共查询到19条相似文献,搜索用时 78 毫秒
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静电场边值问题一般采用直接积分法、分离变量法、镜像法等常规方法求解析解.本文基于积分变换法求解微分方程的思想,运用傅里叶变换等积分变换方法,得出在一定条件下采用积分变换法求解静电场边值问题具有可行性和简便性,为求解相似问题探索出一条新的途径. 相似文献
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光子多普勒速度测量系统的数据处理技术 总被引:1,自引:0,他引:1
光子多普勒速度测量(PDV)系统是一种新型的激光测速系统,可广泛用于冲击波、爆轰波以及其他短时高速运动的测量。数据处理是PDV测速技术重要的组成部分,旨在从含有大量噪声的测量数据中获得靶面等运动体的速度信息。在分析PDV系统测速原理的基础上,分别采用条纹法、短时傅里叶变换法和小波变换法对激光冲击强化实验中自由靶面运动的PDV数据进行了处理。针对其中的去噪、奇异点、小波基的选择等问题,提出了一些独特的处理方法。同时,对3种处理方法的误差、实时性、有效性进行了比较。 相似文献
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基于小波包变换的多阈值法语音信号去噪净化 总被引:3,自引:2,他引:1
文中在小波包变换和传统阈值法的基础上,提出了一种基于小波包变换的多尺度多阈值语音信号去噪净化方法。采用小波包分解,克服了传统的正交小波变换的缺陷。采用多尺度多阈值方法,通过改进噪声方差估计方法,在去噪的同时,进一步提高信噪比。仿真实验结果表明,本方法能有效去除信号中的噪声和较好保留语音细节,达到更佳的语音净化效果。 相似文献
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传统的基于距离变换的骨架算法不能保证骨架的连通性,需要引入鞍点解决连通问题.该类算法复杂,且不够准确,同时鞍点的定义很难推广到三维,限制了传统算法的发展.本文提出一种新型骨架算法,在图形内根据距离变换的约束,由骨架种子点开始以单像素宽度逐点生长出各骨架分支,逐点生长保证了连通性.实验证明该算法的骨架生长过程是骨架由粗到精的演变过程,能够方便地实现骨架的多尺度控制. 相似文献
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噪声背景中离散二值图象的形态表示? 总被引:1,自引:1,他引:0
本文首先提出了一种新的类型的图象的形态变换,研究了该变换可无失真恢复原始图象的条件及形式,给出了若干重要性质。为了消除变换域中可能存在的噪声,本文提出了基于两种变换的表示方式,并讨论了噪声环境中图象的最优恢复问题,理论分析与计算结果表明该方法比通常的形态骨架变换表示具有更佳的性能。 相似文献
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一种改进型PRI变换雷达信号分选方法 总被引:1,自引:0,他引:1
基于PRI分选有多种方法,其中PRI变换法对脉冲重复间隔有较高的估计精度,并克服了传统直方图统计法中的子谐波问题。文中在对PRI变换法进行深入研究的基础上,提出了一种改进的自适应PRI变换法,仿真结果验证了新算法的可靠性。 相似文献
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Because of the limit of angle of view(AOV) of IR imaging seeker during the approach of missile and target, the detector can only get the partial image sequence of aircraft nose after "lose point". Recognizing the axis direction on the basis of partial IR image sequence is a key issue of the advanced IR imaging guide airto-air missile faced. In this paper, a recognition method was proposed based on the morphological skeleton and modified Hough transform, and this method can recognize correctly the axis direction of aircraft nose in different poses during missile-target encounter. Firstly, the morphological skeleton transform was used for the extraction of skeleton features. Secondly, the modified Hough transform was used for the straight-lines detection. Finally, According to the relations between aircraft nose and axis and invariant of nose features in high-speed IR image sequence, the axis direction can be detected and calculated. Experimental results indicate that the method is feasible and effective, and the precision of axis direction recognized can meet the requirement of accurate burst control of GIF fuze. 相似文献
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基于二维小波变换的激光成像雷达目标识别算法 总被引:1,自引:0,他引:1
提出了基于二维小波变换的激光成像雷达目标识别算法,首先对激光成像雷达目标的距离像进行二维小波变换;然后从近似分量和细节分量中提取奇异值特征,利用遗传算法对支持向量机参数进行智能优化;最后应用支持向量机对三种地面目标进行识别.仿真实验表明,该方法与直接应用距离像奇异值特征进行识别的方法相比,在高载噪比20dB时的平均识别... 相似文献
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A generalized discrete morphological skeleton transform with multiple structuring elements for the extraction of structural shape components 总被引:2,自引:0,他引:2
Jianning Xu 《IEEE transactions on image processing》2003,12(12):1677-1686
A common problem shared by several leading morphological shape representation algorithms is that there is much overlapping among the representative disks of the same size. A shape component represented by a group of connected disk centers sometimes uses many heavily overlapping representative disks to represent a relatively simple shape part. A shape component may also contain a large number of representative disks that form a complicated structure. We introduce a generalized discrete morphological skeleton transform that uses eight structuring elements to generate skeleton subsets so that no two skeletal points from the same skeleton subset are adjacent to each other. Each skeletal point represents a shape part that is in general an octagon with four pairs of parallel opposing sides. The number of representative points needed to represent a given shape is significantly lower than that in the standard skeleton transform. A collection of shape components needed to build a structural representation is easily derived from the generalized skeleton transform. Each shape component covers a significant area of the given shape and severe overlapping is avoided. The given shape can also be accurately approximated using a small number of shape components. 相似文献
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图像小波变换低频域的水印嵌入与检测算法 总被引:3,自引:1,他引:2
周熠 《微电子学与计算机》2004,21(5):66-68,75
数字水印是数字媒体版权保护的有效手段。文章详细分析了小波域图像水印嵌入策略,提出一种小波域透明图像水印算法,算法选择图像经过小波多分辨率分解后的低频子带作为水印嵌入区域,并利用人眼视觉掩蔽特性对水印的添加强度进行自适应调节。实验获得了良好的结果。 相似文献
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提出了一种基于小波变换的图像嵌入数字水印及检测的方法。对数字图像进行多级二维小波变换可以得到一个逼近图像和几个高频细节图像,对低频(逼近部分)图像嵌入数字水印,对加入水印的图像进行小波逆变换得到重构图像。检测时,先对重构图像进行小波变换,再对低频图像提取数字水印。 相似文献
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