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1.
基于H.264/AVC的快速运动估计改进算法   总被引:1,自引:0,他引:1  
H.264/AVC中基于块的运动估计是运算量最大的模块.提出了一种基于UMHexagonS的改进整像素快速运动估计算法,该算法改进了UMHexagonS的搜索模板和搜索层,较大幅度减少了整像素运动估计搜索的点数,提高了运动估计效率.实验结果表明,在保持大致一样的率失真性能前提下,算法比UMHexagonS算法减少了20%的搜索点数,更适于实时视频编码.  相似文献   

2.
通过对H.264参考模型JM61 e中运动估计算法进行分析,对整像素、1/2像素和1/4像素搜索提出了改进策略。采用自适应阈值搜索停止算法,减少了运动估计的搜索次数,且保持运动估计的精度不变。采用自适应阈值搜索停止算法,减少了运动估计搜索次数,并且基本保持运动估计的精度不变。实验结果表明,该策略在重建图像质量略有下降的情况下明显提高了编码速度。  相似文献   

3.
文中提出了一种基于全零块检测的快速运动估计方法.算法结合误差曲面特性以及运动矢量中心偏移特性,得到最佳参考运动矢量;利用运动矢量的方向和强度信息,确定搜索方向,切换搜索模式,搜索的同时应用全零块的中止准则.算法无需保存搜索记录,存储开销小,同时搜索策略快速有效,适用于移动视频通信终端设备存储能力有限且实时要求较高的场合.  相似文献   

4.
基于方向信息的快速整像素运动估计优化   总被引:1,自引:0,他引:1  
针对H.264/AVC标准采用的UMHexagonS整像素运动估计算法,提出了一种进一步降低其运算复杂度的改进方法.通过利用UMHexagonS算法中非对称十字型搜索中水平及垂直方向上的运动估计的成本大小和方向信息,自适应地将25点的正方形搜索修改为最大7点搜索,以及将16点非均匀多层次六边形格点搜索修改为最大4点搜索,从而实现减少搜索点数,节省搜索时间.实验结果表明,提出的算法在保证原有UMHexagonS算法码率失真性能的同时,能节省大约23%~42%整像素运动估计时间.  相似文献   

5.
李飞鹏 《科学技术与工程》2011,11(24):5823-5825,5830
运动估计是视频压缩编码中消耗时间最多的部分。H.264标准采纳混合非对称十字多六边形格点搜索(UMHexa-gonS)算法作为其快速运动估计算法。详细介绍了UMHexagonS算法,并从三个方面对算法进行了改进:一是增加一个自适应的提前终止判决门限,二是用一种新的搜索方式替代5×5螺旋搜索,减少搜索点数,三是将多层六边形搜索修改为多层十点搜索。在测试模型JM10.2上进行了算法验证,测试结果表明,在图像质量几乎不变的情况下,改进的算法比原算法节省了7%—14%的运动估计时间。  相似文献   

6.
运动估计是视频压缩中帧间预测编码的关键技术之一.由于运动估计具有较大的运算量,因此对压缩性能有重要影响.在研究分析了影响视频编码性能的传统搜索算法基础上,提出了一种基于六边形搜索算法的改进算法.该算法初始步骤使用十字形搜索模式,然后采用六边形搜索模式中的小钻石搜索模式,进行快速块运动估计.并进行了计算机仿真实验证明了改进算法在压缩处理运算量及信号质量方面的优越性.结果表明,改进算法比新三步搜索算法和传统六边形搜索算法有着更快的搜索速度和更小的失真.  相似文献   

7.
可预测起始搜索点的自适应准十字菱形搜索算法   总被引:1,自引:0,他引:1  
分析了视频图像现有块匹配运动估计的技术特点,通过实验数据定量评价了各算法的优缺点,提出的一种改进的自适应运动估计算法:基于起始搜索点预测的准十字菱形搜索算法.该算法根据序列图像中运动矢量的十字中心偏置分布特性和运动矢量间的时空相关性,设计了一种准十字菱形搜索模板,并对静止块设定阈值,直接中止搜索;结合起始搜索点预测,并根据运动类型自适应选择搜索策略,使本文算法在保证了搜索准确性的同时,提高了运动估计的速度.  相似文献   

8.
分析了Feng等提出的简单自适应全搜索比特面匹配运动估计算法的不足,对其中比特面的计算方法、搜索起点的选择及比特面匹配准则搜索失败后的处理策略等方面作了改进,实验结果表明,改进后的算法的运动估计性能比原算法有较大提高,对于可视电话中的头肩视频序列,性能与全搜索法差别不大,且计算量仅为全搜索法的1/6。  相似文献   

9.
卢艳红 《科技资讯》2007,(36):99-100
AVS是我国自主制定,拥有自主知识产权的音视频编码技术标准.该文通过对AVS参考软件rm52c中快速运动估计算法进行分析,对整像素、1/2像素和1/4像素搜索提出了改进策略.采用自适应阈值搜索停止算法,在保证运动估计精度的同时,减少了运动估计的搜索次数.实验结果表明,该策略在重建图像质量屡有下降的情况下明显提高了编码速度.  相似文献   

10.
在视频编码中,运动估计发挥着相当重要的作用,在很大程度上影响图像精度和压缩比例;同时运动估计也是编码器中复杂度高、运算量特别大的一部分,因此影响了H.264视频编码的实时应用.为了降低计算复杂度并保持图像质量,本文提出了一种整像素运动估计算法.结合UMHexagonS(非对称十字型多层次六边形格点搜索)算法和EPZS(增强的区域搜索)算法的特性,本文算法根据图像的运动类型不同采用不同的模板,同时加入了提前终止技术.实验结果证明该算法与FS(全搜索)、UMHexagonS和EFZS算法相比,在峰值信噪比(PSNR)基本相同的情况下减少了运动估计的时间.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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