共查询到20条相似文献,搜索用时 15 毫秒
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随着基于H.264的视频传输业务越来越广泛的应用,针对视频传输的各种应用而进行的视频差错控制技术也逐渐成为研究的热点之一。针对网络中存在的各种误码问题,介绍了各种差错控制方法,并提出一种基于H.264的混合错误隐藏方法。该方法针对帧间预测块,采用时域错误隐藏和空域错误隐藏方法相结合的方式,将帧间受损宏块分割为4个8×8独立进行错误隐藏。利用JVT发布的JM测试模型进行的仿真结果表明,PSNR值较改进前提高约0·1~0·2db。 相似文献
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Two-dimensional reversible data hiding-based approach for intra-frame error concealment in H.264/AVC
Highly compressed video bit-stream is extremely sensitive to transmission error. A novel two-dimensional reversible data hiding-based approach for intra-frame error concealment is proposed, which aims at improving video quality at decoder when video bit-stream incur transmission errors. The scheme involves embedding the motion vector (MV) of a macroblock (MB) into other MB within the same intra-frame, and extracting the embedded MV from the received video frame for reconstruction of the corrupted MB. Based on the distribution of the motion vector data and the characteristic of histogram shifting, a specific two-dimensional reversible data hiding mechanism is designed. Consequently, the distortion of the marked video can be controlled at a low level. Experimental results show that the damaged macroblocks can be recovered with a higher quality using the reversible data hiding methodology, as compared to the non-reversible data hiding method. Furthermore, experimental results demonstrate that the proposed algorithm outperforms some state-of-the-art reversible data hiding error concealment schemes in improving the perceptual quality. 相似文献
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H.263编码视频流的混合错误掩盖 总被引:1,自引:1,他引:0
当H.263编码视频流在因特网上传输时,易受错误的影响,错误不但会影响当前帧还会继续扩散到以后的解码帧,从而导致图像质量的严重恶化,目前消除错误影响的常用算法是空域掩盖和时域掩盖算法,但是单纯地使用空域算法会造成图像的钝化,而时域算法则无法处理大运动的图像区域,因此,建议了一种时域和空域混合掩盖算法,同时使用两类算法对发生错误的图像帧进行掩盖。模拟结果显示该算法能够达到可以接受的图像质量,适应于视频会议、远程教育等应用的要求。 相似文献
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Spatiotemporal error concealment with optimized mode selection and application to H.264 总被引:2,自引:0,他引:2
S. Belfiore M. Grangetto E. Magli G. Olmo 《Signal Processing: Image Communication》2003,18(10):907-923
In this paper we propose an error concealment algorithm for video transmission over lossy packet networks. The proposed technique is based on temporal and spatial interpolation. A sophisticated mode selection algorithm decides whether to employ the temporal or the spatial part, or a combination thereof, to estimate a missing macroblock; the selection does not rely on knowledge of the original coding modes. The resulting error concealment algorithm is designed so as to optimize both PSNR and visual quality of the restored video sequence, and employs directional interpolation and texture analysis/synthesis. The technique has been applied to H.264 coded video, providing satisfactory results on a number of test sequences. 相似文献
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《Journal of Visual Communication and Image Representation》2014,25(2):410-422
As H.264/AVC video streams are highly compressed, they become sensitive to errors caused by unreliable transmission channels. In order to address this issue, an improved version of Chung et al.’s reversible data hiding-based approach for intra-frame error concealment is proposed for H.264/AVC codec. By using the histogram shifting technique, the original work reversibly embeds the motion vector (MV) of a macroblock (MB) into other MB within the same intra-frame. If an MB is corrupted at the decoder side, the embedded MV can be extracted from the corresponding MB for the recovery of the corrupted MB. However, Chung et al.’s work did not fully exploit the number of coefficients which need to be modified in order to reversibly hiding data, and did not consider many extra nonzero residual blocks produced by data hiding. These two issues could reduce the visual quality of the stego-video. This paper adopts MV data pre-processing, the selection of most suitable embedding region, and the minimum possible amount of histogram modification, which lead to higher PSNR of the stego-video for a given payload. Experimental results further reveal that the proposed method offers stego-video with better visual quality over Chung et al.’s work. 相似文献
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基于H.264/AVC的时空域差错隐藏方案 总被引:1,自引:0,他引:1
为了减小视频传输中的错误对解码端重建视频质量的影响,提出了一套结合时空域差错隐藏算法的方案。针对错误宏块在视频图像中呈随机分布的情况,首先将编码端帧内预测编码的思想引入到解码端,提出了一种方向性插值的空域差错隐藏算法;然后提出了一种基于8×8块的增强型时域差错隐藏算法来改善运动剧烈区域的质量;最后,提出了一种根据相邻宏块编码模式来选择时域或空域差错隐藏算法的切换策略。实验证明,提出的差错隐藏方案无论是在客观质量上,还是在主观质量上,都优于H.264/AVC的效果。 相似文献
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In this paper, a new error concealment algorithm is proposed for the H.264 standard. The algorithm consists of two processes. The first process uses a fuzzy logic method to select the size type of lost blocks. The motion vector of a lost block is calculated from the current frame, if the motion vectors of the neighboring blocks surrounding the lost block are discontinuous. Otherwise, the size type of the lost block can be determined from the preceding frame. The second process is an error concealment algorithm via a proposed adapted multiple‐reference‐frames selection for finding the lost motion vector. The adapted multiple‐reference‐frames selection is based on the motion estimation analysis of H.264 coding so that the number of searched frames can be reduced. Therefore the most accurate mode of the lost block can be determined with much less computation time in the selection of the lost motion vector. Experimental results show that the proposed algorithm achieves from 0.5 to 4.52 dB improvement when compared to the method in VM 9.0. 相似文献
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H.264通过编码端的差错弹性工具,解码端的误码掩盖措施来增强对误码信道的适应性。分析了H.264为增强抗误码性能而采取的主要措施和H.264的校验模型JM对信道误码的处理方法,提出了一种H.264的信道适应性仿真方法,并使用国际上推荐的测试环境进行了仿真,仿真结果表明H.264能够很好地适应有线和无线误码信道。 相似文献
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针对无线应均中的传输错吴和IP网络拥塞导致的视频数据包丢失,H.264采用了一系列的技术.介绍了H.264所使用的差错控制和错误隐藏技术,重点讨论了基于双二叉树GOP(double-binary tree GOP)的差错控制技术.实验结果表明该方案保证了更为有效的抗误码视频码流及良好的修复丢失帧性能. 相似文献
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本文提出了一种新的基于H.264标准的视频加密算法结构。使用改进的FMO机制(advanced-FMO mechanism)将具有相关性的宏块打入不同的Slice中,通过对FMO子图的加密达到对整个视频内容进行加密的目的。本文提出的加密算法具有很高的实时性,加密过程可以和编码过程并行执行。同时本算法还可以和传统的加扰算法结合,进一步提高视频的加密效果。 相似文献
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在易发生错误的卫星信道的传输过程中,视频会产生误码和丢包.根据视频的边缘特征,将丢失块分成平坦块、边缘块和纹理块.然后,自适应地选择双线性内插、方向内插或者新方向加权内插作为内插方法,提高重构视频质量,加速误码掩盖过程.为了减少梯度计算量,将噪声像素从候选预测像素列表中剔除.为了准确地呈现图像的方向信息以及抑制噪声,选择Prewitt算子作为梯度滤波器.另外,使用分数像素内插来提高插值精度,适应高清视频应用.客观评价结果显示,在解码时间稍微增加的情况下,峰值信噪比大约提升了3 dB.主观比较结果显示,提出的算法能够获得更高的视觉质量. 相似文献
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H.264视频误码掩盖综述 总被引:2,自引:0,他引:2
在无线网络和因特网上传输视频,误码掩盖的问题越来越重要。回顾了文献中介绍的误码掩盖的方法。误码掩盖后处理利用图像和视频信号的相关特性,在解码端对丢失区域进行掩盖,并总结了空域、时域,以及时空结合的误码掩盖方法。 相似文献