网络视频传输的错误复原研究

VIP免费
3.0 高德中 2024-11-19 5 4 3.66MB 64 页 15积分
侵权投诉
摘 要
视频编码技术作为多媒体通信的基础，其高效的压缩性能有效地降低了传输
码率。由于使用了预测编码和可变长熵编码，压缩视频码流对网络丢包和延迟极
为敏感。因此，需要采取一些错误复原技术来恢复受损图像质量和提高码流的抗
误码能力，以保证图像的视觉质量，同时，这成为了多媒体实时传输的一项极具
挑战性的任务。
本文详细描述了 H.264 视频压缩编码标准中的基本编解码和错误复原的算法
原理，如预测编码、变换编码、熵编码、解码端的错误隐藏和编码端的差错控制
技术。并针对现有的时域和空域的错误隐藏算法中存在的不足进行改进。
（1）模板匹配的错误隐藏算法在创建模板时，没有考虑到模板中多个纹理
的情况，造成在修复复杂纹理图像时隐藏效率较低。本文结合模板中的纹理空间
位置与匹配度的关系，提出一种改进的匹配算法，仿真结果表明，与现有的模板
匹配算法相比，本文算法获得了较好的图像隐藏效果。
（2）信息隐藏的错误隐藏算法存在隐藏数据量大、对抗连续片的受损时隐
藏效果较差等不足之处。本文采取多种匹配块尺寸以及针对 I帧的信息隐藏方法
来进行改进。并以此为基础，提出一种新的基于信息隐藏的错误复原策略，同时
兼顾由反馈信道获得的网络丢包率和码率要求，动态调整信息隐藏策略。仿真结
果表明，与现有的信息隐藏算法相比，本文算法拥有更好的隐藏性能，错误复原
策略能够有效减轻错误扩散的影响。
关键词：网络传输 视频编码 错误复原 时空域的错误隐藏 差错控制
ABSTRACT
Video coding technology which is foundation of multimedia communication over
network, and its high performance of compression reduces bit rate efficiently.
Compressed video bit stream is sensitive to packet loss and delay, due to the use of
predictive coding and variable length entropy coding. Therefore, taking some error
resilience measure which recovers corrupted images and enhances error resiliency
ability to maintain acceptable perceptual quality is one of the most challenging tasks in
multimedia real-time transmission.
In this dissertation, it is elaborated that basic encoding and error resilience
algorithm which are based on H.264 video compression coding standard including
predictive coding, transform coding, entropy coding, error concealment on decoder and
error control on encoder. The two optimized methods are proposed for efficiency of the
existing spatial and temporal error concealment.
(1) Due to ignoring the exemplar with several kinds of texture while creating mask,
the exemplar-based spatial error concealment algorithm suffers from lower concealed
efficiency problem when recovering complex texture. The optimized matching method
is proposed with the relationship between the position of texture in image and the
exemplar matching degree. Experiment results demonstrate that the quality of concealed
intra-frame by our approach is superior to that of exemplar-based spatial error
concealment algorithm.
(2) Because the data hiding-based error concealment algorithm needs huge
amounts of hided data quantity and gains unexpected concealed image in sequential
erroneous slice situation, an optimized data hiding method is proposed and it adopts
more matching block type and embeds hided data into intra-frame. On the basis of this
data hiding method, a novel error resilience scheme is proposed. Data hiding method is
adjusted with loss packet rate and bit rate in dynamic network. Simulation results show
that the concealed performance of the proposed algorithm outperforms that of temporal
error concealment algorithm in general and error resilience scheme can alleviate the
impact of error propagation.
Key Words: Network Transmission, Video Coding, Error Resilience,
Spatial and Temporal Error Concealment, Error Control
I
目 录
第一章 绪 论 ...................................................................................................................1
§1.1 研究背景与选题意义 ........................................................................................1
§1.2 国内外研究现状 ................................................................................................2
§1.3 论文的工作与内容安排 ....................................................................................5
第二章 视频编码和错误复原的关键技术分析 .......................................................... 7
§2.1 H.264 关键编码技术 ......................................................................................... 7
§2.1.1 帧内预测 ......................................................................................................... 8
§2.1.2 帧间预测 ......................................................................................................... 9
§2.1.3 变换编码 ....................................................................................................... 10
§2.1.4 熵编码 ........................................................................................................... 10
§2.2 H.264 的视频码流结构 ................................................................................... 11
§2.2.1 宏块的预测信息 ........................................................................................... 11
§2.2.2 宏块类型 ....................................................................................................... 12
§2.2.3 解码参数 ....................................................................................................... 13
§2.3 错误复原算法原理 ..........................................................................................13
§2.3.1 差错控制 ....................................................................................................... 13
§2.3.2 错误隐藏 ....................................................................................................... 15
§2.4 本章小结 ..........................................................................................................16
第三章 空域错误隐藏算法 .................................................................................... 17
§3.1 空域错误隐藏算法的应用 ..............................................................................17
§3.2 插值的空域错误隐藏算法 ..............................................................................17
§3.3 模板匹配的空间域错误隐藏算法 ..................................................................20
§3.3.1 图像裁剪 ....................................................................................................... 21
§3.3.2 图像分割 ....................................................................................................... 22
§3.3.3 错误块纹理边界 ........................................................................................... 23
§3.3.4 错误块的恢复 ............................................................................................... 24
§3.4 改进的错误隐藏算法 ......................................................................................26
§3.4.1 单个纹理块的快速搜索 ............................................................................... 26
§3.4.2 多纹理模板的错误隐藏 ............................................................................... 27
§3.5 仿真与结果分析 ..............................................................................................28
§3.5.1 本文算法的仿真 ........................................................................................... 28
§3.5.2 主观评价 ....................................................................................................... 29
§3.5.3 客观评价 ....................................................................................................... 32
§3.6 本章小结 ..........................................................................................................33
第四章 时域错误隐藏算法 .................................................................................... 35
II
§4.1 边界匹配的时域错误隐藏算法 ......................................................................35
§4.2 信息隐藏的时域错误隐藏算法 ......................................................................37
§4.2.1 错误隐藏策略 ............................................................................................... 38
§4.2.2 信息隐藏和提取 ........................................................................................... 38
§4.3 改进的错误隐藏算法 ......................................................................................40
§4.3.1 匹配块的搜索 ............................................................................................... 40
§4.3.2 信息隐藏 ....................................................................................................... 41
§4.4 错误复原策略 ..................................................................................................42
§4.4.1 信息隐藏方法 ............................................................................................... 43
§4.4.2 信息隐藏和嵌入流程 ................................................................................... 44
§4.5 算法仿真 ..........................................................................................................45
§4.5.1 仿真平台 ....................................................................................................... 45
§4.5.2 错误复原策略的仿真 ................................................................................... 45
§4.5.3 仿真结果与分析 ........................................................................................... 47
§4.6 本章小结 ..........................................................................................................51
第五章 总结与展望 ................................................................................................ 53
§5.1 论文工作的总结 ..............................................................................................53
§5.2 展望 ..................................................................................................................54
参考文献 .........................................................................................................................55
在读期间公开发表的论文和承担科研项目及取得成果 ............................................ 61
一、发表论文 .............................................................................................................61
二、科研项目 .............................................................................................................61
致谢 .................................................................................................................................63
III
表目录
表2.1 帧内预测模式的滤波方向（亮度分量）........................................................ 8
表2.2 帧内预测模式的滤波方向（色度分量）........................................................ 9
表3.1 本文算法的性能评估 ..................................................................................... 33
表3.2 几种算法的隐藏性能对比.............................................................................. 33
表4.1 匹配块类型与对应的数值.............................................................................. 42
表4.2 隐藏信息的二进制表达式.............................................................................. 42
表4.3 码率和解码图像质量变化（不同匹配块类型）.......................................... 49
表4.4 本文算法对码流的影响（不同信息嵌入量）.............................................. 50
表4.5 几种算法的错误隐藏性能对比 ..................................................................... 50
IV
图目录
图1-1 错误复原与视频编解码的关系........................................................................ 2
图2-1 H.264 编码器框图............................................................................................. 7
图2-2 片的封装结构.................................................................................................. 11
图2-3 宏块与周围邻块的关系.................................................................................. 12
图2-4 片在帧内的位置.............................................................................................. 14
图2-5 FMO 的宏块映射.............................................................................................14
图3-1 错误宏块及其邻块的示意图.......................................................................... 18
图3-2 错误宏块的边界像素点.................................................................................. 20
图3-3 一个片丢失后的效果图.................................................................................. 21
图3-4 图像分割效果图.............................................................................................. 22
图3-5 错误块的纹理划分示意图.............................................................................. 24
图3-6 参考模块结构 ................................................................................................. 25
图3-7 边界像素位置 ................................................................................................. 26
图3-8 本文算法的参考模板示意图 ......................................................................... 27
图3-9 仿真系统流程框图.......................................................................................... 28
图3-10 本文算法的流程图 ....................................................................................... 29
图3-11 几种算法的隐藏效果对比（Foreman，误码率 5%）................................30
图3-12 几种算法的隐藏效果对比（Akiyo，误码率 5%）....................................30
图3-13 几种算法的隐藏效果对比（Hall，误码率 10%）.....................................31
图3-14 几种算法的隐藏效果对比（Container，误码率 10%）............................ 31
图3-15 几种算法的隐藏效果对比（Walk，误码率 10%）................................... 32
图4-1 内边界匹配...................................................................................................... 36
图4-2 文献[48]的错误隐藏策略 .............................................................................. 38
图4-3 文献[48]的信息隐藏方法 .............................................................................. 38
图4-4 块的空间位置示意图 ..................................................................................... 42
图4-5 视频序列的示意图 ......................................................................................... 43
图4-6 本文算法的信息隐藏与提取.......................................................................... 44
图4-7 本文算法的编解码器系统流程框图.............................................................. 46
图4-8 本文的匹配块搜索算法流程框图.................................................................. 46
图4-9 几种算法的隐藏效果对比（Foreman，误码率 20%）................................48
图4-10 几种算法的隐藏效果对比（Hall，误码率 20%）.....................................48
摘要：

摘要视频编码技术作为多媒体通信的基础，其高效的压缩性能有效地降低了传输码率。由于使用了预测编码和可变长熵编码，压缩视频码流对网络丢包和延迟极为敏感。因此，需要采取一些错误复原技术来恢复受损图像质量和提高码流的抗误码能力，以保证图像的视觉质量，同时，这成为了多媒体实时传输的一项极具挑战性的任务。本文详细描述了H.264视频压缩编码标准中的基本编解码和错误复原的算法原理，如预测编码、变换编码、熵编码、解码端的错误隐藏和编码端的差错控制技术。并针对现有的时域和空域的错误隐藏算法中存在的不足进行改进。（1）模板匹配的错误隐藏算法在创建模板时，没有考虑到模板中多个纹理的情况，造成在修复复杂纹理图像时隐藏...

展开>> 收起<<
网络视频传输的错误复原研究.pdf

共64页,预览7页

还剩页未读， 继续阅读

相关推荐

更多
立即下载
作者：高德中 分类：高等教育资料 价格：15积分 属性：64 页 大小：3.66MB 格式：PDF 时间：2024-11-19

开通VIP享超值会员特权

  • 多端同步记录
  • 高速下载文档
  • 免费文档工具
  • 分享文档赚钱
  • 每日登录抽奖
  • 优质衍生服务

作者详情

相关内容

更多

推荐作者

热门标签

/ 64
评分 收藏
分享
立即下载 VIP免费下载
客服
关注