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

• The KIPS Transactions:PartB
• /
• v.18B no.5
• /
• pp.249-254
• /
• 2011

FGS (fine granularity scalability) supporting scalability in MPEG-4 Part 2 is a scalable video coding scheme that provides bit-rate adaptation to varying network bandwidth thereby achieving of its optimal video quality. In this paper, we proposed FGS coding scheme which performs one more bit-plane coding for residue signal occured in the enhancement-layer of the basic FGS coding scheme. The experiment evaluated in terms of video quality scalability of the proposed FGS coding scheme by comparing with FGS coding scheme of the MPEG-4 verification model (VM-FGS). The comparison was conducted by analysis of PSNR values of three tested video sequences. The results showed that when using rate control algorithm VM5+, the proposed FGS coding scheme obtained Y, U, V PSNR of 0.4 dB, 9.4 dB, 9 dB averagely higher and when using fixed QP value 17, obtained Y, U, V PSNR of 4.61 dB, 20.21 dB, 16.56 dB averagely higher than the existing VM-FGS. From results, we found that the proposed FGS coding scheme has higher video quality scalability to be able to achieve video quality from minimum to maximum than VM-FGS.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.12C
• /
• pp.1173-1183
• /
• 2006

In this paper, we propose an efficient method for improving visual quality of AR-FGS (Adaptive Reference FGS) which is adopted as a key scheme for SVC (Scalable Video Coding) or H.264 scalable extension. The standard FGS (Fine Granularity Scalability) adopts AR-FGS that introduces temporal prediction into FGS layer by using a high quality reference signal which is constructed by the weighted average between the base layer reconstructed imageand enhancement reference to improve the coding efficiency in the FGS layer. However, when the enhancement stream is truncated at certain bitstream position in transmission, the rest of the data of the FGS layer will not be available at the FGS decoder. Thus the most noticeable problem of using the enhancement layer in prediction is the degraded visual quality caused by drifting because of the mismatch between the reference frame used by the FGS encoder and that by the decoder. To solve this problem, we exploit the principle of cyclical block coding that is used to encode quantized transform coefficients in a cyclical manner in the FGS layer. Encoding block coefficients in a cyclical manner places 'higher-value' bits earlier in the bitstream. The quantized transform coefficients included in the ealry coding cycle of cyclical block coding have higher probability to be correctly received and decoded than the others included in the later cycle of the cyclical block coding. Therefore, we can minimize visual quality degradation caused by bitstream truncation by adjusting weighting factor to control the contribution of the bitstream produced in each coding cycle of cyclical block coding when constructing the enhancement layer reference frame. It is shown by simulations that the improved AR-FGS scheme outperforms the standard AR-FGS by about 1 dB in maximum in the reconstructed visual quality.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.3 s.303
• /
• pp.31-40
• /
• 2005

In this paper, we develop an approach toward JSC(Joint Source-Channel Coding) method for MPEG-4 based FGS(Fine Granular Scalability) video coding and transmission in fixed and mobile receiving environment(Digital Audio Broadcasting, DAB). The source coder used MPEG-4 FGS video codec, the channel coder used RCPC(Rate Compatible Punctured Convolution) code and the modulation method used QPSK modulation. We have considered channel environment of AWGN and mobile receiving environment. This study determined optimum Trade-off point between source bit rate and channel coding rate in variable channel states. We compared FGS-JSC method and general single layer CBR(Constant Bit Rate) transmission. In this results, FGS-JSC was appeared better performance than CBR transmission.

• Journal of Broadcast Engineering
• /
• v.6 no.3
• /
• pp.225-233
• /
• 2001

Real-time video communication applications over Internet should be able to support such functionality as scalability because of the unpredictable and varying channel bandwidth between server and client. To accommodatethe wide variety of channel bitrates, a new scalable coding tool, namely the Fine Granular Scalability (FGS) coding tool has been reduce the adopted In the MPEG-4 video standard. This paper presentsa new FGS algorithm with matching Pursuit that can reduce the computational complexity of ordinal matching pursuit-based algorithm. The Proposed coding algorithm can make trade-off between Picture Quality and computationalcomplexity. Our simulation result shows that the proposed algorithm can reduce the computational cumplexity up to 1/5 compared to the conventional FGS method while retaining a similar picture quality.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.40 no.6
• /
• pp.124-131
• /
• 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 Korea Information Processing Society Conference
• /
• 2008.11a
• /
• pp.175-178
• /
• 2008

MPEG-4 Part 2 에서 표준으로 채택된 FGS (fine granularity scalability) 코딩 기법은 전송 선로의 상태가 급변하는 경우에도 주어진 대역폭에서 최적의 화질 향상을 얻을 수 있도록 설계된 망 상태에 적응적인 스케일러블 비디오 코딩 기법이다 [1][2][9]. 본 논문에서는 기존의 FGS 향상 계층에서 영상의 잔여 신호를 다시 한 번 bit-plane 코딩을 해줌으로써 화질 확장성을 더 높인 Advanced FGS 코딩 구조를 제안하였다. 본 논문의 실험에서는 기존의 MPEG-4 VM (verification model)에서 사용된 FGS 코딩과의 비교를 통해 Advanced FGS 구조의 화질 확장성을 평가하였다. 비교는 두 부호화 기술의 PSNR 값의 분석으로 이루어졌고, 결과를 통해 Advanced FGS 구조가 고화질을 가지며, 화질 확장성이 더 높은 구조임을 알 수 있었다.

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.3
• /
• pp.318-327
• /
• 2002

This paper Introduces a new scanning method for network-adaptive scalable streaming video coding methodologies such as the MPEG-4 Fine Granular Scalable (FGS) Coding. Proposed scanning method can guarantee the subjectively improved picture quality of the region of the interest in the decoded video by managing the image information of that interested region to be encoded and transmitted most-preferentially, and also to be decoded most-preferentially. Proposed scanning method can lead the FGS coding method to achieve improved picture quality, in about 1dB ~ 3dB better, especially on the region of interest.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.795-798
• /
• 2002

본 논문에서는 MPEG-4 표준에서 채택된 FGS(Fine Granualrity Scalability)를 이용한 계층적 비디오 부호화 방법을 적용하였다. MPEG-4 FGS는 인터넷에서 이용되는 다양한 특성의 단말기들과 대역폭 변통에서 유연성 있는 기술이다. 적용된 MPEG-4 FGS 기술은 DCT 기반 비트 평면 부호화를 이용한다. 실험에서는 일반적인 SNR 계층 비디오 코딩(Multi-layered SNR scalable video coding)과의 비교를 통해 FGS의 효율성을 평가한다. 비교는 두 부호화 기술의 PSNR 값의 분석을 가지고 이루어졌고 MPEG-4 FGS 기술이 이전의 다층 SNR계층 비디오 부호화 방법보다 평균 $1\sim2dB$ 정도의 높은 값으로 나타났다. 이를 동해 MPEG-4 FGS가 효율성면에서 다층 SNR계층 비디오 부호화 방법보다 우수함을 알 수 있지만, 단일 계층부호화(Single-layered scalable video coding)에 비해서는 효율성이 낮게 나타났다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.8A
• /
• pp.625-632
• /
• 2009

This paper presents the mobile IPTV system for the transmission of FGS-encoded video stream over WiMAX network. The proposed system is implemented to provide more subscribers with an improved mobile IPTV service considering the scarce resource constraint. The proposed system pursues an efficient tradeoff between the number of subscribers that receive the enhancement layer stream and their IPTV service quality. In the proposed system, some parts of the enhancement layer are transmitted with the modulation scheme and the coding rate adaptive to wireless link states of subscribers. Finally, experimental results are provided to show the performance of proposed mobile IPTV system.