• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.493-496
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• 2009

Many AR (Augmented Reality) applications have been interested in a marker-less tracking since the tracking methods give camera poses without attaching explicit markers. In this paper, we propose a new marker-less page recognition and tracking algorithm for an AR book application such as DigilogBook. The proposed method only requires orthogonal images of pages, which need not to be trained for a long time, and the algorithm works in real-time. The page recognition is done in two steps by using SIFT (Scale Invariant Feature Transform) descriptors and the comparison evaluation function. And also, the method provides real-time tracking with 25fps ~ 30fps by separating the page recognition and the frame-to-frame matching into two multi-cores. The proposed algorithm will be extended to various AR applications that require multiple objects tracking.

• Journal of the HCI Society of Korea
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• v.2 no.2
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• pp.11-18
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• 2007

We propose a novel method to conceal fiducial markers observed in augmented scenes using patch-based texture synthesis. Despite the efficiency for simple object recognition and tracking, the markers deliver inherent obtrusiveness. They do not only reduce immersiveness, but also severely degrade usability of augmented reality. The proposed method constructs alternative images in real time to overlay markers present in the sequence of images. The global characteristics of background textures are retained and the results are more adaptive to illumination changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.49-55
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• 2019

This paper presents a marker image evaluation method based on analysis of object distribution in images and classification of images with repetitive patterns for effective marker-based augmented reality (AR) system development. We measure the variance of feature point coordinates to distinguish marker images that are vulnerable to occlusion, since object distribution affects object tracking performance according to partial occlusion in the images. Moreover, we propose a method to classify images suitable for object recognition and tracking based on the fact that the distributions of descriptor vectors among general images and repetitive-pattern images are significantly different. Comprehensive experiments for marker images confirm that the proposed marker image evaluation method distinguishes images vulnerable to occlusion and repetitive-pattern images very well. Furthermore, we suggest that scale-invariant feature transform (SIFT) is superior to speeded up robust features (SURF) in terms of object tracking in marker images. The proposed method provides users with suitability information for various images, and it helps AR systems to be realized more effectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.297-299
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• 2017

Recently, the application fields of augmented reality(AR) are rapidly increasing, and related contents are also increasing in demand. In this way, object-based marker recognition is required for service of AR contents in mobile environment. At this time, in order to provide information corresponding to the marker, a technique of generating and servicing a virtual object corresponding to a specific marker is used. However, when a virtual object corresponding to a marker is held on the AR screen, a phenomenon occurs that an object of the marker unstably shakes due to various reasons such as camera shake and camera movement. As described above, the AR service based on the mobile device has a problem that it is difficult to represent objects stably. In this paper, we propose a stable marker recognition and tracking technique by applying the filtering technique according to the physical state change of the device when recognizing fixed markers in mobile AR environment.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.131-136
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• 2007

본 논문에서는 모바일 증강현실에서 스마트 오브젝트 인식 및 트래킹을 위한 임베디드 마커 시스템을 제안한다. 기존의 증강 현실 연구에서 주로 사용하는 마커는 임의의 패턴을 포함하고 대상 오브젝트와는 분리되어 있다. 이는 부자연스러운 시각적 장애 요인으로 작용한다. 또한 특정한 마커를 사용하기 위해 학습 과정을 거친 후 그 결과를 인식 모듈에서 일일이 등록해야 하는 번거로움이 있다. 이러한 문제점을 해결하기 위해 제안하는 임베디드 마커는 디스플레이 장치의 유무에 따라 고정형 또는 가변 형으로 분류된 스마트 오브젝트의 특성을 고려하여 오브젝트와 마커를 결합한다. 또한 통합된 학습과 인식 모듈을 통해 오브젝트의 추가 및 시스템 확장을 용이하게 한다. 제안된 시스템은 스마트 홈 테스트베드인 ubiHome 에 적용되었다. 또한 사용 성 평가를 통해 그 효용성을 분석하였다. 이러한 임베디드 마커를 사용하면 사용자는 보다 직관적으로 마커의 용도를 예측할 수 있고 대상물과의 시선을 일치시켜 자연스러운 증강현실을 경험할 수 있을 것으로 기대된다.

• Korean Journal of Computational Design and Engineering
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• v.14 no.1
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• pp.42-49
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• 2009

Virtual manufacturing technology has been applied in actual production sites with the development of virtual reality technology. However, the current virtual manufacturing technology requires experts for application of the system. Furthermore, the sense of reality is diminished as the entire simulation is driven by virtual objects. In contrast, mixed reality can visualize virtual objects and an actual work place simultaneously, and thus the sense of reality of the virtual manufacturing simulation can be improved. This paper introduces a method that applies mixed reality in the manufacturing process, and proposes a method to adapt general safety sign post in the factory instead of a black square marker for visual fiducial recognition.

• Korean Journal of Computational Design and Engineering
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• v.18 no.5
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• pp.374-383
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• 2013

Various interaction techniques have been studied for providing the feeling of touch and improve immersion in augmented reality (AR) environments. Tangible AR interaction exploiting two types (product-type and pointer-type) of simple objects has earned great interest for cost-effective design evaluation of digital handheld products. When the sizes of markers attached to the objects are kept big to obtain better marker recognition, the pointer-type object frequently and significantly occludes the product-type object, which deteriorates natural visualization and level of immersion in an AR environment. In this paper, in order to overcome such problems, we propose tangible AR interaction using fingertip touch combined with small-sized markers. The proposed approach facilitates the use of convex polygons to recover the boundaries of AR markers which are partially occluded. It also properly enlarges the pattern area of each AR marker to reduce the sizes of AR markers without sacrificing the quality of marker detection. We empirically verified the quality of the proposed approach, and applied it in the process of design evaluation of digital products. From experimental results, we found that the approach is comparably accurate enough to be applied to the design evaluation process and tangible enough to provide a pseudo feeling of manipulating virtual products with human hands.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.117-123
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• 2016

A hand-gesture interface to manipulate a 3D object of augmented reality is implemented by recognizing the user hand-gesture in this paper. Proposed method extracts the hand region from real image, and creates augmented object by hand marker recognized user hand-gesture. Also, 3D object manipulation corresponding to user hand-gesture is performed by analyzing a hand region ratio, a numbet of finger and a variation ratio of hand region center. In order to evaluate the performance of the our proposed method, after making a 3D object by using the OpenGL library, all processing tasks are implemented by using the Intel OpenCV library and C++ language. As a result, the proposed method showed the average 90% recognition ratio by the user command-modes successfully.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.126-133
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• 2009

In this paper, we propose an object recognition technique for implementing marker less augmented reality. Scale Invariant Feature Transform (SIFT) is used for finding the local features from object images. These features are invariant to scale, rotation, translation, and partially invariant to illumination changes. Extracted Features are distinct and have matched with different image features in the scene. If the trained image is properly matched, then it is expected to find object in scene. In this paper, an object is found from a scene by matching the template images that can be generated from the first frame of the scene. Experimental results of object recognition for 4 kinds of objects showed that the proposed technique has a good performance.

• Journal of Korea Multimedia Society
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• v.23 no.11
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• pp.1428-1434
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• 2020

Virtual reality (VR) and augmented reality (AR) technologies can interact intuitively using virtual 3D images. Information signs on buildings that are frequently used by the public play a very important role in conveying information. However, the current information sign has different understanding and interpretation, and it is difficult to communicate quickly and intuitively for interaction. The purpose of this study is to increase the efficiency of information signing through information provision using mobile augmented reality. The InfoAR app not only guides you to the destination of the building, but also acts as a marker for the logo image. The logo image created based on the feature points recognizes the information of the destination. It is converted to AR through a mobile app, allowing users to easily find their destination by obtaining specific information. In addition, it presents interactions that can enlarge, reduce, move, and rotate information about virtual objects augmented through a function called AR. In the future, if user convenience and usability of the interface are added, research is conducted, and the level of completion is improved, such as using VR contents and promotions and business cards, it is expected that highly useful contents will be produced.