• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.559-565
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• 2005

In this paper, we propose a stereoscopic video coding scheme for subway accident monitoring system. The proposed designed for providing flexible video among various displays, such ass control center, station employees and train driver. We uses MPEG-2 standard for coding the left-view sequence and IBMDC coding scheme predicts matching block by interpolating both motion and disparity predicted macroblocks. To provide efficient stereoscopic video service, we define both temporally and spatially scalable layers for each eye's-view by using the concept of Spatio-Temporal scalability. The experimental results show the efficiency of proposed coding scheme by comparison with already known methods and the advantages of disparity estimation in terms of scalability overhead. According to the experimental results, we expect the proposed functionalities will play a key role in establishing highly flexible stereoscopic video codec for ubiquitous display environment where devices and network connections are heterogeneous.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.77-88
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• 2000

This paper presents an approach for rate control by adaptively selecting macroblock modes in video coding.The problem of rate control has been investigated by many authors where quantizer level is adjustedbased on the buffer fullness. The proposed approach is different fron the previous ones [4] id that it finds the optimal decision curve rather than finding a set of the modes. Proposed algorithm extends the coding decision options for rate control to motion/no-motion compensation as well as inter/intra decisions. Instead of having a fixed motion/no-notion compensation or inter/intra decision curve, one can utilize an adaptive decision curvebased on the characteristics of input frames so that the PSNR at a given bit rate is maximized. Therefore, the proposed approach provides better rate control than simple quantizer feedback approach interns of visual quality. The curve is obtained by utilizing simulated annealing optimization technique. Thealgorithm is implemented and simulations are compared with other approaches within H.261 video codec.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10C
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• pp.805-812
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• 2008

H.264 technology is considered as the heart of the next-generation video codec standard. Europe and other countries have actually specified H.264 technology as the video codec standard for HD broadcasting. However, due to the complexity of algorithm, it is still a difficult job to implement HD-level H.264 decoders in real-time software. In this paper, I have restricted a part of the decoding process, in order to implement an H.264 software video decoder which guarantees a real-time operation, and suggest an H.264 decoder that adaptively selects the algorithm to minimize image degradation. Performance of the suggested H.264 decoder was compared and verified through a PC simulation. As a consequence, when the suggested decoder was used in an environment where real-time decoding was difficult, it has achieved the minimal image degradation as well as real-time decoding in most cases.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.422-425
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• 2012

스트리밍 비디오 시스템의 QoS에 관한 기존 연구가 네트워크의 관점에서 비디오 스트림의 전송률을 조절하는 기법위주로 이루어져 균일한 화질을 제공받고자 하는 사용자에게 VBR 스트리밍 비디오의 장점을 제공하기 어려웠다. 본 논문에서는 스트리밍 비디오 시스템에서 클라이언트의 대역폭 변화에도 사용자에게 균일한 화질을 제공하기 위하여 CBR 스트리밍 비디오의 장점을 VBR 스트리밍 비디오에 적용하는 비디오 코덱을 설계한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.78-80
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• 2021

In this paper, we proposed an improved method on the picture order of coding (POC) of MPEG-5 Essential video Coding (EVC) encoder to support a short intra period for Video-based Point Cloud Compression (V-PCC). As a codec-agnostically designed standard, V-PCC claimed to be able to work with a lot of codecs. Current EVC test model software shows that the baseline profile could not provide appropriate POC calculation. The proposed method offers a solution to this POC-related problem and provides up to 44.6% coding grains for EVC based V-PCC.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.261-270
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• 2013

A stereoscopic 3D video service is able to provide a 3D video service while keeping backward compatibility with the existing 2D video service. In the terrestrial digital television (DTV) system, a stereoscopic video codec is required to have high coding efficiency in order to provide a 3D video service in the same channel capacity. A hybrid codec consisting of MPEG-2 for base video and H.264/AVC or HEVC for 3D auxiliary video is considered. Furthermore, Non-Real-Time (NRT) delivery of stereoscopic video is also considered as a service scenario for 3DTV services to overcome the limited bandwidth. In this paper, we propose a stereoscopic video coding scheme using adaptive loop filter (ALF) which had been considered in HEVC as a pre-/post-filter for enhancing coding efficiency in NRT-based 3DTV services. In order to apply ALF as a post-filter to the reconstructed additional view coded by H.264/AVC, we devise a method in which ALF is adaptively applied based on a structure determined by using macroblock (MB) coding information such as MB mode type and reference index instead of coding unit (CU) structure on which ALF is applied in the HEVC. Experimental results shows that the proposed stereoscopic video coding scheme applying ALF obtains up to 24.9% gain of bit saving.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.225-228
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• 2000

In this paper, a design of the reliable video-conference system using CTI(Computer Telephony Integration) technology is proposed. When video-conference is run on the current existing Internet, the transmission delay problem for voice data traffic can be frequently occurred. In order to transmit the real-time voice data through the Internet efficiently, some complicated algorithms such as CODEC(Code/Decode) should be applied. It can cause further excessive processing delay which can affect the overall performance. The voice traffic is usually transmitted through the reliable PSTN(Public Switched Telephone Network) in the CTI system. In this paper a new architecture, in which PSTN for voice traffic and Internet for video traffic are used at the same time instead of using Internet by itself, is proposed to relieve the problems on a video conference.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.298-300
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• 2004

In the decoding process of interframe wavelet coding, the inverse wavelet transform requires huge computational complexity. However, the decoder may need to be used in various devices such as PDAs, notebooks, PCs or set-top Boxes. Therefore, the decoder's complexity should be adapted to the processor's computational power. A decoder designed in accordance with the processor's computational power would provide optimal services for such devices. So, it is natural that the complexity scalability and the low complexity codec are also listed in the requirements for scalable video coding. In this contribution, we develop a method of controlling and lowering the complexity of the spatial wavelet transform while sustaining almost the same coding efficiency as the conventional spatial wavelet transform. In addition, the proposed method may alleviate the ringing effect for certain video data.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.1
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• pp.35-41
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• 2009

The H.264/SVC enables network-adaptive video transmission to smart device which uses wireless network. But, quality scalability of H.264/SVC does not consider personal subjective image quality. In addition, its network efficiency also does not optimized because it uses MGS(Medium Grained Scalability) and CGS(Coarse Grained Scalability). Thus, this paper proposed a new scalable ROI algorithm for not only subjective image quality improvement but also network adaptation. To experiment our proposed a scheme, we added designed algorithm to JSVM(Joint Scalable Video Model) open source video codec of H.264/SVC. Experiment was performed according to the pre-defined scenario for simulating various network conditions. Finally, experimental result showed our proposed scalable ROI scheme. It is better than traditional non-selective scheme in subjective video quality.