共查询到20条相似文献,搜索用时 109 毫秒
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随着信息技术的进步,空间对地成像已朝着高清、多路方向发展。基于通用DSP和H.264/AVC视频编码标准的实时视频压缩系统,由于具有开发周期短、可靠性高、处理速度快、便于升级以及体积小、功耗低、适应性强等优点,可以为新的需求提供解决方案,研究基于通用DSP、采用先进视频压缩技术的实时视频编码器具有重要意义。为满足越来越多的高清视频采集、编码和传输的应用需求,基于TI的新一代多核DSP TMS320DM8168芯片,给出了方案的设计与实现,在该系统上实现了H.264视频编码算法,可对输入的双路1080p视频进行60 fps实时编码压缩。方案的主处理器只需一片DSP,与传统多路视频压缩方案需要多片处理器相比,这种高度集成方案降低了部件数量和物料(BOM)成本、功耗需求,缩小了PCB尺寸,提高系统集成度。 相似文献
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一种用于实时视频处理的高速二维DCT的电路设计和实现 总被引:2,自引:0,他引:2
绝大多数的国际图像和视频压缩标准都采用DCT(离散余弦变换)进行传输编码。本文介绍了一种基于矩阵分解算法的高速实时二维DCT处理器。为了满足视频处理的实时性,整个电路设计中广泛采用了流水线技术,文中详细介绍了二维DCT处理器的电路结构,最后给出了它的FPGA实现。 相似文献
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针对可见光相机CMOS输出大数据量时出现压缩系统 实时传输困难的问题,提出了一种基于ADV212的实时视频压缩方案。 首先根据CMOS视频格式以及ADV212工 作原理,提出利用Custom-specific工作模式为各种格式的视频提供接口,并通过FPGA内部 的块RAM以 及SDRAM的乒乓操作对数据进行缓存,显著地提高了工作效率;之后,为了适用于不同应用 场合,本文 方法实现了码流的存储后传输以及直接传输之间的切换,并通过纠错编码极大地提升了闪存 的纠错能力; 最后,为了验证方法的可行性,基于压缩板以及解压板进行了实验验证。结果表明,压 缩系统可实现 实时稳定的工作,通过软件设置,系统可以实现极高的压缩比,压缩比为80∶1时的平均峰值信噪比(PSNR) 为28.238dB,压缩比为150∶1时的PSNR为26.165dB,解决了在大数据量下压缩系统硬件实现困难以及实时传输困难等问题。 相似文献
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基于ADV212的高清视频压缩系统设计 总被引:1,自引:0,他引:1
针对JPEG2000的复杂性,仅依靠DSP和软件的优化很难再进一步提高其性能,提出了基于专用处理器件ADV212实现高清视频压缩系统的设计方法.设计以专用ADV212作为视频压缩核心,同时利用FPGA实现ADV212的初始化控制、数据采集和辅助处理功能,最终将视频合并为jp2的高清视频格式。试验结果表明,该系统相对DSP实现的高清视频系统,效率提高10%~15%,同时具有体积小、图像质量高、压缩信号易恢复、压缩率可调等优点,支持SMPTE274M(1080i)视频实时编码。 相似文献
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雾霾使光照条件恶劣,导致采集的视频图像失真.为了解决这个问题,本文采用Altera公司的Cyclone IV系列现场可编程门阵列(Field-Programmable Gate Array,FPGA)芯片作为核心,设计了支持多种分辨率的图像高速去雾实时系统.通过RAM的乒乓操作缓存高速数据流,并利用流水线处理的优势实现了限制对比度自适应直方图均衡化(Contrast Limit-ed Adaptive His-togram Equalization,CLAHE)算法的流程.实验结果表明,该系统能处理高达75 帧/秒的视频图像,具有良好的实时去雾功能. 相似文献
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针对多源、复杂视频处理存在的实时性低,资源占用率高的问题,提出了一种基于软件流水线并行处理多源视频的方法,具有降低视频处理应用的设计难度,优化计算资源使用,提高复杂算法多源视频处理的实时性的特点.首先基于多核CPU构建多任务管理系统,用于任务缓存及调度,并管理资源负载,在此基础上设计软件流水线.软件流水线的每一个stage将对于一帧视频图像的处理封装成任务的形式提交给多任务管理系统调度执行.最后,将软件流水线用于多源视频处理,并行处理6路视频,试验结果表明该方法能够有效提升多源、复杂视频处理的实时性,且在资源利用率,负载均衡等方面具有良好特性. 相似文献
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《Signal Processing: Image Communication》2007,22(4):389-402
Traditional video coders use the previous frame to perform motion estimation and compensation. Though they are less complex and have minimum coding delays, these coders lose their efficiency when subjected to scalability requirements. Recent 3D wavelet coders using lifting schemes offer high compression efficiency and scalability without significant loss in performance. The main drawback of 3D coders is that they process several frames at a time. This introduces additional delay, which makes them less suitable for real time applications.In this work, we propose a novel scheme to minimize drift in scalable wavelet based video coding, which gives a balanced performance between compression efficiency and reconstructed quality with less drift. Our drift control mechanism maintains two frame buffers in the encoder and decoder; one that is based on the base layer and one that is based on the base plus enhancement layers. Drift control is achieved by switching between these two buffers for motion estimation and compensation. Our prediction is initially based on the base plus enhancement layers buffer, which inherently introduces drift in the system if a part of the enhancement layer is not available at the receiver. A measure of drift is computed based on the channel information and a threshold is set. When the measure exceeds the threshold, i.e., when drift becomes significant, we switch the prediction to be based on the base layer buffer, which is always available to the receiver. We also developed an adaptive scheme with additional computation overhead at the encoder to decide the switching instance. The performance of the threshold case that needs fewer computations is comparable with the adaptive scheme. Our coder offers high compression efficiency and sustained video quality for variable bit rate wireless channels. This proves that we need not completely eliminate drift and decrease compression efficiency to get better received video quality. 相似文献
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Dapeng Wu Yiwei Thoms Hou Ya-Qin Zhang 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2000,88(12):1855-1877
Delivering real-time video over the Internet is an important component of many Internet multimedia applications. Transmission of real-time video has bandwidth, delay, and loss requirements. However the current Internet does not offer any quality of service (QoS) guarantees to video transmission over the Internet. In addition, the heterogeneity of the networks and end systems makes it difficult to multicast Internet video in an efficient and flexible way. Thus, designing protocols and mechanisms for Internet video transmission poses many challenges. In this paper, we take a holistic approach to these challenges and present solutions from both transport and compression perspectives. With the holistic approach, we design a framework for transporting real-time Internet video, which includes two components, namely, congestion control and error control. Specifically congestion control consists of rate control, rate-adaptive encoding, and rate shaping; error control consists of forward error correction (FEC), retransmission error resilience, and error concealment. For the design of each component in the framework, we classify approaches and summarize representative research work. We point out there exists a design space which can be explored by video application designers and suggest that the synergy of both transport and compression could provide good solutions 相似文献
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基于数字信号处理器(DSP)TMS320VC5416和复杂可编程逻辑器件(CPLD)的嵌入式车牌识别系统的硬件设计,利用视频处理芯片SAA7111作为视频A/D,在CPLD的控制下将采集到的图像数据写入帧存储器中,DSP对图像数据进行实时分析处理。采用"乒乓"存储结构,实现了图像数据的采集和处理的并行运行。识别结果通过串口传到上位机或者保存在E2PROM中,实现了车牌识别系统脱机、联机工作,在实时高速图像处理系统中有广泛的工程技术应用前景。 相似文献
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视频压缩与信号复接系统设计 总被引:1,自引:1,他引:0
为了满足视频信号传输的高实时性,提高无线信道的利用率,设计并实现了一种以专用视频压缩芯片ADV202实现视频信号压缩,并采用FPGA为信号复接单元的视频压缩与信号复接系统。系统中通过ADV202实现了基于JPEG2000的视频数据压缩,保证了信号传输的高实时性;并通过FPGA实现对压缩数据的复接,提高了无线信道的利用率。 相似文献