• Proceedings of the KSME Conference
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• 2008.11a
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• pp.768-772
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• 2008

Various scanning systems have been studied in many industrial areas to acquire a range data or to reconstruct an explicit 3D model. Currently optical technology has been used widely by virtue of noncontactness and high-accuracy. In this paper, we describe a 3D laser scanning system developped to reconstruct the 3D surface of a large-scale object such as a curved-plate of ship-hull. Our scanning system comprises of 4ch-parallel laser vision modules using a triangulation technique. For multi laser vision, calibration method based on least square technique is applied. In global scanning, an effective method without solving difficulty of matching problem among the scanning results of each camera is presented. Also minimal image processing algorithm and robot-based calibration technique are applied. A prototype had been implemented for testing.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.535-540
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• 2000

The objective of the present study is to visualize the pulsatile flow fields by using three-dimensional computer simulation and the PIV system. A closed flow loop system was built for the steady and unsteady experiments. The Harvard pulsatile pump was used to generate the pulsatile pressure and velocity waveforms. Conifer powder as the tracing particles was added to water to visualize the flow field. Two consecutive particle images were captured by a CCD camera for the image processing. The cross-correlation method in combination with the moving searching area algorithm was applied for the image processing of the flow visualization. The pulsatile flow fields were visualized effectively by the PIV system in conjunction with the applied algorithm. The range validation and the area interpolation methods were used to obtain the final velocity vectors with high accuracy. The finite volume predictions were used to analyze three-dimensional flow patterns in the bifurcation model. The results of the PIV experiment and the computer simulation are in good agreement and the results show the recirculation zones and formation of the paired secondary flow distal to the apex of the bifurcated model. The results also show that the branch flow is pushed strongly to the inner wall due to the inertial force effect and helical motions are generated as the flow proceeds toward the outer wall.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.75-77
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• 2012

In this paper, We proposed that real-time pupil detection using local binarization at each region of eyes in image. In image obtained a single low-resolution web-camera, we detect a region of face using haar-like feature and then detect each region of eyes depending upon the rate of width and height of region of face respectively. In each region of eyes, we detect the pupil after local preprocessing and binarizing. This pupil detection can be variously used for HCI(Human-Computer Interface) systems.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1367-1376
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• 1998

In this paper we propose an real time marker detection algorithm for motion analysis both in 2 dimensions and 3 dimensions with CCD camera and rfame grabber only which has no image processor. The main algorithm consists of the following 3 algorithms; 1) the tracing algorithm that makes it possible to predict the expected marker location by narrowing the searching boundary, 2) the searching algorithm that detects the marker in the expected boundary using Ad-hoc previous screen search technique, tornado search method rotate diagonal search method search technique, 3) the algorithm that finds the central point of the detected marker. We try to narrow the searching boundary for real time processing. Also, it is able to find the central point of the detected marker much faster than typical contour tracing algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.468-471
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• 2008

이 논문은 응급상황을 인식하기 위하여 어안렌즈를 통해 획득된 영상을 이용하여 기절 동작을 인식하는 방법을 제안한다. 거실의 천장 중앙에 위치한 어안렌즈(fish-eye lens)를 장착한 카메라로부터 화각이 170인 RGB 컬러 모델의 어안 영상을 입력 받은 뒤, 가우시안 혼합 모델 기반의 적응적 배경 모델링 방법을 이용하여 동적으로 배경 영상을 갱신한다. 입력 영상의 평균 밝기를 구하고 평균 밝기가 급격하게 변화하지 않도록 영상 픽셀을 보정한 뒤, 입력 영상과 배경 영상과 차이가 큰 픽셀을 찾음으로써 움직이는 객체를 추출하였다. 그리고 연결되어 있는 전경 픽셀 영역들의 외곽점들을 추적하여 타원으로 매핑하고 움직이는 객체 영역의 형태를 단순화하였다. 이 타원을 추적하면서 어안 렌즈 영상을 투시 영상으로 변환한 다음 타원의 크기 변화, 위치 변화, 이동 속도 정보를 추출하여 이동과 정지 및 움직임이 기절동작과 유사한지를 판단하도록 하였다. 본 논문에서는 실험자로 하여금 기절동작, 걷기 동작, 앉기 동작 등 여러 동작을 취하게 하고 기절 동작 인식을 실험하였다. 실험 결과 어안 렌즈 영상을 그대로 사용하는 것보다 투시 영상으로 변환하여 타원의 크기변화, 위치변화, 이동속도 정보를 이용하는 것이 높은 인식률을 보였다.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.237-241
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• 2011

Stable operation of an industry crane becomes more important as current industry facilities become larger and operate at higher speeds. This paper proposes implementing a system for monitoring moving objects within safety lines of an industry crane by camera. The cost of implementing such a system is low, since it requires only a webcam and notebook computer. The detection algorithm of moving objects uses the feature extraction method by image differential histograms. The proposed system is robust to variations in the weather and environment. The area of the inside safety lines is considered and shadow removal algorithm is used for good performance of the system. The system is valuable for practical applications in the industry.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.173-180
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• 2005

This paper proposes an effective algorithm that combines both the stereo matching and the marching cube algorithm. By applying the stereo matching technique to an image obtained from various angles, 3D geometry data are acquired, and using the camera extrinsic parameter, the images are combined. After reconstructing the combined data into mesh using the image index, the normal vector equivalent to each point is obtained and the mesh smoothing is processed. This paper describes the successive processes and techniques on the 3D mesh reconstruction, and by proposing the intermediate iso- surface algorithm. Therefore it improves the 3D data instability problem caused when using the conventional marching cube algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.527-532
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• 2013

Depth estimation is an essential factor for robot vision, 3D scene modeling, and motion control. The depth estimation method is based on focusing values calculated in a series of images by a single camera at different distance between lens and object. In this paper, we proposed a relative depth estimation method using focus measure. The proposed method is implemented by focus value calculated for each image obtained at different lens position and then depth is finally estimated by considering relative distance of two patterns. We performed various experiments on the effective focus measures for depth estimation by using various patterns and their usefulness.

• Journal of Biomedical Engineering Research
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• v.13 no.2
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• pp.165-174
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• 1992

Compliance mismatch across an end-to-end anastomosis was measured In the In vitro experimental setup. A 35mm camera was used and Image process was done in Gould/ DeAnza Image processor. The results showed that compliances of Penrose tubing and synthetic PTFE grafts were In good agreement with the previously reported In vivo data. PTFE grafts exhibited a nonlinear behavior with compliance decreasing with Increasing transmural pressure, whereas the compliance of the Penrose tubing remained relatively constant within the range of the pressures in which data were obtained. The lumen cross sections at the anastomosis were affected by the suture and the mismatch In compliance between the Penrose tubing and vascular grafts. The varla~lons In the lumen dtameter at the anastomosis was more pronounced with increasing transmural pressures. From the present study, it was clearly demonstrated that the compliance of prosthetic grafts Is much lower than that of the arteries. In addition to the hemodynamlc consequences, compliance mismatch across the anastomosis has been known to lead to Increased anastomotlc and suture stresses with resultant suture line dehlscence and false aneurysm formation. Thus, there are good hemodynamic reasons to suppose that Introduction of a less compliant arterial graft Into the arterial circulation wlll be damaging and that grafts should be made to match the elastic behavior of their host arteries as closely possible.

• Journal of radiological science and technology
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• v.9 no.1
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• pp.137-143
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• 1986

This study was undertaken to analyze the changes of radiographical image in avian (chicken) by using scanner and ${\gamma}-camera$ with $Tc^{99m}-MDP$. Experiment was aimed also to observe the changes of calcium, phosphorus and alkaline phosphatase activity in serum after experimental fracture. The results obtained are summerized as follows. 1. 10 chickens grown 6 weeks were scanned within 48 hours after experimental fracture, showed localized increase in uptake. The earlist increased local uptake was observed after 7 hours from experimental fracture at the fracture site. 2. Serum alkaline phosphatase level was increasing continuously during the fracture healing process in comparison with control group and serum alkaline phosphatase activity showed a peak after 2 weeks following the fracture. 3. The change of Ca. amount in serum trended to decrease from 1st day after fracture and it was in the lowest level at the 7 day's group following the fracture. 4. Serum phosphorus level trended to increase after fracture and it was in the highest level at the 7 day's group and showed similar level in comparison with control group.