• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2280-2286
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• 2012

In this paper, we propose a novel nonlinear 3D image correlator using a fast computational integral imaging reconstruction (CIIR) method. In order to implement the fast CIIR method, the magnification process was eliminated. In the proposed correlator, elemental images of the reference and target objects are picked up by lenslet arrays. Using these elemental images, reference and target plane images are reconstructed on the output plane by means of the proposed fast CIIR method. Then, through nonlinear cross-correlations between the reconstructed reference and the target plane images, the pattern recognition can be performed from the correlation outputs. Nonlinear correlation operation can improve the recognition of 3D objects. To show the feasibility of the proposed method, some preliminary experiments are carried out and the results are presented by comparing the conventional method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.3
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• pp.79-87
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• 2000

In this paper, we propose a model based moving object tracking algorithm In dynamic scenes To adapt shape change of the moving object, the Hausdorff distance is applied as the measurement of similarity between model and image To reduce processing time, 2D logarithmic search method is applied for locate the position of moving object Experiments on a running vehicle and motorcycle, the result showed that the mean square error of real position and tracking result is 1150 and 1845; matching times are reduced average 1125times and 523 times than existing algorithm for vehicle image and motorcycle image, respectively It showed that the proposed algorithm could track the moving object accurately.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.374-376
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• 2013

증강 현실(Argument Reality)에 대한 관심이 증가함에 따라 빠르고 강건한 물체 추적(Object Tracking)기법의 개발이 큰 이슈가 되고 있다. 특히, 마커를 사용하지 않는 경우에 추적 속도와 정확도의 정보가 이루어지는 강건한 Markerless 3D 추적 기술은 많은 연구가 이루어지고 있다. 본 논문에서는 SIFT(Scale Invariant Feature Transform)를 이용한 특징점 추출 및 매칭 기법을 통하여 높은 정확도의 물체 추적기법을 제안한다. 그리고 실시간으로 적용하기 어려운 SIFT의 느린 특징점 추출과 매칭 단계를 GPU 기반의 병렬화 작업을 통하여 개선시켜 향상된 추적 속도를 보여준다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.570-573
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• 2020

핀홀 카메라는 그 특성상 전체 공간 중에서 일부분만을 촬영할 수 있으므로 전체 공간을 염두에 두는 3D 재구성에서는 구면 영상에 비해 많은 데이터를 확보해야 한다. 본 논문에서는 다수의 구면 영상에 촬영된 물체의 실제 3차원 위치를 추정하는 방법을 제안한다. 두 카메라의 배치 간격이 가까운 스테레오 비전과는 달리 제안하는 방법에서는 여러 대의 카메라를 넓은 간격으로 배치하여 장애물에 대한 폐색을 극복하도록 한다. 구면 카메라의 화각은 공간 전체를 담을 수 있기 때문에 촬영 간격과 카메라의 회전각이 크더라도 전 영역에 대한 일치 관계를 계산할 수 있다. 실험 결과 구면 영상에 나타난 물체의 실제 위치에 근접한 결과를 얻을 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2563-2568
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• 2010

SAII (synthetic aperture integral imaging) is a useful technique to record many multi view images of 3D objects by using a moving camera and to reconstruct 3D depth images from the recorded multiviews. This is largely composed of two processes. A pickup process provides elemental images of 3D objects and a reconstruction process generates 3D depth images computationally. In this paper, a signal model for SAII is presented. We defined the granular noise and analyzed its characteristics. Our signal model revealed that we could reduce the noise in the reconstructed images and increase the computational speed by reducing the shifting distance of a single camera.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.4
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• pp.513-526
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• 1999

3 차원 입체 형상을 표현하기 위한 수단으로서 도면을 사용하는 방법이 생산현장에서 많이 활용되고 있다. 그러나 이 방법은 정투영 과정에서 정보 손실이 발생하기 때문에 3차원 후보 요소의 빈번한 조합 탐색 및 복잡한 기하 연산을 필요로 한다. 특히 , 이면도로부터 복원과정은 면도의 생략으로 인하여 수많은 허요소를 생성한다. 본 논문은 효율적인 허요소 축소를 통하여 이면도로부터 다면체를 바르게 복원하는 이단계 알고리즘을 제안한다. 1 단계에서는 이면도와의 정합성에 필수적인 최소한의 3차원 후보요소를 생성한후 , 정투영시 이면도와 일치하는 부분 물체를 복원한다. 2단계에서는 부분 물체에 직교면을 덧붙임으로써 기하학적으로 타당한 완전 물체를 복원한다. 실험결과를 통하여 제안방법이 기존 방법들에 비해 적은 수의 3차원 후보 요소를 생성시키면서 이면도로로부터 3차원 물체를 빠르게 생성하는 것을 보인다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4807-4813
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• 2012

Since the existing methods of segmenting target objects from various images mainly use 2-dimensional features, they have several constraints due to the shortage of 3-dimensional information. In this paper, we therefore propose a new method of accurately segmenting target objects from three dimensional stereoscopic images using 2D and 3D feature clustering. The suggested method first estimates depth features from stereo images by using a stereo matching technique, which represent the distance between a camera and an object from left and right images. It then eliminates background areas and detects foreground areas, namely, target objects by effectively clustering depth and color features. To verify the performance of the proposed method, we have applied our approach to various stereoscopic images and found that it can accurately detect target objects compared to other existing 2-dimensional methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.981-988
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• 2013

In this paper, we propose a method to generate defocusing images at the focusing plane using the 3D spatial information of object through pickup process of integral imaging technique. In the proposed method, the focusing and defocusing images are generated by the convolution operation between elemental images and ${\delta}$ function array. We observed the image difference by defocusing degree according to the distance of focusing plane. To show the feasibility of the proposed method, some preliminary experiments are carried out and the results are presented.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.63-72
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• 2022

The purpose of this paper was to understand the dynamics of deployment of large mesh antennas, and to provide a numerical method for determining the dynamic stiffness and the driving forces for the design. The deployment structure was numerically modeled using the frame elements. The eigenvalue analysis was demonstrated, with respect to the folded and unfolded configurations of the antenna. A multibody dynamic model was formulated with Kane's equation, and simulated using the pseudo upper triangular decomposition (PUTD) method for resolving the constrained problem. Based on the multibody model, the kinetics of the deployment, the motor driving forces, and the feasibility of the designed deployment structure were investigated.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.89-101
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• 2015

This paper proposes a statistical model of 3-D positions when tracking moving targets using the uncooled infrared (IR) stereo camera system. The proposed model is derived from two errors. One is the position error which is caused by the sampling pixels in the digital image. The other is the timing jitter which results from the irregular capture-timing in the infrared cameras. The capture-timing in the IR camera is measured using the jitter meter designed in this paper, and the observed jitters are statistically modeled as Gaussian distribution. This paper derives an integrated probability distribution by combining jitter error with pixel position error. The combined error is modeled as the convolution of two error distributions. To verify the proposed statistical position error model, this paper has some experiments in tracking moving objects with IR stereo camera. The 3-D positions of object are accurately measured by the trajectory scanner, and 3-D positions are also estimated by stereo matching from IR stereo camera system. According to the experiments, the positions of moving object are estimated within the statistically reliable range which is derived by convolution of two probability models of pixel position error and timing jitter respectively. It is expected that the proposed statistical model can be applied to estimate the uncertain 3-D positions of moving objects in the diverse fields.