Journal of Computer Applications ›› 2015, Vol. 35 ›› Issue (9): 2640-2647.DOI: 10.11772/j.issn.1001-9081.2015.09.2640

Previous Articles     Next Articles

2D intra string copy for screen content coding

CHEN Xianyi1, ZHAO Liping1,2, CHEN Zhizhong1, LIN Tao1   

  1. 1. Institute of Very Large Scale Integration, Tongji University, Shanghai 200092, China;
    2. College of Mathematics, Physics and Information Engineering, Jiaxing University, Jiaxing Zhejiang 314000, China
  • Received:2015-04-13 Revised:2015-05-29 Online:2015-09-10 Published:2015-09-17


陈先义1, 赵利平1,2, 陈治中1, 林涛1   

  1. 1. 同济大学 超大规模集成电路研究所, 上海 200092;
    2. 嘉兴学院 数理与信息工程学院, 浙江 嘉兴 314000
  • 通讯作者: 陈先义(1981-),男,安徽滁州人,博士研究生,CCF会员,主要研究方向:视频编码算法,
  • 作者简介:赵利平(1984-),女,湖南衡阳人,博士研究生,主要研究方向:视频编码算法;陈治中(1988-),男,江西上饶人,硕士研究生,主要研究方向:视频编码算法;林涛(1958-),男,上海人,教授,博士,主要研究方向:多媒体算法、SoC设计。
  • 基金资助:

Abstract: To solve the problem of that although Intra String Copy (ISC) improved the effect of the screen content coding, but it transformed the 2D image to 1D by Coding Unit (CU), making adjacent regions in an image segmented and spatial correlation not to be used, a new algorithm called 2D Intra String Copy (2D ISC) was proposed. Almost without additional memory in encoder and decoder, the algorithm realized arbitrary 2D shape searching and matching without boundary restriction of CU for pixels in current CU, by using dictionary coding tool in High Efficiency Video Coding (HEVC) reconstruction cache. Also adopted technologies of color quantization preprocessing and horizontal vertical search order self-adaption to enhance coding effect. Experiments on common test for typical screen content test sequences show that compared with HEVC, 2D ISC can achieve bit-rate saving of 46.5%, 34.8%, 25.4% for All Intra(AI), Random Access(RA) and Low-delay B(LB) configurations respectively in lossless coding mode, and 34.0%, 37.2%, 23.9% for AI, RA and LB configurations respectively in lossy coding mode. Even compared with ISC, 2D ISC can also achieve bit-rate saving up to 18.3%, 13.9%, 11.0% for AI, RA and LB configurations in lossless coding mode, and 19.8%, 20.5%, 10.4% for AI, RA and LB configurations in lossy coding mode. The experimental results indicate that the proposed algorithm is feasible and efficient.

Key words: High Efficiency Video Coding (HEVC), Screen Content Coding (SCC), two-dimensional matching, search order self-adaption, color quantization, dictionary coding

摘要: 针对一维帧内串匹配(ISC)算法虽然较好地提高了屏幕图像编码效果,但是其将二维图像逐个编码单元(CU)一维化,使图像中相邻区域被分割,空间相关性得不到利用的问题,提出二维帧内串匹配(2D ISC)算法。该算法在编码器和解码器几乎不增加额外内存消耗的情况下,在高效视频编码(HEVC)的重建缓存内,利用字典编码工具,对当前CU内的像素,实现不受CU边界限制的任意二维形状的搜索和匹配;同时引入色彩量化预处理技术和水平、垂直搜索顺序自适应技术,进一步提升编码效果。通用测试条件的实验结果显示,对于典型的屏幕图像,在全帧内(AI)、随机接入(RA)和低延迟(LB)三种配置下,与HEVC相比,无损编码模式分别最多节省码率46.5%、34.8%、25.4%,有损编码模式分别最多节省码率34.0%、37.2%、23.9%;与一维帧内串匹配算法相比,无损编码模式分别最多节省码率18.3%、13.9%、11.0%,有损编码模式分别最多节省码率19.8%、20.5%、10.4%。实验结果表明了该算法的可行性和有效性。

关键词: 高效视频编码, 屏幕图像编码, 二维匹配, 搜索顺序自适应, 色彩量化, 字典编码

CLC Number: