• Title, Summary, Keyword: Fast Intra Mode Decision

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Fast Intra Prediction Mode Decision for HEVC (HEVC의 고속 화면내 예측 모드 결정 기법)

  • Kim, Dong-Hyun;Kim, Jae-Gon
    • The Journal of the Korea Contents Association
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    • v.14 no.9
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    • pp.102-109
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    • 2014
  • Intra prediction in HEVC is also significantly improved from H.264/AVC with the increased prediction modes up to 35 that results in increase of the complexity cost. Hence, a fast intra mode decision algorithm is required for real-time applications. A fast intra mode decision is proposed in this paper for further complexity reduction in addition to the RMD (Rough Mode Decision) that has been adopted into the HEVC reference software, referred to as HM, for fast intra prediction. The proposed method reduces the complexity of intra mode decision by limiting the number of search modes in both steps of RMD and the final mode decision. Experimental results show that the proposed method provide about 13.2% encoding time reduction with 1.0% BD-rate increase on average over test sequences in HM 12.0.

Fast Mode Decision in H.264/AVC Using Adaptive Selection of Reference Frame and Selective Intra Mode (다중 참조 영상의 적응적 선택 및 선택적 인트라 모드를 이용한 H.264/AVC의 고속 모드 결정 방법)

  • Lee Woong-Ho;Lee Jung-Ho;Cho Ik-Hwan;Jeong Dong-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3C
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    • pp.271-278
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    • 2006
  • Rate-constrained coding is one of the many coding-efficiency oriented tools of H.264/AVC, but mode decision process of RDO(Rate distortion optimization) requires high computational complexity. Many fast mode decision algorithms have been proposed to reduce the computational complexity of mode decision. In this paper, we propose two algorithms for reduction of mode decision in H.264/AVC, which are the fast reference frame selection and selective intra prediction mode decision. Fast reference frame selection is efficient for inter predication and selective intra prediction mode decision can effectively reduce excessive calculation load of intra prediction mode decision. The simulation results showed that the proposed methods could reduce the encoding time of the overall sequences by 44.63% on average without any noticeable degradation of the coding efficiency.

A Fast Intra-Prediction Method in HEVC Using Rate-Distortion Estimation Based on Hadamard Transform

  • Kim, Younhee;Jun, DongSan;Jung, Soon-Heung;Choi, Jin Soo;Kim, Jinwoong
    • ETRI Journal
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    • v.35 no.2
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    • pp.270-280
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    • 2013
  • A fast intra-prediction method is proposed for High Efficiency Video Coding (HEVC) using a fast intra-mode decision and fast coding unit (CU) size decision. HEVC supports very sophisticated intra modes and a recursive quadtree-based CU structure. To provide a high coding efficiency, the mode and CU size are selected in a rate-distortion optimized manner. This causes a high computational complexity in the encoder, and, for practical applications, the complexity should be significantly reduced. In this paper, among the many predefined modes, the intra-prediction mode is chosen without rate-distortion optimization processes, instead using the difference between the minimum and second minimum of the rate-distortion cost estimation based on the Hadamard transform. The experiment results show that the proposed method achieves a 49.04% reduction in the intra-prediction time and a 32.74% reduction in the total encoding time with a nearly similar coding performance to that of HEVC test model 2.1.

Fast Intra Mode Decision Algorithm for Depth Map Coding using Texture Information in 3D-AVC (3D-AVC에서 색상 영상 정보를 이용한 깊이 영상의 빠른 화면 내 예측 모드 결정 기법)

  • Kang, Jinmi;Chung, Kidong
    • Journal of Korea Multimedia Society
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    • v.18 no.2
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    • pp.149-157
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    • 2015
  • The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.

Hierarchical Fast Mode Decision Algorithm for Intra Prediction in HEVC (HEVC 화면 내 예측을 위한 계층적 고속 모드 결정 알고리즘)

  • Kim, Tae Sun;Sunwoo, Myung Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.6
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    • pp.57-61
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    • 2015
  • This paper proposes a fast intra prediction algorithm for the High Efficiency Video Coding (HEVC). HEVC has 35 modes, such as DC mode, Planar mode, and 33 angular modes for the intra-prediction. To reduce the complexity and to support fast decision for intra prediction, this paper proposes a hierarchical mode decision method (HMD). The proposed HMD mainly focuses on how to reduce the number of prediction modes. The experimental results show that the proposed HMD can reduce the encoding time about 39.17% with little BDBR loss. On average, the proposed HMD can achieve the encoding time saving e about 14.13 ~ 19.37% compared to that of the existing algorithms with slightly increasing 0.01 ~ 0.42% BDBR.

Fast Intra Mode Decision using Transform Coefficients (변환 계수를 이용한 고속 인트라모드 결정법)

  • Hwang Gyu-Yong;Park Jong-Bin;Jeon Byeung-Woo
    • 한국정보통신설비학회:학술대회논문집
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    • pp.255-258
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    • 2006
  • In the H.264/AVC standard, intra prediction increases the coding efficiency of intra macroblocks and by applying rate-distortion optimization to each macroblock, it is possible to choose Inter or Intra encoding adaptively. This sort of encoding scheme, however, increases encoding complexity dramatically and causes troubles in practical applications of the real-time mobile environment. In order to decrease the complexity, variety of methods is proposed but most of those take only its current block into consideration for selecting candidate modes which naturally causes degradation in PSNR (Peak Signal to Noise Ratio). The proposed fast intra mode decision finds the candidate modes by analyzing transformed coefficients of neighboring blocks stored in the buffer at the encoder stage of input sequences. We verify this proposed scheme in complexity, PSNR and bit-rate.

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Fast Intra Prediction Mode Decision based on Rough Mode Decision and Most Probable Mode in HEVC (Rough Mode Decision과 Most Probable Mode에 기반을 둔 HEVC 고속 인트라 예측 모드 결정 방법)

  • Lee, Seung-Ho;Park, Sang-Hyo;Jang, Euee Seon
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.158-165
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    • 2014
  • High Efficiency Video Coding (HEVC), the latest video coding standard, has twice of the compression efficiency compared to AVC/H.264 under the same image quality condition. To obtain the improved efficiency, however, it was adopted for many methods which need complicated calculation, and the time complexity of HEVC was increased more than that of AVC/H.264. To solve this problem, the various fast algorithms have been researched. In this paper, we propose a fast intra prediction mode decision method which uses result of Rough Mode Decision (RMD) and Most Probable Mode (MPM). The proposed method selects a best predicted mode by comparing each predicted directions which are calculated through RMD and MPM. We applied the proposed method to HM 10.0 and conducted an comparing experiment in All-Intra environment. The experiment result showed that total encoding time is reduced by about 26% on average with about a 0.8% loss of BD-rate.

Efficient Intra Modes for Fast Intra Mode Decision of H.264/AVC (H.264/AVC의 고속 인트라 모드 결정을 위한 효과적인 인트라 모드)

  • Lee Woong-ho;Lee Jung-ho;Cho Ik-Hwan;Jeong Dong-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.12C
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    • pp.1144-1152
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    • 2005
  • Intra prediction coding is one of the many coding-efficiency oriented tools of H.264/AVC, but it requires high computational complexity. Many fast intra coding algorithms have been proposed to reduce the computational complexity of intra prediction. While most of them have been focused on the mode decision methods themselves, we propose a fast algorithm in which new intra modes are substituted for the conventional intra modes so that the number of intra modes can be reduced. The simulation results show that the proposed method could reduce the encoding time of the overall sequence by $49\%$ without any noticeable degradation of the coding efficiency.

Fast Intra Mode Decision for H.264/AVC based on Directional Information (방향 정보를 이용한 H.264/AVC의 고속 인트라 모드 결정)

  • Lee, Kyung-Hee;Kim, Jong-Gu;Suh, Jae-Won
    • The Journal of the Korea Contents Association
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    • v.9 no.3
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    • pp.20-27
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    • 2009
  • H.264/AVC video coding standard adapting a rate-distortion optimization technique to select the best coding mode with multi reference frames for each macroblock gets a higher coding efficiency than those of previous video coding standards but the computational complexity increases drastically. Therefore, many fast mode decision algorithms are proposed to reduce the computational complexity. Among them, we propose a fast intra mode decision algorithm based on directional information of I4MB. The proposed algorithm achieves consistent time saving about 15% in IPPP sequences and 44% in all I frame sequences with negligible loss in PSNR and small increment of bit rate compared with that of JM11.0.

Fast Intra-Prediction Mode Decision Algorithm for H.264/AVC using Non-parametric Thresholds and Simplified Directional Masks

  • Kim, Young-Ju
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.501-506
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    • 2009
  • In the H.264/ AVC video coding standard, the intra-prediction coding with various block sizes offers a considerably high improvement in coding efficiency compared to previous standards. In order to achieve this, H.264/AVC uses the Rate-distortion optimization (RDO) technique to select the best intraprediction mode for a macroblock, and it brings about the drastic increase of the computation complexity of H.264 encoder. To reduce the computation complexity and stabilize the coding performance on visual quality, this paper proposed a fast intra-prediction mode decision algorithm using non-parametric thresholds and simplified directional masks. The use of nonparametric thresholds makes the intra-coding performance not be dependent on types of video sequences and simplified directional masks reduces the compuation loads needed by the calculation of local edge information. Experiment results show that the proposed algorithm is able to reduce more than 55% of the whole encoding time with a negligible loss in PSNR and bitrates and provides the stable performance regardless types of video sequences.