一种新的SAR图像局部统计活动轮廓模型及算法
A Novel SAR Image Locally Statistical Active Contour Model and Algorithm
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摘要: 近年来变分水平集方法在图像分割中得到了广泛应用,但此类方法的能量泛函是非凸的,易陷入局部极小值解。本文基于AA(Aubert-Aujol)去噪模型和变分水平集方法,提出一个局部统计活动轮廓模型,通过凸松弛技术将提出的分割模型转换成全局优化模型,再加入一个迫近算子项,将提出的模型转化为ROF去噪模型,最后采用快速去噪算法,得到一个全局最优的快速分割算法。此算法不涉及差分或微分方程,只需要简单的差分运算,提高了数值运算速度。对实测SAR图像进行分割实验,结果表明,本文提出的全局分割模型不但能够快速、有效地分割SAR图像,取得全局最小值,而且可以更准确地得到图像分割边缘。Abstract: Recently,variational level set method is widely used in image segmentation,but its energyfunctional is non-convex,which can easily get stuck in local minima.Firstly,we propose a locally(下转第637页) 第40卷第5期段 平等:顾及异向性的局部径向基函数三维空间插值637 (3D),local radial basis function(RBF)interpolation based on exploring spatial anisotropy with vario-gram analysis was proposed.Firstly,three axes of the data was solved by constructing covariance ma-trix of the sampling point data and then the data was transformed into the new coordinate system byrotating transformation;the range of each direction was calculated using geostatistical variograms;thethree values of range was set as three axes of the ellipsoid;at last,node RBF at each sample point wasbuilt.The attribute values of interpolation were solved by linear combination of node RBF.Experi-mental results show that the proposed method is a feasible method for 3Dspatial interpolation consid-ering anisotropy with high accuracy and reliable interpolation result.
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