• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.825-828
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• 2022

In this paper, we propose an efficient image size selection method for video-based point cloud compression. The current MPEG video-based point cloud compression reference encoding process configures a threshold on the size of images while converting point cloud data into images. Because the converted image is compressed and restored by the legacy video codec, the size of the image is one of the main components in influencing the compression efficiency. If the image size can be made smaller than the image size determined by the threshold, compression efficiency can be improved. Here, we studied how to improve the compression efficiency by selecting the best-fit image size generated during video-based point cloud compression. Experimental results show that the proposed method can reduce the encoding time by 6 percent without loss of coding performance compared to the test model 15.0 version of video-based point cloud encoder.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.600-607
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• 2004

The paper describes the implementation of the video conferencing system using public key infrastructure which is used for user authentication and media stream encryption. Using public key infrastructure, we are able to reinforce the authentication for conference participant and block several malicious hacking while protecting conference control information. The paper shows the implementation of the transportation layer secure protocol in conformity with Korea public key authentication algorithm standard and symmetric key encryption algorithm (RC2, SEED, DES and 3DES) for media stream encryption. The feature of the paper is transportation layer secure protocol that is implemented for protection of information on a user authentication and video conference and the media streaming encryption algorithm also can be envisioned with another block encryption algorithm. The key for media streaming encryption may be safely distributed by the transportation layer secure protocol.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1264-1273
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• 1998

In this paper, we implemented a system which provides more effective conference control than that of video conferencing system has been used on MBone. The system provides multicast service on the non-broadcasting network. It multicasts multimedia data using several MTS(Multipoint Transport Server)s and provides a tightly coupled conference control service with a CCS(Conference Control Server). As providing a tightly coupled conference control service, we can perform effectively video conferencing using this system.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.375-378
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• 2005

The multi-view video is a collection of multiple videos capturing the same scene at different viewpoints. The multi-view video can be used in various applications, including free viewpoint TV and three-dimensional TV. Since the data size of the multi-view video linearly increases as the number of cameras, it is necessary to compress multi-view video data for efficient storage and transmission. The multi-view video can be coded using the concept of the layered depth image (LDI). In this paper, we describe a procedure to generate LDI from the natural multi-view video and present a method to encode multi-view video using the concept of LDI.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.294-297
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• 2009

Multi-view video consists of a set of multiple video sequences from multiple viewpoints or view directions in the same scene. It contains extremely a large amount of data and some extra information to be stored or transmitted to the user. This paper presents inter-view correlations among video objects and the background to reduce the prediction complexity while achieving a high coding efficiency in multi-view video coding. Our proposed algorism is based on object-based segmentation scheme that utilizes video object information obtained from the coded base view. This set of data help us to predict disparity vectors and motion vectors in enhancement views by employing object registration, which leads to high compression and low-complexity coding scheme for enhancement views. An experimental results show that the superiority can provide an improvement of PSNR gain 2.5.3 dB compared to the simulcast.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.147-153
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• 1998

This paper provides a method for video augmentation using image interpolation. In computer graphics or augmented reality, 3D information of a model object is necessary to generate 2D views of the model, which are then inserted into or overlayed on environmental views or real video frames. However, we do not require any three dimensional model but images of the model object at some locations to render views according to the motion of video camera which is calculated by an SFM algorithm using point matches under weak-perspective (scaled-orthographic) projection model. Thus, a linear view interpolation algorithm is applied rather than a 3D ray-tracing method to get a view of the model at different viewpoints from model views. In order to get novel views in a way that agrees with the camera motion the camera coordinate system is embedded into model coordinate system at initialization time on the basis of 3D information recovered from video images and model views, respectively. During the sequence, motion parameters from video frames are used to compute interpolation parameters, and rendered model views are overlayed on corresponding video frames. Experimental results for real video frames and model views are given. Finally, discussion on the limitations of the method and subjects for future research are provided.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.439-442
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• 2004

Traditional database systems have been used models supported for the operations and relationships based on simple interval. video data models are required in order to provide supporting temporal paradigm, various object operations and temporal operations, efficient retrieval and browsing in video model. As video model is based on object-oriented paradigm, 1 present entire model structure for video data through the design of metadata which is used of logical schema of video, attribute and operation of object, and inheritance and annotation. by using temporal paradigm through the definition of time point and time interval in object-oriented based model, we tan use video information more efficiently by me variation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.820-827
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• 2010

In these days, video applications for special purposes such as video conference systems among multiple users and video surveillance systems require multiple video connections and QoS guarantee. The video systems employ IEEE 802.11 Wireless LAN devices to support broadband wireless interfaces and easy internet accesses for cheaper prices. However, according to the current IEEE 802.11e HCCA standard, if more than three video sessions are established in WSTA services, some of them must share the TXOP because the available number of TSIDs for video transmission is two. In order to resolve the problem, we devised a method which can establish up to 15 video sessions by slightly modifying the frame structure while maintaining the compatibility with current standard. Our method is implemented on the NCTUns 4.0 network simulator, and evaluated not only numerically in terms of throughput, delay, and PSNR, but also experimentally in the sense of real video clips that are used as input to our simulation. The results showed that our method sufficiently guarantees the transmission bandwidth requested by each video session.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.163-164
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• 2008

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2004.11a
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• pp.38-38
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• 2004