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1.
陈天泽  吴禹昊  李燕 《信号处理》2011,27(1):94-101
针对高分辨率SAR图像复杂背景下的线状目标边缘,提出了一种基于DS证据理论的融合提取方法。首先,分析并建立了线状目标的边缘模型;其次,改进了现有的ROEWA算法,在计算边缘强度的同时,利用方向模板和二次曲线进行方向估计,得到了边缘方向;然后,基于边缘模型设计了DS证据理论识别框架,利用道路边缘点方向,设计了一种一一映射的Hough变换方法,基于线状目标直线边缘的高边缘强度值、直线边缘共线性、直线边缘侧面均匀区域统计特性(灰度均值和方差),构建了三组相互独立的基本概率分配函数(BPAF),并采用DS证据理论的Dempster方法,实现了复杂背景下线状目标边缘提取的融合判决。最后,利用机载SAR图像进行城区道路目标的边缘提取试验,验证了本文方法的性能。   相似文献   

2.
基于局部混合滤波的SAR图像边缘检测   总被引:5,自引:0,他引:5  
该文结合基于非下采样方向滤波-双树复小波变换(NonSubsampled Direction Filter Bank-Dual-Tree Complex Wavelet Transform, NSDFB-DTCWT)的局部混合滤波算法和Dempster-Shafet (DS)证据理论提出一种基于局部混合滤波的 SAR 图像边缘检测算法.该算法首先对 SAR 图像进行局部混合滤波,然后对不同尺度滤波图像使用指数加权均值比(Ratio Of Exponentially Weighted Averages, ROEWA)算子检测边缘的强度,再使用Canny算子检测边缘的方向,从而得到SAR图像各尺度上的边缘,最后使用DS证据理论融合各尺度的边缘形成原始 SAR 图像的边缘.实验结果表明:该文所提出的算法具有很好的边缘检测效果,检测到的 SAR 图像的边缘定位准确和完整,且伪边缘较少.  相似文献   

3.
一种新的基于边缘拟合的图像配准方法   总被引:2,自引:0,他引:2  
为了克服罔像配准中计算效率与稳定性的两难问题,提出一种新的基于边缘特征的图像自动配准算法.利用小波变换对图像进行多尺度边缘检测,提高边缘榆测的稳定性;用直线拟合边缘,并根据几何特件、灰度特性为直线分配可信度;以直线对作为最小配准单位,利用马氏距离计算直线对之间的匹配程度;配准过程采用加权投票算法确定变换参数,每次投票根据直线对之间的匹配程度及各直线可信度拥有不同的权重.实验表明木文算法快速稳定,在没有任何先验知识的情况下,能够有效的配准存在相似变换关系(平移、旋转和尺度)的图像.  相似文献   

4.
针对传统图像边缘检测算法抗噪能力差,定位准确性不高的缺点.提出了一种基干多方向多尺腰小波变换的图像边缘检测算法.该算法利用小波变换各尺度间边缘梯度信息的关联及备方向上边缘梯度信息的互补,首先从多个方向对图像进行多尺度小波变换.然后将各个方向上小波系数根据期望最大规则进行融合,再通过最大墒阈值处理,形成图像的边缘。宾验结果表明,由于算法省去了求模值过程,使计算更加简单.同时通过多方向小波变换能尽可能地搜索各方向的图像边界,使边缘定位更加准确.  相似文献   

5.
基于多尺度边缘响应函数的自适应阈值边缘检测算法   总被引:2,自引:0,他引:2  
该文提出了一种基于多尺度边缘响应函数的自适应阈值边缘检测算法。首先分析二进小波变换,根据边缘和噪声随尺度变化的不同特性,设计了多尺度边缘响应函数(MERF)。通过MERF中的乘积放大作用,增大了边缘响应的幅度,同时也抑制了噪声产生的伪边缘。然后利用小波变换多尺度之间的联合分布关系,计算自适应阈值,检测MERF的梯度模值形成多尺度边缘。该算法直接在小波特征上进行多尺度合成,避免了多个边缘图合成过程的病态问题。实验表明,与LOG,Canny以及Mallat多尺度小波检测方法相比,该算法在检测和定位之间能够达到更好的平衡,既能够实现小尺度下的精确定位,也可以保留大尺度下对噪声的抑制作用。  相似文献   

6.
雷斌  侯帅格  沈艳辉 《电子科技》2011,24(9):104-107
针对水下高速射弹试验获取的超空泡图像中夹杂较多噪声,而传统边缘检测算法在自动边缘检测中抑制噪声效果差的问题。文中采用自适应多尺度小波边缘检测,对超空泡图像进行边缘检测。算法中首先对图像进行多尺度下的小波变换和相邻尺度间的梯度增强,再采用K均值聚类进行边缘的自动检测,得到不同尺度下的边缘,根据小波基的不同选择对应的多尺度融合方法进行多尺度融合,得到最终的边缘图像。实验表明,文中算法相比传统边缘检测算法,有效地抑制了图像中噪声,得到了更完整的边缘信息。  相似文献   

7.
结合了B样条函数良好的逼近特性以及多尺度积算法的抗噪性能,来达到图像边缘检测的最佳效果。首先通过选择合适的小波滤波器对信号进行小波变换,之后通过相邻尺度的小波变换相乘得到尺度积,以检测出图像的模极大值,最后通过阈值滤掉伪边缘,得到图像的边缘信息。实验表明,该算法相比其他传统检测算子能有效地抑制图像噪声,并且图像边缘和细节信息的失真量小。  相似文献   

8.
一种基于形态学的多结构元素多尺度图像边缘检测方法   总被引:1,自引:0,他引:1  
提出了一种基于数学形态学算子的多结构元素多尺度边缘检测方法,首先构造6种具有代表性的结构元素,用改进的形态学边缘检测算子对灰度图像进行边缘检测,然后改变结构元素的尺寸大小得到多尺度下的边缘图像,根据不同尺度抗噪性能不同来确定权值,将不同尺度下的边缘图像合成,得到在噪声存在条件下较为理想的图像边缘,实验结果表明,与传统边缘检测算法相比,该算法在保持图像边缘清晰的同时,有很强的去除噪声能力,具有一定的实用性和可行性.  相似文献   

9.
在对数字图像的处理中,边缘检测是其重要内容.常用的图像边缘检测方法,如检测梯度的最大值法,检测二阶导数的零交叉点法,统计型方法以及小波多尺度边缘检测法等,都存在难以确定合理的参数阈值的问题.由此提出了Edgeflow方法,综合了亮度、纹理和相位等各种图像特征信息,以方向相反的边缘流相遇的位置确定对象的边缘,解决了传统基于边缘的图像分割算法难以确定合理阈值的问题.论述了基于边缘流图像分割算法的原理,对该算法进行了调整,并设计出一套预测编码模型来实现.实验结果表明:Edgeflow方法参数调整少,检测效果好.  相似文献   

10.
针对传统边缘检测方法边缘定位不精确的缺点,结合提升小波变换和数学形态学的优势,提出了一种融合提升小波和多尺度形态学的边缘检测方法.首先,对原始图像进行提升小波变换;再用小波变换和多尺度形态学算子分别对低频图像进行边缘检测,根据异或原则融合成低频边缘;然后,用小波变换检测高频图像边缘;最后,通过提升小波反变换得到边缘图像.实验结果表明,与传统或其他的形态学边缘检测方法相比,该算法在保持图像边缘清晰的同时,具有很强的边缘定位能力.  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
Call for Papers     
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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