• 인터넷정보학회논문지
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• 제20권1호
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• pp.47-55
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• 2019

Free-viewpoint video (FVV) service provides multi viewpoints of contents and synthesizes intermediate video files which are not captured on some view angles so that enables users to watch as they choose wherever they want. Synthesizing video is necessary technique to provide FVV video service, because every video of the FVV contents for different view angles cannot be stored to the content server physically. For the reason, fast view synthesis can improve the quality of video service and increase user's satisfaction. One of the studies for FVV service, a method was proposed to transmit FVV service based on DASH (Dynamic Adaptive Streaming over HTTP). There is big advantage on using DASH that it is commonly used to transport video service. However, the method was only a conceptual proposal, so it is difficult to implement the system using the proposal. In this paper, we propose an implementation method to provide real-time FVV service smoothly. We suggest a system structure and operation method on the server and client side in detail, which is to be applicable to synthesize video quickly. Also, we suggest generating FVV service map additionally which controls a FVV service overall. We manage real-time information of the whole service through the service map. The service can be controlled by reducing the possible delay from network situation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.929-946
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• 2022

Free viewpoint video (FVV) service is an immersive media service that allows a user to watch it from a desired location or viewpoint. It is composed of various forms according to the direction of the viewpoint of the provided video, and includes zoom in/out in the service. As consumers' demand for active watching is increasing, the importance of FVV services is expected to grow gradually. However, additional considerations are needed to seamlessly stream FVV service. FVV includes a plurality of videos, video changes may occur frequently due to movement of the viewpoint. Frequent occurrence of video switching or re-request another video can cause service delay and it also can lower user's quality of service (QoS). In this case, we assumed that if a video showing an object that the user wants to watch is selected and provided, it is highly likely to meet the needs of the viewer. In particular, it is important to provide an object-oriented FVV service when zooming in. When video zooming in in the usual way, it cannot be guaranteed to zoom in around the object. Zoom function does not consider about video viewing. It only considers the viewing screen size and it crop the video view as fixed screen location. To solve this problem, we propose a zoom in/out method of object-centered dynamic adaptive streaming of FVV in this paper. Through the method proposed in this paper, users can enjoy the optimal video service because they are provided with the desired object-based video.

• 한국통신학회논문지
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• 제41권5호
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• pp.546-554
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• 2016

다수의 무선 기기를 통해 하나의 대상을 촬영하여, 이 영상을 통해 실제로 촬영하지 않은 위치에서 바라볼 때의 영상으로 합성하는 기술을 자유시점 비디오라고 한다. 이 기술을 무선기기를 이용한 실시간 스트리밍 서비스에 접목하면 사용자에게 새로운 서비스를 제공할 수 있으나, 모든 시점에서 촬영한 영상을 전부 전송하기에는 다수의 전송 기기가 공유하는 무선 자원의 제한과, 스트리밍 서비스가 가지는 시간적 제약으로 인한 어려움이 해결되어야 한다. 따라서, 최적의 품질을 위해서는 무선 채널의 상태와 사용자의 요청 비율을 고려하여, 서버로 전송하는 기기들을 효과적으로 선별해야 할 필요가 있다. 본 연구는 실시간 자유시점 비디오 스트리밍 서비스 환경을 가정하고, 전송 과정에서 발생할 수 있는 무선 채널 오류와 다양한 시점에 대한 사용자들의 인기도를 반영하여, 최적 품질을 보장하는 전송기기 집합을 선별하는 추단적 알고리즘을 제안한다. 성능분석을 통해 제안된 방식은 가장 인기도가 높은 시점의 품질이 우선적으로 보장되는 효과를 가짐을 보였다. 또한, 이 알고리즘의 성능을 촬영 기기의 위치만을 고려한 기존 연구의 방식과 비교한다.