• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3239-3267
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• 2018

Image and video dehazing is a popular topic in the field of computer vision and digital image processing. A fast, optimized dehazing algorithm was recently proposed that enhances contrast and reduces flickering artifacts in a dehazed video sequence by minimizing a cost function that makes transmission values spatially and temporally coherent. However, its fixed-size block partitioning leads to block effects. The temporal cost function also suffers from the temporal non-coherence of newly appearing objects in a scene. Further, the weak edges in a hazy image are not addressed. Hence, a video dehazing algorithm based on well designed spectral clustering is proposed. To avoid block artifacts, the spectral clustering is customized to segment static scenes to ensure the same target has the same transmission value. Assuming that edge images dehazed with optimized transmission values have richer detail than before restoration, an edge intensity function is added to the spatial consistency cost model. Atmospheric light is estimated using a modified quadtree search. Different temporal transmission models are established for newly appearing objects, static backgrounds, and moving objects. The experimental results demonstrate that the new method provides higher dehazing quality and lower time complexity than the previous technique.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권3호
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• pp.919-940
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• 2012

Video on Demand (VOD) is a multimedia service which allows a remote user to select and then view video at his convenience at any time he wants, which makes the VOD become an important technology for many applications. Numerous periodic VOD broadcasting protocols have been proposed to support a large number of receivers. Broadcasting is an efficient transmission scheme to provide on-demand service for very popular movies. This paper proposes a new broadcasting scheme called Popularity Cushion Staggered Broadcasting (PCSB). The proposed scheme improves the Periodic Broadcasting (PB) protocols in the latest mobile VOD system, which is called MobiVoD system. It also, reduces the maximum waiting time of the mobile node, by partitioning the $1^{st}$ segment of the whole video and storing it in the Local Media Forwarder (LMF) exactly in the Pool of RAM (PoR), and then transmitting them when the mobile nodes miss the $1^{st}$ broadcasted segment. The results show that the PCSB is more efficient and better than the all types of broadcasting and caching techniques in the MobiVoD system. Furthermore, these results exhibits that system performance is stable under high dynamics of the system and the viewer's waiting time are less than the previous system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2075-2078
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• 2002

Internet became the most popular network in spite of its weakness in realtime multimedia service. Many experts believe that the Internet has the potential to become the main multimedia distribution network of the near future. Currently, it does not provide any (BoS guarantees and, even when it does, guaranteed quality delivery of video may turn out to be too expensive. Unavoidable packet losses and delay jitter caused by congestion in a best effort delivery environment require use of intelligent transport techniques for effective video delivery. According to market needs of better quality of service (QoS) fur realtime multimedia services over Internet, they have been standardizing RSVP, IntServ, and DiffServ This paper combines the benefits of QoS mechanisms such as RSVP/IntServ with scalable video encoding. We propose that more important bit stream is given more priority such that limited network resources are guaranteed far the stream. Various prioritizing approaches are proposed and compared to normal approach by using Network Simulator. The calculated QoS parameters such as packet loss rate are used to calculate degree of degradation in video quality. In this Paper, proposed methods can be implemented adaptively to Von protocol, such as H.323, SIP.

• 한국정보과학회논문지:시스템및이론
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• 제32권9호
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• pp.433-444
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• 2005

주문형 비디오 시스템에서 방송에 기초한 스케줄링 기법은 방대한 규모의 클라이언트에게 인기 비디오를 전파하기 위한 매우 효율적인 기술로 알려져 있다. 방송 스케줄링 기법의 주된 동기는 그들은 확장성이 매우 좋으며 아주 적당한 수준의 대역폭을 요구한다는 것이다. 본 논문은 FDBS로 명명된 새로운 동적 방송 스케줄링 기법을 제안하고 이 기법의 정확성을 증명한다. 그리고 시뮬레이션 방법을 통하여 FDBS의 성능을 평가한다 성능 평가 결과에 의하면 FDBS는 매우 적당한 수준의 대역폭을 요구하면서도 UD, CBHD, 그리고 NPB 기법보다 평균 응답시간에 있어서 더 우수한 성능을 보인다.

• 한국멀티미디어학회논문지
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• 제24권10호
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• pp.1380-1390
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• 2021

The video face recognition (FR) is one of the most popular researches in the field of computer vision due to a variety of applications. In particular, research using the attention mechanism is being actively conducted. In video face recognition, attention represents where to focus on by using the input value of the whole or a specific region, or which frame to focus on when there are many frames. In this paper, we propose a novel attention based deep learning method. Main novelties of our method are (1) the use of combining two loss functions, namely weighted Softmax loss function and a Triplet loss function and (2) the feasibility of end-to-end learning which includes the feature embedding network and attention weight computation. The feature embedding network has a positive effect on the attention weight computation by using combined loss function and end-to-end learning. To demonstrate the effectiveness of our proposed method, extensive and comparative experiments have been carried out to evaluate our method on IJB-A dataset with their standard evaluation protocols. Our proposed method represented better or comparable recognition rate compared to other state-of-the-art video FR methods.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.195-207
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• 2021

In recent years, with the rapid growth of China's animation industry, the two-dimensional culture and consumption have been immersed in the daily lives of young people. The two-dimensional culture that mainly exists on young people is gradually entering the public's field of vision, making the two-dimensional culture not It is only restricted to the fixed fan circle, but is known to more people outside the circle. At the same time, the "barrage" (screen text) cultures in video websites has become popular with some film and television works, Internet terms, etc., and has attracted the attention on mainstream culture. On the one hand, its cultural products have appeared on traditional mainstream video websites and advertisements on provincial satellite TV. And in the program, on the other hand, a small part of the screen text and cultural terms are also used by some celebrities and other ordinary people who don't understand the meaning of the terms at all, and have caused widespread dissemination. Sometimes the video website itself is also mentioned, which obviously shows a difference. The tendency towards a kind of screen texts subculture to penetrate the mainstream culture.

• 한국게임학회 논문지
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• 제21권6호
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• pp.97-110
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• 2021

본 연구는 일방향적이고 관람 위주의 콘텐츠를 지향하고 있는 영화와 드라마 등의 영상미디어가 뉴미디어인 게임의 속성을 어떻게 재매개하고 있는지를 구체적인 사례를 통해 분석하고 게임성이 발현되는 양상을 살펴 게임과 영상미디어의 영향 관계 및 융합 양상을 연구하는 것을 목적으로 한다. 영상미디어의 게임문화 융합 양상은 크게 두 가지 유형으로 나타났다. 첫 번째는 게임의 콘텐츠적인 측면을 소극적으로 융합하는 양상이며, 두 번째는 게임의 시스템적인 측면을 적극적으로 융합하는 양상이다. 이와 같은 연구는 게임이 다양한 영상미디어에 영향을 주고 있음을 밝힘과 동시에 게임 미디어가 대중 문화를 이끌어가는 대표적인 미디어로 기능하고 특히 포스트 코로나 시대에 더 강조되는 온택트 패러다임을 이끌어가는 주역으로 자리매김할 수 있음을 증명하는 기초 연구로 그 의의가 있다.

• 방송공학회논문지
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• 제1권2호
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• pp.133-141
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• 1996

본 논문에서는 차세대 영상 서비스 기술인 VOD(Video-on-Demand)시스템을 LAN을 이용하여 구현하였다. LAN을 이용한 VOD 시스템은 네트워크 병목현상과 이에 따른 시간 지연 때문에 기존의 네트워크 구현으로는 원활한 서비스가 되지 못하므로, 그러한 문제점을 해결하기 위한 방안으로, 본 논문에서는 토팔러지의 변경과 그에 따른 네트워크 장비의 선정, 개선된 프로토콜의 제정 등이 제시되었다. 결론적으로 구현된 시스템은 세그먼트 당 최대 3∼4명의 클라이언트를 수용할 수 있었고, 전송하고자 하는 영상 데이터의 크기에 따라 미리 네트워크 버퍼의 크기를 최적화하는 것이 서비스의 품질을 높이는데 필수적이라는 것을 알 수 있었다.

• Journal of Information Processing Systems
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• 제6권4호
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• pp.575-596
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• 2010

Video-on-Demand services are increasing rapidly nowadays. The load on servers can be very high, even exceeding their capacity. For popular contents, we can use a Periodic Broadcast (PB) strategy using multicast to serve all clients. Recent development of PB uses multiple channels broadcasting for segments of movies in certain patterns, so that users only need to wait for a small segment to start the service. However, users need higher download capacity to download multiple segments at a time. In order to compensate for this, a proxy server can help to reduce download bandwidth requirements by holding some segments for a certain time. This research will focus on more recent PB schemes that couldn't be covered by previous Proxy-Assisted Periodic Broadcast strategies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.3196-3210
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• 2014

This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.