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1.
阐述螺旋相位滤波实现图像边缘增强的原理及其国内外研究现状,分析几种螺旋相位实现边缘增强效果,同时对螺旋相位滤波器的应用发展趋势进行展望.  相似文献   

2.
为了提高乳腺超声图像分割的准确率,提出了一种基于相位特征的C-V模型超声图像分割方法.首先,采用LOG-Gabor滤波器对超声图像进行6个不同方向的滤波,提取最大能量所对应的相位信息,得到超声图像的相位特征.然后,采用SRAD方法对超声图像降噪,并将降噪后的图像与相位特征点乘,增强图像目标与背景的对比度.最后,运用C-V模型的分割算法识别图像中的目标区域,并采用腐蚀方法使目标区域边缘完整、平滑.实验结果表明,与基于灰度的C-V模型、GAC模型以及基于相位特征的人工神经网络方法相比,利用该方法分割乳腺超声图像,分割的精确度明显提高,达到92.40%.  相似文献   

3.
利用复数形式的Gabor滤波器, 在对指纹图像进行增强的同时, 得到增强图像的相位, 再利用边缘检测的方法提取相位图中的跳变区域, 直接得到脊线的细化结果。此方法不同于传统的模板匹配的细化算法, 不需要对图像进行二值化, 减少了中间步骤, 从而提高了细化速度和细化结果的准确性。实验结果表明此方法具有更短的细化时间和更好的细化效果。  相似文献   

4.
图像获取过程中往往由于光照不足导致图像出现暗影和低对比度,这严重影响了后期图像各种形式的处理,如人脸检测、边缘提取、图像融合等。文章提出利用MSRCR算法与其它常用动态范围调整的图像增强算法相比,如SSR,MSR,MSRCR和直方图均衡化增强;进一步利用MSRCR增益/偏移校正、基于双边滤波器的单尺度Retinex图像增强和同态滤波器对两组图像对比实验,结果显示这些方法在图像增强中都表现出良好的性能,且MSRCR算法可以弥补传统小波变换在图像增强中的对比度不高和丢失部分信息的不足,提高了图像的亮度,对比度和清晰度;且其峰值信噪比和信息熵普遍高于其它增强方法,并对其运行的时效性进行对比。  相似文献   

5.
虹膜识别算法研究   总被引:1,自引:0,他引:1  
为了提高虹膜识别的速度和准确性,提出一种新的虹膜图像均衡法:将直方图均衡法和局部对比度增强法结合起来调节图像动态范围、增强局部对比度,并利用平衡式零谱矩滤波器对预处理后的虹膜图像进行分解,提取更准确的虹膜纹理特征。整个虹膜识别过程小于1.3s,准确率97.25%。可用于个人身份识别中。  相似文献   

6.
分析了指针式仪表图像的特征,探讨了指针式仪表图像高斯同态滤波增强算法.介绍了同态滤波的基本原理,利用高斯同态滤波算法对指针式仪表图像进行预处理,以增强图像的对比度,并提出了滤波器参数的选取方法.最后对增强后的图像进行最大类间方差二值化,为仪表图像的后续处理和后续识别工作奠定了基础.  相似文献   

7.
为解决对比度差、边缘细节模糊等问题,提出了用分段增强法提高红外图像对比度.分段小波增强算法能有效地同时增强红外图像对比度及边缘细节,并抑制噪声.建立了表征图像边缘的特征向量.根据红外图像边缘的特征,准确提取红外图像的边缘.通过神经网络边缘检测法对样本集训练,使网络具有依据边缘特征向量求解场景中物理边缘的能力.实验结果表明神经网络边缘检测算法的精度优于其他算法,抗噪声能力强、边缘定位能力强、检测精度高.  相似文献   

8.
采用信息熵窗小波低频子带分析的方法,目的是对缺乏足够能量的低照度和低对比度图像进行增强.选择适合的正交小波函数,可使图像的低频子带大幅度提升,对高频子带适度抑制,在信息熵窗系数的调配下实现了图像的增强处理.在小波重构后,获得了具有清晰边缘和良好对比度的图像.实验表明,采用信息熵窗的小波分析方法来增强弱目标图像能够产生良好的效果,对比度增强效率比传统增强方法提高80%以上.  相似文献   

9.
针对传统不连续边缘检测算法利用增强图像边缘对比度进行检测, 只适用于检测灰度值变化不强烈及含有普通噪声的图像边缘, 检测性能具有局限性的问题, 提出一种模糊图像的不连续边缘智能检测改进算法. 首先通过广义交叉验证准则获取图像噪声方差估计值, 对图像中高斯噪声进行判别, 使用自适应模糊滤波器对含噪图像进行模糊滤波处理; 然后采用改进模糊图像边缘检测算法, 按图像含噪情形制定边缘检测策略, 获取模糊图像边缘; 最后通过灰度形态学的模糊图像不连续边缘检测算法, 对模糊图像边缘受灰度值不均匀变化形成的膨胀、 腐蚀、 形态学梯度型不连续边缘进行检测. 实验结果表明, 该算法抗噪性较高, 模糊图像不连续边缘检测的结果更清晰、 完整.  相似文献   

10.
针对传统不连续边缘检测算法利用增强图像边缘对比度进行检测, 只适用于检测灰度值变化不强烈及含有普通噪声的图像边缘, 检测性能具有局限性的问题, 提出一种模糊图像的不连续边缘智能检测改进算法. 首先通过广义交叉验证准则获取图像噪声方差估计值, 对图像中高斯噪声进行判别, 使用自适应模糊滤波器对含噪图像进行模糊滤波处理; 然后采用改进模糊图像边缘检测算法, 按图像含噪情形制定边缘检测策略, 获取模糊图像边缘; 最后通过灰度形态学的模糊图像不连续边缘检测算法, 对模糊图像边缘受灰度值不均匀变化形成的膨胀、 腐蚀、 形态学梯度型不连续边缘进行检测. 实验结果表明, 该算法抗噪性较高, 模糊图像不连续边缘检测的结果更清晰、 完整.  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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