• Title/Summary/Keyword: matching points

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Point Pattern Matching Algorithm Using Unit-Circle Parametrization

  • Choi, Nam-Seok;Lee, Byung-Gook;Lee, Joon-Jae
    • Journal of Korea Multimedia Society
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    • v.13 no.6
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    • pp.825-832
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    • 2010
  • This paper presents only a matching algorithm based on Delaunay triangulation and Parametrization from the extracted minutiae points. This method maps local neighborhood of points of two different point sets to unit-circle using topology information by Delaunay triangulation method from feature points of real fingerprint. Then, a linked convex polygon that includes an interior point is constructed as one-ring which is mapped to unit-circle using Parametrization that keep shape preserve. In local matching, each area of polygon in unit-circle is compared. If the difference of two areas are within tolerance, two polygons are consider to be matched and then translation, rotation and scaling factors for global matching are calculated.

Feature based matching using edge and intensity (에지 정보와 밝기 정보를 이용한 특징 기반 정합)

  • Kim, Jung-Ho;Um, Gi-Mun;Lee, Kwae-Hi
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.414-417
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    • 1993
  • The methods for stereo matching are divided into two techniques: area-based matching and feature-based matching. To find corresponding points by area-based method, it takes a lot of time because there are many points to be matched. Feature-based matching algorithm is often used because with this method it matches only some feature points so that the processing time is fast even though it requires interpolation after matching. In this paper, we propose the smart technique by which we makes features simpler than conventional methods to match an image pair by feature-based matching algorithm.

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Highly Dense 3D Surface Generation Using Multi-image Matching

  • Noh, Myoung-Jong;Cho, Woo-Sug;Bang, Ki-In
    • ETRI Journal
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    • v.34 no.1
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    • pp.87-97
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    • 2012
  • This study presents an automatic matching method for generating a dense, accurate, and discontinuity-preserved digital surface model (DSM) using multiple images acquired by an aerial digital frame camera. The proposed method consists of two main procedures: area-based multi-image matching (AMIM) and stereo-pair epipolar line matching (SELM). AMIM evaluates the sum of the normalized cross correlation of corresponding image points from multiple images to determine the optimal height of an object point. A novel method is introduced for determining the search height range and incremental height, which are necessary for the vertical line locus used in the AMIM. This procedure also includes the means to select the best reference and target images for each strip so that multi-image matching can resolve the common problem over occlusion areas. The SELM extracts densely positioned distinct points along epipolar lines from the multiple images and generates a discontinuity-preserved DSM using geometric and radiometric constraints. The matched points derived by the AMIM are used as anchor points between overlapped images to find conjugate distinct points using epipolar geometry. The performance of the proposed method was evaluated for several different test areas, including urban areas.

Estimation of transformation parameters using shape matching (형상 정합을 통한 변환 파라미터 추출)

  • 박용희;전병호;김태균
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1523-1533
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    • 1997
  • Image registration is concerned with the establishment of correspondence between images of the same scene with translational, rotational, and scaling differences. The estimated transformation parameters between images are very important information in the field of many applications. In this paper, we propose a shape matching scheme for finding correspondence points for images with various differences, Tranditional solutions to this area are unreliable for the rotational and schaling changes between images, and the feature extraction of partially occluded scene. To solve those problems, dominant points on digital curves are detected by scale-space filtering, and initial matching is performed by similarity measure of cumulative curvatures for dominant points. For initial matching segments pairs, optimal matching points are calculated using dynamic programming.Finally, transformation parameters are estimated.

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The Comparison of the SIFT Image Descriptor by Contrast Enhancement Algorithms with Various Types of High-resolution Satellite Imagery

  • Choi, Jaw-Wan;Kim, Dae-Sung;Kim, Yong-Min;Han, Dong-Yeob;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.26 no.3
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    • pp.325-333
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    • 2010
  • Image registration involves overlapping images of an identical region and assigning the data into one coordinate system. Image registration has proved important in remote sensing, enabling registered satellite imagery to be used in various applications such as image fusion, change detection and the generation of digital maps. The image descriptor, which extracts matching points from each image, is necessary for automatic registration of remotely sensed data. Using contrast enhancement algorithms such as histogram equalization and image stretching, the normalized data are applied to the image descriptor. Drawing on the different spectral characteristics of high resolution satellite imagery based on sensor type and acquisition date, the applied normalization method can be used to change the results of matching interest point descriptors. In this paper, the matching points by scale invariant feature transformation (SIFT) are extracted using various contrast enhancement algorithms and injection of Gaussian noise. The results of the extracted matching points are compared with the number of correct matching points and matching rates for each point.

A Short Review on the Principal of Matching Five-Su-Points to O-Haeng Using Hado (하도를 이용한 오수혈 오행배속 원리 고찰)

  • Choi, In Suh;Lee, Bong Hyo
    • Korean Journal of Acupuncture
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    • v.31 no.2
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    • pp.49-55
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    • 2014
  • Objectives : Five transport points are often used in acupuncture treatment. However, there is no clear explanation about the reason why the five transport points are matched five phases in this manner. Therefore, we reviewed the literatures and theses about the principal of matching and researched a new way to understand the reason. Methods : We found 8 theses and 3 literatures related to the matching of five transport points to five phases by searching the web sites. And, we reviewed the principal of matching and researched another new way to understand the reason why they are matched so. Results and Conclusions : In the viewpoint of the natural state and function of five phases, the start points arising in yin- and yang-meridian are matched to wood and metal respectively. Therefore, well point matches the wood and metal in yin- and yang-meridian respectively. And by following the flow of five transport points, the other points match with fire, earth, metal, water in yin-meridian and water, wood, fire, and earth in yang-meridian.

A Rule-Based Stereo Matching Algorithm to Obtain Three Dimesional Information (3차원 정보를 얻기 위한 Rule-Based Stereo Matching Algorithm)

  • 심영석;박성한
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.1
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    • pp.151-163
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    • 1990
  • In this paper, rule-based stereo algorithm is explored to obtain three dimensional information of an object. In the preprocessing of the stereo matching, feature points of stereo images must be less sensitive to noise and well linked. For this purpose, a new feature points detection algorithm is developed. For performing the stereo matching which is most important process of the stereo algorithm, the feature representation of feature points is first described. The feature representation is then used for a rule-based stereo algorithm to determine the correspondence between the input stereo images. Finally, the three dimensional information of the object is determined from the correspondence of the feature points of right and left images.

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Changes in the Number of Matching Points in CCTV's Stereo Images by Indoor/Outdoor Illuminance (실내·외 조도에 따른 스테레오 CCTV 영상 정합점 수 변화)

  • Moon, Kwang Il;Pyeon, Mu Wook;Kim, Jong Hwa;Kim, Kang San
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.129-135
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    • 2015
  • The Ubiquitous City (U-City) spatial information technology aimed to provide services freely anytime and anywhere by converging high-tech information & communication technology in urban infrastructure has been available in diverse patterns. In particular, there have been studies on the development of 3D spatial information after selecting and matching key points with stereo images from the many Closed Circuit TV (CCTV) in the U-City. However, the data mostly used in extracting matching points haven't considered external environmental impacts such as illuminance. This study tested how much the matching points needed to construct 3D spatial information with the CCTV whose image quality is dependent upon changes in illuminance fluctuate under the same hardware performances. According to analysis on the number of matching points by illuminance, the number of matching points increased up to 3,000Lux in proportion to the illuminance when IRIS, shutter speed and ISO were fixed. In addition, a border between an object and background became more distinctive. When there was too much light, however, the page became brighter, and noise occurred. Furthermore, it was difficult to name key points because of the collapse of an inter-object border. It appears that if filmed with the study results, the number of matching points would increase.

A Stereo Matching Algorithm with Projective Distortion of Variable Windows (가변 윈도우의 투영왜곡을 고려한 스테레오 정합 알고리듬)

  • Kim, Gyeong-Beom;Jeong, Seong-Jong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.461-469
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    • 2001
  • Existing area-based stereo algorithms rely heavily on rectangular windows for computing correspondence. While the algorithms with the rectangular windows are efficient, they generate relatively large matching errors due to variations of disparity profiles near depth discontinuities and doesnt take into account local deformations of the windows due to projective distortion. In this paper, in order to deal with these problems, a new correlation function with 4 directional line masks, based on robust estimator, is proposed for the selection of potential matching points. These points is selected to consider depth discontinuities and reduce effects on outliers. The proposed matching method finds an arbitrarily-shaped variable window around a pixel in the 3d array which is constructed with the selected matching points. In addition, the method take into account the local deformation of the variable window with a constant disparity, and perform the estimation of sub-pixel disparities. Experiments with various synthetic images show that the proposed technique significantly reduces matching errors both in the vicinity of depth discontinuities and in continuously smooth areas, and also does not be affected drastically due to outlier and noise.

Fast Hierarchical Block Matching Algorithm by Adaptively Using Spatial Correlation of Motion Field (운동영역의 상관성을 선택적으로 이용한 고속 움직임 추정 기법)

  • 임경원;송병철;나종범
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1996.06a
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    • pp.217-220
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    • 1996
  • This paper describes a new hierarchial block matching algorithm especially appropriate for a large search area. The proposed algorithm consists of higher level search for an initial motion vector estimate by using a new matching criterion over the evenly subsampled search points, and lower level search for the final motion vector refinement. In the higher level matching criterion, mean absolute differences at the search points (or motion vector candidates) similar to motion vectors of causally neighboring blocks, are weighted properly so that these points can have a higher chance to being selected. The proposed algorithm outperforms existing hierarchical block matching algorithms, and its computational regularity makes hardware implementation simple.

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