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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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AN ALGORITHM FOR CODING VIDEO SIGNAL BASED ON 3-D WAVELET TRANSFORMATION
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作者 Wu Peng Zhang Miaolan Li Xianglin (Dept. of Electrical Eng., Graduate School, Uni. of Sci. and Tech. of China, Beijing 100039) 《Journal of Electronics(China)》 2000年第2期97-107,共11页
This paper presents an algorithm for coding video signal based on 3-D wavelet transformation. When the frame order t of a video signal is replaced by order 2, the video signal can be looked as a block in 3-D space. Af... This paper presents an algorithm for coding video signal based on 3-D wavelet transformation. When the frame order t of a video signal is replaced by order 2, the video signal can be looked as a block in 3-D space. After splitting the block into smaller sub-blocks, imitate the method of 2-D wavelet transformation for images, we can transform the sub-blocks with 3-D wavelet. Most of video signal energy is in the decomposed low-frequency sub-bands. These sub-bands affect the visual quality of the video signal most. Quantizing different sub-bands with different precision and then entropy encoding each sub-band, we can eliminate inter- and intra-frame redundancy of the video signal and compress data. Our simulation experiments show that this algorithm can achieve very good result. 展开更多
关键词 WAVELETS 3-d WAVELET TRANSFORMATION video signal CODING
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重力对304不锈钢点蚀行为的影响 被引量:4
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作者 艾莹珺 杜楠 +3 位作者 赵晴 叶超 王力强 文庆杰 《腐蚀与防护》 CAS 北大核心 2014年第12期1182-1186,共5页
采用恒电位极化法、电化学阻抗谱和三维视频显微镜研究了304不锈钢在3.5%NaCl溶液中水平放置和垂直放置时的点蚀行为。结果表明,试样垂直放置比水平放置更易达到稳定点腐蚀,由于重力作用使垂直放置的蚀孔内腐蚀产物更易扩散到孔外,加速... 采用恒电位极化法、电化学阻抗谱和三维视频显微镜研究了304不锈钢在3.5%NaCl溶液中水平放置和垂直放置时的点蚀行为。结果表明,试样垂直放置比水平放置更易达到稳定点腐蚀,由于重力作用使垂直放置的蚀孔内腐蚀产物更易扩散到孔外,加速点蚀的诱发和亚稳态点蚀向稳态点蚀的转变。阻抗谱等效电路中元件参数的分析结果表明,垂直放置的试样表面局部腐蚀比水平放置的更严重。 展开更多
关键词 点蚀 重力 三维视频显微镜 电化学阻抗谱
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Semi-Global Depth Estimation Algorithm for Mobile 3-D Video Applications
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作者 Qiong Liu Hongjiang Xiao 《Tsinghua Science and Technology》 EI CAS 2012年第2期128-135,共8页
Three-dimensional (3-D) video applications, such as 3-D cinema, 3DTV, ana Free Viewpomt Video (FVV) are attracting more attention both from the industry and in the literature. High accuracy of depth video is a fun... Three-dimensional (3-D) video applications, such as 3-D cinema, 3DTV, ana Free Viewpomt Video (FVV) are attracting more attention both from the industry and in the literature. High accuracy of depth video is a fundamental prerequisite for most 3-D applications. However, accurate depth requires computationally intensive global optimization. This high computational complexity is one of the bottlenecks to applying depth generation to 3-D applications, especially for mobile networks since mobile terminals usually have limited computing ability. This paper presents a semi-global depth estimation algorithm based on temporal consis- tency, where the depth propagation is used to generate initial depth values for the computationally intensive global optimization. The accuracy of initial depth is improved by detecting and eliminating the depth propagation outliers before the global optimization. Integrating the initial values without outliers into the global optimization reduces the computational complexity while maintaining the depth accuracy. Tests demonstrate that the algorithm reduces the total computational time by 54%-65% while the quality of the virtual views is essentially equivalent to the benchmark. 展开更多
关键词 3-d video depth estimation temporal propagation graph cuts
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脉冲光纤激光修锐青铜金刚石砂轮试验研究 被引量:7
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作者 陈根余 李宗根 +2 位作者 邓辉 袁勃 陈俊 《激光技术》 CAS CSCD 北大核心 2013年第6期705-711,共7页
为了寻求超硬磨料砂轮的修锐新方法,采用脉冲光纤激光径向辐照,对青铜结合剂金刚石砂轮进行了修锐试验研究。理论分析了脉冲激光修锐青铜结合剂金刚石砂轮的基本原理;借助超景深3维显微系统和粗糙度测试仪,获得了脉冲光纤激光烧蚀青铜... 为了寻求超硬磨料砂轮的修锐新方法,采用脉冲光纤激光径向辐照,对青铜结合剂金刚石砂轮进行了修锐试验研究。理论分析了脉冲激光修锐青铜结合剂金刚石砂轮的基本原理;借助超景深3维显微系统和粗糙度测试仪,获得了脉冲光纤激光烧蚀青铜结合剂轮烧蚀凹坑的表面形貌和深度,总结了激光平均功率、脉冲重复频率和离焦量等参量对烧蚀效果的影响规律;根据试验结果选择最佳工艺参量(P m=20W,f=70kHz,Δ=0.0mm),开展了激光修锐青铜结合剂金刚石砂轮的试验,并采用超景深3维显微系统对修锐后的砂轮表面形貌进行观测。结果表明,在合理工艺参量下,脉冲光纤激光径向辐照修锐青铜结合剂金刚石砂轮,可获得良好的修锐效果。 展开更多
关键词 激光技术 激光修锐 光纤激光器 超景深3维显微系统 青铜结合剂金刚石砂轮
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Technical features in the Portal to CADAL
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作者 吴江琴 庄越挺 潘云鹤 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第11期1249-1257,共9页
China-America Digital Academic Library Project (CADAL) is a collaborative project between universities and institutes in China and the USA, which aims to provide universal access to large scale digital resources and e... China-America Digital Academic Library Project (CADAL) is a collaborative project between universities and institutes in China and the USA, which aims to provide universal access to large scale digital resources and explore the ways of applying multimedia and virtual reality technologies to digital library. The distinct characteristic of the resources in CADAL is that it not only contains one million digital books of different languages, but also contains Terabyte level multimedia resources (image, video, and so on), which are utilized for education and research purposes. So, in the Portal to CADAL, both the traditional services of browsing and searching of digital books, and the services of quickly retrieving and structurally browsing of multimedia documents should be provided. In addition, the services of visual presentation of retrieved results are required too. In this paper, the underlying novel multimedia retrieval methods as well as visualization techniques, which are used in the CADAL portal, are investigated. 展开更多
关键词 CADAL video summarization Multimedia retrieval Chinese calligraphy 3-d visualization
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Three-Dimensional Reconstruction of E.coli SecA at Low Resolution
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作者 潘锡江 隋森芳 《Tsinghua Science and Technology》 SCIE EI CAS 2005年第4期445-448,共4页
SecA is the essential component of the signal-peptide dependent translocation pathway in Escherichia coil (E.coh). The structure and function of SecA must be known to understand the molecular mechanism of preprotein... SecA is the essential component of the signal-peptide dependent translocation pathway in Escherichia coil (E.coh). The structure and function of SecA must be known to understand the molecular mechanism of preprotein translocation. The high flexibility of SecA causes a dynamic conformational heterogeneity which presents a barrier to the growth of crystals of high diffraction quality. Electron microscopy was used to resolve the macromolecular structure of SecA in solution by negative staining and single particle analysis at a resolution of 2.9 nm. The structure of E. coil SecA is similar to the dimeric form of Bacillus subtilis SecA and is 10 nm × 10 nm × 5 nm in size. 展开更多
关键词 single-particle analysis electron microscopy SECA 3-d reconstruction
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