Hyperspectral image (HSI) classification is an important task in many applications, such as environmental monitoring, medical imaging, and land use/land cover (LULC) classification. Due to the significant amount of spectral information from recent HSI sensors, analyzing the acquired images is challenging using traditional Machine Learning (ML) methods. As the number of frequency bands increases, the required number of training samples increases exponentially to achieve a reasonable classification accuracy, also known as the curse of dimensionality. Therefore, separate band selection or dimensionality reduction techniques are often applied before performing any classification task over HSI data. In this study, we investigate recently proposed subspace learning methods for one-class classification (OCC). These methods map high-dimensional data to a lower-dimensional feature space that is optimized for one-class classification. In this way, there is no separate dimensionality reduction or feature selection procedure needed in the proposed classification framework. Moreover, one-class classifiers have the ability to learn a data description from the category of a single class only. Considering the imbalanced labels of the LULC classification problem and rich spectral information (high number of dimensions), the proposed classification approach is well-suited for HSI data. Overall, this is a pioneer study focusing on subspace learning-based one-class classification for HSI data. We analyze the performance of the proposed subspace learning one-class classifiers in the proposed pipeline. Our experiments validate that the proposed approach helps tackle the curse of dimensionality along with the imbalanced nature of HSI data.
翻译:高光谱图像分类是许多应用中的重要任务,如环境监测、医学成像和土地利用/覆盖分类。由于最近高光谱传感器所获得的大量光谱信息,使用传统的机器学习方法对采集到的图像进行分析是一项具有挑战性的任务。随着频带数量的增加,为了达到合理的分类精度,所需的训练样本数量呈指数增长,这也被称为维数灾难。因此,在执行任何HSI数据的分类任务之前,通常会应用单独的波段选择或降维技术。在本研究中,我们研究了最近提出的用于单类分类(OCC)的子空间学习方法。这些方法将高维数据映射到优化了单类分类的低维特征空间中。因此,在所提出的分类框架中无需单独的降维或特征选择程序。此外,单类分类器能够从仅一个类别的数据中学习数据描述。考虑到LULC分类问题的不平衡标签和丰富的光谱信息(高维度数量),本提出分类方法非常适合HSI数据。总的来说,这是一项针对HSI数据的子空间学习单类分类的开创性研究。我们分析所提出的流水线中提出的子空间学习单类分类器的性能。 我们的实验验证所提出的方法有助于解决维数灾难以及HSI数据的不平衡性质。