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MPEG—4视频编码的可分级技术研究 总被引:6,自引:0,他引:6
首先分析了MPGE-4视频分级编码的基本思想,讨论了如何实现时域和空域上的分级编码算法。在此基础上,结合MPEG-4的抗误码技术,提出了一种适应IP网络传输的精细粒度分级视频编码方案。 相似文献
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MPEG-4视频编码算法研究 总被引:2,自引:0,他引:2
MPEG-4由于引入视频对象(VO)和基于内容的存取概念而为多媒体信息处理提供了广阔的应用平台。系统地分析了MPEG-4视频编码算法,并形象地解释了MPEG-4视频标准的一些关键概念。 相似文献
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MPEG—4标准的极低位速率视频技术 总被引:1,自引:1,他引:0
MPEG-4是由ISO/IEC JTC1/ISC29/WG11制定的一种新的音频/视频编码标准,于1999年1月正式成为国际.住房MPEG-4标准1的视频编码模型、视频流语法的语义,从极低位速率的角度分析研究了MPEG-4的VLBV编码设计技术。 相似文献
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基于对象的视频编码方法——MPEG-4 总被引:1,自引:0,他引:1
介绍了MPEG-4的各种编码方法,为了支持众多的多媒体应用,MPEG-4不仅保留了现有标准中的一些解决方案,而且致力于一些新功能的研究与定义,MPEG-4视频编码标准支持MPEG-1,MPEG-2中的大多数功能,提供不同视频标准源格式、码率、帧频下矩形图像的有效编码,同时也将支持基于内容的图像编码。 相似文献
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为满足视频通信中视频压缩的需要,在对MPEG4视频编码标准研究的基础上,提出了基于TMS320DM642DSP的MPEG4视频编码器的实现方案,并讨论了代码优化的方法,通过相关实验对提出的方案进行了验证。实验结果表明,该方案实现了对标准QCIF格式图像序列的MPEG4编码,编码速率达到25 fps,满足了实时编码的要求,图像质量满足了预期效果。 相似文献
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可扩展编码和形状编码技术是MPEG-4视频编码部分的两个关键技术。文章在分析视频图像二值形状信息特点的基础上.提出了一种新的MPEG—4二值形状空域可扩展编码算法。试验结果表明这种算法编解码简单,速度快.码率较小。 相似文献
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Euee Seon Jang 《ETRI Journal》2004,26(2):122-135
Although frame‐based MPEG‐4 video services have been successfully deployed since 2000, MPEG‐4 video coding is now facing great competition in becoming a dominant player in the market. Object‐based coding is one of the key functionalities of MPEG‐4 video coding. Realtime object‐based video encoding is also important for multimedia broadcasting for the near future. Object‐based video services using MPEG‐4 have not yet made a successful debut due to several reasons. One of the critical problems is the coding complexity of object‐based video coding over frame‐based video coding. Since a video object is described with an arbitrary shape, the bitstream contains not only motion and texture data but also shape data. This has introduced additional complexity to the decoder side as well as to the encoder side. In this paper, we have analyzed the current MPEG‐4 video encoding tools and proposed efficient coding technologies that reduce the complexity of the encoder. Using the proposed coding schemes, we have obtained a 56 percent reduction in shape‐coding complexity over the MPEG‐4 video reference software (Microsoft version, 2000 edition). 相似文献
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A novel scheme for scalable video coding using three-band lifting-based motion-compensated transform is presented in this article. A series of flexible three-band motion-compensated lifting steps are used to implement the temporal wavelet transform, which provide improved compression performance by selecting specific motion model according to real video sequences, and offer higher temporal scalability flexibility by using three-band lifting steps. The experimental results compared with motion picture expert group (MPEG)-4 codec concerning standard video sequences demonstrate the effectiveness of the method. 相似文献
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Jörn Ostermann 《Signal Processing: Image Communication》1997,9(4):343-365
MPEG-4 issued two calls for proposals requesting submission of algorithms and tools relevant to standardization of MPEG-4. This paper reports on the evaluation of tools submitted for evaluation in November 1995 and January 1996. Complete video coding schemes submitted in January 1996 are also covered. The goal of the evaluation was to cluster the tools according to the technical areas they address, to evaluate them according to the issues relevant to the standardization process, and finally to suggest areas of core experiments to improve a video verification model (VM) as soon as the VM becomes available. Altogether, MPEG evaluated 87 tools and 19 complete coding algorithms, most of them highlighted in this paper. During the evaluation, 19 areas for core experiments were identified. Each core experiment is targeted at different functionalities like compression efficiency, content-based coding, error resilience, scalability. This definition of core experiments caused close collaboration and supported mutual fertilization between organizations working on similar tools, which allowed the VM to progress much faster than expected. 相似文献
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In this paper, we propose an adaptive multiview video coding scheme based on spatiotemporal correlation analyses using hierarchical B picture (AMVC‐HBP) for the integrative encoding performances, including high compression efficiency, low complexity, fast random access, and view scalability, by integrating multiple prediction structures. We also propose an in‐coding mode‐switching algorithm that enables AMVC‐HBP to adaptively select a better prediction structure in the encoding process without any additional complexity. Experimental results show that AMVC‐HBP outperforms the previous multiview video coding scheme based on H.264/MPEG‐4 AVC using the hierarchical B picture (MVC‐HBP) on low complexity for 21.5%, on fast random access for about 20%, and on view scalability for 11% to 15% on average. In addition, distinct coding gain can be achieved by AMVC‐HBP for dense and fast‐moving sequences compared with MVC‐HBP. 相似文献
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基于无线视频监控传输技术进行无线信道视频图像传输的过程中,经常面临数据传输错误、带宽变化、网络拥塞导致的视频数据丢失问题,严重影响了图像质量。Joint Video Team(JVT)of ISO/IECMPEG and ITU-T VCEG提出了可伸缩视频编码(SVC),可实现视频空间、时间和图像质量的完全伸缩,本文结合率失真优化算法将可伸缩编码作为容错工具,引入了不同层数据,根据B-D代价函数决定自动重传机制,降低了视频数据丢失对图像质量的影响。仿真结果表明,该方法大大提高了视频码流的抗误码能力和传输的鲁棒性。 相似文献
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本文简略报道国际活动图像专家组近年对多媒体通信草拟新标准MPEG 4的进展情况。其中音频编码包括语音、音乐 (自然的和合成的 ) ,比特率从 2至 6 4kb /s。视频编码包括甚低比特率 5~ 6 4kb /s和较高比特率 6 4kb /s至 2Mb /s。视频编码可将图像中每一对象分开编码为不同的比特流层 ,又可操纵对象的尺度、位置等 ,具有以内容为基础的交互式功能。除了核心编码器外 ,对输入视频序列的每一帧分成若干个任意形状的“视频对象平面” ,编码成各个分开的“视频对象层”。另外 ,利用“子图形”编码技术 ,将图像的背景以及前景中的每一对象分开编码成视频序列后传输 ,可以改善视像质量。 相似文献
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Huifang Sun Joel W. Zdepski Wilson Kwok D. Raychaudhuri 《Signal Processing: Image Communication》1997,10(4):249-268
This paper provides some research results on the topic of error resilience for robust decoding of MPEG (Moving Picture Experts Group) compressed video. It introduces and characterizes the performance of a general class of error concealment algorithms. Such receiver-based error concealment techniques are essential for many practical video transmission scenarios such as terrestrial HDTV broadcasting, packet network based teleconferencing/multimedia, and digital SDTV/HDTV delivery via ATM (asynchronous transfer mode). Error concealment is intended to ameliorate the impact of channel impairments (i.e., bit-errors in noisy channels, or cell-loss in ATM networks) by utilizing available picture redundancy to provide a subjectively acceptable rendition of affected picture regions. The concealment process must be supported by an appropriate transport format which helps to identify image pixel regions which correspond to lost or damaged data. Once the image regions (i.e., macroblocks, slices, etc.) to be concealed are identified, a combination of spatial and temporal replacement techniques may be applied to fill in lost picture elements. A specific class of spatio-temporal error concealment algorithms for MPEG video is described and alternative realizations are compared via detailed end-to-end simulations for both one- or two-tier transmission media. Several algorithm enhancements based on directional interpolation, ‘I-picture motion vectors’, and use of MPEG-2 ‘scalability’ features are also presented. In each case, achievable performance improvements are estimated via simulation. Overall, these results demonstrate that the proposed class of error concealment algorithms provides significant robustness for MPEG video delivery in the presence of channel impairments, permitting useful operation at ATM cell-loss rates in the region of 10−4 to 10−3 and 10−2 to 10−1 for one- and two-tier transmission scenarios, respectively. 相似文献
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在引入MPEG-4规视标准的基础上,对基于对视频编码模型及功能进行了描述,介绍了基于对象编码的概念及某些算法结构。 相似文献