• Journal of Computational Design and Engineering
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• 제1권1호
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• pp.1-12
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• 2014

In this paper, we propose a new method of reconstructing the hand models for individuals, which include the link structure models, the homologous skin surface models and the homologous tetrahedral mesh models in a reference posture. As for the link structure model, the local coordinate system related to each link consists of the joint rotation center and the axes of joint rotation, which can be estimated based on the trajectories of optimal markers on the relative skin surface region of the subject obtained from the motion capture system. The skin surface model is defined as a three-dimensional triangular mesh, obtained by deforming a template mesh so as to fit the landmark vertices to the relative marker positions obtained motion capture system. In this process, anatomical dimensions for the subject, manually measured by a caliper, are also used as the deformation constraints.

• 동력기계공학회지
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• 제11권4호
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• pp.103-108
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• 2007

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In many papers reported by us, we suggested a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. The measuring system is based on laser sensor or others. However it is not so useful in real world. Especially, in this paper, the image sensor is used to measures the motions of the spreader and the measured data are fed back to the controller in real time. The applied image processing technique is a kind of robust template matching method which is named Vector Code Correlation (VCC) and devised to consider the real environmental conditions. And the $H_{\infty}$ based control technique is applied to suppress swing motion of the crane. And the experimental result shows that the proposed measurement system based on image sensor and control system is useful and robust to disturbances.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.707-720
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• 2014

This paper proposes a face tracking scheme that is a combination of a face detection algorithm and a face tracking algorithm. The proposed face detection algorithm basically uses the Adaboost algorithm, but the amount of search area is dramatically reduced, by using skin color and motion information in the depth map. Also, we propose a face tracking algorithm that uses a template matching method with depth information only. It also includes an early termination scheme, by a spiral search for template matching, which reduces the operation time with small loss in accuracy. It also incorporates an additional simple refinement process to make the loss in accuracy smaller. When the face tracking scheme fails to track the face, it automatically goes back to the face detection scheme, to find a new face to track. The two schemes are experimented with some home-made test sequences, and some in public. The experimental results are compared to show that they outperform the existing methods in accuracy and speed. Also we show some trade-offs between the tracking accuracy and the execution time for broader application.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.61-68
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• 2008

A set of modal parameters of a stay-cable have been extracted from a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.621-624
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• 1999

This paper describes a distance estimation method of object's motion in soccer image sequence by tracking field features. And we quantitatively evaluate the estimation accuracy We suppose that the input image sequence is taken with a camera on static axis and includes only zooming and panning transformation between frames. Adaptive template matching is adopted for non-rigid object tracking. For background compensation, feature templates selected from reference frame image are matched in following frames and the matched feature point pairs are used in computing Affine motion parameters. A perspective displacement field model is used for estimating the real distance between two position on Input Image. To quantitatively evaluate the accuracy of the estimation, we synthesized a 3 dimensional virtual stadium with graphic tools and experimented on the synthesized 2 dimensional image sequences. The experiment shows that the average of the error between the actual moving distance and the estimated distance is 1.84%.

• 한국소음진동공학회논문집
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• 제18권12호
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• pp.1229-1236
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• 2008

A set of modal parameters of a stay-cable have been extracted fi:on a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권2호
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• pp.120-133
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• 2008

This paper presents a novel approach for facial motion tracking and facial expression cloning to create a realistic facial animation of a 3D avatar. The exact head pose estimation and facial expression tracking are critical issues that must be solved when developing vision-based computer animation. In this paper, we deal with these two problems. The proposed approach consists of two phases: dynamic head pose estimation and facial expression cloning. The dynamic head pose estimation can robustly estimate a 3D head pose from input video images. Given an initial reference template of a face image and the corresponding 3D head pose, the full head motion is recovered by projecting a cylindrical head model onto the face image. It is possible to recover the head pose regardless of light variations and self-occlusion by updating the template dynamically. In the phase of synthesizing the facial expression, the variations of the major facial feature points of the face images are tracked by using optical flow and the variations are retargeted to the 3D face model. At the same time, we exploit the RBF (Radial Basis Function) to deform the local area of the face model around the major feature points. Consequently, facial expression synthesis is done by directly tracking the variations of the major feature points and indirectly estimating the variations of the regional feature points. From the experiments, we can prove that the proposed vision-based facial expression cloning method automatically estimates the 3D head pose and produces realistic 3D facial expressions in real time.

• 한국컴퓨터그래픽스학회논문지
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• 제29권3호
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• pp.59-67
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• 2023

본 논문은 몸체 3D 스캔과 모션 캡처 장비를 활용한 3D 애니메이션 형태의 바디 프로필을 제안한다. 사용자는 미리 정해진 몇 개의 포즈에 대하여 3D 스캔을 수행함으로써 애니메이션 형태를 가진 자신만의 바디 프로필을 제작할 수 있다. 이를 위하여 일련의 포즈를 수행하는 템플릿 애니메이션을 모션 캡처를 통하여 획득하였고, 사용자로부터 획득된 3D 스캔 데이터를 애니메이션의 각 정점 포즈에 포즈 공간 디포머(Pose-space deformer)를 통하여 매핑시켰다. 이를 통하여 만들어진 3D 애니메이션 형태의 바디 프로필은 기존의 정적인 2D 이미지나 3D 스캔데이터보다 사용자에게 더 큰 만족도를 줄 수 있음을 확인할 수 있다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.461-463
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• 2012

본 연구는 실시간 영상에서 정면 얼굴을 가지고 있는 이미지를 탐지하는 방법에 대한 것이다. 모든 프레임마다 얼굴 인식 등의 연산을 수행한다면 계산량과 시간이 문제이다. 우리가 제안하는 방법은 동일인이 등장하는 영상 중 동일한 얼굴을 추적하여 움직임의 차이를 이용하여 정면 이미지를 판단하는 것이다. Gaussian Mixture Model 과 Motion template 을 이용하였으며, 실험을 통해 도출된 결과는 제안 알고리즘의 유용성을 어느 정도 증명할 수 있었다.

• Journal of Acupuncture Research
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• 제31권4호
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• pp.11-19
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• 2014

Objectives : Acupuncture manipulation, a kind of sophisticated hand movements, has been considered a fundamental skill for acupuncture practice. In this study, we aimed to develop acupuncture manipulation education system(AMES) using visual feedback of acupuncture manipulation. We also investigated whether or not acupuncture practice-$na{\ddot{i}}ve$ students could enhance their acupuncture manipulation skills after AMES training. Methods : Using AMES and motion sensor, we visualized a time-series motion template(intended motion) and participant's own motion(actual motion) manipulating an acupuncture needle. Ten students were trained with complex lifting/thrusting techniques for 8 training trials. We compared the motion pattern error of the students between the first and the last trials. Results : In our pilot experiment, half of the participants showed significantly improved manipulation skills in complex lifting/thrusting techniques after training with AMES which is developed in this study, while the other half of the participants did not show significant improvements. Conclusions : The AMES could be useful in acupuncture-manipulation training for students. Our findings suggest that novice can improve sophisticated hand movement for acupuncture manipulation with sensorimotor learning using visual feedback.