• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.231-236
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• 2003

Video conferencing system it is various at internet and uses the reading is become accomplished. Research of like this portion synchronization of audio, the video compression technique and multimedia data, supports the video conference the research of the Mbone of the If multicast for being active, being become accomplished the multimedia service which is various an video from internet, the line speed of communication becomes high-speed anger and to follow leads is become accomplished. The video conference from opening elder brother dispersion internet network environment the problem against the image which is an image conference data and a voice security is serious and it raises its head. To sleep it presents the security method which from the video conference it follows in quality of multimedia data from the dissertation which it sees and it does.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1439-1445
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• 2007

In this paper, we propose a fast motion estimation algorithm using initial matching errors by sorting square sub-blocks to find complex sub-block area adaptively based on partial calculation of SAD(sum of absolute difference) while keeping the same prediction quality compared with the PDE(partial distortion elimination) algorithm. We reduced unnecessary calculations with square sub-block adaptive matching scan based initial SAD calculation of square sub-block in each matching block. Our algorithm reduces about 45% of computations for block matching error compared with conventional PDE(partial distortion elimination) algorithm without any degradation of prediction quality, and for algorithm will be useful to real-time video coding applications using MPEG-4 AVC or MPEG-2.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.315-320
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• 2007

본 논문에서는 동시 접속자 수의 제약과 서버 증설에 의한 고비용 문제를 효과적으로 해결할 수 있는 실시간 웹캐스팅 시스템이 설계 구현된다. 기존의 시스템과는 다르게, 다양한 해상도를 지원할 수 있는 IP 카메라로부터 실시간으로 스트리밍 되는 동영상 데이터를 콘텐츠로 하는 라이브 웹캐스팅과, 저장 공간에 저장된 후, 사용자 요구에 따라 파일 데이터를 콘텐츠로 스트리밍 하는 주문형 비디오(VOD) 서비스 모두를 포함하는 total 시스템이다. 압축률이 높은 마이크로소프트사의 WMV(혹은 VC-1) 형식의 동영상 데이터를 사용함으로써 사용 대역폭을 줄여, 많은 Tuner들을 수용할 수 있도록 하였으며, 각 Tuner는 미디어플레이어를 뷰어로써 사용할 수 있도록 하여 시청자들이 별도의 소프트웨어를 설치하지 않도록 하였다. 가능한 모든 시스템 구성 요소들 또한 마이크로소프트에서 제공되는 유틸리티들을 사용할 수 있도록 하여 기존 시스템과의 호환성을 최대화 시켰으며, 특히, Caster, Distributor, 그리고 Tuner, 3 부분으로 나누어, Caster의 규모, 혹은 Tuner의 규모에 따라 Distributor의 확장이 모듈 단위로 가능하도록 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.946-953
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• 2004

Fast search and conventional boolean matching motion estimation algorithms reduce computational complexity and data processing time but this algorithms have disadvantages that is difficult of implementation of hardware because of high control overhead and that is less performance than Full search Algorithm(FA). This paper present new all binary block matching algorithm, called Bit Converted All Binary Block Matching(BC-ABBM). Proposed algorithm have performance closed to the FA by boolean only block matching that may be very efficiently implemented in hardware for low bit rate video communication. Simulation results show that the PSNR of the proposed algorithm is about 0.04dB loss than FA but is about 0.6 ∼ 1.4dB gain than fast search algorithm and conventional boolean matching algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3C
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• pp.249-255
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• 2007

In general, a large amount of the memory accesses are required for the CAVLC decoding in H.264/AVC. It is a serious problem for the applications such as a DMB and videophone services because the considerable power is consumed for accessing the memory. In order to solve this problem, we propose an efficient decoding method for the coeff-token which is one of the syntax elements of CAVLC. In this paper, the variable length code table is re-designed with the new codewords which are defined by investigating the architecture of the conventional codeword for the coeff_token element. A new coeff_token decoding method is developed based on the suggested table. The simulation results show that the proposed algorithm achieves an approximately 85% memory access saving without video-quality degradation, compared to the conventional CAVLC decoding.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.221-229
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• 2004

We present new digital watermarking scheme that embeds a watermark according to the characteristics of the image or video. The scheme is compatible with established image compression standard. We define a weighting function using a parent-child structure of the DCT coefficients in a block to embed a maximum watermark. The spatio-frequency localization of the DCT coefficients can be achieved with this structure. In the detection stage, we present an optimum a posteriori threshold with a given false detection error probability based on the statistical analysis. Simulation results show that the proposed algorithm is efficient and robust against various signal processing techniques. Especially, they are robust against widely used coding standards, such as JPEG and MPEG.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.165-173
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• 2004

H.264 is the newest international video coding standard that provides high coding efficiency. A macroblock in H.264 has 7 different motion-compensation block sizes in the Inter mode, and several different prediction directions in the Intra mode. In order to achieve as highest coding efficiency as possible, H.264 reference model employs complex mode decision technique based on rate-distortion (RD) optimization which requires high computational complexity. In this paper, we propose two techniques -'early SKIP mode decision' and 'selective intra mode decision' - which can further reduce the computational complexity. Simulation results show that without considerable performance degradation, the proposed methods reduce encoding time by 30% on average and save the number of computing rate-distortion cost by 72%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.389-395
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• 2000

Digital Watermarking is a research area which aims at hiding secret information in digital multimedia content such as images, audio, and video. In this paper, we propose a new watermarking method with visually recognizable symbols into the digital images using wavelet transform, spread spectrum method and multilevel threshold value in considering the wavelet coefficients. The information of watermark can be extracted by subtracting wavelet coefficients with the original image and the watermarked image. The results of this experiment show that the proposed algorithm was superior to other similar watermarking algorithms. We showed Watermarking algorithm in JPEG lossy compression, resizing, LSB(Least Significant Bit) masking, and filtering.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.96-100
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• 1998

Due to expected wide spread use of DCT based image/video coding standard, it is advantageous to process data directly in the DCT domain rather than decoding the source back to the spatial domain. The block processing algorithm provides a parallel processing method since multiple input data are processed in the block filter structure. Hence a fast implementation of the algorithm is well suited. In this paper, we propose the JPEG browse by Block Transform Domain Filtering(BTDF) using subband filter banks. Instead of decompressing the entire image to retrieve at full resolution from compressed format, a user can select the level of expansion required$(2^N{\times}2^N)$. Also this approach reduces the computer cpu time by reducing the number of multiplication through BTDF in the filter banks.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.500-504
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• 2013

In this paper, we have developed the application of a remote multi-lingual video guide that allows interaction with Set Top Box of a thin client by using the WebRTC, an web browser-based communication method. A server accesses a web camera in conjunction with digital information display of a thin client connected remotely and is exchanged guide information with user. This server can be played in thin client STB using virtualization based the high-quality video compression technology. Further, it is not dependent on the performance of the STB and provides a video guide remotely.