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关于3D不可压Navier-Stokes方程H1正则性的注记
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作者 杨成明 崔振琼 《应用数学进展》 2021年第7期2529-2552,共24页
这篇论文主要研究了3D不可压Navier-Stokes方程解的H1正则性. 首先, 本论文给出井详细证明 了3D不可压Navier-Stokes方程解的局部适定性引理. 其次, 应用上述解的局部适定性引理, 第一, 可以严格证明解在小初始数据情形时的全局正则性.... 这篇论文主要研究了3D不可压Navier-Stokes方程解的H1正则性. 首先, 本论文给出井详细证明 了3D不可压Navier-Stokes方程解的局部适定性引理. 其次, 应用上述解的局部适定性引理, 第一, 可以严格证明解在小初始数据情形时的全局正则性. 第二, 对于最大可能的所有U0和最大可能的所 有F , 证明出3D不可压Navier-Stokes方程解的H1 正则性. 本论文强调不仅对最大可能U0和某一 固定F 这一情形, 解具有H1正则性, 而且对最大可能U0和最大可能的F 这一情形, 解同样具有H1正则性。 展开更多
关键词 H1正则性 局部适定性引理 3d不可压navier-stokes方程
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Saint-Venant and Navier-Stokes Models for Tsunami Simulations
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作者 Camille Journeau Kevin Pons Richard Marcer 《Journal of Shipping and Ocean Engineering》 2019年第1期42-63,共22页
Into the frame of the French TANDEM project (Tsunamis in the Atlantic and the English ChaNnel: Definition of the Effects through numerical Modelling) Principia has been working on the development and qualification of ... Into the frame of the French TANDEM project (Tsunamis in the Atlantic and the English ChaNnel: Definition of the Effects through numerical Modelling) Principia has been working on the development and qualification of two in-house CFD software: the 2D EOLE-SV (Saint-Venant) model for simulation of large scale tsunami propagation from the source up to coastal scale and the 3D EOLE-NS (Navier-Stokes) model dedicated to tsunami coastal impact modelling. This paper presents a large range of test cases carried out into the frame of the project and dedicated to the validation of numerical codes in various tsunami wave conditions. The main aspects of phenomena such as wave generation, propagation and coastal impact are investigated on academic situations. A real case simulation is concerned as well, the devastating 2011 Tohoku event which is compared with in-situ data. 展开更多
关键词 TSUNAMI CFd Saint-Venant (SV) MOdEL Adaptive Mesh REFINEMENT (AMR) large scale propagation 3d navier-stokes (NS) MOdEL coastal impact
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FDM彩色3D打印机控制系统的研究 被引量:7
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作者 郑喜贵 黄子帆 +2 位作者 李俊美 李欧阳 马跃龙 《现代制造工程》 CSCD 北大核心 2017年第12期66-70,77,共6页
目前FDM 3D打印机存在成型件颜色单一的缺陷,为了解决这一问题,通过对现有挤出系统及传统配色标准的研究,提出了CMYKW的配色方案,并对标准G-Code指令进行研究。开发了控制电路板,通过打印实验,验证了CMYKW的配色方案及控制系统有效性。... 目前FDM 3D打印机存在成型件颜色单一的缺陷,为了解决这一问题,通过对现有挤出系统及传统配色标准的研究,提出了CMYKW的配色方案,并对标准G-Code指令进行研究。开发了控制电路板,通过打印实验,验证了CMYKW的配色方案及控制系统有效性。实现了彩色3D打印,为进一步研究彩色3D打印技术提供了一种解决方案。 展开更多
关键词 彩色3d打印 G代码 配色方案 挤出系统 控制系统
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一种新的3-D小波变换图像编码方法 被引量:9
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作者 张文忠 沈兰荪 《电子学报》 EI CAS CSCD 北大核心 1997年第10期32-36,共5页
基于图像序列三维小波变换的视频编码技术是一种很有潜力的编码方法.本文针对目前实际中采用的三维小波变换只是一种准三维变换,不能提供对变换结果的统一描述等不足,推导了信号真正的三维小波变换的有关理论及其实现方法.在此基础... 基于图像序列三维小波变换的视频编码技术是一种很有潜力的编码方法.本文针对目前实际中采用的三维小波变换只是一种准三维变换,不能提供对变换结果的统一描述等不足,推导了信号真正的三维小波变换的有关理论及其实现方法.在此基础上,我们将这种三维小波变换方法用于视频图像的编码,模拟结果表明这种编码结构具有良好性能,值得进一步的深入研究. 展开更多
关键词 视频图像编码 3-d小波变换 多分辨率分析
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用于光码分多址系统的一种3-D地址码 被引量:1
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作者 周秀丽 胡渝 谭庆贵 《应用光学》 CAS CSCD 2004年第4期18-20,25,共4页
 在构造2-D码的基础上,提出并构造了一种用于OCDMA系统的新的空域/频域/时域3-D地址码,与2-D码相比,基于R-S序列运算的3-D码容量大,系统带宽效率高,误码率低,表现出更好的性能,大大增强了OCDMA系统的可行性。
关键词 OCdMA 空域 波长域 时域扩展 3-d地址码 2-d地址码
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OCDMA系统中2-D码和3-D码 被引量:1
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作者 周秀丽 谭庆贵 胡渝 《应用光学》 CAS CSCD 2005年第2期15-17,46,共4页
 光码分多址(OCDMA)技术主要应用在接入网中。设计大容量的地址码是该技术实用化的前提。本文在构造2-D素数码的基础上提出了一种用于OCDMA系统的空域/频域/时域3-D地址码。这种码基于素数序列运算。理论分析和数学计算结果表明,3-D码...  光码分多址(OCDMA)技术主要应用在接入网中。设计大容量的地址码是该技术实用化的前提。本文在构造2-D素数码的基础上提出了一种用于OCDMA系统的空域/频域/时域3-D地址码。这种码基于素数序列运算。理论分析和数学计算结果表明,3-D码比2-D码的容量更大,系统带宽效率更高,误码率(BER)更低,表现出的性能更好。 展开更多
关键词 光码分多址 3-d地址码12-d地址码 误码率
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基于IPCT/3-D Tarp的高光谱图像无损压缩 被引量:1
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作者 罗欣 郭雷 刘震 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2007年第6期443-446,共4页
研究了一种将变换矩阵分解为三角元素可逆矩阵(TERM)实现的主成分变换整数近似算法(IPCT).为限制误差和提高计算效率,改进了TERM分解中选择主元的方法.结合可逆整数PCT和三维Tarp编码技术,提出了一种新的高光谱图像无损压缩算法.该算法... 研究了一种将变换矩阵分解为三角元素可逆矩阵(TERM)实现的主成分变换整数近似算法(IPCT).为限制误差和提高计算效率,改进了TERM分解中选择主元的方法.结合可逆整数PCT和三维Tarp编码技术,提出了一种新的高光谱图像无损压缩算法.该算法在进行空间维小波变换以后,利用改进的IPCT去除谱间相关;在编码阶段,新颖的三维Tarp编码器能利用五个简单的递归滤波器进行概率估计,以驱动一个非自适应算术编码器,对变换系数的显著性映射和细化信息进行熵编码.该算法复杂度较低,能够产生嵌入式码流,并且较已有的算法能获得更高的压缩比. 展开更多
关键词 高光谱图像 无损压缩 整数主成分变换 三维Tarp编码
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高维D=3 SM阵列编码构造和实现 被引量:2
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作者 林柏钢 邱宏端 《电子科学学刊》 EI CSCD 2000年第2期198-204,共7页
本文基于第一作者1994年提出的D=2 SM阵列码的概念体系,进一步给出D=3 SM阵列码的编码规则和存在条件,并讨论其结构特点、构造步骤和设计分析。最后指出其编码性能和用途。
关键词 SM阵列码 结构模型 密码设计 密码学
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3-D图象压缩编码的一种新方法
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作者 黄端旭 罗斌 《安徽大学学报(自然科学版)》 CAS 1990年第2期57-61,共5页
根据三维表面的可见不变特征分割图象,采用连续逻辑对瓶体三维图象进行编码,并且实现3-D形状的重构。计算机模拟结果表明这是一种可行的图象数据的压缩传输方式。
关键词 三维图象 数据压缩 编码 区域分割
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新一代基于HEVC的3D视频编码技术 被引量:6
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作者 田恬 姜秀华 王彩虹 《电视技术》 北大核心 2014年第11期5-8,19,共5页
HEVC标准出台后,新一代基于HEVC的多视点加深度编码也将正式推出。基于HEVC的3D视频编码作为HEVC标准的扩展部分,主要面向立体电视和自由立体视频。从该编码方式的基本结构出发,较全面地介绍了视频编码方式、深度图编码方式和对深度图... HEVC标准出台后,新一代基于HEVC的多视点加深度编码也将正式推出。基于HEVC的3D视频编码作为HEVC标准的扩展部分,主要面向立体电视和自由立体视频。从该编码方式的基本结构出发,较全面地介绍了视频编码方式、深度图编码方式和对深度图的编码控制三个方面的关键技术,包括视点间运动预测、深度图建模模式和视点合成优化等技术。 展开更多
关键词 3d视频编码 HEVC MVC
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基于3-D整数小波变换的视频压缩算法研究
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作者 周武 傅忠谦 +1 位作者 朱晓鸣 周学友 《计算机工程与应用》 CSCD 北大核心 2006年第35期55-57,60,共4页
视频图像数据可以被看成三维数据体来进行3-D小波变换,对变换后的数据进行编码就可以达到压缩视频数据的目的。主要讨论了这种变换的整数实现方法,以及对小波系数使用SPIHT算法进行编码压缩,并对SPIHT算法进行了有针对性的优化。仿真实... 视频图像数据可以被看成三维数据体来进行3-D小波变换,对变换后的数据进行编码就可以达到压缩视频数据的目的。主要讨论了这种变换的整数实现方法,以及对小波系数使用SPIHT算法进行编码压缩,并对SPIHT算法进行了有针对性的优化。仿真实验证明,该文方法压缩效果良好,运行效率高,输出码流具有嵌入式特性,是一种有应用前景的算法。 展开更多
关键词 3-d整数小波变换 视频压缩 小波系数编码
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Multiple description scalable video coding based on 3D lifted wavelet transform 被引量:3
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作者 KIM Yong-deak 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第5期857-863,共7页
In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multi... In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multiple description scalable coding (MDSC) is investigated, and novel MDSC schemes based on 3D wavelet coding are proposed, using the lifting imple- mentation of temporal filtering. The proposed MDSC schemes can avoid the mismatch problem in multiple description video coding, and have high scalability and robustness of video transmission. Experimental results showed that the proposed schemes are feasible and adequately effective. 展开更多
关键词 Multiple description SCALABLE coding (MdSC) MOTION compensated temporal filtering (MCTF) Block-split bidi-rectional MOTION estimation 3d lifted WAVELET TRANSFORM
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Quantitative determination of PFC3D microscopic parameters 被引量:3
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作者 LI Zhuo RAO Qiu-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第3期911-925,共15页
It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the mi... It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the microscopic parameters of parallel-bonded particle model for three-dimensional discrete element particle flow code(PFC3D).Variation ranges of microscopic of the microscopic parameters are created by analyzing the effects of microscopic parameters on macroscopic parameters(elastic modulus E,Poisson ratio v,uniaxial compressive strengthσc,and ratio of crack initial stress to uniaxial compressive strengthσci/σc)in order to obtain the actual uniform design talbe.The calculation equations of the microscopic and macroscopic parameters of rock materials can be established by the actual uniform design table and the regression analysis and thus the PFC3D microscopic parameters can be quantitatively determined.The PFC3D simulated results of the intact and pre-cracked rock specimens under uniaxial and triaxial compressions(including the macroscopic mechanical parameters,stress−strain curves and failure process)are in good agreement with experimental results,which can prove the validity of the calculation equations of microscopic and macroscopic parameters. 展开更多
关键词 quantitative relationship of microscopic and macroscopic parameters uniform design method three-dimensional particle flow code(PFC3d) ROCK
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3D surface reconstruction based on binocular vision using structured light 被引量:1
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作者 MA Zhi-feng HAN Fu-hai WANG Teng-fei 《Journal of Beijing Institute of Technology》 EI CAS 2016年第3期413-417,共5页
A 3D surface reconstruction method using a binocular stereo vision technology and a coded structured light,which combines a gray code with phase-shift has been studied.The accuracy of the 3 D surface reconstruction ma... A 3D surface reconstruction method using a binocular stereo vision technology and a coded structured light,which combines a gray code with phase-shift has been studied.The accuracy of the 3 D surface reconstruction mainly depends on the decoding of gray code views and phase-shift views.In order to find the boundary accurately,gray code patterns and their inverses are projected onto a human eye plaster model.The period dislocation between the gray code views and the phase-shift views in the course of decoding has been analyzed and a new method has been proposed to solve it.The splicing method is based on feature points.The result of the 3D surface reconstruction shows the accuracy and reliability of our method. 展开更多
关键词 3d surface reconstruction structured light gray code PHASE-SHIFT
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AVS 3D Video Coding Technology and System 被引量:1
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作者 Siwei Ma Shiqi Wang Wen Gao 《ZTE Communications》 2012年第2期13-18,共6页
Following the success of the audio video standard (AVS) for 2D video coding, in 2008, the China AVS workgroup started developing 3D video (3DV) coding techniques. In this paper, we discuss the background, technica... Following the success of the audio video standard (AVS) for 2D video coding, in 2008, the China AVS workgroup started developing 3D video (3DV) coding techniques. In this paper, we discuss the background, technical features, and applications of AVS 3DV coding technology. We introduce two core techniques used in AVS 3DV coding: inter-view prediction and enhanced stereo packing coding. We elaborate on these techniques, which are used in the AVS real-time 3DV encoder. An application of the AVS 3DV coding system is presented to show the great practical value of this system. Simulation results show that the advanced techniques used in AVS 3DV coding provide remarkable coding gain compared with techniques used in a simulcast scheme. 展开更多
关键词 AVS 3d video coding inter-view prediction stereo packing
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AN EFFICIENT 3-DIMENSIONAL DISCRETE WAVELET TRANSFORM ARCHITECTURE FOR VIDEO PROCESSING APPLICATION 被引量:1
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作者 Ganapathi Hegde Pukhraj Vaya 《Journal of Electronics(China)》 2012年第6期534-540,共7页
This paper presents an optimized 3-D Discrete Wavelet Transform (3-DDWT) architecture. 1-DDWT employed for the design of 3-DDWT architecture uses reduced lifting scheme approach. Further the architecture is optimized ... This paper presents an optimized 3-D Discrete Wavelet Transform (3-DDWT) architecture. 1-DDWT employed for the design of 3-DDWT architecture uses reduced lifting scheme approach. Further the architecture is optimized by applying block enabling technique, scaling, and rounding of the filter coefficients. The proposed architecture uses biorthogonal (9/7) wavelet filter. The architecture is modeled using Verilog HDL, simulated using ModelSim, synthesized using Xilinx ISE and finally implemented on Virtex-5 FPGA. The proposed 3-DDWT architecture has slice register utilization of 5%, operating frequency of 396 MHz and a power consumption of 0.45 W. 展开更多
关键词 3-d discrete Wavelet Transform (3-ddWT) Lifting scheme PIPELINING Video coding Low power
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3D obstacle detection of indoor mobile robots by floor detection and rejection 被引量:1
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作者 Donggeun Cha Woojin Chung 《Journal of Measurement Science and Instrumentation》 CAS 2013年第4期381-384,共4页
Obstacle detection is essential for mobile robots to avoid collision with obstacles.Mobile robots usually operate in indoor environments,where they encounter various kinds of obstacles;however,2D range sensor can sens... Obstacle detection is essential for mobile robots to avoid collision with obstacles.Mobile robots usually operate in indoor environments,where they encounter various kinds of obstacles;however,2D range sensor can sense obstacles only in 2D plane.In contrast,by using 3D range sensor,it is possible to detect ground and aerial obstacles that 2D range sensor cannot sense.In this paper,we present a 3D obstacle detection method that will help overcome the limitations of 2D range sensor with regard to obstacle detection.The indoor environment typically consists of a flat floor.The position of the floor can be determined by estimating the plane using the least squares method.Having determined the position of the floor,the points of obstacles can be known by rejecting the points of the floor.In the experimental section,we show the results of this approach using a Kinect sensor. 展开更多
关键词 3d obstacle detection mobile robot Kinect sensordocument code:AArticle Id:1674-8042(2013)04-0381-04
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LncRNA HAGLR激活RUNX2并抑制NLRP3炎症小体对胫骨骨折愈合的影响 被引量:2
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作者 王文 陈新宇 +2 位作者 黄兹艺 邓杨柳 崔红旺 《安徽医科大学学报》 CAS 北大核心 2023年第5期830-837,共8页
目的研究长链非编码RNA(LncRNA)HAGLR对胫骨骨折(TF)小鼠的NOD样受体蛋白3(NLRP3)炎症小体表达和骨折愈合的影响并探讨机制。方法体外对成骨细胞MC3T3-E1沉默HAGLR,CCK-8法检测细胞活力,TUNEL法检测细胞凋亡,qPCR法检测骨碱性磷酸酶(BA... 目的研究长链非编码RNA(LncRNA)HAGLR对胫骨骨折(TF)小鼠的NOD样受体蛋白3(NLRP3)炎症小体表达和骨折愈合的影响并探讨机制。方法体外对成骨细胞MC3T3-E1沉默HAGLR,CCK-8法检测细胞活力,TUNEL法检测细胞凋亡,qPCR法检测骨碱性磷酸酶(BALP)和骨钙素的表达。Western blot法检测RUNX2、磷酸化RUNX2(p-RUNX2)以及NLRP3、半胱天冬酶1(Caspase1)、凋亡相关斑点样蛋白(ASC)、白细胞介素-1β(IL-1β)的表达。通过小鼠TF手术建立TF小鼠模型,在模型小鼠体内过表达HAGLR,并在过表达HAGLR的基础上沉默RUNX2或加入炎症小体抑制剂MCC950。qPCR法检测HAGLR和RUNX2的表达,Western blot法检测胰岛素样生长因子-1(IGF-1)的表达。microCT测量小鼠骨痂体积(MBV),称量小鼠的全长胫骨湿重。结果沉默HAGLR导致MC3T3-E1细胞活力降低且凋亡率增加(P<0.05),且RUNX2、p-RUNX2、BALP和骨钙素表达量均降低(P<0.05),NLRP3、Caspase1、ASC、IL-1β的表达量都增加(P<0.05)。与健康组织比较,TF小鼠体内HAGLR和RUNX2表达量降低(P<0.05)。过表达HAGLR促进TF小鼠体内的HAGLR和RUNX2表达,并增加MBV和全长胫骨湿重以及IGF-1的表达量(P<0.05)。在过表达HAGLR的基础上沉默RUNX2导致TF小鼠的MBV、全长胫骨湿重和IGF-1表达量都降低(P<0.05)。而在过表达HAGLR的基础上加入NLRP3炎症小体抑制剂MCC950导致MBV、全长胫骨湿重和IGF-1表达又增加(P<0.05)。结论LncRNA HAGLR通过激活RUNX2并抑制NLRP3炎症小体促进TF的愈合。 展开更多
关键词 胫骨骨折 同源框d基因簇反义生长相关的长非编码RNA Runt相关转录因子2 NOd样受体热蛋白结构域相关蛋白3 炎症小体
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3-D Wavelet Transform for Very Low Bit-Rate Video Coding
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作者 Hou Weidong Mo Yulong Zhu Qiuyu Wei Chunlong (Shool of Communication and Information Engineering, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第2期48-51,共4页
A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, c... A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, compression ratios and visual quality of reconstructions, when compared to the other existing 3 D WT coding methods and the 2 D WT based coding methods. The new 3 D WT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding video compression very low bit rate 3 d wavelet transform
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Very Low Bit Rate Video Coding Using Motion Compensated 3 D Wavelet Transform
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作者 HOU Wei dong MO Yu long (School of Communication and Information Engineering, Shanghai University) HU Hai ping (School of Sciences, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第4期342-344,共3页
A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconst... A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconstructions compared with the existing 3 D wavelet transform (3DWT) coding methods and motion compensated 2 D wavelet transform (MC WT) coding method. The new MC 3DWT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding very low bit rate 3 d wavelet transform motion compensation
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