• Title/Summary/Keyword: Fast Intra Mode Decision

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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.

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 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 mode decision using DCT coefficient distribution in H.264/AVC (H.264/AVC에서 DCT계수 분포를 이용한 고속 인트라 모드 결정 방법)

  • Hong, Sung-Wook;Lee, Yung-Lyul
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.582-590
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    • 2010
  • he rate-distortion optimization (RDO) method in the H.264/AVC encoder is a technology that improves the coding efficiency, but increases the computational complexity. In this paper, a fast Intra mode decision algorithm using DCT (Discrete Cosine Transform) coefficients distribution is proposed to reduce the H.264 encoder complexity. The proposed method reduces the encoder complexity on average 68.40%, while the coding efficiency is slightly decreased compared with the H.264/AVC encoder.

Fast Intra Mode Decision Algorithm Using Neighboring Block (주변 블록을 이용한 고속 화면내 모드 결정 알고리즘)

  • Kim, Younjoo;Seo, Young-Ho;Kim, Dong-Wook
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.222-223
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    • 2014
  • 본 논문에서는 HEVC의 화면내 모드에서 예측을 수행할 블록의 주변적 특성을 이용한 고속 모드 결정 알고리즘을 제안한다. 기존의 화면내 예측 방법으로는 33가지 방향성 예측방법과 두 가지의 무 방향성 방법을 이용하게 된다. 이때 최적의 예측 모드를 선택하기 위하여 RD cost 계산을 하게 된다. 본 논문에서는 모드 선택의 복잡성을 줄이고 고속 모드를 결정하기 위하여 예측 할 블록의 주변 중 가장 자리와 가중치 특성을 고려하였다.

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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 Intra Mode Decision for H.264/AVC by Using the Approximation of DCT Coefficient (H.264/AVC에서 DCT 계수의 근사화를 이용한 고속 인트라 모드 결정 기법)

  • La, Byeong-Du;Eom, Min-Young;Choe, Yoon-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.3
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    • pp.23-32
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    • 2007
  • The H.264/AVC video coding standard uses rate distortion optimization (RDO) method to improve the compression performance in the intra prediction. The complexity and computational load are increased more than previous standard by using this method, even though this standard selects the best coding mode for the current macroblock. This paper proposes a fast intra mode decision algorithm for H.264/AVC encoder based on dominant edge direction (DED). To apply the idea, this algorithm uses the approximation of discrete cosine transform (DCT) coefficient. By detecting the DED, 3 modes instead of 9 modes are chosen for RDO calculation to decide the best mode in the $4{\times}4$ luma block. As for the $16{\times}16$ luma and $8{\times}8$ chroma block, instead of 4 modes, only 2 modes are searched. Experimental results show that the computation time of the proposed algorithm is decreased to about 72% of the full search method with negligible quality loss.

Gradient-Based Methods of Fast Intra Mode Decision and Block Partitioning in VVC (VVC의 기울기 기반 화면내 예측모드 결정 및 블록분할 고속화 기법)

  • Yoon, Yong-Uk;Park, Dohyeon;Kim, Jae-Gon
    • Journal of Broadcast Engineering
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    • v.25 no.3
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    • pp.338-345
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    • 2020
  • Versatile Video Coding (VVC), which has been developing as a next generation video coding standard, has adopted various techniques to achieve more than twice the compression performance of HEVC (High Efficiency Video Coding). The recently released VVC Test Model (VTM) shows 38% Bjontegaard Delta bitrate (BD-rate) improvement and 9x/1.6x encoding/decoding complexity over HEVC. In order to reduce such increased complexity, various fast algorithms have been proposed. In this paper, gradient-based methods of fast intra mode decision and block splitting are presented. Experimental results show that, compared to VTM6.0, the proposed method gives up to 65% encoding time reduction with 3.54% BD-rate loss in All-Intra (AI) configuration.

Fast Intra Mode Decision for JEM (차세대 비디오 코덱(JEM)의 고속 화면내 부호화 모드 결정 방법)

  • Baek, Songju;Gwon, Daehyeok;Baek, A Ram;Choi, Haechul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.78-80
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    • 2017
  • 본 논문에서는 Joint Exploration Model (JEM)을 위한 고속 화면내 부호화 알고리즘을 제안한다. 제안 방법은 JEM의 화면내 부호화 과정에서 Most Probable Mode와 Sum of Absolute Transformed Differences(SATD) 과정의 결과로 얻어지는 후보 모드들의 SATD 비용 비교를 통하여 화면내 부호화에서 높은 계산 복잡도를 요구하는 Rate-Distortion Optimization 과정의 후보 개수를 줄여 전체 부호화기의 부호화 복잡도를 낮추고자 한다. 실험 결과에서는 제안 방법이 BD-Rate 평균 0.38%의 부호화 손실만으로 평균 17%의 부호화 복잡도를 감소시킬 수 있음을 확인하였다.

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Edge-Based Fast Intra Mode Decision in HEVC

  • Na, Sangkwon;Lee, Wonjae;Lee, Kyohyuk;Yoo, Kiwon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.180-181
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    • 2013
  • High efficiency video coding (HEVC) appears due to the demand on high compression video coding beyond H.264/AVC in ultra-high definition (UHD) videos. As for intra prediction, HEVC has 35 prediction modes while H.264/AVC has 9 intra modes. To exploit the spatial correlation, we adopt an edge detection method, establish the edge map, and adaptively select the candidate modes using the acquired edge information in a block. The number of the candidate modes is determined through trade-off between computational complexity and coding efficiency. Besides, the range of coding unit sizes is determined using the uniqueness of the edge directions for the given image block. As a result, we reduced the encoding time by 56.8% at the cost of 2.5% BD-BR increase on average compared to Full modes at the HEVC reference software (HM 6.0 [1]).

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