• 로봇학회논문지
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• 제13권4호
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• pp.230-236
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• 2018

3D depth perception has played an important role in robotics, and many sensory methods have also proposed for it. As a photodetector for 3D sensing, single photon avalanche diode (SPAD) is suggested due to sensitivity and accuracy. We have researched for applying a SPAD chip in our fusion system of time-of-fight (ToF) sensor and stereo camera. Our goal is to upsample of SPAD resolution using RGB stereo camera. Currently, we have 64 x 32 resolution SPAD ToF Sensor, even though there are higher resolution depth sensors such as Kinect V2 and Cube-Eye. This may be a weak point of our system, however we exploit this gap using a transition of idea. A convolution neural network (CNN) is designed to upsample our low resolution depth map using the data of the higher resolution depth as label data. Then, the upsampled depth data using CNN and stereo camera depth data are fused using semi-global matching (SGM) algorithm. We proposed simplified fusion method created for the embedded system.

• 한국통신학회논문지
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• 제29권4C호
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• pp.514-523
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• 2004

본 논문에서는 팬/틸트가 탑재된 스테레오 카메라를 이용한 새로운 지능형 이동표적 추적감시 시스템을 제안하고 구현하였다. 제안된 시스템은 먼저, 스테레오 카메라에서 입력된 영상으로부터 YCbCr 칼라 임계치 기법을 사용하여 표적 얼굴영역을 검출한 다음, 지능형 시각 시스템에 기반한 팬/틸트 탑재형 스테레오 카메라의 능동적인 제어를 통해 표적의 다양한 변화에 관계없이 표적의 거리정보 및 3차원적 이동 정보를 실시간적으로 검출함으로써 표적의 적응적 추적감시를 수행하게 된다. 80 프레임의 스테레오 영상을 사용한 실험 결과, 이동표적에 대한 실시간적 위치정보 검출 및 적응적 추적을 확인하였으며 특히, 팬/틸트 추적후 표적 중심좌표의 수평, 수직 표준편차가 매우 작은 값인 1.82, 1.11로 각각 유지되고, 표적의 3차원적 위치 좌표값의 오차 역시 평균 0.5% 이하로 유지됨이 분석됨으로써 이를 통한 새로운 실시간 스테레오 표적 감시추적 시스템의 구현 가능성을 제시하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.768-772
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• 2009

This paper proposes a method for measurement three-dimensional trajectories of bubbles generated around a swimmer's arms from stereo high-speed camera videos. This method is based on two techniques: two-dimensional trajectory estimation in single-camera images and trajectory pair matching in stereo-camera images. The two-dimensional trajectory is estimated by block matching using similarity of bubble shape and probability of bubble displacement. The trajectory matching is achieved by a consistensy test using epipolar constraint in multiple frames. The experimental results in two-dimensional trajectory estimation showed the estimation accuracy of 47% solely by the general optical flow estimation, whereas 71% taking the bubble displacement into consideration. This concludes bubble displacement is an efficient aspect in this estimation. In three-dimensional trajectory estimation, bubbles were visually captured moving along the flow generated by an arm; which means an efficient material for swimmers to swim faster.

• 대한기계학회논문집
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• 제19권6호
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• pp.1431-1438
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• 1995

In this paper, we present a multiple-view stereo matching method in case of moving in the direction of optical axis with stereo camera. Also we analyze the obtainable depth precision to show that multiple-view stereo increases the virtual baseline with single-view stereo. This method decides candidate points for correspondence in each image pair and then search for the correct combinations of correspondences among them using the geometrical consistency they must satisfy. Adantages of this method are capability in increasing the accuracy in matching by using the multiple stereo images and less computation due to local processing. This method computes 3-D depth by averaging the depth obtained in each multiple-view stereo. We show that the resulting depth has more precision than depth obtainable by each independent stereo when the position of image feature is uncertain due to image noise. This paper first defines a multipleview stereo agorithm in case of moving in the direction of optical axis with stereo camera and analyze the obtainable precision of computed depth. Then we represent the effect of removing the incorrect matching candidate and precision enhancement with experimental result.

• 한국통신학회논문지
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• 제27권4A호
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• pp.371-382
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• 2002

현재까지 스테레오 시각 분야에서 사용된 카메라 구조는 대부분 두 광축이 평행한 시각 모델이였으나, 본 논문에서는 인간시각체계에 기반한 교차시각 스테레오 카메라 모델을 사용한다. 교차시각에서 획득한 스테레오 영상을 고정점에 대해서 4개의 영역으로 구분한다. 이러한 사분면 형태의 영역 분할 근거를 인간시각체계에서 살펴보고, 타당성을 기하학적으로 입증할 것이다. 그리고 분할된 한 쌍의 스테레오 영상으로부터 합성 영상 조각들을 형성한 후, 수정된 켑스트럼 작용과 피크 검출 알고리즘을 수행하여, 수평 및 수직 변위를 추출한다. 측정된 변위 벡터와 교차시각 스테레오 카메라 모델의 변수로부터 합성영상의 3차원 정보를 계산한다. 여러 스테레오 영상에 대해서 제안 방법의 결과가 인간시각체계처럼 고정점 부근에서 정확함을 보여주었다.

• 한국항행학회논문지
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• 제17권3호
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• pp.354-360
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• 2013

모션 및 무인 차량의 깊이 제어를 위해 스테레오 비전 분석을 하였다. 스테레오 비전에서 3차원 좌표의 깊이 정보는 스테레오 이미지 사이의 포인트를 식별한 후 삼각 측량을 통해 얻을 수 있다. 그러나 항상 몇몇 이유 때문에 삼각 측량의 오류가 발생한다. 비전 삼각 측량의 이러한 오류는 카메라의 위치와 방향에 주의하여 배열함으로써 완화 될 수 있다. 본 논문에서는 무인 차량을 위해 카메라의 최적의 위치와 방향을 결정하는 방법을 제시하였다.

• 전기학회논문지
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• 제59권8호
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• pp.1436-1440
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• 2010

In this paper, we proposed that stereo camera system using fuzzy control for moving object tracking. We extract some features of the moving object from overall image. This informations send to the PC and the PC calculate the coordinate of the object in the image frame. To make the object set in the middle of the image, the step motor should be controlled accurately and rapidly with the location information received by the PC. Then we design a fuzzy logic system for controlling stereo camera system. To verify the better performance of the proposed algorithm, we exemplified by experimental results.

• International Journal of Internet, Broadcasting and Communication
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• 제8권4호
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• pp.54-57
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• 2016

In this paper, the method for an effective and intelligent route decision of the automatic ground vehicle (AGV) using a 2D spatial map of the stereo camera system is proposed. The depth information and disparity map are detected in the inputting images of a parallel stereo camera. The distance between the automatic moving robot and the obstacle detected and the 2D spatial map obtained from the location coordinates, and then the relative distance between the obstacle and the other objects obtained from them. The AGV moves automatically by effective and intelligent route decision using the obtained 2D spatial map. From some experiments on robot driving with 480 frames of the stereo images, it is analyzed that error ratio between the calculated and measured values of the distance between the objects is found to be very low value of 1.57% on average, respectably.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.590-593
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• 2001

In this paper we describe the 6-axes robot's position determination using a stereo vision and an image based control method. When use a stereo vision, it need a additional time to compare with mono vision system. So to reduce the time required, we use the stereo vision not image Jacobian matrix estimation but depth estimation. Image based control is not needed the high-precision of camera calibration by using a image Jacobian. The experiment is executed as devide by two part. The first is depth estimation by stereo vision and the second is robot manipulator's positioning.

• 디지털산업정보학회논문지
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• 제4권1호
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• pp.25-31
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• 2008

In this paper, we propose a new method that separates background and foreground from stereo images. This method can be improved automatic target tracking system by using disparity map of the stereo vision system and background-separating mask, which can be obtained camera configuration parameters. We use disparity map and camera configuration parameters to separate object from background. Disparity map is made with block matching algorithm from stereo images. A morphology filter is used to compensate disparity error that can be caused by occlusion area. We could obtain a separated object from background when the proposed method was applied to real stereo cameras system.