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1.
本文根据小波变换与视觉初级的共同之处,提出一种采用小波变换来进行视觉预处理,并结合神经网络、注意控制等技术的计算机视觉系统方案。这种方案既符合人类视觉进行信息处理的机制,又有利于进行图象分析与模式识别。  相似文献   

2.
在对理想和实际原始图象信号的二维频谱及其幅频特性进行数学分析的基础上,提出了对小波变换二维频谱分解的两种改进方案。  相似文献   

3.
小波变换在红外图象处理中的应用   总被引:3,自引:3,他引:0  
小波变换近年来在图象处理中的应用日益受到人们的关注。小波变换可能同时在时间(或空间)和频率域对信号进行分析,是多分辨率分析的有力工具。本文介绍了小波变换在红外图象处理中的应用,例如红外/可见光图象的配准与融合,红外图象增强,红外图像中的微弱目标探测等。  相似文献   

4.
一种基于小波变换的遥感图象压缩方案   总被引:2,自引:0,他引:2  
针对卫星遥感图象数据的特点,提出了一种基于小波变换的图象压缩编码方案。实验表明了本方案具有简便高效的特点。  相似文献   

5.
基于小波变换的红外图象多尺度边缘检测   总被引:3,自引:3,他引:0  
本文讨论了小波变换及其应用于多尺度图象边缘检测的原理,对一幅红外图象给出其多尺度边缘检测的计算机仿真结果,而且与传统的边缘检测方法进行比较,从而得出基于小波变换的多尺度边缘检测是一种较好的方法  相似文献   

6.
本文研究了医学图象小波变换系数的统计特征。根据医学图象的特点,提出了基于小波变换的医学图象编码方法。实验表明,这种方法具有较好的压缩编码性能,优于JPEG标准。同时,它支持逐次浮现式传输,从而能满足医学图象存储、通信、检索的需要。  相似文献   

7.
利用小波分析来抑制合成孔径雷达图象的相干斑噪声   总被引:11,自引:0,他引:11  
本文利用小波变换来对合成径雷达图象做多分辨率分析,说明了相干斑噪声对图象的不同频率成份的影响程度是不同的,同时也说明了相干斑噪声与图象在小波变换下具有截然不同的奇异性,因此,本文提出了用小波分析来抑制相干斑噪声,实验证明了,小波分析除了能够对相干斑具有很好的抑制效果外,还保留了尽可能多的原图象的目标特征,利用小波分析来抑制相干斑噪声是一个十分吸收人的新方法。  相似文献   

8.
基于小波变换的盲图象恢复   总被引:1,自引:1,他引:0  
提出一种基于小波分解的盲图象恢复算法。该算法根据图象小波变换各个子频段所具有的不同频率特性和不同的方向特性,对各子频段分别进行盲图象恢复;各子频段采用不同的正则化算子。实验结果表明该算法的盲图象恢复的性能优于空域算法。  相似文献   

9.
三维小波多分等级树视频压缩编码   总被引:2,自引:0,他引:2  
提出了基于三维小波多发等级树视频压缩编码方法。通过将原始图象序列进行帧分组,并对每个图象帧组在时间、水平和垂直三维空间上进行小波变换。然后,对变换域的各个空间-时间频率了带按照其方向的不同。构成多个小波等级树,并对每个等级树分别进行SPIHT编码算法。仿真实验表明了该方法的有效性。  相似文献   

10.
使用小波变换的图象边缘检测算法   总被引:1,自引:0,他引:1  
将小波变换理论应用于图象边缘提取,提出了一种新的图象边缘检测算法。一种相对于(c0,c3)=(0.05,0.05)的对称尺度函数被用于二进小波变换,得到原图象的一个多分辨率表达式,再提取图象的边缘特征。  相似文献   

11.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

12.
IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…  相似文献   

13.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

14.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.  相似文献   

15.
A doping system consisting of NPB and PVK is employed as a composite hole transporting layer (CHTL). By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK : NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK : NPB at 1:3.  相似文献   

16.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

17.
Due to variable symbol length of digital pulse interval modulation(DPIM), it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation(FDPIM) method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.  相似文献   

18.
It is a key problem to accurately calculate beam spots' center of measuring the warp by using a collimated laser. A new method, named double geometrical center method (DGCM), is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device (CCD) is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What's more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.  相似文献   

19.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

20.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

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