• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1048-1057
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• 2015

In this paper, we propose a fast MAS reallocation method that can avoid reservation conflicts in the DRP process of WiMedia system in real time. WiMedia MAC DRP has been developed aimed QoS support for audio and video transmission that generate traffic periodically. The size variation of the video streaming data causes DRP reservation conflicts frequently, so that DRP could not support QoS of the video streaming service which is delay-sensitive. Fast MAS reallocation method could avoid reservation conflicts in real-time analyzing reservation requests information of the other device. Our proposed method is evaluated with test sequences using the software simulation and implemented in hardware/software with the integrated WiMedia MAC/PHY system.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.949-956
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• 2007

This paper describes the design and implementation of the database which is used in Personal Life Log Media system. The database contains information about media that capture personal experiences and enables the user to retrieve the media in a user friendly ways. The implementation of the database design is done by managing video data, which captures user's personal experiences, with its spatial and temporal information. The database enables the user to retrieve the video by mentioning where and/or when the video has been taken.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.600-607
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• 2017

Virtual Reality (VR) has lately gained significant attention primarily driven by the recent market availability of consumer devices, such as mobile phone-based Head Mounted Displays (HMDs). Apart from classic gaming use cases, the delivery of $360^{\circ}$ video is considered as another major application and is expected to be ubiquitous in the near future. However, the delivery and decoding of high-resolution $360^{\circ}$ videos in desirable quality is a challenging task due to network limitations and constraints on available end device decoding and processing. In this paper, we focus on aspects of $360^{\circ}$ video streaming and provide an overview and discussion of possible solutions as well as considerations for future VR video streaming applications. This paper mainly focuses on the status of the standardization activities, Omnidirectional MediA Format (OMAF), to support interoperable $360^{\circ}$ video streaming services. More concretely, MPEG's ongoing work for OMA aims at harmonization of VR video platforms and applications. The paper also discusses the integration in MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH), which is considered as $360^{\circ}$ video streaming services with OMAF content. In context of the general OMAF service architecture.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.196-206
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• 2011

The development of projection technology produces series of discussions associated to various form of visual immersing possibilities by the way of projecting image directly to the obscure surface surrounded us. Besides, the significance can be found in terms of that this kind of image projection offers chance to citizens to enjoy high standard images and makes people consider media environment of city. Video art as the digital technology grafts penetrates formative space of city by projecting images. The certain thing about questions how the media has status in city is that media is now not existing for self neither for abstractly and virtual reality is existing in the general appearance of metropolis. This paper treats media environment of city and the meaning of image projection as from of video art in the city. It accesses about the meaning of video form visual art in big city- new reality, the virtual and the real, immersion and interactivity. And media reality of metropolis defines that there is not one major discourse in the gigantic text -metropolis rather they are different discourses each other simultaneously compatible in the gigantic text -metropolis and in fact, they affect each other and interact.

• ETRI Journal
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• v.36 no.4
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• pp.528-536
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• 2014

High Efficiency Video Coding (HEVC) is the most recent video coding standard to achieve a higher coding performance than the previous H.264/AVC. In order to accomplish this improved coding performance, HEVC adopted several advanced coding tools; however, these cause heavy computational complexity. Similar to previous video coding standards, motion estimation (ME) of HEVC requires the most computational complexity; this is because ME is conducted for three inter prediction modes - namely, uniprediction in list 0, uniprediction in list 1, and biprediction. In this paper, we propose an efficient inter prediction mode (EIPM) decision method to reduce the complexity of ME. The proposed EIPM method computes the priority of all inter prediction modes and performs ME only on a selected inter prediction mode. Experimental results show that the proposed method reduces computational complexity arising from ME by up to 51.76% and achieves near similar coding performance compared to HEVC test model version 10.1.

• ETRI Journal
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• v.44 no.1
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• pp.73-84
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• 2022

The moving picture experts group (MPEG) immersive video (MIV) technology has been actively developed and standardized to efficiently deliver immersive video to viewers in order for them to experience immersion and realism in various realistic and virtual environments. Such services are provided by MIV technology, which uses multiview videos as input. The pruning process, which is an important component of MIV technology, reduces interview redundancy in multiviews videos. The primary aim of the pruning process is to reduce the amount of data that available video codec must handle. In this study, two approaches are presented to improve the existing pruning algorithm. The first method determines the order in which images are pruned. The amount of overlapping region between the source views is then used to determine the pruning order. The second method considers global region-wise color similarity to minimize matching ambiguity when determining the pruning area. The proposed methods are evaluated under common test condition of MIV, and the results show that incorporating the proposed methods can improve both objective and subjective quality.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.607-616
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• 2005

Due to the limited resources in thin-client and the large amount of computation for decoding MPEG media, it is not easy to support the QoS stream media to clients. To solve the problems, the terminal servers would be charged for decoding the MPEG media and thin-clients have a role to update only the changed areas in their screen. However, these previous approaches cause severely low video quality. In addition, since servers perform all procedures to decode MPEG media, they are easily saturated even under a small number of clients. In this paper, the sources of the low video duality are investigated in the previous thin-clients' solutions working in wireless and wired environments. From the detailed experiments, an intelligent media player is proposed to achieve the QoS streams by supporting both the enhanced video duality and the audio synchronized with video frames.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.9-15
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• 2001

Very low bit rate video coding uses the inter-picture video coding method for high compression. The inter-picture video coding is coded based on the information of the previous frames so any packet loss can lead to reduce the image quality on the transmission. In this paper, we proposed the multi-stream generation method for inter-media synchronization of very low bit rate video based on TCP for reliable transmission. The proposed approach performs a reliable transmission via a TCP based protocol. This method incorporates multi-streams in order to enhance the robustness of delivery and can withstand against network jitter. Moreover, the client bandwidths are fully utilized in a highly efficient way.

• Journal of Multimedia Information System
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• v.4 no.4
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• pp.311-316
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• 2017

High Efficiency Video Coding (HEVC) is the newest video coding standard for improvement in video data compression. This new standard provides a significant improvement in picture quality, especially for high-resolution videos. A quadtree-based structure is created for the encoding and decoding processes and the rate-distortion (RD) cost is calculated for all possible dimensions of coding units in the quadtree. To get the best combination of the block an optimization process is performed in the encoder, called rate distortion optimization (RDO). In this work we are proposing a novel approach to enhance the overall RDO process of HEVC encoder. The proposed algorithm is performed in two steps. In the first step, like HEVC, it performs general rate distortion optimization. The second step is an extra checking where a SSIM based cost is evaluated. Moreover, a fast SSIM (FSSIM) calculation technique is also proposed in this paper.

• Broadcasting and Media Magazine
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• v.15 no.4
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• pp.135-145
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• 2010