标题: | 快速分数像素之二元动量估测演算法 Fast Fractional Pixel Binary Motion Estimation |
作者: | 李鉴明 Gen-Ming Lee 蒋迪豪 Tihao Chiang 电子研究所 |
关键字: | 视讯编码;动量估测;分数像素精确度;二元动量估测;阶层式动量搜寻;Video Coding;Motion Estimation;Fast Motion Search;Sub-pixel accuracy;Fractional pixel accuracy;Binary Motion Estimation;Hierarchical Motion Search |
公开日期: | 2004 |
摘要: | 随着通讯与多媒体技术的发展,视讯应用变得越来越普遍。动量估测在视讯编码中扮演一个很重要的角色,不仅因为编码过程里它占了很多的运算时间,也因为它会直接影响到编码效率。近代的视讯编码标准多使用分数像素精确度的动量补偿与双向动量补偿等预测技术以增进编码效率,但付出的代价是动量估测中运算复杂度与所需记忆体频宽的增加。因此,为了实现即时视讯通讯,快速的动量估测是必须的。 在本文中,我们发展了一个可提供分数像素精确度的快速的二元动量估测演算法。在以单一位元代表八个位元之像素资料与全二元金字塔形架构的使用下,动量可经由阶层式搜寻得到,同时降低了运算复杂度与所需记忆体频宽。本演算法实现在MPEG-4视讯编码标准中P-VOP与B-VOP所需的动量估测部份。经由较佳的量化参数设定,实验结果显示,快速分数的像素之二元动量估测演算法加速了动量估测并且维持可接受的视觉品质。 Video applications become more and more popular with the developments of communications and multimedia technologies. Motion estimation that takes much computational time and directly affects the coding efficiency and visual quality of video signals plays an important role in video coding. Modern video coding standards use the techniques of motion compensated prediction at subpixel accuracy and bidirectional motion compensated prediction to improve the coding efficiency with drastically increasing computational complexity and required memory bandwidth in motion estimation. The faster motion estimation methods become essential for realizing real-time video communication. In this thesis, we develop a fast binary motion estimation algorithm providing fractional pixel motion accuracy. With the pyramidal structure and one-bit representation of pixel data, motion vectors at the accuracy of half or quarter pixel are got via hierarchical search, which can reduce both the computational complexity and required memory bandwidth. The algorithm is realized in the MPEG-4 reference software and evaluated for fractional-pel motion estimation of both P-VOPs and B-VOPs in MPEG-4. With the better quantization parameter setup, experimental results show that the fast fractional pixel binary motion estimation can speed up the encoding process with an acceptable visual quality. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009011617 http://hdl.handle.net/11536/80446 |
显示于类别: | Thesis |
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