基于DCT的HEVC帧内预测快速算法研究及优化
发布时间：2018-11-28 12:16
【摘要】：High Efficiency Video Coding(HEVC)是H.264/AVC之后的新一代视频编码标准,其目的是为了达到更高的编码效率,更好的网络适应性,满足人们对高质量视频的需求。HEVC保留了预测加变换的混合编码框架,同时改进和采纳了诸多近年来视频编码的研究成果。在帧内预测方面采用了灵活的编码结构和多角度预测,包括编码单元(CU)、预测单元(PU)、变换单元(TU)和35种预测模式。然而,这些新技术的引入在提高编码性能的同时提高了编码复杂度。 为了解决HEVC编码器中运算量庞大的问题,论文研究和改进了两种帧内预测快速算法。第一,针对CU的四叉树划分,研究和改进了基于离散余弦变换(Discrete Cosine Transform, DCT)的帧内预测CU快速深度选择算法,通过统计和分析DCT系数与CU纹理复杂度的关系,采用DCT的低频交流系数并结合率失真代价进行CU纹理复杂度的判定,从而提前结束CU的划分。第二,针对35种帧内预测模式,论文研究和改进的算法利用DCT预测编码块的纹理方向,减少进行粗选择的模式数,并且通过分析粗选择后预测模式的特点,采用分组算法,减少最后进行率失真代价计算的模式数。 实验结果表明,论文研究的两种算法在官方测试模型HM10.0,全I帧的条件下,平均缩短30.14%和24.88%的编码时间,码率和图像质量几乎保持不变。
[Abstract]:High Efficiency Video Coding (HEVC) is a new generation of video coding standard after H.264/AVC. Its purpose is to achieve higher coding efficiency and better network adaptability. To meet the needs of high quality video, HEVC retains the hybrid coding framework of predictive plus transform, while improving and adopting many recent research achievements in video coding. In intra-frame prediction, flexible coding structure and multi-angle prediction are adopted, including coding unit (CU), prediction unit (PU), transform unit (TU) and 35 prediction modes. However, the introduction of these new techniques not only improves the coding performance, but also increases the coding complexity. In order to solve the problem of huge computation in HEVC encoder, two fast intra prediction algorithms are studied and improved in this paper. Firstly, aiming at the quadtree partition of CU, the fast depth selection algorithm of intra prediction CU based on discrete cosine transform (Discrete Cosine Transform, DCT) is studied and improved. The relationship between DCT coefficients and CU texture complexity is analyzed by statistics and analysis. The low frequency AC coefficient of DCT and the cost of rate-distortion are used to judge the complexity of CU texture, so that the division of CU is finished in advance. Secondly, aiming at 35 intra prediction modes, this paper uses DCT to predict the texture direction of coding block, and reduces the number of rough selection modes. By analyzing the characteristics of prediction mode after rough selection, the paper adopts grouping algorithm. Reduce the number of modes for final rate-distortion cost calculations. The experimental results show that the two algorithms in this paper can reduce the coding time by 30.14% and 24.88% under the condition of the official test model HM10.0, full I frame, and the code rate and image quality are almost unchanged.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.81
本文编号：2362796
[Abstract]:High Efficiency Video Coding (HEVC) is a new generation of video coding standard after H.264/AVC. Its purpose is to achieve higher coding efficiency and better network adaptability. To meet the needs of high quality video, HEVC retains the hybrid coding framework of predictive plus transform, while improving and adopting many recent research achievements in video coding. In intra-frame prediction, flexible coding structure and multi-angle prediction are adopted, including coding unit (CU), prediction unit (PU), transform unit (TU) and 35 prediction modes. However, the introduction of these new techniques not only improves the coding performance, but also increases the coding complexity. In order to solve the problem of huge computation in HEVC encoder, two fast intra prediction algorithms are studied and improved in this paper. Firstly, aiming at the quadtree partition of CU, the fast depth selection algorithm of intra prediction CU based on discrete cosine transform (Discrete Cosine Transform, DCT) is studied and improved. The relationship between DCT coefficients and CU texture complexity is analyzed by statistics and analysis. The low frequency AC coefficient of DCT and the cost of rate-distortion are used to judge the complexity of CU texture, so that the division of CU is finished in advance. Secondly, aiming at 35 intra prediction modes, this paper uses DCT to predict the texture direction of coding block, and reduces the number of rough selection modes. By analyzing the characteristics of prediction mode after rough selection, the paper adopts grouping algorithm. Reduce the number of modes for final rate-distortion cost calculations. The experimental results show that the two algorithms in this paper can reduce the coding time by 30.14% and 24.88% under the condition of the official test model HM10.0, full I frame, and the code rate and image quality are almost unchanged.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.81
【参考文献】
相关期刊论文 前5条
1 黄铁军,高文;AVS标准制定背景与知识产权状况[J];电视技术;2005年07期
2 石飞宇;刘昱;;一种HEVC快速帧内模式判断算法[J];电视技术;2013年11期
3 赵文强;沈礼权;张兆杨;;HEVC帧内预测算法的优化[J];电视技术;2012年08期
4 张晓芸,宋建社,郑永安;视频编码技术研究进展[J];计算机工程;2004年14期
5 蒋洁;郭宝龙;莫玮;焦昶哲;孙伟;;利用平滑区域检测的HEVC帧内编码快速算法[J];西安电子科技大学学报;2013年03期
，本文编号：2362796
本文链接：https://www.wllwen.com/kejilunwen/wltx/2362796.html
