• 제어로봇시스템학회논문지
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• 제21권11호
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• pp.989-995
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• 2015

Due to the recent increase of the importance and demand of security services, the importance of a surveillance monitor system that makes an automatic security system possible is increasing. As the market for surveillance monitor systems is growing, price competitiveness is becoming important. As a result of this trend, surveillance monitor systems based on an embedded system are widely used. In this paper, an object detection algorithm based on an embedded system for a surveillance monitor system is introduced. To apply the object detection algorithm to the embedded system, the most important issue is the efficient use of resources, such as memory and processors. Therefore, designing an appropriate algorithm considering the limit of resources is required. The proposed algorithm uses two background models; therefore, the embedded system is designed to have two independent processors. One processor checks the sub-background models for if there are any changes with high update frequency, and another processor makes the main background model, which is used for object detection. In this way, a background model will be made with images that have no objects to detect and improve the object detection performance. The object detection algorithm utilizes one-dimensional histogram distribution, which makes the detection faster. The proposed object detection algorithm works fast and accurately even in a low-priced embedded system.

• 한국게임학회 논문지
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• 제2권1호
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• pp.49-54
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• 2002

In this paper we propose the methodology for 3D background image construction in computer games. This methodology was developed based on TIP (Tour Into the Picture) using a vanishing line Proposed by Kang et at. The methodology Proposed in this study can simply implement a 3D background for a computer game with a background model which is very complex or based on a real picture. Compared to the graphics technologies generally used, the proposed methodology does not need the process of modeling elaborate 3D information of a background, and hence can display the background even on a low grade personal computer using a small reference image. TIP technology was successfully applied to the implementation of a background model for a computer game and was found to be appropriate especially for real time games.

• 한국컴퓨터정보학회논문지
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• 제13권6호
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• pp.117-125
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• 2008

실시간 입력영상 분석에 의한 객체 추적은 사람의 시각이 요구되는 여러 응용분야에서 관심 있는 주제 중 하나이다. 객체를 추적하기 위해서는 객체 검지가 선행 된다. 실외 환경에서 안정적인 객체 검지 성능의 달성은 태양의 남중고도 변화에 따른 빛과 그림자의 변화, 자연현상 등의 다양한 환경변화를 수용하는 효과적인 적응적 배경영상 생성 방법이 필요하다. 본 논문에서는 불법 주정차 무인 자동 단속 응용에 효과적으로 활용 가능한 환경 변화에 강건한 적응적 배경영상 생성과 이동 객체의 정지 여부를 판단하는 방법을 제안한다. 본 논문에서 제안하는 적응적 배경영상 생성 방법은 먼저, 초기 배경영상을 생성 후, 생성된 초기 배경영상과 입력영상 프레임 간의 차연산 기법으로 객체를 검지하고, 객체 검지 결과로 이동객체를 추적한다. 또한 객체 검지의 결과로부터 얻어진 객체영역을 제외한 입력영상의 영역을 활용하여 배경영상을 갱신한다. 이후 갱신된 배경영상과 입력영상 간의 차연산 방법으로 객체 검지를 수행하고 이후, 추적, 객체영역을 제외한 영역으로 배경영상 갱신의 과정을 반복한다. 실험에서는 제안방법을 가변하는 실제 도로환경에 적용하여 효과적으로 객체 검지가 가능함과 서행하는 객체 또한 효과적으로 검지됨을 보이고 이동 객체의 정지 여부를 판단할 수 있음을 보인다.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.101-108
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• 1988

In this paper the power spectrum of background EEG is estimated by the LMS PHD based on least mean square. At the power spectrum estimatiom, the stocastic process of background EEG is assumed to consist of the nonharmonic sinusoid and the white noise. In the LMS PHD the model parameters are obtained by the least mean square at optimal order which is obtained from the fact that the eigenvalue's fluctuation of autocorrelation matrix of the normal back-ground EEG is smaller at some order than at other order when the power spectrum of background EEG is esitmated by PHD. The optimal order of this model is the 6-th order when the eigenvalue's fluctuation of autocorrelation matrix of background EEG is considered. The estimation results are with compared the results from the Maximum Entropy Spectral Estimation and Pisarenko Harmonic Decomposition. From the comparison results. The LMS PHD is possible to estimate the power spectrum of background EEG.

• 정보학연구
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• 제10권4호
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• pp.27-39
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• 2007

Object tracking in a real time environment is one of challenging subjects in computer vision area during past couple of years. This paper proposes a method of object detection and tracking using adaptive background estimation in real time environment. To obtain a stable and adaptive background, we combine 3-frame differential method and running average single gaussian background model. Using this background model, we can successfully detect moving objects while minimizing false moving objects caused by noise. In the tracking phase, we propose a matching criteria where the weight of position and inner brightness distribution can be controlled by the size of objects. Also, we adopt a Kalman Filter to overcome the occlusion of tracked objects. By experiments, we can successfully detect and track objects in real time environment.

• 대기
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• 제23권1호
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• pp.33-37
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• 2013

In meteorology, exploitation of Kalman filter as a data assimilation system is virtually impossible due to simultaneous requirements of adjoint model and large computer resource. The other substitute of utilizing ensemble Kalman filter is only affordable by compensating an enormous usage of computing resource. Furthermore, the latter employs ensemble integration sets for evolving the background error covariance matrix by compensating the dynamical feature of the temporal evolution of weather conditions. We propose a new implementation method that works without the adjoint model by utilizing the explicit expression of the background error covariance matrix in backward evolution. It will also break a barrier in the evolution of the covariance matrix. The method may be applied with a slight modification to the real time assimilation or the retrospective analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.245-248
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• 2002

This paper has been studied a new method to update the background image of a visual surveillance system which is not stationary. In order to do this, we use another background model designed with the whole monitored images in a regular time period. By comparing each changed area computed from the two background model images and current monitored image, the areas which will be updated are decided.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.366-369
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• 2005

연속 영상을 이용하여 실시간으로 움직임 객체를 추출하고 추적하기 위해 배경분리(Background Subtraction) 기법을 주로 사용한다. 외부 환경에서는 조명의 변화, 나무의 흔들림과 같은 반복적인 움직임 그리고 급격히 움직이는 객체 등과 같이 고려해야할 많은 환경 변화 요인들이 존재한다. 이러한 외부 환경의 변화를 적응적으로 반영하여 배경을 분리할 수 있는 배경 모델로는 주로 가우시안 혼합 모델(GMM: Gaussian Mixture Model)이 적용되고 있으며, 실시간 성능 등을 개선시킨 적응적 가우시안 혼합 모델 등이 사용되고 있다. 본 논문은 개선된 적응적 가우시안 혼합 모델을 적용하고 고정된 학습률 ${\alpha}$(일반적으로 작은 값)을 사용함으로써 물체의 갑작스러운 움직임 등에 빠르게 적응하지 못하는 문제점을 해결하기 위해 가우시안 분포 수의 적응적 조절 기능과 픽셀 값을 분산을 이용하여 학습률 ${\alpha}$값을 동적으로 제어하는 방법을 제안하고 성능을 평가하였다.

• 정보처리학회논문지B
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• 제13B권5호
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• pp.515-524
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• 2006

배경추출은 비디오 감시 시스템에서 움직이는 물체를 찾는데 중요한 기술이다. 본 논문에서는 벡터 정렬을 이용한 새로운 온라인 컬러 배경 추출 방법을 제안한다. 제안된 방법에서 배경은 물체보다 발생빈도가 높다는 사실을 이용하여, 연속된 프레임의 컬러화소 값들의 벡터 미디언을 그 화소에서의 배경이라 간주한다. 본 알고리즘에서 현재 프레임의 물체는 얻어진 배경과의 거리가 문턱치보다 큰 화소들의 집합으로 구성된다. 알고리즘의 성능을 평가하기 위하여 온라인 가우시안 혼합 모델(Gaussian Mixture Model)을 이용한 다중 배경추출 방법과 비교하였으며, 비교결과 유사 또는 우월한 실험 결과를 확인하였다.

• International Journal of CAD/CAM
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• 제7권1호
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• pp.31-40
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• 2007

Reverse engineering of reliefs aims to turn an existing relief superimposed on an underlying surface into a geometric model which may be applied to a different base surface. Steps in this process include segmenting the relief from the background, and describing it as an offset height field relative to the underlying surface. We have previously considered relief segmentation using a geometric snake. Here, we show how to use this initial segmentation to estimate the background surface lying under the relief, which can be used (i) to refine the segmentation and (ii) to express the relief as an offset field. Our approach fits a B-spline surface patch to the measured background data surrounding the relief, while tension terms ensure this background surface smoothly continues underneath the relief where there are no measured background data points to fit. After making an initial estimate of relief offset height everywhere within the patch, we use a support vector machine to refine the segmentation. Tests demonstrate that this approach can accurately model the background surface where it underlies the relief, providing more accurate segmentation, as well as relief height field estimation. In particular, this approach provides significant improvements for relief concavities with narrow mouths and can segment reliefs with small internal holes.