共查询到18条相似文献,搜索用时 296 毫秒
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《纳米技术与精密工程》2015,(3)
基于原子力显微镜(atomic force microscope,AFM)的关键尺寸(critical dimension,CD)测量技术可有效测量MEMS结构的侧壁形貌和线宽,针对CD-AFM的关键共性技术之一提出了一种三维图像拼接方法,旨在把结构正表面图像和侧壁图像拼接成为一幅完整的三维图像.通过旋转样品的方式,利用AFM扫描结构形貌,分别得到其正表面和侧壁的扫描图像.在两幅图像的重叠区域进行图像预处理和快速图像相关匹配,可准确获取图像匹配点.随后,对侧壁扫描图像进行逐列翻转、切割、旋转和拼接等操作,最终可得到结构的三维形貌图像.采用C++语言编写的算法对AFM获得的实际扫描图像进行了三维拼接,拼缝边缘曲线相似程度达到97.62%,结果表明该算法具有很好的准确度. 相似文献
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纳米栅格和台阶等结构的线宽准确测量,是国内外计量领域的研究热点与难点。采用原子力显微镜(AFM)能获得上述结构的三维形貌信息,但其扫描图像却是探针针尖的形貌和被测样品表面的形貌共同作用的结果,这种作用往往导致线宽边缘测量失真。为了更加精确地获得样品的表面形貌特征,首先需要重建探针针尖形貌,进而从得到的扫描图像中尽可能地消除由探针形貌带来的失真影响。基于数学形态学的盲重建理论,利用Matlab对不同形状参数的探针针尖扫描台阶样品表面进行了仿真,评价了探针形状对扫描结果的影响,初步实现了基于真实粗糙测量表面的探针针尖形状重建。 相似文献
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目的为了赋予固定尺寸水印自适应不同尺寸宿主图像的尺寸普适性,提出一种多尺寸普适的抗印刷扫描水印算法。方法对宿主图像进行裁剪、分层、分块获得图块,计算每个图块的最大奇异值,取最大奇异值前九的图块组成拼接图像,结合水印嵌入算法在拼接图像中抽取获得待嵌图像,将制成全息图的水印嵌入待嵌图像的DWT域内。结果实验表明,将固定尺寸水印嵌入不同尺寸宿主图像后,随着宿主图像尺寸的增加,水印图像的不可见性明显提高,并且经历模拟印刷扫描可顺利提取水印。结论该算法不仅可以赋予固定尺寸水印适应不同尺寸宿主图像的普适性,且提升了水印嵌入后的不可见性,对印刷扫描具有较好的鲁棒性,为数字水印在印刷防伪领域的应用研究提供了新思路。 相似文献
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原子力显微镜探针原位有效参数对线宽测量的修正 总被引:1,自引:0,他引:1
针对原子力显微镜(AFM)的线宽和轮廓的精确测量,对AFM探针的原位有效参数进行了定义和表征,提出使用AFM探针的原位有效参数对AFM的线宽测量结果进行修正的模型。采用有效半径和半内角表征AFM探针的复合形状,悬臂轴倾角表征探针的安装状态,设计了具有不同梯形截面的两个表征样板,通过对表征样板进行AFM和扫描电子显微镜(SEM)的比对测量获得了探针的原位有效参数。提出了在线宽测量中,当AFM的扫描轮廓线具有不同的斜度时分别采用的不同的修正公式。采用此公式和探针的原位参数对掩膜板的AFM线宽测量结果进行了修正。 相似文献
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一种新的字符提取和组合算法 总被引:2,自引:1,他引:2
工程图纸的扫描转换处理是CAD/CAM领域亟待解决的一个重要难题。图纸中通常包含了大量的字符,用以表示尺寸等信息,其处理方式完全不同于其他线型,提取并识别这些字符,是图纸处理中的关键组成部分。本文分析了现有的字符提取方法的不足,详细描述了一个新的提取算法,并且给出了算法在图纸扫描转换中的一个实例。该算法具有快速、高效和可靠的特点。 相似文献
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Linear feature detection is an important technique in different applications of image processing. To detect linear features in different types of images, a simple but effective algorithm based on a multiple-structuring-element center-surround top-hat transform is proposed. The center-surround top-hat transform is discussed and analyzed. Based on the properties of this transform for image feature detection, multiple structuring elements are constructed corresponding to the possible linear features at different directions. The whole algorithm is divided into four parts. First, the algorithm uses the center-surround top-hat transform to detect all the possible linear features at different directions through constructing multiple structuring elements. Second, the detected linear feature regions at each direction are processed by a closing operation to remove the possible holes or unconnected regions. Third, the processed results of the detected linear feature regions at all directions are combined to form all the possible detected linear feature regions. Fourth, the combined result is refined by using some simple operations to form the final result. Experimental results on different types of images from different applications verified the effective performance of the proposed algorithm. Moreover, the experimental results indicate that the proposed algorithm could be used in different applications. 相似文献
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基于虚拟点的可见光和SAR图像配准研究 总被引:1,自引:1,他引:0
本文以机场场景下的可见光和SAR图像为研究对象,提出了一种基于虚拟点特征的可见光和SAR图像配准方法.该方法以虚拟点特征和控制点匹配技术为基础,处理具有全局仿射几何失真的异源图像配准问题.首先根据两类图像的特点,使用Canny算子和一种兴趣算子提取两幅图像中的共有特征一直线特征,然后在直线特征的基础上拟合虚拟点特征,采用基于特征一致的粗配准和基于虚拟点特征的精确配准相结合的方法,对两幅图像实现由粗到精的自动配准,实验结果表明,本文方法可行且能取得较高的配准精度. 相似文献
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Dual-energy CT can be represented as the dual-energy equations by decomposing the linear attenuation coefficient of the X-ray scanned object into two material basis functions of photoelectric absorption and Compton scatter. To solve the dual-energy equations, in this paper, we apply the mean-value theorem for integrals and propose a new projection-based iterative algorithm. We discuss the convergence of the proposed algorithm and carry out various numerical simulations for demonstrating its feasibility. 相似文献
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一种改进的边界轮廓矢量化算法 总被引:4,自引:0,他引:4
左右于断层测量的反向建模中,物体断面图像序列的区域边界和实现模型重构的基础,如何从边界轮廓精确提取几何特征是实现重构的关键。本文提出一种改进的矢量化算法,该算法的基本思想是首先提取曲率极值点作为初始分段点。然后判定每两个相邻初始分段点之间轮廓线的形状,并区别直线段与曲线段分别进行拟合和矢量化。实践表明,该算法既能准确提取边界形状的特征关键点,又保证了重构后曲面的光滑规整。 相似文献
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针对中药三维荧光光谱信号非线性问题,应用局部线性嵌入算法(LLE)对补虚类中药三维荧光光谱信号进行特征提取。使用荧光光谱仪测得不同浓度的24味补虚类中药的三维荧光光谱和等高线光谱图,并利用总体平均经验模态分解(EEMD)算法进行降噪处理,在此基础上,采用LLE算法对经过降噪处理后的三维荧光光谱数据进行特征提取; 然后,应用随机森林(RF)算法对提取的特征向量进行分类识别。为了验证LLE算法的有效性,将其与主成分分析(PCA)算法进行比较。实验结果表明: LLE-RF组合算法分类准确率达95%,比PCA-RF算法分类准确率高,从而验证了该算法的有效性。 相似文献
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Franco Cardin Alberto Lovison Mario Putti 《International journal for numerical methods in engineering》2007,69(9):1804-1818
In this paper we propose the numerical solution of a steady‐state reaction‐diffusion problem by means of application of a non‐local Lyapunov–Schmidt type reduction originally devised for field theory. A numerical algorithm is developed on the basis of the discretization of the differential operator by means of simple finite differences. The eigendecomposition of the resulting matrix is used to implement a discrete version of the reduction process. By the new algorithm the problem is decomposed into two coupled subproblems of different dimensions. A large subproblem is solved by means of a fixed point iteration completely controlled by the features of the original equation, and a second problem, with dimensions that can be made much smaller than the former, which inherits most of the non‐linear difficulties of the original system. The advantage of this approach is that sophisticated linearization strategies can be used to solve this small non‐linear system, at the expense of a partial eigendecomposition of the discretized linear differential operator. The proposed scheme is used for the solution of a simple non‐linear one‐dimensional problem. The applicability of the procedure is tested and experimental convergence estimates are consolidated. Numerical results are used to show the performance of the new algorithm. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献