• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.762-766
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• 2003

In this paper, we present a new approach to solve the problem of estimating the camera 3-D location and orientation from a matched set of 3-D model and 2-D image features. An iterative least-square method is used to solve both rotation and translation simultaneously. Because conventional methods that solved for rotation first and then translation do not provide good solutions, we derive an error equation using roll-pitch-yaw angle to present the rotation matrix. To minimize the error equation, Levenberg-Marquardt algorithm is introduced with uniform sampling strategy of rotation space to avoid stuck in local minimum. Experimental results using real images are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.793-797
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• 2003

In this paper, we present a self-localization method for mobile robots using vertical line features of indoor environment. When a 2D map including feature points and color information is given, a mobile robot moves to the destination, and acquires images by one camera from the surroundings having vertical line edges. From the image, vertical line edges are detected, and pattern vectors meaning averaged color values of the left and right region of each line segment are computed. The pattern vectors are matched with the feature points of the map using the color information and the geometrical relationship of the points. From the perspective transformation of the corresponded points, nonlinear equations are derived. Localization is carried out from solving the equations by using Newton's method. Experimental results show that the proposed method using mono view is simple and applicable to indoor environment.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.89-92
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• 2001

In this paper, we propose a new approach for tracking a moving object in moving image sequences using active contour models and optical flow. In our approach object segmentation is achieved by active contours, and object tracking is done by motion estimation based on optical flow. To get more dynamic characteristics, Lagrangian dynamics combined to the active contour models. For the optical flow computation, a method, which is based on Spatiotempo-ral Energy Models, is employed to perform robust tracking under poor environments. A prototype real tracking system has been developed and applied to a contents-based video retrieval systems.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.267-270
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• 2000

In this paper, we describe implementation of efficient wavelet image compression and decompression system for DVR(Digital Video Recoder). We used various methods to remove time redundancy, spatial redundancy and statistical redundancy of video camera inputs. Motion detection, wavelet transform, RLC(Run Length Coding) and huffman coding techniques are combined for efficient compression / decompression.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1261-1264
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• 2005

In this paper, a new intelligent moving target tracking and surveillance system basing on the pan/tilt-embedded stereo camera system is suggested and implemented. In the proposed system, once the face area of a target is detected from the input stereo image by using a YCbCr color model and then, using this data as well as the geometric information of the tracking system, the distance and 3D information of the target are effectively extracted in real-time.

• Korean Journal of Computational Design and Engineering
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• v.16 no.6
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• pp.437-448
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• 2011

A robotic spatial augmented reality (RSAR) system combines a robotics technology with a spatial augmented reality system (SAR) where cameras are used to recognize real objects and projectors augment information and user interface directly on the surface of the recognized objects, rather than relying on handheld display devices. Moreover, a robotic module is actively used to discover and utilize the context of users and environments. The control of a RSAR system involves several issues from different technical fields such as classical inverse kinematics of motors where projector-camera pairs are mounted, inverse projection problems to find appropriate internal/external parameters of projectors and cameras, and image warping in graphics pipeline to compensate the kinematic constraints. In this paper, we investigate various control issues related to a RSAR system and propose basic approaches to handle them, specially focused on the prototype RSAR system developed in ETRI.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.199-200
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• 2016

스포츠 산업 응용 분야에서 공의 실시간 품질검사는 산업 생산성과 경쟁력 견지에서 중요한 이슈이다. 컴퓨터 비전 기반 자동 품질검사는 이 문제를 해결하는 하나의 방법이다. 머신 비전 시스템은 품질관리 및 산업프로세스의 실시간 피드백을 주어, 물리적인 제한과 사람의 주관적인 판단을 극복할 수 있다. 컴퓨터비전 기반 시스템에서 디지털카메라에서 취득되는 디지털이미지는 주로 24-비트 컬러이미지이다. 이처럼 많은 레벨을 가지는 이미지분석은 복잡한 이미지 처리기법을 필요로 한다. 그러나 실시간 애플리케이션에서, 한 부분은 실시간으로 검사되어져야 한다. 이 논문에서는 최적의 임계값을 사용하여 스포츠산업계의 산업요구 사항을 만족하는 골프공 품질검사 시스템을 개발하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.330-335
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• 2015

Approximately 23% of traffic accidents appear to be caused by drowsiness while driving. This fact shows that drowsy driving is a big factor in many traffic accidents. Therefore, the development of a drowsiness checking system is necessary to prevent drowsy driving. In this paper, we analyse the changes of the histogram of eye region images which are acquired using a CCD camera. We develop a drowsiness checking system using this histogram change information. The experimental results show that our proposed method enhances the accuracy of checking drowsiness by nearly 98%, and can be used to prevent vehicle accidents due to the drowsiness of a driver.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.763-774
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• 2015

Hand posture recognition has been a wide region of applications in Human Computer Interaction and Computer Vision for many years. The problem arises mainly due to the high dexterity of hand and self-occlusions created in the limited view of the camera or illumination variations. To remedy these problems, a hand posture recognition method using 3-D point cloud is proposed to explicitly utilize 3-D information from depth maps in this paper. Firstly, hand region is segmented by a set of depth threshold. Next, hand image normalization will be performed to ensure that the extracted feature descriptors are scale and rotation invariant. By robustly coding and pooling 3-D facets, the proposed descriptor can effectively represent the various hand postures. After that, SVM with Gaussian kernel function is used to address the issue of posture recognition. Experimental results based on posture dataset captured by Kinect sensor (from 1 to 10) demonstrate the effectiveness of the proposed approach and the average recognition rate of our method is over 96%.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.733-737
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• 2001

Heat generated from the electronic parts in PDP is undesirable physical properties. To attain optimal arrangement of the electronic parts in PDP, thermal flows in PDP should be analyzed. PIV measurement has been made to quantify the characteristics of the inner flows and outer flows of an actual PDP. The quantity of heat flux from PDP has been estimated using the PIV results. Measurement system consists of Ar-ion laser, CCD camera and an image grabber installed on a host computer.