Liu Qing-Jie, Jing Lin-Hai, Wang Meng-Fei, Lin Qi-Zhong
Center for Earth Observation and Digital Earth, Chinese Academy of Sciences, Beijing, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2013 Mar;33(3):746-51.
Model selection for support vector machine (SVM) involving kernel and the margin parameter values selection is usually time-consuming, impacts training efficiency of SVM model and final classification accuracies of SVM hyperspectral remote sensing image classifier greatly. Firstly, based on combinatorial optimization theory and cross-validation method, artificial immune clonal selection algorithm is introduced to the optimal selection of SVM (CSSVM) kernel parameter a and margin parameter C to improve the training efficiency of SVM model. Then an experiment of classifying AVIRIS in India Pine site of USA was performed for testing the novel CSSVM, as well as a traditional SVM classifier with general Grid Searching cross-validation method (GSSVM) for comparison. And then, evaluation indexes including SVM model training time, classification overall accuracy (OA) and Kappa index of both CSSVM and GSSVM were all analyzed quantitatively. It is demonstrated that OA of CSSVM on test samples and whole image are 85.1% and 81.58, the differences from that of GSSVM are both within 0.08% respectively; And Kappa indexes reach 0.8213 and 0.7728, the differences from that of GSSVM are both within 0.001; While the ratio of model training time of CSSVM and GSSVM is between 1/6 and 1/10. Therefore, CSSVM is fast and accurate algorithm for hyperspectral image classification and is superior to GSSVM.
支持向量机(SVM)的模型选择,包括核函数和边缘参数值的选择,通常很耗时,对SVM模型的训练效率以及SVM高光谱遥感图像分类器的最终分类精度有很大影响。首先,基于组合优化理论和交叉验证方法,将人工免疫克隆选择算法引入到SVM(CSSVM)核参数a和边缘参数C的优化选择中,以提高SVM模型的训练效率。然后,在美国印第安纳松树站点对AVIRIS进行分类实验,以测试新型CSSVM,同时与采用常规网格搜索交叉验证方法(GSSVM)的传统SVM分类器进行比较。接着,对CSSVM和GSSVM的SVM模型训练时间、分类总体精度(OA)和Kappa指数等评估指标进行定量分析。结果表明,CSSVM在测试样本和整幅图像上的OA分别为85.1%和81.58,与GSSVM的差异均在0.08%以内;Kappa指数分别达到0.8213和0.7728,与GSSVM的差异均在0.001以内;而CSSVM与GSSVM的模型训练时间比在1/6到1/10之间。因此,CSSVM是一种用于高光谱图像分类的快速准确算法,优于GSSVM。