首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 796 毫秒
1.
家蚕微粒子病的图象形状特征分析   总被引:1,自引:0,他引:1  
通过对家蚕研磨后显微图象分析,提出了含微粒子图象的形状特征提取方法,并把面积,长宽比,复杂度等作为微粒子和其它组织区分的重要形状特征。  相似文献   

2.
利用计算机视觉检测家蚕微粒子病的改进研究   总被引:3,自引:2,他引:3  
在家蚕微粒子病显微图像自动识别图像分割问题中,首先应从显微图像中将微粒子从复杂背景中提取出来.由于显微图像对比度差、光照不均匀及噪音等因素的影响,采用传统的阈值分割方法和边缘检测方法不能顾及到图像局部的实际有用的目标信息,因此很难准确提取微粒子孢子区域.利用数学形态学的方法根据微粒子图像的形状特征来检测微粒子区域,实现微粒子和背景的分割,取得了较好的效果.运用基于遗传算法的BP网络进行了识别和分类,结果证明此方法是有效的.  相似文献   

3.
家蚕微粒子病病原图象分析周业为,曾传相,谢建(光电科学技术系)家蚕微粒子病蔓延极快,对蚕业生产危害极大,使丝绸业蒙受重大的经济损失,各养蚕国投入了极大的人力、物力,研究如何防治家蚕微粒子病的蔓延。一百多年来,人们一直使用法国巴斯德博士创立的母蛾人工镜...  相似文献   

4.
基于特征的图象查询和检索系统   总被引:6,自引:0,他引:6  
介绍了一个基于特征的图象查询和检索系统.该系统由查询模块、特征提取和描述模块、匹配模块、图象显示模块和图象库管理模块组成.系统既支持基于颜色、纹理、形状的单一特征查询,也支持结合不同特征的更符合视觉要求的综合特征查询.该系统已结合实际图象库进行了查询和检索实验,中给出一些实际检索结果。  相似文献   

5.
离线中文签名鉴别的特征提取及预处理   总被引:1,自引:0,他引:1  
针对中文签名的特点,提出了一组用于离线中文签名鉴别的形状特征.同时提出了一组间接提取签名图象中动态信息的重笔道特征.两组特征综合使用,对简单模仿签名可获得错误率只有2.5%的鉴别效果.文中还介绍了中文签名图象的预处理算法.  相似文献   

6.
针对具封闭的几何形状的目标图象,提出了一种用几何意义明确的四特征形状因子RRRS描述目标形状的方法,用此方法描述了一类刀具图象,效果良好,证明用四特征形状因子描述具有封闭几形状的图象是可行的。  相似文献   

7.
针对具封闭的几何形状的目标图象,提出了一种用几何意义明确的四特征形状因子RRRS(周长平方与面积之比,边界函数的变化率,平均半径的方差,形状的对称性)描述目标形状的方法,用此方法描述了一类刀具图象,效果良好,证明用四特征形状因子描述具有封闭几何形状的图象是可行的  相似文献   

8.
一种有效的SAR图象典型目标特征提取和识别方法   总被引:1,自引:1,他引:1  
在合成孔径雷达(SAR)图象中,需要对其中的人工和自然目标进行识别和分类,目标的特征提取是自动目标识别系统中的关键部分.一般图象的特征会采用颜色、纹理、形状等特征量.在SAR图象中,由于存在大量的背景噪声、目标边界模糊等问题,造成以上特征量在分类时往往不能达到很好的分类效果.作者提出了一种典型目标特征提取和分类识别方法、这种方法基于SAR成像的原理,在图象灰度阂值分割后做粗搜索分别提取灰度特征,椭圆矢量特征,以及栅格特征,然后进行SAR图象典型目标的分类识别、实验表明,这种方法效果较好.  相似文献   

9.
基于数学形态学的运动区域估计及运动图象编码   总被引:1,自引:0,他引:1  
提出了基于数学形态学的运动区域估计和运动图象编码新算法.这种算法利用数学形态变换提取帧间物体运动块和运动区域,并进行自然形状对应的区域匹配和运动补偿.实验表明,与MPEG等分块运动补偿相比,本算法运动匹配准确,搜索快速,避免了方块效应,在相同码率下较好地改善了图象质量,特别适用于低码率运动图象编码.  相似文献   

10.
目前,高分辨率遥感图象正愈来愈多地应用于土地与水资源的监测和管理,其中,IKONOS图象数据因其具有较高的空间分辨率和人机交互的解译效果.在省市土地利用信息获取及在城市研究中更具有广阔的应用前景.以南京幅的IKONOS图象数据为基础.以城乡接合部的不同试验区为对象,着重讨论了高分辨率遥感图象城市土地利用信息的提取与分类方法其主要思想是先应用常用的多光谱分类算法对试验区的土地利用现状进行初始的类别划分,然后采用Majority Filtering技术获取图象的上下信息,并给你根据地物的形状特征和空间关系对初始分类结果进行校正与调整.研究结果表明,当初始的类别划分能满足一定精度时,采用本所提出的方法能进一步改善高分辨率图象城市土地利用信息的分类效果.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号