• Title/Summary/Keyword: 3-D Reconstruction

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A Study on 8-Directional Complex Wavelet Transform for Efficient Image Processing (효율적인 영상처리를 위한 8방향 컴플렉스 웨이브렛 변환에 관한 연구)

  • Shin, Seong;Moon, Sung Ryong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.3
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    • pp.129-138
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    • 2013
  • This paper is a study on Dual Tree Complex Wavelet Transform, which improved directional information for efficient image processing. Dual Tree Complex Wavelet Transform satisfies characteristics of shift invariance, and includes 6 directional information, which is more than previous Discrete Wavelet Transform. However, in images of buildings, there are many horizontal and vertical edge components. Therefore, all the high-frequency components of image are not expressed by 6 directional information subbands. This paper proposes 8-directional Complex Wavelet Transform with excellent high-frequency separation features by creating horizontal vertical($0^{\circ}$, $90^{\circ}$) subband besides 6 directional information subband of previous Dual Tree Complex Wavelet Transform. The proposed method can create and combine various directional information subbands according to features of image. Performance is evaluated by applying the method to noise removal.

Motion Capture using both Human Structural Characteristic and Inverse Kinematics (인체의 구조적 특성과 역운동학을 이용한 모션 캡처)

  • Seo, Yung-Ho;Doo, Kyoung-Soo;Choi, Jong-Soo;Lee, Chil-Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.2
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    • pp.20-32
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    • 2010
  • Previous hardware devices to capture human motion have many limitations; expensive equipment, complexity of manipulation or constraints of human motion. In order to overcome these problems, real-time motion capture algorithms based on computer vision have been actively proposed. This paper presents an efficient analysis method of multiple view images for real-time motion capture. First, we detect the skin color regions of human being, and then correct the image coordinates of the regions by using camera calibration and epipolar geometry. Finally, we track the human body part and capture human motion using kalman filter. Experimental results show that the proposed algorithm can estimate a precise position of the human body.

SIFT based Image Similarity Search using an Edge Image Pyramid and an Interesting Region Detection (윤곽선 이미지 피라미드와 관심영역 검출을 이용한 SIFT 기반 이미지 유사성 검색)

  • Yu, Seung-Hoon;Kim, Deok-Hwan;Lee, Seok-Lyong;Chung, Chin-Wan;Kim, Sang-Hee
    • Journal of KIISE:Databases
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    • v.35 no.4
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    • pp.345-355
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    • 2008
  • SIFT is popularly used in computer vision application such as object recognition, motion tracking, and 3D reconstruction among various shape descriptors. However, it is not easy to apply SIFT into the image similarity search as it is since it uses many high dimensional keypoint vectors. In this paper, we present a SIFT based image similarity search method using an edge image pyramid and an interesting region detection. The proposed method extracts keypoints, which is invariant to contrast, scale, and rotation of image, by using the edge image pyramid and removes many unnecessary keypoints from the image by using the hough transform. The proposed hough transform can detect objects of ellipse type so that it can be used to find interesting regions. Experimental results demonstrate that the retrieval performance of the proposed method is about 20% better than that of traditional SIFT in average recall.

Investigation of the Central Carbon Metabolism of Sorangium cellulosum: Metabolic Network Reconstruction and Quantification of Pathway Fluxes

  • Bolten, Christoph J.;Heinzle, Elmar;Muller, Rolf;Wittmann, Christoph
    • Journal of Microbiology and Biotechnology
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    • v.19 no.1
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    • pp.23-36
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    • 2009
  • In the present work, the metabolic network of primary metabolism of the slow-growing myxobacterium Sorangium cellulosum was reconstructed from the annotated genome sequence of the type strain So ce56. During growth on glucose as the carbon source and asparagine as the nitrogen source, So ce56 showed a very low growth rate of $0.23\;d^{-1}$, equivalent to a doubling time of 3 days. Based on a complete stoichiometric and isotopomer model of the central metabolism, $^{13}C$ metabolic flux analysis was carried out for growth with glucose as carbon and asparagine as nitrogen sources. Normalized to the uptake flux for glucose (100%), cells recruited glycolysis (51%) and the pentose phosphate pathway (48%) as major catabolic pathways. The Entner-Doudoroff pathway and glyoxylate shunt were not active. A high flux through the TCA cycle (118%) enabled a strong formation of ATP, but cells revealed a rather low yield for biomass. Inspection of fluxes linked to energy metabolism revealed that S. cellulosum utilized only 10% of the ATP formed for growth, whereas 90% is required for maintenance. This explains the apparent discrepancy between the relatively low biomass yield and the high flux through the energy-delivering TCA cycle. The total flux of NADPH supply (216%) was higher than the demand for anabolism (156%), indicating additional reactions for balancing of NADPH. The cells further exhibited a highly active metabolic cycle, interconverting $C_3$ and $C_4$ metabolites of glycolysis and the TCA cycle. The present work provides the first insight into fluxes of the primary metabolism of myxobacteria, especially for future investigation on the supply of cofactors, building blocks, and energy in myxobacteria, producing natural compounds of biotechnological interest.

Measurement of Rotor Blade Deformation and Motions using Stereo Pattern Recognition Method (SPR 기법을 이용한 회전 블레이드의 변형 및 모션 측정)

  • Park, Jae-Won;Kim, Hong-Il;Han, Jae-Hung;Kim, Do-Hyung;Song, Keun-Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.5
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    • pp.442-450
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    • 2011
  • A measurement system using stereo pattern recognition (SPR) method was configured to measure the rotor blade deformations and motions. An SPR-based measurement system was prepared using six stereo cameras. Through a series of experiments to evaluate the system measurement uncertainty, it was verified that the SPR system had less than 0.2mm standard uncertainty. The combined standard uncertainties for the lead-lag, flapping, and pitching motions were estimated as 0.296mm, 0.209mm, and $0.238^{\circ}$, respectively. The SPR system was installed at a general small-scaled rotor test system at Korea Aerospace Research Institute. The blade motions and elastic deformation were successfully measured under the conditions with rotating speeds of 360rpm or 589rpm, and collective pitch angles of $0^{\circ}$, $4^{\circ}$, or $6^{\circ}$. The advantages of the SPR system was analyzed in comparison with the measurement system used in Higher Harmonic Control Aeroacoustic Rotor Test -II.

Analysis of Sunshine Amount for Education Environment according to Installation of Apartment Structures (아파트 구조물 설치에 따른 교육환경 일조량 분석)

  • Jang, Ho-Sik
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.117-124
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    • 2012
  • Due to recent urban maintenance project for the aged towns, the reconstruction of apartments into super-high-rise and high-rise apartment structures has been approved for concentrated use of land, and accordingly the infringement on sunshine for nearby residential area is rising as a social issue. Especially the educational environment conditions according to infringement on sunshine in educational facilities are posing many problems. Accordingly in this study, for such sunshine analysis of educational environment, Auto $CAD^{(R)}$ software has been used to construct the 3D model for the educational facility structures. And with the simulation technique, the windows and the schoolyard of the education facility were set to be the lighting standard surface to take measurements for the sunshine environment of the educational facilities by the minute from 8:00AM until 4:00PM for the sunshine amount by true solar time according to the movement of the sun. Also, the sunshine environment of the education facility according to the damage before/after new construction of apartments was charted, and through comparison with the video produced by sun shadow projection method, the sunshine amount of the educational environment could be verified. In future, it is expected to be efficiently used in the sunshine analysis of education environment utilizing such simulation techniques.

A Real-time Particle Filtering Framework for Robust Camera Tracking in An AR Environment (증강현실 환경에서의 강건한 카메라 추적을 위한 실시간 입자 필터링 기법)

  • Lee, Seok-Han
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.597-606
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    • 2010
  • This paper describes a real-time camera tracking framework specifically designed to track a monocular camera in an AR workspace. Typically, the Kalman filter is often employed for the camera tracking. In general, however, tracking performances of conventional methods are seriously affected by unpredictable situations such as ambiguity in feature detection, occlusion of features and rapid camera shake. In this paper, a recursive Bayesian sampling framework which is also known as the particle filter is adopted for the camera pose estimation. In our system, the camera state is estimated on the basis of the Gaussian distribution without employing additional uncertainty model and sample weight computation. In addition, the camera state is directly computed based on new sample particles which are distributed according to the true posterior of system state. In order to verify the proposed system, we conduct several experiments for unstable situations in the desktop AR environments.

An Efficient Analysis Method of Multiple View Images for Motion Capture (모션 캡쳐를 위한 다시점 영상의 효율적인 분석법)

  • Seo, Yung-Ho;Park, You-Shin;Koo, Ddeo-Ol-Ra;Doo, Kyoung-Soo;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.6
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    • pp.44-56
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    • 2008
  • Previous hardware devices to capture human motion have many limitations; expensive equipment, complexity of manipulation or constraints of human motion. In order to overcome these problems, real-time motion capture algorithms based on computer vision have been actively proposed. This paper presents an efficient analysis method of multiple view images for real-time motion capture. First, we detect the skin color regions of human being, and then correct the image coordinates of the regions by using camera calibration and epipolar geometry. Finally, we track the human body part and capture human motion using kalman filter. Experimental results show that the proposed algorithm can estimate a precise position of the human body.

Calibration of Omnidirectional Camera by Considering Inlier Distribution (인라이어 분포를 이용한 전방향 카메라의 보정)

  • Hong, Hyun-Ki;Hwang, Yong-Ho
    • Journal of Korea Game Society
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    • v.7 no.4
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    • pp.63-70
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    • 2007
  • Since the fisheye lens has a wide field of view, it can capture the scene and illumination from all directions from far less number of omnidirectional images. Due to these advantages of the omnidirectional camera, it is widely used in surveillance and reconstruction of 3D structure of the scene In this paper, we present a new self-calibration algorithm of omnidirectional camera from uncalibrated images by considering the inlier distribution. First, one parametric non-linear projection model of omnidirectional camera is estimated with the known rotation and translation parameters. After deriving projection model, we can compute an essential matrix of the camera with unknown motions, and then determine the camera information: rotation and translations. The standard deviations are used as a quantitative measure to select a proper inlier set. The experimental results showed that we can achieve a precise estimation of the omnidirectional camera model and extrinsic parameters including rotation and translation.

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Waveform Simulation of Full-Waveform LIDAR (풀웨이브폼 라이다의 반사파형 시뮬레이션)

  • Kim, Seong-Joon;Lee, Im-Pyeong
    • Korean Journal of Remote Sensing
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    • v.26 no.1
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    • pp.9-20
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    • 2010
  • The LIDAR data can be efficiently utilized for automatic reconstruction of 3D models of objects on the terrain and the terrain itself. In this paper, we attempted to generate simulated waveforms of FW (Full-Waveform) LIDAR (LIght Detection And Ranging). We performed the geometric modeling of the sensor and objects, and the radiometric modeling of the waveform intensity. First, we compute the origins and directions of the sub-beams by considering the divergence effects of a laser beam. We then searched for the locations at which the sub-beams intersected with the objects, such as ground, buildings and trees. Finally, we generate the individual waveforms of the reflected sub-beams and the waveform of the entire beam by summing the individual ones. With the experimental results, we confirmed the waveforms were reasonably generated, showing the characteristics of the surfaces the beam interacted with.