• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.829-834
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• 2008

Augmented reality makes the relationship between real world and virtual world. The basic goal of an AR system is to enhance the user's perception of and interaction with the real world through supplementing the real world with 3D virtual objects that appear to coexist in the same space as the real world. ARToolkit is widely used toolkit to develop any AR application. However, to do so, a lot of researcher faced many challenges and limitations. In this paper we comprehensively review some selected challenging issues using ARToolkit to develop AR system. And then, we implement a real application for augmented text book with sounds and 3D virtual objects which we called here AR Traffic Book concerning these challenging issues by ARToolkit. In this paper our foremost approaches on the most common challenging issues such as virtual object rendering, camera calibration and tracking.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.97-104
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• 2012

Natural User Interface(NUI) technologies introduce new trends in using devices such as computer and any other electronic devices. In this paper, an augmented reality on a mobile device is implemented by using face detection, recognition and motion tracking. The face detection is obtained by using Viola-Jones algorithm from the images of the front camera. The Eigenface algorithm is employed for face recognition and face motion tracking. The augmented reality is implemented by overlapping the rear camera image and GPS, accelerator sensors' data with the 3D graphic object which is correspond with the recognized face. The algorithms and methods are limited by the mobile device specification such as processing ability and main memory capacity.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1907-1910
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• 2003

This paper describes a method of stereo image composition for mixed reality without camera calibration or complicate tracking algorithm. The proposed system tracks the panel which has blob makers, and composes virtual objects naturally using the method of texture mapping which is often used in geological computer graphics mapping when we do mapping 2D computer graphic data or man-made 2D images. The proposed algorithm makes it possible for us to compose virtual data even in the case that the panel is bent. For composing 3D object, the system uses depth information obtained from stereo image so that we do not need cumbersome procedure of camera calibration.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.215-217
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• 2021

본 논문은 3D 공간에서 사용자를 추출한 뒤, 체적 정보 분석을 통한 3D 스켈레톤(skeleton) 분석 과정을 통해 정확도 높은 다수 사용자의 위치 추적 기술에 대해 연구하였다. 이를 위하여 YOLO(You Only Look Once)를 활용하여 실시간으로 객체를 검출(Real-Time Object Detection)한 뒤 Google의 Mediapipe를 활용해 스켈레톤 추출, 스켈레톤 정규화(normalization)를 통한 스켈레톤의 크기 및 상대적 비율 계산, RGB 영상 스케일링(Scaling) 후 주요 마디 인접 영역의 RGB 색상 정보를 추출하는 방법을 통해 정확도가 개선된 높은 성능의 다중 사용자 추적 기술을 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.781-784
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• 2004

본 시스템은 어항속에 있는 물고기 움직임을 추적하기 위해 두 대의 카메라로부터 동시에 독립된 영상을 획득하고 획득된 영상을 처리하여 좌표를 얻어내고 3차원 좌표로 생성해내는 시스템이다. 제안하는 방법은 크게 두 대의 카메라로부터 동시에 영상을 획득하는 방법과 획득된 영상에 대한 처리 및 물체 위치 검출, 그리고 3차원 좌표 생성으로 구성된다. Frame grabber를 사용하여 두 개의 카메라로부터 동시에 영상을 획득하며, 3개의 연속된 프레임에 대한 차영상과 ART2(Adaptive Resonance Theory)를 이용하여 각각의 영상에서의 물고기 위치를 검출한다. 검출된 각각의 좌표를 병합하여 3차원 좌표를 생성하며, 추적 결과는 OpenGL을 이용하여 3차원으로 재생한다.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.582-584
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• 2006

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 compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 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's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.

• Journal of Internet Computing and Services
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• v.21 no.3
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• pp.113-121
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• 2020

Human Pose Estimation (HPE) which localizes the human body joints becomes a high potential for high-level applications in the field of computer vision. The main challenges of HPE in real-time are occlusion, illumination change and diversity of pose appearance. The single RGB image is fed into HPE framework in order to reduce the computation cost by using depth-independent device such as a common camera, webcam, or phone cam. However, HPE based on the single RGB is not able to solve the above challenges due to inherent characteristics of color or texture. On the other hand, depth information which is fed into HPE framework and detects the human body parts in 3D coordinates can be usefully used to solve the above challenges. However, the depth information-based HPE requires the depth-dependent device which has space constraint and is cost consuming. Especially, the result of depth information-based HPE is less reliable due to the requirement of pose initialization and less stabilization of frame tracking. Therefore, this paper proposes a new method of HPE which is robust in estimating self-occlusion. There are many human parts which can be occluded by other body parts. However, this paper focuses only on head self-occlusion. The new method is a combination of the RGB image-based HPE framework and the depth information-based HPE framework. We evaluated the performance of the proposed method by COCO Object Keypoint Similarity library. By taking an advantage of RGB image-based HPE method and depth information-based HPE method, our HPE method based on RGB-D achieved the mAP of 0.903 and mAR of 0.938. It proved that our method outperforms the RGB-based HPE and the depth-based HPE.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.415-416
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• 2012

모델 기반 카메라 추적에서 추적을 위한 3 차원 객체 모델의 정확도는 매우 중요하다. 하지만 3 차원 객체의 실측 모델링은 일반적으로 정교한 작업을 요구할 뿐 아니라, 오차 없이 모델링 하기가 매우 어렵다. 반면에 오차를 포함하고 있는 객체 모델을 이용하더라도 실제 추적 환경에서 사용자가 느끼는 성공적인 추적의 허용 오차는 실제 추적 오차와 다를 수 있다. 따라서, 본 논문에서는 모델 기반 카메라 추적에서 모델링 오차에 따른 모델과 영상 정보 간의 실제 정합 오차와 육안으로 판단되는 정합의 허용 오차를 사용자 평가를 통해 비교 분석하고, 3 차원 객체 모델링의 허용 오차 범위에 대해 논의한다.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.3
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• pp.21-29
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• 2000

In this paper, we propose a way to detect a moving object efficiently and to track it using the active blocks. Instead of all Pixels in 8*8 Pixel value, any special pixel is extracted and we detect a moving object by comparison and by analysis the difference image information from darkness value of the same area. In the acquisition of image data by software processing, we reduce the number of data which obtain by convert high resolution image to low resolution image, and we can track a moving object in real time. So it can track a moving object in simple system without all the pixel value of the image data or additional VxD(Virtual x Driver). This system can be useful to track of a moving object in fixed block on PC(Personal Computer) and low custom.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.11a
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• pp.185-188
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• 2015

미리 저장된 객체의 3차원 특징점(Feature point) 좌표와 카메라 영상의 2차원 특징점 좌표를 매칭(Matching)하여 객체를 추적하는 방식의 경우, 카메라의 시점이 변할 때 특징점에서 발생되는 원근 효과(Perspective effect)가 반영되지 못하여 특징점 매칭 오류가 발생한다. 따라서 특징점에서 발생하는 원근 효과를 반영하여 정확한 카메라 포즈를 추정하기 위해 이전 프레임(Frame)의 카메라 포즈(Camera Pose)에 맞추어 텍스쳐가 포함 된 3차원 객체의 모델을 렌더링 하여 원근 효과를 적용한 후, 현재 카메라 영상과 특징점 매칭하여 프레임 사이의 카메라 움직임을 구하여 객체를 추적한다. 더 나아가 본 논문에서는 특징점 매칭에서 발생하는 작은 오류들로 인한 미세한 카메라 움직임은 2단계의 임계치(Threshold)를 적용하여 떨림 현상으로 간주하여 떨림 현상이 제거된 객체 추적을 수행한다. 매 프레임마다 카메라 포즈에 맞춘 추적 객체를 렌더링 하기 때문에 떨림 현상으로 간주되어 제거된 카메라 움직임은 누적되지 않고, 추적 오류도 발생시키지 않는다.