• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.1053-1063
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• 2019

Recently, tile-based streaming that transmits one 360 video in several tiles, is actively being studied in order to transmit these 360 video more efficiently. In this paper, for the transmission of high-definition 360 video corresponding to user's viewport in tile-based streaming scenarios, a system of assigning the quality of tiles at each tile by applying the saliency map generated by existing network models is proposed. As a result of usage of Motion-Constrained Tile Set (MCTS) technique to encode each tile independently, the user's viewport was rendered and tested based on Salient360! dataset, streaming 360 video based on the proposed system results in gain to 23% of the user's viewport compared to using the existing high-efficiency video coding (HEVC).

• Journal of IKEEE
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• v.24 no.2
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• pp.419-425
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• 2020

The market size of immersive 360-degree video contents, which are noted as one of the main technology of the fourth industry, increases every year. However, since most of the images are distributed through illegal distribution networks such as Torrent after the DRM gets lifted, the damage caused by illegal copying is also increasing. Although filtering technology is used as a technology to respond to these issues in 2D videos, most of those filtering technology has issues in that it has to overcome the technical limitation such as huge feature-point data volume and the related processing capacity due to ultra high resolution such as 4K UHD or higher in order to apply the existing technology to immersive 360° videos. To solve these problems, this paper proposes a feature-point recognition ratio improvement method for immersive 360-degree videos using deep learning technology.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.39-40
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• 2018

현재의 게임 영상 작품 중에서 파괴 특수효과는 그 강렬한 충격과 놀라움으로 광범위하게 사용된다. 360도 파노라마 영상이 가져다 주는 몰입감과 공간 감각은 파괴 특수효과의 시각 충격력을 더 강화시킨다. 본 논문의 핵심은 Houdini의 RBDSolver를 통해서 연서 소재를 모의하여 사실적인 파괴 특수효과를 제작에 있으며 또한 실질적인 제작의 방식으로 작업 흐름을 표현하고 분석하는데 있다. 따라서 Houdini이 제작한 파괴 특수효과와 360도 파노라마 영상을 결합하고 거기에다 Youtube를 사용하여 표현하는 것이 이번 연구의 새로운 포인트가 된다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.839-842
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• 2022

실감적인 가상 현실을 위해서는 고화질의 360 도 영상 스트리밍이 필요하다. 그러나 이는 높은 대역폭과 연산량을 요구하기 때문에 일반적인 가상 현실 기기로는 감당하기 힘들다. 이를 보완하기 위한 360 도 영상 부호화 및 전송 기술이 활발히 연구되고 있으며, 대표적으로 사용자 시점 기반 타일 스트리밍 기법 등이 있다. 본 논문은 기존의 CTU 기반 스트리밍과 타일 기반 스트리밍과 함께 복호기 적응적인 단일 계층 타일 바인딩을 활용한 타일기반 스트리밍의 부호화 및 복호화 성능을 비교한다. 수행된 실험결과, 단일 계층 타일 바인딩을 활용한 타일 스트리밍 방법이 기존의 타일 스트리밍 기법에 비해 유사한 비트율 성능에 대비하여 복호화 시간에서 큰 이득을 볼 수 있음을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.556-559
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• 2021

해당 연구는 Insta evo 360° 카메라로 촬영한 Equirectangular 형태의 영상을 활용하여 보행자에게 위험한 차량을 구분한 후 실시간적으로 차량 접근 알림을 주는 시스템에 관한 연구이다. 360° 영상 속 위험 차량 탐지와 추적을 위해 파노라마와 일반도로 이미지 데이터 세트로 전이학습 된 You Look Only Once v5 (YOLOv5), 객체 추적 알고리즘 Simple Online and Realtime Tracking with a Deep Association Metric (DeepSORT), 그리고 실험을 통해 개발한 비 위험 차량 필터링 알고리즘을 활용한다. Insta evo 360° 카메라를 머리 위에 얹어 촬영한 영상을 개발한 최종 시스템에 적용한 결과, 약 90% 정확도로 영상에서 비 위험 차량과 위험 차량을 구분할 수 있고, 위험 차량의 경우 차량의 방향을 시각적으로 알려줄 수 있다. 본 연구를 바탕으로 보행자 시야각 외부의 위험 차량에 대한 경고 알림을 주어 보행자 교통사고 발생 가능성을 줄이고, 전방위를 볼 수 있는 360° 카메라의 활용 분야가 보행 안전 시스템뿐만 아니라 더 다양해질 것으로 기대한다.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.185-190
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• 2020

Purpose: Gait and cognitive impairment in stroke patients exacerbate fall risk and mobility difficulties during multi-task walking. Virtual reality can provide interesting and challenging training in a community setting. This study evaluated the effect of community-based virtual reality gait training (VRGT) using a 360-degree image on the gait ability of chronic stroke patients. Methods: Forty-five chronic stroke patients who were admitted to a rehabilitation hospital participated in this study. Patients meeting the selection criteria were randomly divided into a VRGT group (n=23) and a control group (n=22). Both these groups received general rehabilitation. The VRGT group was evaluated using a 360-degree image that was recorded for 50 minutes a day, 5 days per week for a total of 6 weeks after their training. The control group received general treadmill training for the same amount of time as that of the VRGT group. The improvement in the spatiotemporal parameters of gait was evaluated using a gait analyzer system before and after training. Results: The spatiotemporal gait parameters showed significant improvements in both groups compare with the baseline measurements (p<0.05), and the VRGT group showed more improvement than the control group (p<0.05). Conclusion: Community-based VRGT has been shown to improve the walking ability of chronic stroke patients and is expected to be used in rehabilitation of stroke patients in the future.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.85-92
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• 2019

In this paper, we propose a efficient feature point extraction method that can solve the problem of performance degradation by introducing a preprocessing process when extracting feature points by utilizing the characteristics of 360-degree realistic media. 360-degree realistic media is composed of images produced by two or more cameras and this image combining process is accomplished by extracting feature points at the edges of each image and combining them into one image if they cover the same area. In this production process, however, the stitching process where images are combined into one piece can lead to the distortion of non-seamlessness. Since the realistic media of 4K-class image has higher resolution than that of a general image, the feature point extraction and matching process takes much more time than general media cases.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.93-98
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• 2020

In this paper, we proposed a technique in which subtitles are followed according to changes in the user's viewpoint in 360 VR. Create a Sphere object in Unity's Scene and insert a 360-degree image on the surface of the Sphere object. At this time, the ReverseNormals script is used to convert the viewpoint to the inside. The SightOrbitproved script is used to modify the camera view. Use this script to set the environment in which subtitles can move depending on the viewpoint. Next, add the 3D text (subtitle) that the user wants to the lower layer of the main camera and build a 360 VR object. The 3D text subtitles implemented through this study were compared according to the change of the user's viewpoint. As a result, as the viewpoint changes, normal subtitles flow out of line of sight according to the user's point of view, but 3D Text subtitles move according to the user's point of view, and it can be seen that the user can always view the subtitles.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.102-108
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• 2017

Videos for 360-degree virtual reality (VR) systems have a large amount of data because they are made with several different videos from multiple cameras. To store the VR data in limited space or to transmit it through a channel with limited bandwidth, the data need to be compressed at a high ratio. This paper focuses on the compression efficiency of VR videos for good visual quality. Generally, 360-degree VR videos should be projected into the planer format to cope with modern video coding standards. Among various projection schemes, three typical schemes (equirectangular, line-cubic, and cross-cubic) are selected and compared in terms of compression efficiency and quality using various videos.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.965-968
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• 2004

This paper describes the development of the test path for Eclipse-II, a parallel mechanism motion simulator. Eclipse-II which can be used as a base for general motion simulators, enables unlimited continuous 360-degree spinning in any rotational axes plus finite X, Y, and Z translation motions. The advantage of enabling continuous 360-degree spinning allows various motions for virtual reality. In this paper, the development of the test path to verify the robustness of the Eclipse-II motion simulator is described. The test motions, which satisfy the requirements of test path, are suggested and washout filter enables these motions reproduced in the limited workspace. The trial run is conducted to verify the robustness of the Eclipse-II motion simulator. Additionally the standard data format of virtual reality for Eclipse-II One Man Ride is suggested.