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1.
1 Introduction The emerging H.264/AVC video coding standard hasbeen developed and standardized collaboratively byboth ITU-T VCEG and ISO/IEC MPEG organizations .As the newest international video coding standard ,H.264/AVC represents a number of advances i…  相似文献   

2.
The emerging video coding standard H.264[1],provides the state-of-the-art video coding techniquesto meet a wide range of applications. Among thosetechniques, intra prediction is regarded as one of themain factors that contribute to the success ofH.264[2]. The rate distortion optimization (RDO)technology has been employed in H.264 for intra pre-diction mode selection to achieve good codingefficien-cy, which makes encoder extremely complex. Efforts have been made in developing fast H.264intra…  相似文献   

3.
The H.264/AVC video coding standard uses an intra prediction mode with 4×4 and 16×16 blocks for luma and 8×8 blocks for chroma. This standard uses the rate distortion optimization (RDO) method to determine the best coding mode based on the compression performance and video quality. This method offers a large improvement in coding efficiency compared to other compression standards, but the computational complexity is greater due to the various intra prediction modes. This paper proposes a fast intra mode decision algorithm for real-time encoding of H.264/AVC based on the dominant edge direction (DED). The DED is extracted using pixel value summation and subtraction in the horizontal and vertical directions. By using the DED, three modes instead of nine are chosen for RDO calculation to decide on the best mode in the 4×4 luma block. For the 16×16 luma and the 8 × 8 chroma, only two modes are chosen instead of four. Experimental results show that the entire encoding time saving of the proposed algorithm is about 67% compared to the full intra search method with negligible loss of quality.  相似文献   

4.
对线性回归分类算法进行了改进。考虑了线性回归分类算法中没有考虑的类间信息,通过选择类模式的投影方向判别不同类的模式,不同类的模式互相远离,相同类的模式尽可能靠近来估计投影矩阵;再利用投影矩阵将训练图像及测试图像投影到各类的特征子空间;最后,计算出测试图像与训练图像间的距离,利用K-近邻分类器完成人脸的识别。在FERET人脸数据库上进行实验验证。实验结果表明,相比其他回归分类算法,本算法取得了更好的识别效果。  相似文献   

5.
在货物起运地和目的地之间构建运输方式组合虚拟网络有向图.并将各种可选运输方式的总成本赋予在相应的虚拟网络图的有向路径上.将运输方式组合问题转化成该虚拟网络的最短路问题,然后通过集成运用Dijkstra启发式算法和k最短路算法,搜索检验出满足运输总时间要求的第七最小总成本,以实现运输总成本和运输总时间的最佳统一,可得出运输时间限定条件下的运输总成本最低的运输方式组合方案。  相似文献   

6.
从两个真歧义句的组合谈起,借以抽象出“vp ap的np”格式,该格式可以有若干种定界模式,可以举出包括以上两个真歧义句的许多实例;同时介绍了Farley算法的基本操作,构造了一个初步的CFG文法,尝试讨论了歧义的消解策略,并试图通过对以上两个真歧义句的Farley算法的演示表明该算法也可以推广到其他实例的分析中去.  相似文献   

7.
With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate.  相似文献   

8.
文本分析发现,现阶段存在四种不同的师生交往模式,分别是权力控制型、平等对话型、服务契约型和代理监护型;师生交往模式受制于学校组织各自不同的目标、任务和功能定位;权力控制型师生交往模式仍处主导地位,平等对话型师生交往模式的确立尚需时日;师生交往模式的健康发展需要更加完备的立法予以引导、规范和调节。  相似文献   

9.
我国现阶段的个人收入分配方式应划分为按劳分配、按生产要素分配和其他分配方式三大类。按生产要素分配和其他分配方式又各有多种具体形式;按生产要素分配即生产要素按贡献参与分配的依据主要有劳动价值论、所有制结构、生产要素所有权和市场经济;个人收入应划分为合法收入和非法收入两类.国家应保护合法收入,打击和取缔非法收入。  相似文献   

10.
n元一次不定方程的计算机解法   总被引:2,自引:0,他引:2  
给出了用矩阵方法求解n元一次不定方程的算法与计算机程序。与其它方法相比,本方法具有算法简单、易于实现以及通用性好等优点。  相似文献   

11.
An adaptive FEC to protect RoHC and UDP-Lite H.264 video critical data   总被引:1,自引:0,他引:1  
INTRODUCTION Recommendation H.264 was approved by ITU-T in May 2003 and the approved draft specifi cation is available for public review (Wiegand, 2003) The H.264 video codec has a very broad application range that covers all forms of digital compressed video from low bit rate Internet streaming applica tions to HDTV broadcast and digital cinema applica tions with near lossless coding. About 50% band width would be saved by using H.264 when compared to the existing most efficient com…  相似文献   

12.
利用传输矩阵方法研究了多个周期性分布的负折射率缺陷的一维光子晶体的透射谱.以32个周期的1/4波堆存在5个负折射率缺陷的光子晶体为例进行了数值计算.结果表明:在带隙中产生多个缺陷模,这些缺陷模的分布依赖于缺陷在晶体中的分布.当缺陷密集时,缺陷耦合较强,缺陷模相距较远;当缺陷稀疏时,缺陷耦合较弱,缺陷模相距较近,分立的缺陷模趋于简并,由此形成一个很窄的通带.与正折射率缺陷情形相比较,负折射率缺陷间的相互作用对缺陷模的影响更大,缺陷模谱线也更宽.  相似文献   

13.
This paper presents a novel current feedforward control strategy for a three-phase pulse-width modulation (PWM) DC voltage-type converter based on phase and amplitude control (PAC). With right-angle triangle relation of phasors and principle of conservation of energy, a phasor adjustment method and the relevant low-frequency mathematical model of the system are analyzed in detail, both in rectification and regeneration modes for the converter, are discussed. For improving the traditional PAC dynamic performance, variable load current is detected indirectly by the change of the DC voltage, which is fed to the control system as an additional control variable to generate modulation index and phase angle. Also, the algorithm is derived and the system principle is introduced. Experimental results from a 3 kw laboratory device are included to demonstrate the effectiveness of the proposed control strategy.  相似文献   

14.
EM算法是在不完全信息资料下实现参数估计的一种通用迭代方法,其在现代科学的许多领域已有着广泛的应用。文章导出了双位点不同标记类型,包括共显性-共显性,共显性-显性和显性-显性三种模式下,部分个体缺失标记基因型时,重组率估计率的EM算法。用编制的SAS/IML程序进行了Monte Carlo模拟研究,验证了文章所述方法在遗传连锁分析中的有效性和实用性。  相似文献   

15.
分析指出一类八自由度矩形板元具有能量正交的形函数空间,且其单元刚度矩阵为对角块:Ke=krc+Kh,其中Krc只和形函数空间的常应变模态有关,Kh由高阶模态决定.  相似文献   

16.
The dynamic securityregion(DSR) is definedas are-gionininjectionspacein whicha power systemwill betran-siently stable for a given fault[1].The DSRis usually de-noted asΩd(i,j,F) ,whereiandjdenote the networkstructures of pre-fault and post-fault ,respect…  相似文献   

17.
基于遗传算法的汽车悬置系统优化软件开发   总被引:1,自引:0,他引:1  
首先阐述了动力总成悬置系统以能量解耦指标为目标函数的优化设计方法,接着给出了所采用的遗传算法的计算方法,并以此为基础开发了用于悬置系统优化计算的软件——DMOUNT。最后应用DMOUNT对2个算例进行了计算,结果表明:利用遗传算法往往可以找到各个坐标方向均具有很高解耦程度的计算方案。  相似文献   

18.
油樟组织培养污染率控制试验   总被引:4,自引:0,他引:4  
以油樟带芽茎段为材料,在初代培养中进行了不同表面消毒方式、不同年龄、不同季节的外植体污染率试验。结果表明,Ca(ClO)2和HgCl2的配合使用有利于污染率的降低;当年生枝条的污染率低于二年生枝条。3月采集的材料污染率低于10月。这为增加油樟组培中无菌苗的得率提供了指导,也对其它木本植物组培的研究有一定的意义。  相似文献   

19.
DES作为长期使用的加密算法标准被广泛应用于软件加密和硬件加密,研究、分析DES加密算法的原理、特性,对推动现代密码学的发展具有十分重要的意义。本文围绕DES加密算法展开,通过S-DES算法模型,较详尽地阐述了DES加密原理及S-盒的一些特性:S-盒不唯一、S-盒的输入方式不唯一。  相似文献   

20.
在斜Haar变换的基础上提出了一种有效的改进算法,描述出了其计算复杂度及变化性能.与其他正交变换相比,在没有增加原斜Haar变换计算复杂度的前提下,提高了其在图像压缩中的效果,并且在一阶Markov模型下优于传统的斜Haar变换和DCT变换.  相似文献   

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