• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.10B
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• pp.1390-1398
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• 2001

시선 위치 추적이란 사용자가 모니터 상의 어느 지점을 쳐다보고 있는 지를 파악해 내는 기술이다. 시선 위치를 파악하기 위해 본 논문에서는 2차원 카메라 영상으로부터 얼굴 영역 및 얼굴 특징점을 추출한다. 초기에 모니터상의 3 지점을 쳐다볼 때 얼굴 특징점들은 움직임의 변화를 나타내며, 이로부터 카메라 보정 및 매개변수 추정 방법을 이용하여 얼굴특징점의 3차원 위치를 추정한다. 이후 사용자가 모니터 상의 또 다른 지점을 쳐다볼 때 얼굴 특징점의 변화된 3차원 위치는 3차원 움직임 추정방법 및 아핀변환을 이용하여 구해낸다. 이로부터 변화된 얼굴 특징점 및 이러한 얼굴 특징점으로 구성된 얼굴평면이 구해지며, 이러한 평면의 법선으로부터 모니터 상의 시선위치를 구할 수 있다. 실험 결과 19인치 모니터를 사용하여 모니터와 사용자까지의 거리를 50∼70cm정도 유지하였을 때 약 2.08인치의 시선위치에러 성능을 얻었다. 이 결과는 Rikert의 논문에서 나타낸 시선위치추적 성능(5.08cm 에러)과 비슷한 결과를 나타낸다. 그러나 Rikert의 방법은 모니터와 사용자 얼굴까지의 거리는 항상 고정시켜야 한다는 단점이 있으며, 얼굴의 자연스러운 움직임(회전 및 이동)이 발생하는 경우 시선위치추적 에러가 증가되는 문제점이 있다. 동시에 그들의 방법은 사용자 얼굴의 뒤 배경에 복잡한 물체가 없는 것으로 제한조건을 두고 있으며 처리 시간이 상당히 오래 걸리는 문제점이 있다. 그러나 본 논문에서 제안하는 시선 위치 추적 방법은 배경이 복잡한 사무실 환경에서도 사용가능하며, 약 3초 이내의 처리 시간(200MHz Pentium PC)이 소요됨을 알 수 있었다.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.163-172
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• 2010

The free viewpoint video delivers an active contents where users can see the images rendered from the viewpoints chosen by them. Its applications are found in broad areas, especially museum tour, entertainment and so forth. As a new free-viewpoint application, this paper presents a stereoscopic free-viewpoint TIP (Tour Into Picture) where users can navigate the inside of a single image controlling a virtual camera and utilizing depth data. Unlike conventional TIP methods providing 2D image or video, our proposed method can provide users with 3D stereoscopic and free-viewpoint contents. Navigating a picture with stereoscopic viewing can deliver more realistic and immersive perception. The method uses semi-automatic processing to make foreground mask, background image, and depth map. The second step is to navigate the single picture and to obtain rendered images by perspective projection. For the free-viewpoint viewing, a virtual camera whose operations include translation, rotation, look-around, and zooming is operated. In experiments, the proposed method was tested eth 'Danopungjun' that is one of famous paintings made in Chosun Dynasty. The free-viewpoint software is developed based on MFC Visual C++ and OpenGL libraries.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.123-128
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• 2017

This paper deals with performing missions through autonomous navigation using camera and other sensors. Extracting pose of the car is necessary to navigate safely within the given road. Homography is used to find it. Color image is converted into grey image and thresholding and edge is used to find control points. Two control ponits are converted into world coordinates using homography to find the angle and position of the car. Color is used to find traffic signal. It was confirmed that the given tasks performed well through experiments.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.193-196
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• 2013

Purpose: This study was investigated to find out a useful instrument instead of direct ophthalmoscope for ocular photostress recovery time (PSRT) test. Methods: The PSRT test was performed using direct ophthalmoscope, trans illuminator, pen light, and camera flash for 48 subjects (average age 22.88 years, 96 eyes) who were corrected to 0.8~1.2 of visual acuity. Results: Each mean of PSRT measured by direct ophthalmoscope, trans illuminator, pen light, and camera flash was $27.90{\pm}18.40$ sec, $23.73{\pm}12.99$ sec, $21.31{\pm}15.57$ sec, and $18.98{\pm}11.64$ sec, respectively. The difference of PSRT between the eyes corrected more than 1.0 and the other eyes corrected under 1.0 of visual acuity was not found significantly. And there was no difference between dominant eyes and nondominant eyes of PSRT. Conclusions: Though the nearest instrument to direct ophthalmoscope was trans illuminator, pen light and camera flash could be the useful instruments for PSRT test.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.3
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• pp.101-108
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• 2019

Due to recent improvements in computer processing speed and image processing technology, researches are being actively carried out to combine information from camera with existing GNSS (Global Navigation Satellite System) and dead reckoning. In this study, developed a vision-based positioning assistant algorithm to estimate the distance to the object from stereo images. In addition, GNSS/on-board vehicle sensor/vision based positioning algorithm is developed by combining vision based positioning algorithm with existing positioning algorithm. For the performance analysis, the velocity calculated from the actual driving test was used for the navigation solution correction, simulation tests were performed to analyse the effects of velocity precision. As a result of analysis, it is confirmed that about 4% of position accuracy is improved when vision information is added compared to existing GNSS/on-board based positioning algorithm.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1025-1026
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• 2008

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The micro-controller calculates the 3D position of the markers using only the measured intensity and the 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system has the advantages of the compact size, the low cost, the easy installation, and the high frame rates to be suitable for high speed motion tracking in games.

• The Journal of Korea Robotics Society
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• v.11 no.4
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• pp.226-234
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• 2016

In this study, a model-referenced underwater navigation algorithm is proposed for high-precise underwater navigation using monocular vision near underwater structures. The main idea of this navigation algorithm is that a 3D model-based pose estimation is combined with the inertial navigation using an extended Kalman filter (EKF). The spatial information obtained from the navigation algorithm is utilized for enabling the underwater robot to navigate near underwater structures whose geometric models are known a priori. For investigating the performance of the proposed approach the model-referenced navigation algorithm was applied to an underwater robot and a set of experiments was carried out in a water tank.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.716-718
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• 2016

본 연구는 차량이 정차해 있거나 차량을 후진하여 이동시키고자 할 때 운전자의 시야에 보이지 않는 차량의 후방 좌 우측에서 접근하는 차량 또는 보행자와 같은 움직임을 가지는 물체와 충돌을 회피하기 위한 방법에 관한 연구이다. 해당 물체와 충돌을 피하기 위해서는 후방의 영상을 획득하여 움직임을 가진 물체를 식별하고 차량과의 거리, 속도 및 충돌 가능성을 계산할 수 있어야 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.637-640
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• 2022

3차원 물체의 탐지와 자세 추정은 실내외 환경에서 장면 이해, 로봇의 물체 조작 작업, 자율 주행, 증강 현실 등과 같은 다양한 응용 분야들에서 공통적으로 요구되는 매우 중요한 시각 인식 기술이다. 깊이 지도를 요구하는 기존 연구들과는 달리, 본 논문에서는 RGB 컬러 영상만을 이용해 미지의 물체들, 즉 3차원 CAD 모델을 가지고 있지 않은 새로운 물체들을 탐지해내고, 이들의 자세를 추정해낼 수 있는 새로운 신경망 모델을 제안한다. 제안 모델에서는 최근 빠른 속도로 발전하고 있는 깊이 추정 기술을 이용함으로써, 깊이 측정 센서 없이도 물체 자세 추정에 필요한 깊이 지도를 컬러 영상에서 구해낼 수 있다. 본 논문에서는 벤치마크 데이터 집합을 이용한 실험을 통해, 제안 모델의 유용성을 평가한다.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.117-122
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• 2010

Purpose: The purpose of this study was to measure the active force of extraocular muscles on mono- and binocular movements for 62 healthy koreans (male: 29, female: 33). Methods: The force of adduction, abduction, elevation and depression, of right and left eye on monocular movement were tested with horizontal moving distance based on corneal limbus and the force of superior oblique muscle and inferior oblique muscle on binocular movement were measured with vertical moving distance between corneal limbus. The distances were obtained by high resolution digital image processing. Results: At monocular movements of tested subjects. the power of abduction, adduction, elevation and depression of right and left eye were (male) 9.35 nun, 9.75 mm, (female) 9.02 mm, 9.52 mm, (male) 10.23 mm, 10.16 mm, (female) 10.17 mm, 10.07 mm, (male) 7.01 mm,6.91 mm, (female) 6.98 mm, 6.64 mm, (male) 7.52 mm, 6.82 mm, (female) 7.52 mm, 6.67 mm, respectively. The active force of binocular movements were 54.8% hyperergasia and 45.1% hypergasia/67.7% hyperergasia and 32.2% hypergasia with inferior oblique muscle, 64.5% hyperergasia and 35.5% hypergasia/58.1% hyperergasia and 41.9% hypergasia with superior oblique muscle, respectively. Conclusions: The force of horizontal movement was higher than vertical movement. The value of adduction was higher than abduction on horizontal movement, and the value of depression was higher than elevation on vertical movement. In the both of inferior and superior oblique muscle, the ratio of hyperergasia was higher than that of hypergasia.