• Convergence Security Journal
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• v.11 no.3
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• pp.47-54
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• 2011

To protect SVC(Scalable Video Coding) media, the encryption mechanism need to consider two fundamental issues; First, What is to be encrypted? Second, When encryption is performed with respect to compression? In this paper, we analyze the several encryption approaches with regard to the above issue. And we propose hybrid-based protection mechanism. This mechanism ensures the media scalability, layered access control and reuse protected content. In this experiment the proposed mechanism generates under 3% security overhead against standard scalable video coding.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.650-657
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• 2011

This paper proposes a novel bit allocation algorithm for H.264 scalable extension(SE) based on a human visual system (HVS) to improve the coding efficiency. The proposed algorithm is consist of two stages: visual weighting model and visual weighting-based bit allocation algorithm. In the first stage, the visual weighting for each macroblock (MB) is analyzed according to the region of interests. Then the adaptation of the visual weighting into the bit allocation routine for each quality layer is performed for improving the visual quality. In the simulation results, it is observed that the proposed scheme can improve the subjective and objective video quality in the same bit rate, compared to the previous scalable video coding in H.264.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.129-137
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• 2007

MPEG-4 FGS is one of scalable video coding schemes specified In ISO/IEC 14496-2 Amendment 2, and particularly standardized as a scheme for providing fine granular quality and temporal scalabilities. In this paper, we propose a sign-bit reduction technique in embedded bit-plane coding to enhance the coding efficiency of MPEG-4 FGS system. The general structure of the FGS system for the proposed scheme is based on the standard MPEG-4 FGS system. The proposed FGS enhancement-layer encoder takes as input the difference between the original DCT coefficient and the decision level of the quantizer instead of the difference between the original DCT coefficient and its reconstruction level. By this approach, the sign information of the enhancement-layer DCT coefficients can be the same as that of the base-layer ones at the same frequency index in DCT domain. Thus, overhead bits required for coding a lot of sign information of the enhancement-layer DCT coefficients in embedded bit-plane coding can be removed from the generated bitstream. It is shown by simulations that the proposed FGS coding system provides better coding performance, compared to the MPEG-4 FGS system in terms of compression efficiency.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.45-48
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• 2008

This paper presents a brief overview of scalable video coding (SVC) with a focus on spatial scalability and its application to Advanced Terrestrial-DMB (AT-DMB). By adopting SVC with two spatial-layers and hierarchical modulation, AT-DMB provides standard definition (SD)-level video while maintaining compatability with the existing CIF-level video. In this paper, we suggest a layer-configuration and coding parameters of SVC which are well suit for an AT-DMB system. In order to reduce extremely large encoding time resulted by an exhaustive search of a macroblock coding mode in spatial scalability, we propose a fast mode decision method which excludes redundant modes in each layer. It utilizes the mode distribution of each layer and their correlations. Experimental results show that a simplified encoding model with the method reduces the computational complexity significantly with negligible coding loss.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.190-192
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• 2013

최근 HD(High Definition)화질 및 UHD(Ultra High Definition)화질과 같은 고품질 방송 서비스가 등장하고, 무선 네트워크 기술의 발달로 스마트폰, 태블릿PC 등과 같은 다양한 휴대용 멀티미디어 기기들이 존재함에 따라, 소비자들은 다양한 환경에서 고해상도 영상을 고품질로 사용하기를 원하고 있다. 따라서 스케일러빌러티의 현실적 필요성이 점점 대두되고 있으며, 이에 따라 ISO/IEC의 MPEG(Moving Picture Experts Group)와 ITU-T의 VCEG(Video Coding Experts Group)이 공동으로 결성한 Joint Collaborative Team on Video Coding(JCT-VC)에 의해 시간, 공간, 화질 등이 확장성을 제공하는 Scalable Video Coding(SVC)의 표준화가 진행되고 있다. 이에 본 논문은 공간적, 시간적, 화질적 스케일러빌러티(Scalability)를 제공하기 위한 SHVC의 표준 기술들에 대해 설명하고, 기존 단일 계층 부호화 방식(Single Video Coding)으로 서로 다른 해상도의영상을 Simulcast부호화한 결과와 비교하여 SHVC의 부호화한 결과와 비교하여 SHVC의 보호화 효율에 대한 성능을 분석 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.379-394
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• 2012

The ever-increasing demand for H.264 scalable video coding (H.264/SVC) distribution motivates researchers to devise ways to enhance the quality of video delivered on the Internet. Furthermore, researchers and practitioners in general depend on computer simulators to analyze or evaluate their designed network architecture or proposed protocols. Therefore, a complete toolset, which is called myEvalSVC, for evaluating the delivered quality of H.264/SVC transmissions in a simulated environment is proposed to help the network and video coding research communities. The toolset is based on the H.264 Scalable Video coding streaming Evaluation Framework (SVEF) and extended to connect to the NS2 simulator. With this combination, people who work on video coding can simulate the effects of a more realistic network on video sequences resulting from their coding schemes, while people who work on network technology can evaluate the impact of real video streams on the proposed network architecture or protocols. To demonstrate the usefulness of the proposed new toolset, examples of H.264/SVC transmissions over 802.11 and 802.11e are provided.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.235-238
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• 1995

In this paper, we propose an effective coding method of the angiography by using the scalable structure in the frequency domain for MPACS(Medical Picture Archiving and Communication System). We employed the subband decomposition method and MPEG-2 system which is the international standard coding method of the general moving picture. After the subband decomposition is applied to split an input image into 4 bands in the spatial frequency domain, the motion compensated DPCM coding method of MPEG-2 is carried out for each subband. As a result, an easily controllable coding Structure is accomplished by composing the compound hit stream for each subband group. Follows are the simulation results of the proposed sheme for the angiography. A scalable structure which can be easily controlled for a loss of transmission or the band limit can be accomplisbed in the MPEG-2 stucture by the subband decomposition minimizing the side information. And by reducing the search area of the motion vector between -4 and 3, the processing speed of a codec is enhanced by more than two times without a loss of the picture quality compare with the conventional DCT coefficients decompositon method. And the processing speed is considerably improved in the case of the parallel construction of each subband in the hardware.

• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.225-235
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• 2004

In this paper, we propose a new stereoscopic video coding approach for heterogeneous consumer devices by exploiting the concept of spatio-temporal scalability. The proposed method uses MPEG-2 standard for coding the left or main sequence and an enhanced compatible coding scheme for predicting the P- and B-type of frames of the right or auxiliary sequence. The enhanced compatible coding scheme predicts matching block by interpolating both two forward and backward motion predicted macroblocks and disparity predicted macroblock. To provide flexible stereo video service, we define both a temporally scalable layer and a spatially scalable layer for each eye-view. 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 stereo video service for ubiquitous computing environment where devices and network connections are heterogeneous.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.124-131
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• 2003

In this paper, we propose a Progressive scalable video coding algorithm using frequency weighting in the DCT domain. Since the human visual system (HVS) can be modeled as a nonlinear point transformation, called the modulation transfer function (MTF), we tan use the frequency weighting matrix to enhance the video image quality. We change this frequency weighting matrix into the frequency shift matrix to apply to the bit-plane coding method for the fine granular scalable (FGS) video coding We also define a new error metric JNDE (just noticeable difference) to measure the perceptual image quality in terms of human vision.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.443-444
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• 2007

본 연구에 따른 영상 신호의 처리 방법은, 하나의 화면을 중요도에 따라 복수의 영역들로 분할하는 단계 그리고 분할된 화면들 각각에 대응하는 영상 신호를 서로 다른 프레임을 (Frame-rate)로 디코딩하는 단계를 포함한다. 상술한 영상 신호의 처리 방법에 따라 시야에서 민감한 화면만을 인코딩한 최대 화질로 재생하고 덜 민감한 화면 영역은 상대적으로 낮은 화질로 재생하여 이득을 제공할 수 있다.