Liang Liang, Yang Min-hua, Li Ying-fang
School of Info-Physics and Geomatics Engineering, Central South University, Changsha 410083, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2010 Oct;30(10):2724-8.
A novel method was developed to classify hyperspectral remote sensing image based on independent component analysis (ICA) and support vector machine (SVM) algorithms. The characteristic information of the hyperspectral remote sensing image captured by PHI (made in China, with 80 bands) was extracted by ICA algorithm, and SVM classifier was established with the extracted image data (20 spectral dimensions). After kernel function selecting and parameter optimizing, it was found that the SVM algorithm(RBF kernel function; parameter C = 1093), gamma = 0.05) with accuracy 94.5127% and kappa coefficient 0.9351 has the best classification result, better than the results of four kinds of conventional algorithms, including neural net classification (accuracy 39.4758% and kappa coefficient 0.3155), spectral angle mapper classification (accuracy 80.2826% and kappa coefficient 0.7709), minimum distance classification (accuracy 85.4627% and kappa coefficient 0.8277) and maximum likelihood classification (accuracy 86.0156% and Kappa coefficient 0.8351). In order to control the "pepper and salt" phenomenon which appeared in classification map frequently, the classification result of SVM (RBF kernel) was operated by the method of clump classes using the morphological operators, and that the classification map closer to actual situation was acquired, with the accuracy and kappa coefficient increasing to 94.7584% and 0.9380, respectively. The study indicated that the ICA combined with SVM was an preferred method for hyperspectral remote sensing image classification, and clump classes was a effective method to optimized the classification result.
提出了一种基于独立分量分析(ICA)和支持向量机(SVM)算法的高光谱遥感图像分类新方法。利用ICA算法提取了由PHI(中国制造,80波段)获取的高光谱遥感图像的特征信息,并利用提取的图像数据(20个光谱维度)建立了SVM分类器。经过核函数选择和参数优化,发现SVM算法(径向基核函数;参数C = 1093,γ = 0.05)的分类精度为94.5127%,kappa系数为0.9351,分类效果最佳,优于神经网络分类(精度39.4758%,kappa系数0.3155)、光谱角映射器分类(精度80.2826%,kappa系数0.7709)、最小距离分类(精度85.4627%,kappa系数0.8277)和最大似然分类(精度86.0156%,kappa系数0.8351)这四种传统算法。为了控制分类图中频繁出现的“椒盐”现象,采用形态学算子的聚类方法对SVM(径向基核)的分类结果进行处理,得到了更接近实际情况的分类图,精度和kappa系数分别提高到94.7584%和0.9380。研究表明,ICA与SVM相结合是高光谱遥感图像分类的一种优选方法,聚类方法是优化分类结果的有效方法。