• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.43-51
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• 2010

Speed, accuracy and smoothness are the important properties of pan-tilt camera. In the case of a high ratio zoom lens system, low vibration characteristic is a crucial point in driving pan-tilt mechanism. In this paper, a novel micro-stepping controller with a function of reducing vibration was designed using field programmable gate arrays (FPGA) technology for high zoom ratio pan-tilt camera. The proposed variable reference current (VRC) control scheme reduces vibration decently and optimizing coil current in order to prevent the step motor from occurring missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378kpps micro-step driving, and increase maximum acceleration in motion profiles.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.931-933
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• 2005

감시 시스템에서 많이 사용되는 팬틸트줌(Pan-Tilt-Zoom) 카메라로 객체 검출과 추적을 할 때 카메라를 섬세하게 제어하는 것이 중요하다. 본 논문은 팬틸트줌 카메라를 이용하여 얼굴을 검출 및 추적하는 감시 시스템 구성과 카메라 제어 방법을 제안한다. 얼굴 검출을 위해서 P. Viola가 제안한 Haar-like feature를 이용한 빠른 객체 검출방법을 이용하고 얼굴 추적을 위해서 CAMSHIFT와 AAM을 이용하여 얼굴 추적과 얼굴 특징 정보 추출이 가능한 감시 시스템 구현을 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3C
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• pp.271-277
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• 2010

In this paper we proposed an object tracking system using PTZ camera. Once the target object is detected, the CAMshift tracking algorithm focuses it in realtime mode as the camera is moving accordingly. Since the CAMShift algorithm takes into account the object size, zoom related tracking is possible. We used the spherical coordinate to gain pan and tilt position. The position information is used to set the center of target object in the middle of the image by using the PTZ protocol and RS-485 interface. Our system showed excellent experimental results in various environments.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.333-349
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• 2005

In this paper, we propose a real tine moving object tracking system based on block-based image processing technique and human visual processing. The system has two nun features. First, to take advantage of the merit of the biological mechanism of human retina, the system has two cameras, a CCD(Charge-Coupled Device) camera equipped with wide angle lens for more wide scope vision and a Pan-Tilt-Zoon tamers. Second, the system divides the input image into a numbers of blocks and processes coarsely to reduce the rate of tracking error and the processing time. Tn an experiment, the system showed satisfactory performances coping with almost every noisy image, detecting moving objects very int and controlling the Pan-Tilt-Zoom camera precisely.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.55-63
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• 2008

This paper presents a panorama background generation and object tracking technique using a Pan-Tilt-Zoom camera. The proposed method estimates local motion vectors rapidly using phase correlation matching at the prespecified multiple local regions, and it makes minimized estimation error by vector quantization. We obtain the required image patches, by estimating the overlapped region using local motion vectors, we can then project the images to cylinder and realign the images to make the panoramic image. The object tracking is performed by extracting object's motion and by separating foreground from input image using background subtraction. The proposed PTZ-based object tracking method can efficiently generated a stable panorama background, which covers up to 360 degree FOV The proposed algorithm is designed for real-time implementation and it can be applied to many commercial applications such as object shape detection and face recognition in various surveillance video systems.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.764-769
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• 2003

The paper introduces a development result for displacement measurement system of multiple moving objects based on image processing technique. The image processing method adopts inertia moment theory for obtaining the centroid of the targets and basic processing algorithms of gray, binary, closing, labeling and etc. To get precise displacement measurement in spite of multiple moving targets, a CCD camera with zoom is used and the position of camera is changed by a pan/tilt system. The fiducial marks on the fixed positions are used as the sensing points for the image processing to recognize the position errors in directions of X -Y coordinates. The precise alignment device is pan /tilt of X - Y type and the pan/tilt is controlled by DC servomotors which are driven by 80c196kc microprocessor based controller. The centers of the fiducial marks are obtained by a inertia moment method. By applying the developed precise position control system for multiple targets, the displacement of multiple moving targets are detected automatically and are stored in the database system in a real time. By using database system and internet, displacement data can be confirmed at a great distance and analyzed. The developed system shows the effectiveness such that it realizes the precision about 0.12mm in the position control of X -Y coordinates.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.8
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• pp.673-679
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• 2004

In this paper, we develop the displacement measurement system of multiple moving objects based on image processing techniques. The image processing method adopts inertia moment theory for obtaining the centroid measurement of the targets and basic processing algorithm of gray, binary, closing, labeling and so on. To get precise displacement measurement in spite of multiple moving targets, a CGD camera with zoom is used and the position of camera is changed by a pan/tilt system. The fiducial marks on the fixed positions are used as the sensing points for the image processing to recognize the position errors in direction of XY-coordinates. The precise alignment device is pan/tilt of XY-type and the pan/tilt is controlled by DC servomotors which are driven by a microprocessor. Morover, the centers of fiducial marks are obtainted by an inertia moment method. By applying the developed precise position control system for multiple targets, the displacement of multiple moving targets are detected automatically and are also stored in the database system in a real time. By using database system and internet, the displacement datum can be confirmed at a great distance and analyzed. Finally, the effectiveness of developed system is shown in experimental results and realized the precision about 0.12[mm] in the position control of XY-coordinates.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.77-82
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• 1999

Information about camera operating such as zoom, focus, pan, tilt and tracking is useful not only for efficient video coding, but also for content-based video representation. A camera operating parameter measurement system designed specifically for these applications is therefore developed. This system, implemented in real time and synchronized with the video signal, measures the precise camera operating parameters. We calibrated the camera lens using a camera model that accounts for redial lens distortion. The system is then applied to infer image motion from pan and tilt operating parameters. The experimental results show that the inferred motion coincides with the actual motion very well, with an error of less than 0.5 pixel even for large motion up to 80 pixels.

• Journal of Korea Multimedia Society
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• v.4 no.6
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• pp.510-517
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• 2001

In this paper, we implement a real time speaker close-up system using lip motion information from input images having some people. After detecting a speaker from input moving pictures through one color CCD camera, the other camera closes up the speaker by using lip motion information. The implemented system detects a face and lip area of each person by means of a facial color and a morphological information, and then finds out a speaker by using lip area variation. A PTZ(Pan/Tilt/Zoom) camera is used in order to close up the detected speaker and it is controlled by RS-232C serial port. Consequently, we can exactly detect a speaker in input moving pictures including more than three people.

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.63-71
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• 2003

In sport programs, real-time virtual imaging system come into notice for new technology which can compose information like team logos, scores. distances directly on playing ground, so it can compensate for the defects of general character generator. In order to synchronize graphics to camera movements, generally two method is used. One is for using sensors attached to camera moving axis and the other is for analyzing camera video itself. KBS technical research institute developed real-time sensor-based virtual imaging system 'VIVA', which uses four sensors on pan, tilt, zoom, focus axis and controls virtual graphic camera in three dimensional coordinates in real-time. In this paper, we introduce our system 'VIVA' and it's technology. For accurate camera tracking we calculated view-point movement occurred by zooming based on optical principal point variation data and we considered field of view variation not only by zoom but also by focus. We developed our system based on three dimensional graphic environment. so many useful three dimensional graphic techniques such as keyframe animation can be used. VIVA was successfully used both in Busan Asian Games and 2002 presidential election. We confirmed that it can be used not only in the field but also in the studio programs in which camera is used within more close range.