• Title/Summary/Keyword: intraframe coding

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Fast Intraframe Coding for High Efficiency Video Coding

  • Huang, Han;Zhao, Yao;Lin, Chunyu;Bai, Huihui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.3
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    • pp.1093-1104
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    • 2014
  • The High Efficiency Video Coding (HEVC) is a new video coding standard that can provide much better compression efficiency than its predecessor H.264/AVC. However, it is computationally more intensive due to the use of flexible quadtree coding unit structure and more choices of prediction modes. In this paper, a fast intraframe coding scheme is proposed for HEVC. Firstly, a fast bottom-up pruning algorithm is designed to skip the mode decision process or reduce the candidate modes at larger block size coding unit. Then, a low complexity rough mode decision process is adopted to choose a small candidate set, followed by early DC and Planar mode decision and mode filtering to further reduce the number of candidate modes. The proposed method is evaluated by the HEVC reference software HM8.2. Averaging over 5 classes of HEVC test sequences, 41.39% encoding time saving is achieved with only 0.77% bitrate increase.

Improved Intraframe Coding Method based on H.263 Annex I (H.263 Annex I 기반 화면내 부호화 기법의 성능개선)

  • 유국열
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.213-216
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    • 2001
  • The H.263 Annex I method for the intraframe coding is based on the prediction in DCT domain, unlike JPEG, MPEG-1, and MPEG-2 where the intraframe coding uses block DCT, independent of the neighboring blocks. In this paper, we show the ineffectiveness of H.263 Annex I prediction method by mathematically deriving the spatial domain meaning of H.263 Annex I prediction method. Based on the derivation, we propose a prediction method which is based on the spatial correlation property of image signals. From the experiment and derivation, we verified the proposed method.

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Efficient Correlation Noise Modeling and Performance Analysis for Distributed Video Coding System (분산 동영상 부호화 시스템을 위한 효과적인 상관 잡음 모델링 및 성능평가)

  • Moon, Hak-Soo;Lee, Chang-Woo;Lee, Seong-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.6C
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    • pp.368-375
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    • 2011
  • In the distributed video coding system, the parity bits, which are generated in encoders, are used to reconstruct Wyner-Ziv frames. Since the original Wyner-Ziv frames are not known in decoders, the efficient correlation noise modeling for turbo or LDPC code is necessary. In this paper, an efficient correlation noise modeling method is proposed and the performance is analyzed. The method to estimate the quantization parameters for key frames, which are encoded using H.264 intraframe coding technique, is also proposed. The performance of the proposed system is evaluated by extensive computer simulations.

A Hierarchical Mode Decision Method for H.264 Intra Image Coding

  • Liu, Jiantan;Yoo, Kook-Yeol
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.05a
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    • pp.297-300
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    • 2007
  • Due to its impressive compression performance, the H.264 video coder is highlighted in the video communications industry, such as DMB (Digital Multimedia Broadcasting), PMP (Portable Multimedia Player), etc. The main bottleneck to use the H.264 coder lays in the computational complexity, i.e. five times more complex than the market leading MPEG-4 Simple Profile codec. In this paper, we propose the hierarchical mode decision method for intraframe coding for the reduction of the computation complexity of the encoder. By determining the mode group early, the propose algorithm can skip the computationally demanding computation in the mode decision. The proposed algorithm is composed of three steps: $16{\times}16$ mode decision, $4{\times}4$ mode-group decisions, and final mode decision among the selected mode group. The simulation results show that the proposed algorithm achieves 20% to 50% reduction in the computational complexity compared with the conventional algorithm.

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An Image Data Compression Algorithm for a Home-Use Digital VCR Using SBC with Block-Adaptive Quantization (SBC와 블럭 적응 양자화를 이용한 가정용 디지탈 VCR 영상 압축 알고리듬)

  • 김주희;서정태;박용철;이제형;윤대희
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.9
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    • pp.124-132
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    • 1994
  • An image data compression method for a digital VCR must satisfy special requirements such as high speed playback. various edting capabilities and error concealment to provide immunity to tape dropouts. Taking these requirements requirements into consideration, this paper proposes a new interframe subband coding algorithm for a digital VCR. In the proposed method, continuous input images are fist partitioned into four frequency bands. The lowest frequency subband is coded with 3-D block adaptive quantization that removes the level redundancy within each level. The other higher frequency subbands are coded by an intraframe coding method using the property of the human visual system. To keep reasonable image quality in high speed palyback, a segment forming method in the frequency domaing is also proposed Computer simulation results demonstrate that the proposed algorithm has the potential of achieving virtually lossless compression in normal play and produces an image with less mosaic errors in high speed play.

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Improved DCT Coefficient Prediction Method for H.263-based Intraframe Coding (DCT 계수 예측을 이용한 H.263기반 화면내 부호화 성능 개선)

  • 유국열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.8B
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    • pp.1168-1175
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    • 2001
  • H.263부호기에서 정지영상 부호화를 위한 부가 부호기법인 Annex I는 기존의 JPEG, MPEG-1, -2와는 달리 부호화하고자 하는 현재 블록의 DCT 계수를 기부호화된 블록의 DCT 계수들을 이용하여 예측부호화 (Differential Pulse Coded Modulation; DPCM)를 행하고, 이를 통한 부호화 이득의 향상을 얻고 있다. 본 논문에서는 이런 H.263 Annex I의 예측기법을 공간영역에서의 의미를 수학적으로 유도한다. 이를 통해서 H.263 Annex I의 예측기법의 비효율성을 지적하고, 영상신호의 특성에 맞게 예측방식을 수정한다. 제안된 DCT 계수 예측 방식과 기존의 H.263 Annex I 방식의 이론적인 예측성능을 평가하고, H.263 부호기에 적용하여 제안방식의 효율성을 검증한다.

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A Study on Intra/Interframe Vector Quantized Block Truncation Coding for Image Data Compression (화상데이터 압축을 위한 프레임내/프레임간 벡터양자화된 블록절단부호화에 관한 연구)

  • Ko, Hyung Hwa;Lee, Choong Woong
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.5
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    • pp.732-736
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    • 1986
  • This paper propose a novel vector-quantized block truncation coder for image data compression. A data compression ratio of about 3-6 times larger than that of the BTC can be achieved by utilizign a vector quantizer with the BTC. A vector quantizer was realized by computer simulation. The compressed data rate of 0.7~1.0 bit/pel with intraframe coder and that of 0.3~0.5 bit/pel with interframe coder gives a good performance.

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Baseline based Binary Shape Coder (기준선 기반 이진 형상 부호화기)

  • 이시화;조대성;조유신;손세훈;장의선;신재섭;서양석
    • Journal of Broadcast Engineering
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    • v.2 no.2
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    • pp.114-124
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    • 1997
  • In object based coding, binary shape ccx:ling plays an important role by ccx:ling the outer shape of object. Here we propose a new shape ccx:ling tool, which enccx:les the outline of shape from a baseline. Different from 2-D (Vertex) shape ccx:ling algorithms. the proposed method encodeds the data that are extracted in a I-D fashion. The enccx:led data consist of the starting position, distance lists, and turning point lists. In the lossless ccx:ling mode, every contour pixel is input for ccx:ling, whereas variable sampling has been employed to enccx:le fewer contour pixels while preserving reasonable distortion. For interframe ccx:ling, a fast motion compensation was achieved by use of distance and turning point lists. Subjective viewing tests proved that the proposed method outperforms the current shape ccx:ling standard, CAE, in MPEG-4. In objective results for compression efficiency, the proposed method was significantly better in intraframe coding than CAE, whereas CAE was better in interframe ccx:ling.

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Intra MB Prediction Mode Decision Method for Fast MPEG-2 to H.264/AVC Transcoding (고속 MPEG-2-H.264/AVC 변 환부호화를 위한 화면내 MB 예측 모드 결정 기법)

  • Liu, Xingang;Yoo, Kook-Yeol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12C
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    • pp.1046-1054
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    • 2008
  • Since the high quality digital TV systems are broadly deployed in the market, the digital video contents will be edited and distributed in MPEG-2 MP@HL fonnat. Due to its impressive coding efficiency, the H.264/AVC codec has rapidly replaced the MPEG-4 SP codec for mobile digital video terminal with low quality. For the bro ad distribution of digitial video contents produced in MPEG-2 format, the MPEG-2 to H.264/AVC transcoding is highly necessary nowadays. In this paper, we propose a fast intra MB prediction mode decision method to reduce the computational complexity in the transcoding, which is the main bottleneck in the transcoders. The proposed method is based on the several relationships such as DCT coefficients and edge orientation, correlation between prediction directions in the $Intra16{\times}16$ and $Intra4{\times}4$ modes, correlation between edge-orientations of luminance an d chrominance components. The simulation results show that the proposed method can reduce the computational complexity upto 70% and 40%, compared with the cascaded transcoder and the well-known fast intraframe transc oder, respectively.