• Title/Summary/Keyword: global motion

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Adaptive Keyframe and ROI selection for Real-time Video Stabilization (실시간 영상 안정화를 위한 키프레임과 관심영역 선정)

  • Bae, Ju-Han;Hwang, Young-Bae;Choi, Byung-Ho;Chon, Je-Youl
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.11a
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    • pp.288-291
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    • 2011
  • Video stabilization is an important image enhancement widely used in surveillance system in order to improve recognition performance. Most previous methods calculate inter-frame homography to estimate global motion. These methods are relatively slow and suffer from significant depth variations or multiple moving object. In this paper, we propose a fast and practical approach for video stabilization that selects the most reliable key frame as a reference frame to a current frame. We use optical flow to estimate global motion within an adaptively selected region of interest in static camera environment. Optimal global motion is found by probabilistic voting in the space of optical flow. Experiments show that our method can perform real-time video stabilization validated by stabilized images and remarkable reduction of mean color difference between stabilized frames.

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Crustal Movement at Ol Doinyo Lengai based on GPS Measurements

  • Meshili, Valerie Ayubu;Kwon, Jay Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.5
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    • pp.401-406
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    • 2020
  • Continuously monitoring of Horizontal and Vertical movements in vulnerable areas due to earthquakes and volcanic activities is vital. These geohazard activities are the result of a slow deformation rate at the tectonic plate boundaries. The recent development of GPS (Global Positioning System) technology has made it possible to attain a millimeter level changes in the Earth's crust. This study used continuously observed GPS data at the flank of Ol Doinyo Lengai volcanic Mountain to determine crustal motion caused by impinging volcano from mantle convention. We analyzed 8 GPS observed from June 2016 to Dec 2019 using a well-documented Global Kalman Filter GAMIT/GLOBK software. The resulting velocity from GAMIT/GLOBK analysis was then used to compute the relative motion of our study area with respect to Nubia plate. Our analysis discovered a minor motion of less than 5mm/year in both horizontal and vertical components.

Moving Target Tracking Algorithm based on the Confidence Measure of Motion Vectors (움직임 벡터의 신뢰도에 기반한 이동 목표물 추적 기법)

  • Lee, Jin-Seong;Lee, Gwang-Yeon;Kim, Seong-Dae
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.2
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    • pp.160-168
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    • 2001
  • Change detection using difference picture has been used to detect the location of moving targets and to track them. This method needs the assumption of static camera, and the global motion compensation is required in case of a moving camera. This paper suggests a method for finding a minimum bounding rectangles(MBR) of moving targets in the image sequences using moving region detection, especially with a moving camera. If the global motion parameter is inaccurately estimated, the estimated locations of targets will be accurate either To alleviate this problem, we introduce the concept of the confidence measure and achieve more accurate estimation of global motion. Experimental results show that the proposed method successfully removes background region and extracts MBRs of the targets. Even with a moving camera, the new global motion estimation algorithm performs more precise]y and it reduces the background compensation errors of change detection.

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The Design of Motion Estimation Hardware for High-Performance HEVC Encoder (고성능 HEVC 부호기를 위한 움직임추정 하드웨어 설계)

  • Park, Seungyong;Jeon, Sunghun;Ryoo, Kwangki
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.3
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    • pp.594-600
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    • 2017
  • This paper proposes a global search based motion estimation algorithm for high performance HEVC encoder and its hardware architecture. To eliminate temporal redundancy, motion estimation in HEVC inter-view prediction uses global search and fast search algorithm to search for a predicted block having a high correlation with the current PU in an interpolated reference picture. The global search method predicts the motion of all candidate blocks in a given search area, thus ensuring optimal results, but has a disadvantage of large computation time. Therefore we propose a new algorithm that reduces computational complexity by reusing SAD operation in global search to reduce computation time of inter prediction. As a result of applying the proposed algorithm to standard software HM16.12, the computation time was reduced by 61%, BDBitrate by 11.81%, and BDPSNR by about 0.5% compared with the existing search algorithm. As a result of hardware design, the maximum operating frequency is 255 MHz and the total number of gates is 65.1K.

Numerical simulation of wave interacting with a free rolling body

  • Jung, Jae Hwan;Yoon, Hyun Sik;Chun, Ho Hwan;Lee, Inwon;Park, Hyun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.3
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    • pp.333-347
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    • 2013
  • The present study numerically models the interaction between a regular wave and the roll motion of a rectangular floating structure. In order to simulate two-dimensional incompressible viscous two-phase flow in a numerical wave tank with the rectangular floating structure, the present study used the volume of fluid method based on the finite volume method. The sliding mesh technique is adopted to handle the motion of the rectangular floating structure induced by fluid-structure interaction. The effect of the wave period on the flow, roll motion and forces acting on the structure is examined by considering three different wave periods. The time variations of the wave height and the roll motion of the rectangular structure are in good agreement with experimental results for all wave periods. The present response amplitude operator is in good agreement with experimental results with the linear potential theory. The present numerical results effectively represent the entire process of vortex generation and evolution described by the experimental results. The longer wave period showed a different mechanism of the vortex evolution near each bottom corner of the structure compared to cases of shorter wave periods. In addition, the x-directional and z-directional forces acting on the structure are analyzed.

Temporal Transfer of Locomotion Style

  • Kim, Yejin;Kim, Myunggyu;Neff, Michael
    • ETRI Journal
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    • v.37 no.2
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    • pp.406-416
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    • 2015
  • Timing plays a key role in expressing the qualitative aspects of a character's motion; that is, conveying emotional state, personality, and character role, all potentially without changing spatial positions. Temporal editing of locomotion style is particularly difficult for a novice animator since observers are not well attuned to the sense of weight and energy displayed through motion timing; and the interface for adjusting timing is far less intuitive to use than that for adjusting pose. In this paper, we propose an editing system that effectively captures the timing variations in an example locomotion set and utilizes them for style transfer from one motion to another via both global and upper-body timing transfers. The global timing transfer focuses on matching the input motion to the body speed of the selected example motion, while the upper-body timing transfer propagates the sense of movement flow - succession - through the torso and arms. Our transfer process is based on key times detected from the example set and transferring the relative changes of angle rotation in the upper body joints from a timing source to an input target motion. We demonstrate that our approach is practical in an interactive application such that a set of short locomotion cycles can be applied to generate a longer sequence with continuously varied timings.

A Fast Motion Detection and Tracking Algorithm for Automatic Control of an Object Tracking Camera (객체 추적 카메라 제어를 위한 고속의 움직임 검출 및 추적 알고리즘)

  • 강동구;나종범
    • Journal of Broadcast Engineering
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    • v.7 no.2
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    • pp.181-191
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    • 2002
  • Video based surveillance systems based on an active camera require a fast algorithm for real time detection and tracking of local motion in the presence of global motion. This paper presents a new fast and efficient motion detection and tracking algorithm using the displaced frame difference (DFD). In the Proposed algorithm, first, a Previous frame is adaptively selected according to the magnitude of object motion, and the global motion is estimated by using only a few confident matching blocks for a fast and accurate result. Then, a DFD is obtained between the current frame and the selected previous frame displaced by the global motion. Finally, a moving object is extracted from the noisy DFD by utilizing the correlation between the DFD and current frame. We implement this algorithm into an active camera system including a pan-tilt unit and a standard PC equipped with an AMD 800MHz processor. The system can perform the exhaustive search for a search range of 120, and achieve the processing speed of about 50 frames/sec for video sequences of 320$\times$240. Thereby, it provides satisfactory tracking results.

A Study on the Global Motion Performance of Floater and Mooring Due to Arrangement of Detachable Mooring System (탈착형 계류시스템 배치에 따른 부유식 해양구조물의 운동 및 계류성능에 관한 연구)

  • Kangsu Lee;Hyun-Sung Kim;Byoung Wan Kim
    • Journal of Wind Energy
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    • v.14 no.2
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    • pp.26-33
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    • 2023
  • In this study, the global response characteristics of floater and mooring for floating offshore wind turbine with a detachable mooring system are performed. Global motion and structural response result extracted from the coupled motion analysis of 10MW DTU floating offshore wind turbine with detachable mooring system modeled by high-order boundary element model and finite element mesh, were used to study the characteristics of tension on mooring lines subjected to three different types of ocean loads. Breaking limit of mooring line characterized by wind, current and wave load has a major effect on the distribution of mooring tension found in time domain analysis. Based on the numerical results of coupled motion analysis, governing equation for calculating the motion response of a floater under ocean loads, and excitation force and surge motion and tension respectively are presented using excursion curve. It is found that the response of floater is reliable and accurate for calculating the tension distributions along the mooring lines under complex loadings. This means that the minimun breaking limit of mooring system satisfied a design criteria at ultimate ocean environmental loading condtions.

Comparison of the 6-DOF Motion Sensor and Stain Gauge Data for Ice Load Estimation on IBRV ARAON (쇄빙연구선 ARAON호의 빙하중 추정을 위한 6자유도 운동계측 및 스트레인 게이지 데이터의 비교 분석)

  • Min, Jung Ki;Cheon, Eun-Jee;Kim, Jin Myung;Lee, Sang Chul;Choi, Kyungsik
    • Journal of the Society of Naval Architects of Korea
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    • v.53 no.6
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    • pp.529-535
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    • 2016
  • This study focuses on the comparison of measured data from 6-DOF motion sensor and strain gauge installed in the IBRV ARAON during 2015 summer voyage in the Arctic. Procedures to calculate the global ice load from MotionPak II inertial measurement system and the local load from stain gauge system are discussed. The ship's speed and peak load are determined in the concept of an ice collision "event". It is found that the peak values in the global ice calculated form whole ship motion analysis fall in the range of 1.5~3 times of the local ice load based in strain gauge measurement.

Efficient Rolling Shutter Distortion Removal using Hierarchical Block-based Motion Estimation

  • Lee, Donggeun;Choi, Kang-Sun
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.4
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    • pp.205-211
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    • 2014
  • This paper reports an efficient algorithm for accurate rolling shutter distortion removal. A hierarchical global motion estimation approach for a group of blocks reduces the level of computation by three orders of magnitude. In addition, the motion of each scanline is determined accurately by averaging two candidates obtained through cubic spline interpolation. The experimental results show that the proposed method produces accurate motion information with significant computation reduction and corrects the rolling shutter distortion effectively.