• Title/Summary/Keyword: Correspondence Problem

Search Result 160, Processing Time 0.025 seconds

Applications of Bootstrap Methods for Canonical Correspondence Analysis (정준대응분석에서 붓스트랩 방법 활용)

  • Ko, Hyeon-Seok;Jhun, Myoungshic;Jeong, Hyeong Chul
    • The Korean Journal of Applied Statistics
    • /
    • v.28 no.3
    • /
    • pp.485-494
    • /
    • 2015
  • Canonical correspondence analysis is an ordination method used to visualize the relationships among sites, species and environmental variables. However, projection results are fluctuations if the samples slightly change and consistent interpretation on ecological similarity among species tends to be difficult. We use the bootstrap methods for canonical correspondence analysis to solve this problem. The bootstrap method results show that the variations of coordinate points are inversely proportional to the number of observations and coverage rates with bootstrap confidence interval approximates to nominal probabilities.

An Improvement of Cadastral Non-coincidence Surveying Method using Digital Orthophoto (수치정사사진을 이용한 지적불부합지 조사 방법의 개선)

  • Hong, Sung-Eon
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.14 no.2 s.36
    • /
    • pp.23-32
    • /
    • 2006
  • This study shows that new methodology improved the problem of unaided eye test level with the digital orthophoto technique can survey more objectively and efficiently any cadastral non-coincidence than existing prior methodologies. For applying to it, we explore eligible other methodologies, and then build up the application strategy of them. New prototype system is implemented with it. Also, we say the availability of new methodology by applying to study area. As a result, we suggest cadastral non-coincidence surveying method based on point-correspondence more objective and more efficient. As a result of comparing with old method and new on same study area for making adequacy, they hardly ever has the difference of accuracy. Constantly, cadastral non-coincidence surveying method based on point-correspondence is acceptable way on the cadastral survey.

  • PDF

Relaxation algorithm to solve correspondence problem based on possibility distribution (정합 문제 해결을 위한 가능도 기반의 이완 처리 알고리즘)

  • 한규필;김용석;박영식;송근원;하영호
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.34S no.9
    • /
    • pp.109-117
    • /
    • 1997
  • A new relaxation algorithm based on distribution of matched errors and possibility is proposed to solve efficiently correspondence problem. This algorithm can be applied to various method, such as BMA, feature-, and region-based matching methods, by modifying its smoothness function. It consists of two stages which are transformation and iteration process. In transformation stage, the errors obtained by any matching algorithm are transformed to possibility values according to these statistical distribution. Each grade of possility is updated by some constraints which are defined as smoothness, uniqueness, and discontinuity factor in iteration stage. The discontinuity factor is used to reserve discontinuity of disparity. In conventional methods, it is difficult to find proper weights and stop condition, because only two factors, smoothness and uniqueness, have been used. However, in the proposed mthod, the more smoothing is not ocurred because of discontinuity factor. And it is efective to the various image, even if the image has a severe noise and repeating patterns. In addition, it is shown that the convergence rate and the quality of output are improved.

  • PDF

Region Based Object Tracking with Snakes (스네이크를 이용한 영역기반 물체추적 알고리즘)

  • Kim, Young-Sub;Han, Kyu-Bum;Baek, Yoon-Su
    • Proceedings of the KSME Conference
    • /
    • 2001.06b
    • /
    • pp.307-312
    • /
    • 2001
  • In this paper, we proposed the object-tracking algorithm that recognizes and estimates the any shaped and size objects using vision system. For the extraction of the object from the background of the acquired images, spatio-temporal filter and signature parsing algorithm are used. Specially, for the solution of correspondence problem of the multiple objects tracking, we compute snake energy and position information of the target objects. Through the real-time tracking experiment, we verified the effectiveness of the suggested tracking algorithm.

  • PDF

Panoramic Image Stitching using SURF

  • You, Meng;Lim, Jong-Seok;Kim, Wook-Hyun
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.12 no.1
    • /
    • pp.26-32
    • /
    • 2011
  • This paper proposes a new method to process panoramic image stitching using SURF(Speeded Up Robust Features). Panoramic image stitching is considered a problem of the correspondence matching. In computer vision, it is difficult to find corresponding points in variable environment where a scale, rotation, view point and illumination are changed. However, SURF algorithm have been widely used to solve the problem of the correspondence matching because it is faster than SIFT(Scale Invariant Feature Transform). In this work, we also describe an efficient approach to decreasing computation time through the homography estimation using RANSAC(random sample consensus). RANSAC is a robust estimation procedure that uses a minimal set of randomly sampled correspondences to estimate image transformation parameters. Experimental results show that our method is robust to rotation, zoom, Gaussian noise and illumination change of the input images and computation time is greatly reduced.

Effect of Calcium Carbonate on Properties of Paper in Alkali Paper Masking (중성초지에서 탄산칼슘의 성질이 종이의 물성에 미치는 영향)

  • 신종순
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.8 no.1
    • /
    • pp.71-87
    • /
    • 1990
  • This paper presents a simple algorithm to obtain three dimensional information of an object. In the preprocessing of the stereo matching,feature point informations of stero image must be less sensitive to noise and well liked the correspondance problem. This paper described a simple technique of struture feature extraction of 3-D object and used edge-end point expanding method for unconnected line instade of Hough transform. The feature such as corner point and their angles are used for matching problem. The experimental results show that the described algorithm is a useful method for stereo correspondence problem.

  • PDF

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

  • Jeong, Jong-Myeon;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.37 no.6
    • /
    • pp.25-37
    • /
    • 2000
  • The trajectories of feature points can be defined by the correspondences between points in consecutive frames. The correspondence problem is known to be difficult to solve because false positives and false negatives almost always exist in real image sequences. In this paper, we propose a robust feature tracking algorithm considering incomplete trajectories such as entering and/or vanishing trajectories. The trajectories of feature points are determined by calculating the matching measure, which is defined as the minimum weighted Euclidean distance between two feature points. The weights are automatically updated in order to properly reflect the motion characteristics. We solve the correspondence problem as an optimal graph search problem, considering that the existence of false feature points may have serious effect on the correspondence search. The proposed algorithm finds a local optimal correspondence so that the effect of false feature point can be minimized in the decision process. The time complexity of the proposed graph search algorithm is given by O(mn) in the best case and O($m^2n$) in the worst case, where m and n arc the number of feature points in two consecutive frames. By considering false feature points and by properly reflecting motion characteristics, the proposed algorithm can find trajectories correctly and robustly, which has been shown by experimental results.

  • PDF

Building a 3D Morphable Face Model using Finding Semi-automatic Dense Correspondence (반자동적인 대응점 찾기를 이용한 3차원 얼굴 모델 생성)

  • Choi, In-Ho;Cho, Sun-Young;Kim, Dai-Jin
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.14 no.7
    • /
    • pp.723-727
    • /
    • 2008
  • 2D face analysis has some limitations which are pose and illumination sensitive. For these reasons, even if many researchers try to study in the 3D face analysis and processing, because of the low computing performance and the absence of a high-speed 3D scanner then a lot of research is not being able to proceed. But, due to improving of the computing performance in these days, the advanced 3D face research was now underway. In this paper, we propose the method of building a 3D face model which deal successfully with dense correspondence problem.

A Framework for Real Time Vehicle Pose Estimation based on synthetic method of obtaining 2D-to-3D Point Correspondence

  • Yun, Sergey;Jeon, Moongu
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2014.04a
    • /
    • pp.904-907
    • /
    • 2014
  • In this work we present a robust and fast approach to estimate 3D vehicle pose that can provide results under a specific traffic surveillance conditions. Such limitations are expressed by single fixed CCTV camera that is located relatively high above the ground, its pitch axes is parallel to the reference plane and the camera focus assumed to be known. The benefit of our framework that it does not require prior training, camera calibration and does not heavily rely on 3D model shape as most common technics do. Also it deals with a bad shape condition of the objects as we focused on low resolution surveillance scenes. Pose estimation task is presented as PnP problem to solve it we use well known "POSIT" algorithm [1]. In order to use this algorithm at least 4 non coplanar point's correspondence is required. To find such we propose a set of techniques based on model and scene geometry. Our framework can be applied in real time video sequence. Results for estimated vehicle pose are shown in real image scene.