面向高光谱图像分类的半监督空谱判别分析

Semi-supervised Spatial-spectral Discriminant Analysis for Hyperspectral Image Classification

为充分利用高光谱图像蕴藏的空间信息提升分类精度,提出了面向高光谱图像分类的半监督空谱判别分析(S3 DA)算法。考虑高光谱图像数据集的空间一致性,首先利用少量标记样本定义类内散度矩阵,保存数据集同类像元的光谱近邻结构;再利用无标记样本定义空间近邻像元散度矩阵,揭示像元间的空间近邻结构和地物的空间分布结构信息。S3 DA既保持数据集在光谱域的可分性,又保存了无标记样本蕴藏的空间域近邻结构,增强了同类像元和空间近邻像元在投影子空间的聚集性,从而提升分类性能。在PaviaU和Indian Pines数据集的试验表明,总体分类精度分别达到81.50%和71.77%。与传统的光谱方法比较,该算法能有效提升高光谱图像数据集的地物分类精度。

In order to make full use of the spatial information embedded in the hyperspectral image to improve the classification accuracy,a semi-supervised spatial-spectral discriminant analysis（S3 DA）algorithm for hyperspectral image classification is proposed.According to the spatial consistency property of hyperspectral image,the intra-class scatter matrix infered from a little labeled samples preserves the spectral similarity of the same class pixels,while the spatial local pixel scatter matrix defined by the unlabeled spatial neighbors uncovers the spatial-domain local pixel neighborhood structures and the ground objects detailed distribution.The S3 DA method not only maintains the spectral-domain separability of the data set,but also preserves the spatial-domain local pixel neighborhood structure,which promotes the compactness of the same class pixels or the spatial neighbor pixels in the projected subspace and enhances the classification performance.The overall classification accuracies respectively reach 81.50%and 71.77%on the PaviaU and Indian Pines data sets.Compared with the traditional spectral methods,the proposed method can effectively improve ground objects classification accuracy.