• Title/Summary/Keyword: Error Resilient Coding

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JPEG-2000 Based Error Resilient Entropy Coding Using Rate-Distortion Optimization (율왜곡 최적기법을 이용한 JPEG-2000의 에러강인 엔트로피부호화)

  • 한성욱;최윤식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.4C
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    • pp.541-549
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    • 2004
  • In this paper, a new improved EREC based error resilient coding in JPEG-2000 standard is proposed, considering the error sensitive wireless environment with limited channel capacity. In order to apply EREC, we use the variable bit-rate by using R-D optimization. Simulation results demonstrate that the proposed EREC based error resilient coding is more resilient than the error resilient schemes used in JPEG-2000.

Multiple Description Coding using Whitening Transform (Whitening Transform을 이용한 Multiple Description Coding)

  • 최광표;이근영
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.41-44
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    • 2002
  • In the communications systems with diversity, we are commonly faced on needing of new source coding technique, error resilient coding. The error resilient coding addresses the coding algorithm that has the robustness to unreliability of communications channel. In recent years, many error resilient coding techniques were proposed such as data partitioning, resynchronization, error detection, concealment, reference picture selection and multiple description coding (MDC). In this paper, we proposed an MDC using whitening transform. The conventional MDC using correlating transform is need additional information to decode the image. But, if an image is transformed using the whitening transform, the additional information is not necessary to transform because the coefficients of whitening transform have uni-variance statistics.

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Multiple Description Coding using Whitening Ttansform

  • Park, Kwang-Pyo;Lee, Keun-Young
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1003-1006
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    • 2002
  • In the communications systems with diversity, we are commonly faced on needing of new source coding technique, error resilient coding. The error resilient coding addresses the coding algorithm that has the robustness to unreliability of communications channel. In recent years, many error resilient coding techniques were proposed such as data partitioning, resynchronization, error detection, concealment, reference picture selection and multiple description coding (MDC). Especially, the MDC using correlating transform explicitly adds correlation between two descriptions to enable the estimation of one set from the other. However, in the conventional correlating transform method, there is a critical problem that decoder must know statistics of original image. In this paper, we propose an enhanced method, the MDC using whitening transform that is not necessary additional statistical information to decode image because the DCT coefficients to apply whitening transform to an image have uni-variance statistics. Our experimental results show that the proposed method achieves a good trade-off between the coding efficiency and the reconstruction quality. In the proposed method, the PSNR of images reconstructed from two descriptions is about 0.7dB higher than conventional method at the 1.0 BPP and from only one description is about 1,8dB higher at the same rate.

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Error Resilience Coding Techniques for Mobile Videotelephony (모바일 화상통신을 위한 오류강인 부호화 기법)

  • Suh, Jae-Won
    • The Journal of the Korea Contents Association
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    • v.7 no.12
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    • pp.303-310
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    • 2007
  • Compressed video bitstreams are intended for real-time transmission over communication networks. Because video compression algorithms eliminate the temporal, spatial, and statistical redundancies, the coded video bitstreams are very sensitive to transmission errors. We propose an error resilient video coding technique to limit the effect of error propagation in low bit-rate video coding. The success of error resilient coding techniques relies on how accurately the transmission errors can be detected. To detect the transmission error, we propose a very simple error detection technique based on data hiding Next, we conceal the corrupted MB data using intra MB refresh and motion compensation with the estimated motion vector and compare the simulation results. This method will be useful in video communication in error Prone environment such as WCDMA networks.

An Improvement of Still Image Quality Based on Error Resilient Entropy Coding for Random Error over Wireless Communications (무선 통신상 임의 에러에 대한 에러내성 엔트로피 부호화에 기반한 정지영상의 화질 개선)

  • Kim Jeong-Sig;Lee Keun-Young
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.3 s.309
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    • pp.9-16
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    • 2006
  • Many image and video compression algorithms work by splitting the image into blocks and producing variable-length code bits for each block data. If variable-length code data are transmitted consecutively over error-prone channel without any error protection technique, the receiving decoder cannot decode the stream properly. So the standard image and video compression algorithms insert some redundant information into the stream to provide some protection against channel errors. One of redundancies is resynchronization marker, which enables the decoder to restart the decoding process from a known state in the event of transmission errors, but its usage should be restricted not to consume bandwidth too much. The Error Resilient Entropy Code(EREC) is well blown method which can regain synchronization without any redundant information. It can work with the overall prefix codes, which many image compression methods use. This paper proposes EREREC method to improve FEREC(Fast Error-Resilient Entropy Coding). It first calculates initial searching position according to bit lengths of consecutive blocks. Second, initial offset is decided using statistical distribution of long and short blocks, and initial offset can be adjusted to insure all offset sequence values can be used. The proposed EREREC algorithm can speed up the construction of FEREC slots, and can improve the compressed image quality in the event of transmission errors. The simulation result shows that the quality of transmitted image is enhanced about $0.3{\sim}3.5dB$ compared with the existing FEREC when random channel error happens.

A New Data Partitioning of DCT Coefficients for Error-resilient Transmission of Video (비디오의 에러내성 전송을 위한 DCT 계수의 새로운 분할 기법)

  • Roh, Kyu-Chan;Kim, Jae-Kyoon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.6
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    • pp.585-590
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    • 2002
  • In the typical data partitioning for error-resilient video coding, motion and macroblock header information is separated from the texture information. It can be an effective tool for the transmission of video over the error prone environment. For Intra-coded frames, however, the loss of DCT (discrete cosine transform) coefficients is fatal because there is no ther information to reconstruct the corrupted macroblocks by errors. For Inter-coded frames, when error occurs in DCT coefficients, the picture quality is degraded because all DCT coefficients are discarded in those packets. In this paper, we propose an efficient data partitioning and coding method for DCT-based error-resilient video. The quantized DCT coefficients are partitioned into the even-value approximation and the remainder parts. It is shown that the proposed algorithm provides a better quality of the high priority part than the conventional methods.

Subblock Based Temporal Error Concealment of Intra Frame for MPEG-2 (서브 블록을 이용한 MPEG-2 인트라 프레임의 시간적 오류 은닉)

  • Ryu, Chul;Kim, Won-Rak
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.167-169
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    • 2005
  • The occurrence of a single bit error in transmission bitstream leads to serious temporal and spatial errors. Because moving picture coding as MPEG-2 based on block coding algorithm uses variable length coding and motion compensation coding algorithm. In this paper, we propose algorithm to conceal occurred error of I-frames in transmission channel using data of the neighboring blocks in decoder. We divide a damaged macroblock of I-frame into four sub blocks and compose new macroblock using the neighboring blocks for each sub block. We estimate the block with minimum difference value through block matching with previous frame for new macroblocks and replace each estimated block with damaged sub block in the same position. Through simulation results, the proposed algorithm will be applied to a characteristic of moving with effect and shows better performance than conventional error concealment algorithms from visual and PSNR of view.

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Novel Motion Estimation Technique Based Error-Resilient Video Coding (새로운 움직임 예측기법 기반의 에러 내성이 있는 영상 부호화)

  • Hwang, Min-Cheol;Kim, Jun-Hyung;Ko, Sung-Jea
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.108-115
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    • 2009
  • In this paper, we propose a novel true-motion estimation technique supporting efficient frame error concealment for error-resilient video coding. In general, it is important to accurately obtain the true-motion of objects in video sequences for effectively recovering the corrupted frame due to transmission errors. However, the conventional motion estimation (ME) technique, which minimizes a sum of absolute different (SAD) between pixels of the current block and the motion-compensated block, does not always reflect the true-movement of objects. To solve this problem, we introduce a new metric called an absolute difference of motion vectors (ADMV) which is the distance between motion vectors of the current block and its motion-compensated block. The proposed ME method can prevent unreliable motion vectors by minimizing the weighted combination of SAD and ADMV. In addition, the proposed ME method can significantly improve the performance of error concealment at the decoder since error concealment using the ADMV can effectively recover the missing motion vector without any information of the lost frame. Experimental results show that the proposed method provides similar coding efficiency to the conventional ME method and outperforms the existing error-resilient method.

Error Resilient Performance Evaluation of MPEG-4 and H.264/AVC (MPEG-4 와 H.264/AVC의 에러 강인 기술 성능 평가)

  • 정봉수;황영휘;전병우;김명돈;최송인
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.203-216
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    • 2004
  • Recent advances in video coding technology have resulted in rapid growth of application in mobile communication, With this explosive growth reliable transmission and error resilient technique become increasingly necessary to offer high quality multimedia service. In this paper, we present the result of our investigation on the error resilient performance evaluation of the MPEG-4 simple profile under the H.324/M and the H.264/AVC baseline under the IP packet networks. Especially, we have tested error resilient tools of MPEG-4 simple profile such as resynchronization marker insertion, data partitioning, and of H.264/AVC baseline such as the flexible macroblock ordering (FMO) scheme. The objective quality of decoded video is measured in terms of rate and PSNR under various random bit and burst error conditions.

Error-Resilient Video Transmission Techniques over Unreliable Networks (비 신뢰성 네트워크에서 에러를 극복하는 비디오 전송 기법)

  • 노경택
    • Journal of the Korea Society of Computer and Information
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    • v.6 no.3
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    • pp.50-55
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    • 2001
  • We review error resilience techniques for real-time video transport over unreliable networks. For error control on the source coding level, each decoder has to make provisions for error detection, resynchronization. and error concealment. and we review techniques suitable for that purpose. Further, techniques are discussed for intelligent processing of acknowledgment information by the coding control to adapt the source coder to the channel. We review and compare error tracking, error confinement. and reference picture selection techniques for channel-adaptive source coding. We review how feedback-based source codings are related with the precompressed video stored on a media server

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