二维视频序列转换为伪3D视频的方法

本文提出了一种二维视频到三维视频的转换方法。采用时域和空域相结合的方法,根据边缘信息．从图像序列中提取运动对象。对二维视频序列来说,其本身并不包含有视差信息,但是可以根据运动信息来估算视差。本文中采用基于三角形网格的浓密视差提取方法来估算。根据双目立体视觉原理和立体显示技术．我们将二维视频帧经过变换,得到伪三维立体视频帧,并合成视频序列。     

基于最小二乘法B样条曲线的视频去雾研究

针对现有视频图像去雾存在信息丢失导致视频抖动的问题,提出了基于最小二乘法的B样条曲线的视频去雾方法 .首先,利用快速Harris角点检测提取视频关键帧的特征点;其次,对视频序列图像帧的特征点进行匹配;再次,基于最小二乘法利用关键帧像素点的估计非关键帧对应像素点的值点;最后,输出稳定完整的视频序列.实验结果表明,该算法利用曲线构建对特征点的处理能够有效地消除视频抖动现象.     

一种新的基于频域的图像信息隐藏方法

在信息隐藏领域,基于频域的信息隐藏由于其鲁棒性好而被广泛应用。提出了一种新的基于频域的图像信息隐藏方法:基于W系的图像信息隐藏方法。该方法实施过程是：利用W系下的W变换将图像由空域变换到频域,通过调整图像频谱中两个系数的相对大小来嵌入秘密信息;再通过W变换的逆变换由频域还原到空域,重构秘密图像。实验结果表明：该新方法具有很好的隐藏效果和重构效果,是一种可行的图像信息隐藏方法。     

基于3D卷积神经网络的人体行为识别方法

为了提高视频中人体行为识别的准确率,更好地利用视频中的原始信息,提取出更具有代表性的特征,提出一种基于3D卷积神经网络的人体行为识别方法。该方法构建了一个深层三维卷积神经网络模型,使用三维卷积核进行卷积操作,提取视频中人体行为的时域和空域特征,通过多层卷积操作对底层特征进行再组合,得到抽象的高维特征。在KTH数据集上的实验结果表明,该方法有较好的识别效果。     

像素域Wyner-Ziv视频编码系统性能优化方法

以分布式视频编码理论为基础,对Wyner-Ziv编码方案开展了深入研究。在对典型的边信息生成方法进行分析与比较的基础上,提出了一种改进的多路径边信息生成策略,并提出用错误隐藏技术来对传输出错的关键帧进行处理。实验结果表明,多路径边信息生成策略与运动补偿外推法相比可以生成质量更好的边信息;使用错误隐藏技术可以保证关键帧的传输质量,提高系统的鲁棒性;对错误恢复过的解码帧用多路径边信息生成策略进行边信息生成,使边信息精确度进一步得以提高,实现了对Wyner-Ziv系统进行优化的目的。     

浅议基于相邻两像素差值的无损数据隐藏算法的改进

基于相邻两像素差值的无损数据隐藏算法,提出一种新的改进方法:采用新方法被SPAM侦测到的概率比基于相邻两像素差值的无损数据隐藏方法的概率小。当错误率小于10%时,基于相邻两像素差值的无损数据隐藏无法避开SPAM的侦测;当错误率小于0.2%的时候,改进的新算法虽也不能完全避开SPAM的侦测,但其不被侦测率获得了有效提高。实验结果显示隐藏的信息不被侦测率提高了5%到10%。     

基于静止图像的信息隐藏算法设计和实现

基于Qt库设计并实现了一个基于静止图像的信息隐藏算法及对应的提取算法。算法以基于空域隐藏算法的最低有效位替换算法为核心思想,为需要隐藏的信息设计了一个特有的格式,以该格式输出的信息作为被隐藏的信息的主体,嵌入到载体图像中,实现了信息隐藏的目的;同时根据信息隐藏的过程,实现了一个信息提取的算法,从而将隐藏信息提取出来。实验结果表明,该算法达到了将文本和文件隐藏到静止图像中的目的。     

H.264/AVC视频容错传输的菱形FMO分布方法

图像压缩技术是基于在空域,时域或者频域上移除数据冗余的算法。它相当大地减少了数据转换率,但是随之的视频压缩信号对于传输误差更加敏感。差错恢复技术相对于通道误差增强了视频比特流的鲁棒性。在H.264/AVC的条带编码作为一种差错恢复技术之一被用于限制接收视频品质的数据丢失效应。有一种模式非常重要,它是将图像的宏块分配成不同的条带组,并能够提供不同的差错恢复标准。该文将深入分析这一类分散类型的灵活的宏块顺序(FMO)模式性能,并提出一个定义明确的系统模式,可以更完全地挖掘宏块顺序中离差概念从而克服误差损失。仿真结果显示:新的改进方案的性能优于传统模式。     

文本信息的隐藏技术

文本信息隐藏技术是继利用图像、音频、视频为载体的信息隐藏技术之后一个新的隐藏技术,本文介绍了信息隐藏技术的基本知识,分析了文本信息隐藏技术,结合目前几种基于文本的信息隐藏方法的特性,提出了一种基于文本颜色的信息隐藏算法,并对此算法进行了分析.     

基于空域和人类视觉特性的数字水印方法

本文提出一种基于空域技术和LBS改进算法,利用人类的视觉特性设计了一种将一串有意义的字符串水印信息隐藏于位图数据的低位,经过将信息循环嵌入提高了水印的稳定性,从而改进了传统LBS算法的稳健性差的缺点.实验结果表明,应用所提出的算法实现的水印对各种图像处理具有很好的稳健性.     

基于加权的运动矢量恢复差错掩盖算法

为了解决视频图像在传输过程中产生运动矢量丢失问题,本文提出一种新的后处理差错掩盖算法。我们在DCT域进行边缘检测,把与丢失块相邻的图像块分为边缘块和平滑块,同时把丢失块周围的图像块运动矢量的大小和方向分成九类。结合边缘检测与运动矢量分类,我们提出一种加权运动矢量恢复算法。仿真结果表明对不同视频序列,此算法都能比传统的方法恢复出质量更高的图像。     

基于大型隐马尔可夫模型的宽带语音丢帧补偿(英文)

研究了在语音传输过程中由于参数丢失导致语音质量急剧下降的丢帧补偿问题.利用大规模隐式马尔可夫模型对自适应多速率宽带语音编码(AMR-WB)的ISF参数进行建模,然后对丢失的ISF参数进行基于最小均方误差(MMSE)准则的最优估计,将估计的ISF参数和前帧的ISF参数进行加权以平滑估计值,得到补偿的ISF参数.在接收端,利用ISF参数的估计值进行语音合成.将本算法的合成语音和由G.722.2标准附件Ⅰ的基准补偿的合成语音进行比较,仿真结果表明,本补偿算法可以得到更好的性能,在频率加权谱失真和信噪比这2种评价准则上都有所改善,信噪比提高约2.41 dB,频率加权谱失真下降约0.885 dB,证明了该算法的有效性.     

Temporal Error Concealment Technique for MPEG-4 Video Streams

Concerning inter4v mode employed widely in MPEG-4 video, a new temporal error concealment scheme for MPEG-4 video sequences is proposed, which can selectively interpolate one or four motion vectors (MVs) for the missing macroblock (MB) according to the estimated MB coding mode. Performance of the proposed scheme is compared with the existing schemes with multiple testing sequences at different bit error rates. Experimental results show that the proposed algorithm can mask the impairments caused by transmission errors more efficiently than 0 MV and average MV methods by consuming more time for different bit error rates. It has an acceptable image quality close to that obtained by the selective motion vector matching (SMVM) algorithm, while taking less than half of cycles of operations. The proposed concealment scheme is suitable for low complexity video real-time implementations.     

A channel distortion model for video over lossy packet networks

Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for video over lossy packet networks and proposes a new model that, compared to previous models, more accurately estimates the expected mean-squared error distortion for different packet loss patterns by accounting for inter-frame error propagation and the correlation between error frames. The accuracy of the proposed model is validated with JVT/H.264 encoded standard test sequences and previous frame concealment, where the proposed model provides an obvious accuracy gain over previous models.     

A channel distortion model for video over lossy packet networks

Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for video over lossy packet networks and proposes a new model that, compared to previous models, more accurately estimates the expected mean-squared error distortion for different packet loss patterns by accounting for inter-frame error propagation and the correlation between error frames. The accuracy of the proposed model is validated with JVT/H.264 encoded standard test sequences and previous frame concealment, where the proposed model provides an obvious accuracy gain over previous models.     

Analysis and application of error concealment tools in AVS-M decoder

Audio Video coding Standard (AVS) is the latest audio and video coding standard of China. AVS Part 7 (also known as AVS-M) targets mobility applications where error concealment is of great importance. This paper first briefly introduces the general concept of error concealment. Then two error concealment schemes are proposed and implemented on AVS-M decoder under different test conditions. Simulation results of the schemes and suggestions on how to use these tools are also provided.     

Analysis and application of error concealment tools in AVS-M decoder

Audio Video coding Standard (AVS) is the latest audio and video coding standard of China. AVS Part 7 (also known as A VS-M) targets mobility applications where error concealment is of great importance. This paper first briefly introduces the general concept of error concealment. Then two error concealment schemes are proposed and implemented on AVS-M decoder under different test conditions. Simulation results of the schemes and suggestions on how to use these tools are also provided.     

Frame loss error concealment for SVC

INTRODUCTION Real-time transmission of video data in network environments, such as wireless and Internet, is a challenging task, as it requires coding efficiency, network friendliness and error robustness. Scalability is a possible solution for network adaptive applica- tions. The Scalable Extension of H.264/AVC (SVC) (JVT of ISO/IEC MPEG & ITU-T VCEG, 2005b) aims at achieving both high compression performance and adaptivity for video delivery over heterogeneous networks. SVC…     

An error resilient scheme for H.264 video coding based on distortion estimated mode decision and nearest neighbor error concealment

Although H.264 video coding standard provides several error resilience tools, the damage caused by error propagation may still be tremendous. This work is aimed at developing a robust and standard-compliant error resilient coding scheme for H.264 and uses techniques of mode decision, data hiding, and error concealment to reduce the damage from error propagation. This paper proposes a system with two error resilience techniques that can improve the robustness of H.264 in noisy channels. The first technique is Nearest Neighbor motion compensated Error Concealment (NNEC) that chooses the nearest neighbors in the reference frames for error concealment. The second technique is Distortion Estimated Mode Decision (DEMD) that selects an optimal mode based on stochastically distorted frames. Observed simulation results showed that the rate-distortion performances of the proposed algorithms are better than those of the compared algorithms.