Cube-CNN-SVM: A Novel Hyperspectral Image Classification Method

Abstract

CNNs (convolutional neural networks) have been proved to be efficient deep learning models that can directly extract high level features from raw data. In this paper, a novel CCS (Cube-CNN-SVM) method is proposed for hyperspectral image classification, which is a spectral-spatial feature based hybrid model of CNN and SVM (support vector machine). Different from most of traditional methods that only take spectral information into consideration, a target pixel and the spectral information of its neighbors are organized into a spectral-spatial multi-feature cube used in hyperspectral image classification. It is a straightforward but valid spatial strategy that can easily improve classification accuracy without extra modification of deep CNN's structure except the size of input layer and convolutional kernel. Our deep CNN consists of the input layer, convolutional layer, max pooling layer, full connection layer and output layer. To further improve hyperspectral image classification accuracy, SVM is trained as hyperspectral image classifier with the features extracted by deep CNN from spectral-spatial fusion information. Three hyperspectral image datasets such as the KSC (Kennedy Space Center), PU (Pavia University Scene) and Indian Pines are used to evaluate the performance of CCS method. Experimental results indicate that the hyperspectral image classification can be improved efficiently with the spectral-spatial fusion strategy and CCS method. Firstly, it is easy to implement the spatial strategy to improve classification accuracy about 4% compared with only spectral information used for classification, in which 98.49% is gained on the KSC dataset. Secondly, CCS method can further improve classification accuracy about 1%~3% compared to the best performance of deep CNN, in which 99.45% is gained on the PU dataset.