Technology
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    • 제13권6호
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    • pp.2511-2520
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    • 2018
  • In this study, Multi-Radial Basis Function Support Vector Machine (Multi-RBF SVM) classifier is introduced based on a composite kernel function. In the proposed multi-RBF support vector machine classifier, the input space is divided into several local subsets considered for extremely nonlinear classification tasks. Each local subset is expressed as nonlinear classification subspace and mapped into feature space by using kernel function. The composite kernel function employs the dual RBF structure. By capturing the nonlinear distribution knowledge of local subsets, the training data is mapped into higher feature space, then Multi-SVM classifier is realized by using the composite kernel function through optimization procedure similar to conventional SVM classifier. The original training data set is partitioned by using some unsupervised learning methods such as clustering methods. In this study, three types of clustering method are considered such as Affinity propagation (AP), Hard C-Mean (HCM) and Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA). Experimental results on benchmark machine learning datasets show that the proposed method improves the classification performance efficiently.

TELE-OPERATIVE SYSTEM FOR BIOPRODUCTION - REMOTE LOCAL IMAGE PROCESSING FOR OBJECT IDENTIFICATION -

  • Kim, S. C.;H. Hwang;J. E. Son;Park, D. Y.
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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    • pp.300-306
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    • 2000
  • This paper introduces a new concept of automation for bio-production with tele-operative system. The proposed system showed practical and feasible way of automation for the volatile bio-production process. Based on the proposition, recognition of the job environment with object identification was performed using computer vision system. A man-machine interactive hybrid decision-making, which utilized a concept of tele-operation was proposed to overcome limitations of the capability of computer in image processing and feature extraction from the complex environment image. Identifying watermelons from the outdoor scene of the cultivation field was selected to realize the proposed concept. Identifying watermelon from the camera image of the outdoor cultivation field is very difficult because of the ambiguity among stems, leaves, shades, and especially fruits covered partly by leaves or stems. The analog signal of the outdoor image was captured and transmitted wireless to the host computer by R.F module. The localized window was formed from the outdoor image by pointing to the touch screen. And then a sequence of algorithms to identify the location and size of the watermelon was performed with the local window image. The effect of the light reflectance of fruits, stems, ground, and leaves were also investigated.

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Evaluation of Histograms Local Features and Dimensionality Reduction for 3D Face Verification

  • Ammar, Chouchane;Mebarka, Belahcene;Abdelmalik, Ouamane;Salah, Bourennane
    • Journal of Information Processing Systems
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    • 제12권3호
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    • pp.468-488
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    • 2016
  • The paper proposes a novel framework for 3D face verification using dimensionality reduction based on highly distinctive local features in the presence of illumination and expression variations. The histograms of efficient local descriptors are used to represent distinctively the facial images. For this purpose, different local descriptors are evaluated, Local Binary Patterns (LBP), Three-Patch Local Binary Patterns (TPLBP), Four-Patch Local Binary Patterns (FPLBP), Binarized Statistical Image Features (BSIF) and Local Phase Quantization (LPQ). Furthermore, experiments on the combinations of the four local descriptors at feature level using simply histograms concatenation are provided. The performance of the proposed approach is evaluated with different dimensionality reduction algorithms: Principal Component Analysis (PCA), Orthogonal Locality Preserving Projection (OLPP) and the combined PCA+EFM (Enhanced Fisher linear discriminate Model). Finally, multi-class Support Vector Machine (SVM) is used as a classifier to carry out the verification between imposters and customers. The proposed method has been tested on CASIA-3D face database and the experimental results show that our method achieves a high verification performance.

물체 인식의 성능 및 속도 개선 방향에 대한 비교 연구 (A Comparative Study on Object Recognition about Performance and Speed)

  • 김준철;김학일
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.1055-1056
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    • 2008
  • In this paper, we survey various Robust Object Recognition Algorithms. One of the core technologies for local feature detector is Scale Invariant Feature Transform. And we compared several algorithms with SIFT based on IPP technology. As a result, the conversion of source codes using IPP is sped up. And this will be more improved recognition speed using SIMD Instructions.

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인간친화형 인터페이스를 위한 사용자 얼굴에서의 효과적인 의도 파악 (An Effective Intention Reading from User Face for Human-Friendly Interface)

  • 김대진;송원경;김종성;변증남
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(3)
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    • pp.25-28
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    • 2000
  • In this paper, an effective intention reading scheme is proposed for human-friendly interface. Soft computing techniques such as fuzzy logic and artificial neural networks are used for this. And Gabor filter based feature(GG feature) is also proposed to deal with local activity in the human face. It is based on human visual system and Gabor filter based approach is very popular in these days. The proposed scheme is adopted for human-friendly interface for rehabilitation service robotic system KARES II.

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Recognition of Profile Contours of Human Face by Approximation - Recognition

  • Yang, Yun-Mo
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.683-686
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    • 1988
  • In the recognition of similar patterns like profile contours of human faces, feature measure plays important role. We extracted effective and general feature by B-spline approximation. The nodes and vertices of the approximated curve are normalized and used as features. Since the features have both local property of curvature extrema and global property by B-spline approximation, they are superior to those of curvature extrema of the profile contour. For the image data of six sets of 56 persons, some of which are ill-made, averaged accuracy rate of 97.6 % is obtained in recognizing combinational 333 test samples.

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KLT 특징점에 기반한 비접촉 장문인식 (Contactless Palmprint Recognition Based on the KLT Feature Points)

  • 김민기
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제3권11호
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    • pp.495-502
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    • 2014
  • 비접촉 장문을 인식하기 위해서는 영상의 크기 및 회전 변형을 효과적으로 해결해야 한다. 본 연구에서는 손의 크기와 방향에 따라 관심영역(ROI)을 추출한 후 정규화하여 일차적으로 이러한 변형을 최소화하였다. 본 논문에서는 KLT(Kanade-Lukas-Tomasi) 특징점에 기반한 비접촉 장문인식 방법을 제안한다. 대응되는 KLT 특징점 주위의 국소영역에 대한 텍스처를 비교하여 대응되는 특징점을 검출한 후, 특징점 쌍의 변위 크기와 방향을 나타내는 변위벡터들 간의 유사도를 비교하여 장문을 인식한다. CASIA 공개 데이터베이스를 이용한 실험결과 제안된 방법이 비접촉 장문인식에 효과적임을 확인할 수 있었다. 특히 다중 가버 필터를 이용하였을 때 99%를 상회하는 정인식률을 얻을 수 있었다.