• Korean Journal of Digital Imaging in Medicine
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• v.5 no.1
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• pp.26-31
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• 2002

This paper represents the design of 3D endoscopic video system in order to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. Minimally invasive techniques have set new standards in all surgical may experience less post-operative discomfort, shorter hospitalization, and quicker recuperation. Finally, the aim of the present study was to determine the influence of 2D and 3D video imaging on defined tasks on a laparoscopic trainer.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.519-525
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• 2016

This paper addresses the framework of object-oriented image coding, describing a new algorithm, based on monodimensional Legendre polynomials, for texture approximation. Through the use of 1D orthogonal basis functions, the computational complexity which usually makes prohibitive most of 2D region-oriented approaches is significantly reduced, while only a slight increment of distortion is introduced. In the aim of preserving the bidimensional intersample correlation of the texture information as much as possible, suitable pseudo-bidimensional basis functions have been used, yielding significant improvements with respect to the straightforward 1D approach. The algorithm has been experimented for coding still images as well as motion compensated sequences, showing interesting possibilities of application for very low bitrate video coding.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.151-153
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• 2021

포인트 클라우드는 특정 개체 혹은 장면을 다수의 3 차원 포인터를 사용하여 표현하는 데이터의 표현 방식 중 하나로 3D 데이터를 정밀하게 수집하고 표현할 수 있는 방법이다. 하지만 방대한 양의 데이터를 필요로 하기 때문에 효율적인 압축이 필수적이다. 이에 따라 국제 표준화 단체인 Moving Picture Experts Group 에서는 포인트 클라우드 데이터의 효율적인 압축 방법 중 하나로 Video based Point Cloud Compression(V-PCC)에 대한 표준을 제정하였다. V-PCC 는 포인트 클라우드 정보를 Occupancy, Geometry, Texture 와 같은 다수의 2D 영상으로 변환하고 각 2D 영상을 전통적인 2D 비디오 코덱을 활용하여 압축하는 방법이다. 본 논문에서는 V-PCC 에서 변환하는 Occupancy 의 정보를 활용하여 효율적으로 Texture 영상을 압축할 수 있은 방법을 소개한다. 또한 제안방법이 V-PCC 에서 약 1%의 부호화 효율을 얻을 수 있음을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.721-726
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• 2011

The compression performance of HEVC (high efficiency video coding) is improved 40%, compared to H.264/AVC. Since the existing 3D video CODEC is based on H.264/AVC or MPEG-2, we can improve the compression performance when we use the proposed stereoscopic video coding method based on HEVC. Since the stereoscopic video has the temporal and inter-view correlations, the videos of the left and right cameras encode together to improve the performance. Especially, we implemented the proposed technique using HM(HEVC test model) 3.4. To compare the performance of the proposed method, we only compare the right view video which is coded using the inter-view prediction. The proposed method which is considered inter-view correlation is improved the performance which BDBR reduce about 36.24% and BDPSNR increase approximately 1.19 dB compared to the separated-coding method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.812-815
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• 2009

This paper discusses a searching method for special markers attached with persons in a surveillance video stream. The marker is a small plate with infrared LEDs, which is called a spatiotemporal marker because it shows a 2-D sequential pattern synchronized with video frames. The search is based on the motion vectors which is the same as one in video compression. The experiments using prototype markers show that the proposed method is practical. Though the method is applicable to a video stream independently, it can decrease total computation cost if motion vector analyses of a video compression and the proposed method is unified.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.521-530
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• 2003

Various multimedia application services have been developed with techniques of high speed networks and computer. Among these services, a video-conference system over internet is useful and important, and its standardization has been shown in ITU-T H.323 and IETF SIP. H.323 standardization is currently used in many products, but two standardizations will coexist for a long time. Since the interoperability is needed between two standardizations, H.323-SIP gateway is developed for it. In audition, a video-conference system supporting two standardizations is necessary to be developed. We have implemented the video-conference terminal supporting both ITU-T H.323 and IETF SIP standardizations over internet. The system implementation has been designed using the common modules of two standardizations maximally, and the interoperability among different systems is satisfied through experiments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.13-18
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• 2017

With the advancement of internet technology, the importance of data protection is gaining more attention. As a possible data protection solution, we propose a novel video encryption method using complemented maximum-length cellular automata (C-MLCA). The first step for encryption is to use 90/150 CA rule to generate a transition matrix T of a C-MLCA state followed by a 2D C-MLCA basis image. Then, we divide the video into multiple frames. Once, we perform exclusive-OR operation with the split frames and the 2D basis image, the final encrypted video can be obtained. By altering values of pixel, the fundamental information in visualizing image data, the proposed method provides improved security. Moreover, we carry out some computational experiments to further evaluate our method where the results confirm its feasibility.

• The KIPS Transactions:PartD
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• v.14D no.7
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• pp.801-808
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• 2007

Video coding standards such as MPEG-2, MPEG-4, H.263, and H.264 transmit a compressed video data using wired/wireless communication line with limited bandwidth. Because highly compressed bit-streams is likely to fragile to error from channel noise, video is damaged by error. There have been many research works on error concealment techniques, which recover transmission errors at decoder side [1, 2]. We designed an error concealment technique for lost motion vectors of H.264 video coding. In this paper, we propose a Kalman filter based motion vector recovery scheme, and experimented with standard video sequences. The experimental results show that our scheme restores original motion vector with more precision of 0.91 - 1.12 on average over conventional H.264 decoding with no error recovery.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.17-32
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• 1996

In this paper, a model for two-layered video traffic is proposed. The performance analysis of the proposed model and the effects of two-layer coding scehemes in ATM networks are also studied. ATM-based networks give the possibility to support image codingat variable bit rate(VBR). Two layer coding is one of the very promising methods among many proposed methods to compensate the cell loss, the major drawback in ATM networks. From the experimental data of the 2-layer coded video traffics, it is observed that traffic patterns of base layer and enhanced layer are highly correlate to each other, when constant image quality is kept. With this observation, coded two layered video traffic can be modeled as 2-dimensional Markov chain. The model well fit the real experimental data. The model was used for the analysis of the performance of statistical multiplexer with priorites in ATM networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3558-3577
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• 2017

In 2D-to-3D video conversion process, the virtual left and right view can be generated from 2D video and its corresponding depth map by depth image based rendering (DIBR). The depth map plays an important role in conversion system, so the copyright protection for depth map is necessary. However, the provided virtual views may be distributed illegally and the depth map does not directly expose to viewers. In previous works, the copyright information embedded into the depth map cannot be extracted from virtual views after the DIBR process. In this paper, a new copyright protection scheme for the depth map is proposed, in which the copyright information can be detected from the virtual views even without the depth map. The experimental results have shown that the proposed method has a good robustness against JPEG attacks, filtering and noise.