共查询到20条相似文献,搜索用时 62 毫秒
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本文基于ρ域线性率失真模型提出一种适用于H.264的帧级码率控制算法.先验证线性率失真函数对H.264编码算法的适用性,再通过使用混合自适应估计方法精确地估计出该模型惟一的参数θ,实现线性率失真函数在H.264码率控制中的应用.仿真结果表明,与JVT-H017算法相比,新算法不仅获得更精确的码率控制,而且获得更平稳的输出码率和PSNR,同时实现简单,适用于实时视频通信. 相似文献
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提出了一种基于ρ域线性率失真模型的H.264/AVC码率控制方法。算法主要利用ρ域线性率失真模型来解决量化参数同时用于码率控制和率失真优化的矛盾。同时,用非零运动向量个数来估计宏块的头比特数,进而解决头比特的合理估计问题。实验通过对新算法和JVT—H017算法的比较,得到本文算法不但可以获得更精确的码率控制,而且使输出码率更加的平稳,本文算法实现相对简单,适用于实时视频通信。 相似文献
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码率控制是视频编码中非常重要的技术之一,任何标准离开码率控制其应用都会受到限制.H.264/AVC是目前最新的视频编码标准,本文根据H.264/AVC编码标准的特性及其HRD部分对码率控制的要求,提出了一种新的适合H.264/AVC的码率控制算法,该算法实现了率失真优化与码率控制的结合,使得在达到码率控制的同时也能保证较高的编码效率,同时在码率控制的过程中根据HRD缓冲区状态进行位分配调整,保证了编解码缓冲区既不上溢又不下溢.该算法作为技术提案已被H.264/AVC接受,并集成到H.264/AVC的校验模型软件中. 相似文献
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提出了一种基于ρ域线性率失真模型的H.264/AVC码率控制方法.算法主要利用ρ域线性率失真模型来解决量化参数同时用于码率控制和率失真优化的矛盾.同时,用非零运动向量个数来估计宏块的头比特数,进而解决头比特的合理估计问题.实验通过对新算法和JVT-H017 算法的比较,得到本文算法不但可以获得更精确的码率控制,而且使输出码率更加的平稳,本文算法实现相对简单,适用于实时视频通信. 相似文献
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H.264/AVC编码中的码率控制是通过有效控制输出码流的码率来提高其压缩视频质量的重要技术。本文基于H.264/AVC中的JVT-H017码率控制方案提出了一种改进算法。新算法根据H.264中DCT系数的分布特征,将柯西分布引入到码率控制模块,用更精确的柯西率失真模型取代了原先的二次率失真模型。在此基础上,进一步引入了一种联合PSNR比率和MAD比率进行图像复杂度预测的方法,并依此来调整帧级比特的分配和量化参数,克服了在出现复杂运动或场景切换时,因视频序列相邻帧之间相关性降低而导致的MAD预测失准的情况。实验结果表明,与JVT-H017方案及文献[5]中的算法比较,新的算法不仅具有更精确的码率控制,而且明显改善了输出码率的平稳性及重建图像的PSNR。 相似文献
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H.264结构相似性最优的宏块层码率控制算法 总被引:1,自引:1,他引:0
传统码率控制(RC)大多以客观失真作为失真度量,无法得到最优的主观质量。该文将基于结构相似(SSIM)的主观失真用于H.264视频编码的率失真优化和码率控制,提出了一种SSIM最优的宏块(MB)层码率控制(RC)算法。首先提出了一种经验型的SSIM线性失真模型,并结合改进的二次码率-量化(R-Q)模型用Lagrange乘子法得到了SSIM最优的MB层量化步长的闭式解。实验结果表明:该文算法相比客观质量最优的MB层RC算法JVT-O016更好地编码了图像结构信息,得到了更好的主观质量。 相似文献
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提出了一种基于人眼视觉模型加权的率失真优化自适应调整量化器死区算法。该算法应用率失真优化技术自适应地调整量化器死区的大小,提高量化器的编码性能,改进后的量化器在高码率下增益可以达到1dB以上。通过将人眼视觉模型引入率失真代价值的计算,进一步提高了量化器的主观性能。在H.264上的软件模拟结果表明,该算法不但能有效提高视频的主观视觉质量,而且在相同主观质量条件下平均能够节约10%的码率。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
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Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
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A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
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《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献
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《中国通信》2014,(8)
正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first 相似文献